### PROPOSED AIRBORNE TOXIC CONTROL MEASURE TO REDUCE

FORMALDEHYDE EMISSIONS FROM COMPOSITE WOOD PRODUCTS

Stationary Source Division Air Quality Measures Branch

Release Date: March 9, 2007

To Be Considered by the Board: April 26, 2007State of California 

### AIR RESOURCES BOARD



## STAFF REPORT: INITIAL STATEMENT OF REASONS

FOR PROPOSED RULEMAKING

Public Hearing to Consider

ADOPTION OF THE PROPOSED AIRBORNE TOXIC CONTROL MEA SURE

TO REDUCE FORMALDEHYDE EMISSIONS FROM COMPOSITE WOO D

PRODUCTS

To be considered by the Air Resources Board on Apri l 26, 2007, at:

California Environmental Protection Agency

Headquarters Building

1001 “I” Street Sacramento, California

Stationary Source Division: Robert Fletcher, P.E., Chief, Stationary Source Div ision Robert D. Barham, Ph.D., Assistant Division Chief, Stationary Source Division

Janette Brooks, Chief, Air Quality Measures Branch Jim Aguila, Manager, Substance Evaluation Section

This report has been prepared by the staff of the A ir Resources Board. Publication does not signify t hat the contents reflect the views and policies of the Air Resources Board, nor does mention of trade names or commercial products constitute endorsement or recommendation for use.

# Acknowledgements

Contributing Authors Brent Takemoto, Ph.D. (Lead)

James Stebbins Lynn Baker Angela Csondes Susie Chung Melanie Marty, Ph.D. Andy Salmon, Ph.D. Robert Blaisdell, Ph.D. Reza Mahdavi, Ph.D. Peggy Jenkins Linying Li

Webster Tasat Andy Delao

Elizabeth Miller

Darrell Hawkins

Michael Poore

Russell Grace

Jose Saldana

Legal Counsel

Robert Jenne, Esq., Office of Legal Affairs

___________________________________________________ ___________

We also wish to acknowledge the assistance and coop eration we received from many individuals and organizations. In partic ular, we would like to

thank:

Composite Panel Association, Hardwood Plywood and V eneer Association, American Home Furnishers Association, Kitchen Cabin et Manufacturers Association, Woodwork Institute, Formaldehyde-Free Coalition, California Wood Industries Coalition, Columbia Forest Products, Sie rra Pine, Professional Service Industries, Inc., General Veneer, G.L. Veneer, Geor gia Pacific, Hexion,i 

### TABLE OF CONTENTS

Executive Summary ES-1

I. Introduction ...................................

................................................... ..........1

A. Regulatory Authority...........................

................................................... .....2

B. Formaldehyde in California .....................

................................................... 3

C. Need for Reducing Formaldehyde Emissions from C omposite Wood

Products...........................................

................................................... .......5

D. Regulations Applicable to Formaldehyde......... ..........................................6

E. Indoor Air Quality .............................

................................................... .......7

F. References.....................................

................................................... .........7

II. Public Outreach...............................

................................................... ........9

A. Outreach Efforts...............................

................................................... .......9

B. Public Involvement .............................

................................................... .....9

C. Survey of Products Manufactured in 2002 ........ .......................................11

D. References.....................................

................................................... .......12

III. Need for Regulation of Formaldehyde (HCHO) .... ...................................13

A. Health Effects of Formaldehyde................. ..............................................13

B. Physical and Chemical Properties............... .............................................13

C. Sources and Emissions of Formaldehyde.......... ......................................14

D. Emissions from Composite Wood Products ......... ....................................19

E. Natural Occurrences ............................

................................................... .20

F. Measured Formaldehyde Concentrations ........... .....................................21

G. Modeled Formaldehyde Concentrations ........... ......................................32

H. Atmospheric Persistence........................ ..................................................3 3

I. Risk Characterization ..........................

................................................... ..33

J. References.....................................

................................................... .......34

IV. Manufacturing of Composite Wood Products...... .....................................42

A. Background.....................................

................................................... ......42

B. Composite Wood Product Manufacturing Plants.... ..................................42ii

C. Resins Currently Used in Composite Wood Product s ..............................45

D. References.....................................

................................................... .......59

V. Assessment of Best Available Control Technolog y (BACT) .....................63

A. Introduction ...................................

................................................... ........63

B. Product Descriptions and Survey Results ......... .......................................70

C. Present-day Resin Technologies ................. ............................................75

D. Candidate Low-formaldehyde Resin Systems....... ...................................83

E. Technical Basis for the Proposed Emission Stand ards..........................101

F. References.....................................

................................................... .....108

VI. Proposed Airborne Toxic Control Measure (ATCM) ...............................116

A. Summary of the Proposed Airborne Toxic Control M easure.....................116

B. Alternatives to the Proposed Airborne Toxic Con trol Measure...............128

C. Conclusion .....................................

................................................... .....129

VII. Health Impacts of the Proposed Airborne Toxic Control Measure..........130

A. Overview of the Health Risk Assessment ......... .....................................130

B. Total Daily Formaldehyde Exposure as the Basis for Risk Assessment 132

C. Factors that Affect the Outcome of a Health Ris k Assessment..............155

D. Summary of Potential Health Impacts ............ ........................................155

E. Multi-pathway Health Risk Assessment ........... ......................................157

F. Statewide Emission and Risk Reduction Benefits. .................................157

G. Potential Adverse Health Effects from Replaceme nt Compounds .........159

H. Workplace Exposure ............................. .................................................16 0

I. References.....................................

................................................... .....161

VIII. Economic Impacts of the Proposed Airborne To xic Control Measure ....178

A. Background.....................................

................................................... ....178

B. Cost of Compliance.............................

................................................... 189

C. Cost to the Composite Wood Manufacturing Indust ry ............................205

D. Distributor and Importer Costs ................. ..............................................209

E. Fabricator Costs...............................

................................................... ...211

F. Retailer Costs.................................

................................................... .....213

G. Consumer Costs .................................

................................................... 213iii

H. Impacts to Small Business ...................... ...............................................216

I. References.....................................

................................................... .....216

IX. Environmental Impacts of the Proposed Airborne Toxic Control Measure

................................................... ................................................... .........221

A. Legal Requirements ............................. ..................................................2 21

B. Analysis of Reasonably Foreseeable Environmenta l Impacts................221

C. Reasonably Foreseeable Feasible Mitigation Meas ures........................224

D. Reasonably Foreseeable Alternative Means of Com pliance..................224

E. Community Health and Environmental Justice..... ..................................224

F. References.....................................

................................................... .....224iv 

### List of Tables

Table ES-1. Proposed Phase 1 and Phase 2 Emission Standards ..................3

Table ES-2. Estimated Reductions in Cancer Risk Af ter Phase 1 and

Phase 2............................................ .............................................6
Table ES-3. Total Estimated Cost to the Industry in 2002 ................................9

Table II-1. Selected ATCM-related Outreach Effort s .....................................9

Table III-1. Physical and Chemical Properties of F ormaldehyde ..................14
Table III-2. Product Distribution for Formaldehyde in the U.S. (2003)...........15
Table III-3. Formaldehyde – 2005 Statewide Emissio n Inventory .................16

Table III-4. Emission Rates of Selected Indoor Sou rces of Formaldehyde

(μg/m 2 /hr)............................................... .....................................18
Table III-5. Statewide Annual Average Formaldehyde Concentrations

(μg/m3): 1996-2005................................. ....................................22
Table III-6. Summary of Ambient Formaldehyde Conc entrations (μg/m 3 ): 1

January 2005 through 30 April 2006................. ..........................25
Table III-7. Formaldehyde Emissions in the Top Te n California Counties ....26
Table III-8. Measured Indoor Formaldehyde Concentr ations (μg/m 3 ) ...........27

Table IV-1. Advantages and Disadvantages of Urea-f ormaldehyde

Resins............................................. ............................................47
Table IV-2. Characteristics of Urea-formaldehyde ( UF) Resins ....................49
Table IV-3. Characteristics of Phenol-formaldehyde (PF) Resins .................51
Table IV-4. Summary of Melamine-based Resin Proper ties and Uses..........53
Table IV-5. Advantages and Disadvantages of Polyd iphenylmethane

Diisocyanate (pMDI) Resins ......................... ..............................54

Table IV-6. Characteristics of MDI Resins............... .....................................55 Table IV-7. Characteristics of Polyvinyl Acetate ( PVA) Resins .....................57

Table V-1. List of Researchers, Manufacturers, an d Academia

Contacted .......................................... .........................................65
Table V-2. Japanese Building Standard Law Classif ications for

Building Material Formaldehyde (HCHO) Emissions .. ..............68
Table V-3. Formaldehyde (HCHO) Emission Standards for Composite

Wood Products in the U.S., Europe, and Japan ....... ..................70

Table V-4. Measured or Estimated ASTM E1333 Avera ge Data for

Hardwood Plywood-Veneer Core from Selected U.S.

Manufacturers...................................... .......................................72v

Table V-5. Measured or Estimated ASTM E1333 Data for Hardwood

Plywood-Composite Core from Selected U.S. Manufactu rers ....73
Table V-6. Effect of Melamine Acetate (Mac) on Pl ywood Tensile

Strength ........................................... ...........................................76
Table V-7. Comparison of Strength and HCHO Emissi on Properties of

Particleboard Made with Two Melamine-formaldehyde ( MF)

Resins............................................. ............................................78
Table V-8. Selected Measures of Tensile Strength (N/mm 2 ) in

Plywood Made with Urea-formaldehyde (UF) and UF-Methylene Diisocyanate (UF-MDI) Hybrid Resins... ..............80

Table V-9. Effect of MDI and/or Urea Additions on Selected Resin

and Panel Properties in Particleboard Made with Phe nol-ureaformaldehyde (PUF) Resins.......................... ..............................81
Table V-10. Dry and Wet Internal Bond (IB) Streng th and Density in

Particleboard Made Phenol-melamine-urea-formaldehyd e (PMUF)-MDI Resins .................................. .................................82
Table V-11. Soy-based Adhesives: Problems and Sol utions .........................86
Table V-12. Physical Properties of Phenol-formald ehyde (PF) and

Soy-PF Resins...................................... ......................................87
Table V-13. Effect of Tris(hydroxymethyl)nitrometh ane (TN) Addition

on the Breaking Loads and Formaldehyde Contents of Plywood Made with Quebracho Tannin Resin ........... .................91
Table V-14. Gel Times (minutes) for Particleboard Made with Phenolformaldehyde (PF) Resins Co-reacted with Urea ...... .................93
Table V-15. Effect of Urea Addition on Dry and We t Internal Bond

Strengths in Softwood Particleboard Bonded Phenolformaldehyde (PF) Resin............................ ................................94
Table V-16. Effect of Press Time on Dry and Wet I nternal Bond Strength

in Hardwood Particleboard Bonded with a Phenol-urea

formaldehyde (PUF) Resin with Triacetin ............ .......................95

Table V-17. Minimum American National Standards I nstitute (ANSI)

Strength Requirements for Medium (M) Industrial and Shelving Grade Particleboard....................... ..............................97
Table V-18. Strength Responses in Particleboard M ade with Phenolformaldehyde (PF) and Cashew Shell Nut Liquid (CNSL )

Resins............................................. ............................................98
Table V-19. Density, Swell, Strength, and Formald ehyde Content in

Medium Density Fiberboard Made with Ureaformaldehyde (UF) and Quebracho Tannin-based Resins .........99
Table V-20. Dry and Wet Internal Bond Strengths o f Medium Density

Fiberboard Made with Phenol-formaldehyde (PF) and Phenol-urea-formaldehyde-tannin (PUFT) Resins...... ..............100vi

Table V-21. Proposed Phase 1 (P1) and 2 (P2) Form aldehyde (HCHO)

Emission Standards for Hardwood Plywood............ .................101
Table V-22. Available Low-formaldehyde Hardwood P lywood (HWPW) or

HWPW-Resins........................................ ..................................103
Table V-23. Proposed Phase 1 (P1) and 2 (P2) Emis sion Standards for

Particleboard...................................... .......................................104
Table V-24. Available Low-formaldehyde Particlebo ard (PB) and

PB-Resin Systems................................... .................................104
Table V-25. Proposed Phase 1 (P1) and Phase 2 (P2 ) Standards for

Medium Density Fiberboard.......................... ............................105
Table V-26. Available Low-formaldehyde Medium Den sity Fiberboard

(MDF) or MDF-resins................................ ................................106

Table VI-1. Proposed Phase 1 and Phase 2 Standards for Hardwood

Plywood (HWPW), Particleboard (PB), and Medium Dens ity Fiberboard (MDF) ................................... ..................................117
Table VI-2. Schedule of Composite Wood Product Sel l-through for

Manufacturers...................................... .....................................119
Table VI-3. Schedule of Composite Wood Product Sel l-through for

Distributors....................................... .........................................121
Table VI-4. Schedule of Composite Wood Product Sel l-through for

Importers.......................................... .........................................123
Table VI-5. Schedule of Composite Wood Product Sel l-through for

Fabricators........................................ ........................................124
Table VI-6. Schedule of Composite Wood Panel Sell- through for

Retailers.......................................... ..........................................126
Table VI-7. Development Plan for Fully Covered Fin ished Products...........127

Table VII-1. Average and Elevated Formaldehyde Co ncentrations ( μ g/m 3 ).133

Table VII-2. Health Effects Values for Formaldehy de ..................................133
Table VII-3. Age-group Specific and Average Child and Adult Activity

Patterns ........................................... .........................................156
Table VII-4. Estimates of Total Formaldehyde (HCHO ) Exposure and

Daily Time-weighted Average (TWA) Formaldehyde

Concentration ...................................... .....................................157

Table VII-5. Estimated Cancer Risk in Children and Adults After

Implementation of the Phase 1 and Phase 2 Emission

Standards .......................................... .......................................158

Table VIII-1. Particleboard Manufacturers in the Composite Panel

Association ........................................ .......................................179vii

Table VIII-2. Medium Density Fiberboard Manufactu rers in the Composite

Panel Association .................................. ...................................181
Table. VIII-3. Hardwood Plywood Facilities in Nort h America ........................182
Table VIII-4. Cost per Plant by Type of Affected P roduct..............................186
Table VIII-5. Change in Return on Owner’s Equity (ROEs) for Typical

Manufacturers in the Composite Wood Products Indust ry........187
Table VIII-6. Establishments, Employees, and Payro ll by Industry ...............188

Table VIII-7. Unit Cost of Industrial Particleboar d: 1995-2005 ......................190
Table VIII-8. Unit Cost of Medium Density Fiberboa rd: 1995-2005 ...............192
Table VIII-9. Unit Cost of Hardwood Plywood ....... ........................................193

Table VIII-10. Breakdown of Costs in Particleboar d Manufacturing ................197

Table VIII-11. Estimated Cost of UF Resin in Part icleboard of Varying

Thickness.......................................... ........................................198

Table VIII-12. Estimated Price Increase in Partic leboard Made to Comply

with the Phase 2 Standard with an Alternate Resin.. ................199
Table VIII-13. Estimated Cost of Urea-formaldehyde (UF) Resin in

Medium Density Fiberboard (MDF) of Varying Thicknes s ........202

Table VIII-14. Estimated Price Increase in Medium Density Fiberboard

Made to Comply with the Phase 2 Standard with an Al ternate

Resin .............................................. ..........................................202

Table VIII-15. Estimated Cost of the Urea-formalde hyde (UF) Resin in

Hardwood Plywood of Varying Board Thickness ........ ..............204

Table VIII-16. Estimated Price Increases in Hardw ood Plywood Made

with Alternate Resins ............................. ..................................204

Table VIII-17. Estimated Cost of Particleboard, M edium Density Fiberboard,

and Hardwood Plywood Panels Following the Effective

Date of the Phase 2 Standard....................... ............................214viii 

### List of Figures

Figure III-1. Annual Statewide Summary for Ambien t Formaldehyde ............23
Figure III-2. Mean Ambient Formaldehyde Concentrat ions by Air Basin........24

Figure IV-1. Types of Hardwood Plywood ........... ...........................................42
Figure IV-2. Plywood Manufacturing Process....... ..........................................43
Figure IV-3: Schematic of a Particleboard Manufact uring Line.......................44
Figure IV-4. Reaction between a Nucleophile (Nu) and Formaldehyde..........46
Figure IV-5. Addition of Urea and Formaldehyde to Form

Hydroxymethylureas ................................. ..................................48
Figure IV-6. Condensation Reaction and Polymerizat ion of UF Resins..........48
Figure IV-7. Addition Reaction for Phenol and Form aldehyde........................50
Figure IV-8. Phenol-formaldehyde (PF) Resin: Conde nsation Reaction ........50
Figure IV-9. Phenol-Formaldehyde Cross-linked Poly mer..............................51
Figure IV-10. Addition Reaction for Formaldehyde a nd Melamine ...................52
Figure IV-11. Condensation Reaction of Hydroxymet hylated Melamines.........52

Figure IV-12. Isocyanate and Water React to Produc e a Urethane..................54
Figure IV-13. Reaction of an Amine and Isocyanate to Form a

Substituted Urea................................... ......................................54
Figure IV-14. Urethane Bridge and Substituted Urea s React with

Isocyanates........................................ .........................................55
Figure IV-15. Polymerization of PVA ............... .................................................57
Figure IV-16. Average Yield of Extractives from Di fferent Woods and Barks ...58
Figure IV-17. The A-Ring Unit of a Tannin Compound .....................................59

Figure V-1. Polyurethane Cross-linking in a PF-MDI Hybrid Resin ...............81
Figure V-2. Cationic Polyamidoamine-epichlorohydr in (PAE) .......................84
Figure V-3. Effect of Reaction Time on the Dry an d Water-Soaking-and

Drying (WSAD) Shear Strength of Plywood Made with a Soy Protein Isolate-Kymene ® Resin 1 ..........................................85
Figure V-4. Dry Internal Bond Strengths for Orien ted Strand Board

made with PF and Soy-PF Resins ..................... .........................87
Figure V-5. Wet Internal Bond Strengths for Orien ted Strand Board

Made with Phenol-formaldehyde (PF) and Soy-PF Resin s.........88
Figure V-6. Chemical Structure of Hexamine ..................... ...........................90
Figure V-7. Chemical Structure of a Monoflavonoid Unit...............................90
Figure V-8. Mole Ratios of Free Formaldehyde:Phen ol in Phenol-ureaformaldehyde (PUF) and PUF-Tannin Resins ........... .................92
Figure V-9. Chemical Structure of Triacetin...... .............................................94ix

Figure V-10. Chemical Composition of Cashew Nut S hell Liquid ....................98

Figure VIII-1. Value ($) of U.S. Imports of Partic leboard from China:

1997 to 2006....................................... ......................................191 Figure VIII-2. Value ($) of U.S. Imports of Mediu m Density Fiberboard

from China: 1997 to 2006 ........................... ..............................193 Figure VIII-3. Value ($) of U.S. Imports of Hardw ood Plywood from China:

1997 to 2006....................................... ......................................194x 

### List of Appendices

Appendix A Proposed Regulation Order

Appendix B Planning & Technical Support Division. 2007. Estimation of

2002 Formaldehyde Emission Inventory from Composite Wood Products. Draft Report

Appendix C-1 Summary of Refined Air Dispersion Mode ling Using ISC3 of

Formaldehyde from Composite Wood Product Exposure

Scenarios

Appendix C-2 Composite Wood Product ATCM – Modeling Scenario No. 1:

HCHO Emissions from Composite Wood Products Stored at
a Warehouse Store

Appendix C-3 California Air Resources Board Memoran dum: Vernon

Hughes to James Aguila, 12 June 2006, RE: Air Quali ty Modeling of Emissions from Composite Wood Products

Appendix D Basis for Formaldehyde Emission Factors

Appendix E Estimation of the Amount of Composite Wo od Products in a

Home

Appendix F Basis for Estimating Reductions in Daily Time-Weighted

Average Formaldehyde Concentration

Appendix G Calculations of Per Panel and Industry- wide Costs

Appendix H Comparison of CARB Emission Standards to Other

International StandardsES-1



### Executive Summary

The California Air Resources Board (CARB) staff is proposing to establish an Airborne Toxic Control Measure (ATCM) to reduce for maldehyde emissions from composite wood products. “Composite wood products” is a general term for wood-based panels made from wood plies, particles, or fibers that are bound together with a resin or adhesive. They include ha rdwood plywood, particleboard and medium density fiberboard. These products emit formaldehyde because the resins typically used to bond the wood materials co ntain formaldehyde. Emissions from these products result from the relea se of unreacted formaldehyde from the resins and from chemical degr adation over time.

Composite wood products are sold in large volumes t o California, and are among the highest formaldehyde emitting products used in everyday applications. In this regard, formaldehyde is emitted into the air f rom composite wood products at the panel manufacturing plant, fabrication faciliti es, new home construction, remodeling construction, truck, rail, and ship tran sportation, lumberyards, and through windows, doors, and ventilation systems in homes and other buildings. The proposed ATCM was developed in consideration of the results of a survey of panels produced in 2002, which indicated that actua l formaldehyde emissions from U.S. composite wood products were much higher than those allowed in Europe, Japan, and Australia.

A. Background

In 1992, the Board identified formaldehyde as a tox ic air contaminant (TAC) based primarily on the determination that it was a human carcinogen with no known safe level of exposure (CARB, 1992). Because formaldehyde is a TAC, CARB is required to prepare a report on the need an d appropriate degree of regulation to reduce formaldehyde emissions (Health & Safety Code §39665). Regulations that bring about reductions in TAC emis sions are known as ATCMs. State law requires that ATCMs be based on the use o f the best available control technology (BACT) or a more effective control metho d, in consideration of cost and human health risk (Health & Safety Code §39666) , if the TAC has no safe level of exposure. Exposure to formaldehyde has bo th non-cancer and cancer

health effects. The non-cancer health effects of f ormaldehyde are eye, nose, and/or throat irritation. The International Agency for Research on Cancer conducted an evaluation of formaldehyde and conclud ed that there is sufficient evidence that formaldehyde causes nasopharyngeal ca ncer in humans (i.e., in the region of the throat behind the nose).

Current emissions of formaldehyde from composite wo od products are estimated to be about 900 tons per year. For the most part, formaldehyde emissions from these products are not regulated in the U.S.; altho ugh many manufacturers met an essentially voluntary standard established by th e U.S. Department of HousingES-2

and Urban Development (HUD) that applies to plywood and particleboard used in manufactured homes. Current annual average concent rations of formaldehyde in ambient air range from 3 to 4 micrograms per cub ic meter ( μ g/m 3 ) across California, with indoor and in-vehicle concentratio ns typically many times higher. The risk from exposure to annual average concentrat ions of formaldehyde in ambient air is about 20 to 24 potential excess canc er cases per million. The risk from current total daily formaldehyde exposure is e stimated to range from 86 to 231 excess cancer cases per million over a lifetime , and from 23 to 63 excess cancer cases per million due to exposures during ch ildhood. The proposed ATCM would reduce emissions to ambient air and very significantly reduce total daily exposures to formaldehyde. Exposures to form aldehyde, which occur throughout the day in both the outdoor and indoor e nvironment, pose a serious health risk to the people of California.

B. Staff Proposal

Because there is no safe threshold exposure level f or formaldehyde, we are proposing a control measure to limit formaldehyde e missions from three composite wood products – hardwood plywood (HWPW), particleboard (PB), and medium density fiberboard (MDF) to the maximum amou nt feasible. Based on our survey results, these three products are still primarly being made with ureaformaldehyde resins that have the highest formaldeh yde emission rates. Formaldehyde emission rates from other composite wo od products (e.g., oriented strandboard, hardboard, peg board, etc.) u sed for exterior applications

are about 90% lower and contribute far less to form aldehyde concentrations in

California.

Hardwood plywood is made by gluing together hardwoo d plies, and used to make paneling, flooring, cabinets and furniture. P articleboard is made of wood fragments or particles glued together, and used to make countertops, cabinets, and floor underlayments. Medium density fiberboard is made of wood fibers glued together, and used to make furniture, cabinet s, moldings, and door skins.

The proposed ATCM would reduce emissions of formald ehyde from HWPW, PB, and MDF panels, and finished goods, such as furnitu re and cabinets fabricated with those materials. The ATCM would apply to pane l manufacturers, distributors, importers, fabricators, and retailers . We are excluding from the regulation architectural plywood, military specifie d plywood, plywood used inside of motor vehicles, and windows that contain small a mounts of HWPW, PB, or MDF (i.e., less than 5% by volume of wood products)

.

The proposed ATCM would establish new formaldehyde emission standards in two phases for HWPW, PB, and MDF, and would also ap ply to finished goods or products utilizing those materials. The intent of the Phase 1 emission standards is to set an industry cap and to stop the low-cost, high-emitting products fromES-3

overseas that can no longer be sent to other market s from coming into California.

The Phase 2 emission standards reflect the use of B ACT (Table ES-1).

Beginning January 1, 2009, the proposed Phase 1 emi ssion standards would become effective, starting with HWPW made with a ve neer core (HWPW-VC), PB, MDF, and thin MDF (tMDF), followed by the stand ard for HWPW made with a composite core (HWPW-CC), six months later (Table ES-1). A separate standard is proposed for tMDF that considers the te chnological limitations specific to MDF made to be 8 millimeters or less. Beginning January 1, 2011, a comparable suite of increasingly more stringent Pha se 2 formaldehyde emissions standards is proposed. All of the standards are ma ximum allowable or “cap” standards, and would apply to products made in the U.S. or imported from other countries. By “cap” standards, we mean standards t hat cannot be exceeded. Panel producers will need to operate routinely belo w the “cap” to ensure that they standards will always be met.

To ensure compliance with the proposed ATCM, panel manufacturers, foreign and domestic, would need to be “third party certifi ed.” This requirement calls for independent formaldehyde emission testing of panels and manufacturing processes for all manufacturers that sell panels us ed in the California market. Third party certifiers would be required to be appr oved by the Executive Officer. As an incentive, manufacturers that use “no added f ormaldehyde” resins would not be required to conduct third party certificatio n.

Table ES-1. Proposed Phase 1 and Phase 2 Emission Standards 1

--------------- Standard Concentrations (ppm) -- -------------

Phase 1 Formaldehyde Emission Standards

Eff. Date HWPW-VC HWPW-CC PB MDF tMDF

Jan 2009 0.08 ----- 0.18 0.21 0.21 July 2009 ----- 0.08 ----- ----- -----

Phase 2 Formaldehyde Emission Standards

Eff. Date HWPW-VC HWPW-CC PB MDF tMDF

Jan 2011 0.05 ----- 0.09 0.11 -----

Jan 2012 ----- ----- ----- ----- 0.13 July 2012 ----- 0.05 ----- ----- -----

(1) “ppm” = parts per million; “Eff. Date” = effective date; “HWPW-VC” = hardwood plywood – veneer core; “HWPW-CC” = hardwood plywood – composi te core;”tMDF” = thin medium density fiberboard (8-mm or thinner). “Standard Concentrat ions” are allowable limits based on measurements made using the American Standards & Te sting Method E1333-96.ES-4

To provide assurances of compliant products to down stream customers, manufacturers would be required to provide chain-of -custody records to their customers. An example of such a document would be an invoice that states that the composite wood products comply with applicable Phase 1 or Phase 2

emission standards. These would include the necess ary information to track a composite wood product to its original manufacturer . Chain-of-custody documents must accompany all HWPW, PB, and MDF pane ls and finished goods made with those materials if sold to Californ ia.

Beginning in 2009, all PB, HWPW, and MDF offered fo r sale in California would be required to have a label on each panel or a desi gnation on a bill-of-lading that specifies that the product complies with California formaldehyde emission limits. Composite wood product manufacturers would be requi red to verify product compliance with prescribed emission testing protoco ls (i.e., American Standards and Testing Method E1333-96).

Beginning in 2012, businesses that sell in Californ ia and utilize PB, HWPW, or MDF as a raw material to fabricate other products, would be required to use only products that comply with the California formaldehy de emission limit. Fabricators are also required to label each finished good or pr oduct and provide chain-ofcustody documentation. Moreover, retailers of PB, HWPW, and MDF or products containing those materials, could only sell HWPW, P B, or MDF meeting the California formaldehyde emission limits or fabricat ed finished goods or products containing composite wood products compliant with t he California formaldehyde emission limits, imported or domestic.

C. Options for Meeting the Proposed Emission Standa rds

In 2001, staff initiated efforts to determine how f ormaldehyde emissions from HWPW, PB, and MDF could be reduced. The ATCM defin es BACT as the emission limits in Table ES-1. In our analysis of potential BACT options, we initially found that there are “niche” products pre sently being sold with very low formaldehyde emissions. In addition, there are pro ducts being made with proprietary “no added formaldehyde” resins, such as resins made from soy flour.

In addition, we learned that manufacturers have an array of options for lowering formaldehyde emissions from the urea-formaldehyde r esins that they presently use, or they could opt to use an alternative resin system. In addition to the manufacture of low-formaldehyde content materials, laboratory studies have

shown that additives can be used to further lower f ormaldehyde emissions (e.g., melamine, hexamine) in panels made with urea-formal dehyde resins beyond those levels achieved with today’s use of additives . Alternatively, considerable work has been done to demonstrate the utility of ta nnin-based resins.ES-5

We believe that manufacturers will generally have m ore than one option for meeting the proposed formaldehyde emission standard s. To produce products that meet the Phase 1 standards, we believe that ma nufacturers that choose to use urea-formaldehyde resins could comply by optimi zing their current production processes and using resins with lower am ounts of formaldehyde. Alternatively, manufacturers could opt to follow an alternative compliance option and use a “no added formaldehyde” resin, which coul d also allow for producing panels that immediately comply with the proposed Ph ase 2 standards in Table

ES-1.

To meet the Phase 2 standards, we believe that manu facturers that choose to continue using urea-formaldehyde resins will need t o make further changes. They would likely need to use additives such as mel amine, in concentrations ranging from 8 to 15% by weight, to achieve the emi ssion limits in Table ES-1. In terms of alternative resin systems, HWPW manufactur ers could use polyvinyl acetate resins, which are already being used to mak e panels for Green Building Programs across the U.S. For PB, we believe that a promising alternative resin system is phenol-formaldehyde resin, which is the r esin currently being used to produce exterior-grade products in the U.S.

D. Emission Reductions and Health Benefits

Within the category of area-wide sources, formaldeh yde emissions from HWPW, PB, and MDF in California are estimated to be about 900 tons per year. The proposed Phase 1 emission standards for HWPW, PB, a nd MDF are about 66%, 49%, and 41% tighter, respectively, than the volunt ary HUD-based standard met by many manufacturers. Based on the average emissi ons of existing products, the ATCM would reduce emissions of formaldehyde by about 20% in Phase 1. The proposed Phase 2 emission standards for HWPW, P B, and MDF are about 79%, 75%, and 69% tighter, respectively, than the v oluntary HUD-based standard met by many manufacturers. Based on the a verage emissions of existing products, the ATCM would reduce emissions of formaldehyde by about

57% in Phase 2. This is an estimated annual emissi ons reduction of about 180 tons per year from Phase 1 and 500 tons per year fr om Phase 2.

Because these emissions would also substantially re duce indoor formaldehyde exposures, the largest benefit would be realized by buyers of new homes. Substantial benefits would also be realized by thos e in existing homes due to reduced emissions from new remodeling projects and newly purchased furniture. These reductions benefit ambient air quality as nea rly all formaldehyde directly

emitted indoors moves to the outdoors. Most of the formaldehyde moves outdoors within hours, primarily through indoor-out door air exchange from natural ventilation and building leakage. A very small amo unt of formaldehyde (< 1% up to 7%) is estimated to be removed through chemical reactions with other compounds in indoor air or on surfaces.ES-6

To estimate the reduction in cancer risk resulting from the implementation of the proposed Phase 1 and Phase 2 standards, we calculat ed the potential cancer risk from total formaldehyde exposures to current-a verage and current-elevated formaldehyde concentrations. In the two scenarios, average or elevated outdoor, indoor, and in-vehicle formaldehyde concentrations were obtained from the literature to estimate daily time-weighted average and elevated exposures, respectively. Based on projected decreases in dail y average or elevated formaldehyde exposure, formaldehyde-related cancer risk in adults would be reduced by 35 to 97 excess cancers per million, ove r a 70-year lifetime exposure (Table ES-2). In children, it would result in a re duction of 9 to 26 excess cancers per million, based on a 9-year childhood exposure. Risk reductions would be far greater for those living in new or nearly new homes , where formaldehyde levels can be significantly higher.

Table ES-2. Estimated Reductions in Cancer Risk Aft er Phase 1 and Phase 2 1

A. Childhood Exposure: 9-year Exposure to Formaldeh yde

Exposure Scenario TWA Formaldehyde Cancer Risk

Per Million Cancer Cases

Reduced Current-average 16 μ g/m 3 23 -----

• Post Phase 1 13 μ g/m 3 20 3

• Post Phase 2 9 μ g/m 3 14 9

Current-elevated 42 μ g/m 3 63 -----

• Post Phase 1 36 μ g/m 3 54 9

• Post Phase 2 25 μ g/m 3 37 26

B. Lifetime Exposure: 70-year Exposure to Formaldeh yde

Exposure Scenario TWA Formaldehyde Cancer Risk

Per Million Cancer Cases

Reduced Current-average 16 μ g/m 3 86 -----

• Post Phase 1 14 μ g/m 3 74 12

• Post Phase 2 9 μ g/m 3 51 35

Current-elevated 42 μ g/m 3 231 -----

• Post Phase 1 36 μ g/m 3 196 35

• Post Phase 2 25 μ g/m 3 134 97

(1) “TWA formaldehyde” = Daily time-weighted average f ormaldehyde concentration. “Cancer Risk” = number of estimated chances per million of developing cancer in a 9- or 70-years.ES-7

E. Estimated Costs

HWPW, PB, and MDF panels that comply with the propo sed Phase 1 and Phase 2 standards can be produced using a range of availa ble options used today to minimize formaldehyde emissions. For Phase 1, esti mated production cost increases for HWPW, PB, and MDF panels, were betwee n 1% and 7%. For Phase 2, the increases were estimated to range betw een 8% and 30%. Based on these incremental per panel cost increases, the total cost to the industry was calculated. In Phase 1, this would average $19 mil lion per year. After full implementation of Phase 2, costs were estimated at $127 million per year.

1. Hardwood Plywood Industry

Presently, about 40% of HWPW produced for Californi a complies with the proposed Phase 1 and Phase 2 standards. For the re maining 60%, we believe manufacturers could apply a range of low-cost modif ications that have been proven to lower formaldehyde emissions. As only a modest amount of reduction is needed, we believe that the production cost of a Phase 1 compliant HWPW panel would be increased by about 1%, due almost en tirely to the increase in cost for improving the urea-formaldehyde resin (i.e ., would raise the production cost of a $20 HWPW panel up to $20.25).

For the proposed Phase 2 standard, manufacturers wo uld likely choose to add additional scavengers, namely melamine or hexamine, to reduce formaldehyde emissions from panels made with urea-formaldehyde r esins. Alternatively, selected manufacturers may choose to use polyvinyl acetate resins, which may require some minor upgrading of equipment. Through either option, it is estimated that the cost to produce a Phase 2 compli ant HWPW panel would be increased by about 8% to 19% (i.e., would raise the production cost of a $20 HWPW panel to a range of $21.50 to $23.75).

2. Particleboard Industry

Based on the CARB survey of products manufactured i n 2002, about 55% of PB produced in the U.S. already complies with the prop osed Phase 1 standard, and only a small amount of specialty products (< 1%) co mplies with the proposed Phase 2 standard. For about 45% of U.S. production , we believe that to produce a panel with a urea-formaldehyde resin that complie s with the Phase 1 standard, manufacturers would apply many of the same measures as noted previously for HWPW. By the same reasoning, it is estimated that the production cost of a Phase 1 compliant PB panel would be increased by ab out 4% to 7%, due almost entirely to the increase in resin cost (i.e., would raise the production cost of a $10.50 PB panel to a range of $11 to $11.80).ES-8

For the proposed Phase 2 standards, manufacturers w ould likely use a melamine-urea-formaldehyde (MUF) resin in combinati on with the use of lower mole ratio urea formaldehyde resins (i.e. F:U<1). We believe that to meet the Phase 2 standard, the MUF resin would need to conta in about 8% melamine by weight. In addition to increased resin costs, it w as further assumed that processing times would be lengthened by about 10%. Thus, the cost to produce a Phase 2 compliant PB panel would be increased by about 17% to 30% (i.e., would raise the production cost of $10.50 PB panel to a range of $12.30 to $13.80).

3. Medium Density Fiberboard Industry

Based on the CARB survey of panel products manufact ured in 2002, about 25% of MDF produced in the U.S. already complies with t he proposed Phase 1 standard, and only a small amount of specialty prod ucts (< 1%) complies with the proposed Phase 2 standard. For about 75% of U.S. p roduction, manufacturers will likely apply similar modifications to their ur ea-formaldehyde resins, as noted for PB and HWPW. Thus, the cost of a Phase 1 compl iant MDF panel would be increased by about 4% to 6%, due to the increase in resin cost (i.e., would raise the price of a $14.00 MDF panel to a range of $14.5 0 to $15.00).

For the proposed Phase 2 standards, manufacturers w ould likely choose to use a melamine urea-formaldehyde resin with 12% melamine in combination with the use of lower mole ratio urea formaldehyde resins (i .e. F:U <1). In addition to increased resin costs, we assumed that processing t imes would be lengthened by about 30%. Thus, we believe that the cost to pr oduce a Phase 2 compliant MDF panel would be increased by about 30% (i.e., wo uld raise the price of a $14.00 MDF panel to $18.20). A few manufacturers p roduce MDF with pMDI, however pMDI is much more costly than urea formalde hyde resins (see Table VIII-14). The cost of an MDF panel made from (poly meric Methylene Diphenyl Diisocyanate) pMDI would be increased by about 135% , due to the increase in resin cost (i.e., would raise the price of a $14.00 MDF panel to $33). So, staff believes that manufacturers would opt to use the le ss expensive melamine fortified, low mole ratio urea-formaldehyde resin t o meet the Phase 2 emission

standard.

4. Total Combined Cost to the Industry

The above estimated “per panel” production cost inc reases were used to calculate the total cost to the HWPW, PB, and MDF i ndustries and are shown in Table ES-3. Using production data for 2002, the to tal estimated cost in California

are estimated to be about 19 million dollars annual ly to meet the Phase 1 standards and about 127 million dollars annually to meet the Phase 2 standards.ES-9 Table ES-3. Total Estimated Cost to the Industry i n 2002

Product Production

(Million Panels) Phase 1 Annual

Costs (Millions) Phase 2 Annual

Costs (Millions)

HWPW 9.3 6 17

PB 19.5 4 61

MDF 8.7 9 49

Total Estimated Cost ----- 19 127

5. Consumer Costs

Most of the composite wood in a new home is used in cabinets, shelving, countertops, and moldings. The increased cost of c omposite wood products

would have a limited effect on new home constructio n costs. Staff estimates that for a 2000 square foot home, the increased cost of construction is about $390.00 for a medium priced house of $574,000.00, the estim ated price increase is

0.07 %.

Based on the estimated cost of meeting the phase 2 emission standards, the increase in the price of a panel would range from a bout $3.00 to $6.00, among various product types.

F. Comments on the Staff Proposal

Some manufacturers have expressed concerns about th e stringency of the proposed Phase 2 standards and the amount of time t hey are provided to implement changes in their plants. We believe that the proposed standards are achievable with the application of one or several a dditives and through improvements in the manufacturing process. With re spect to the amount of time needed to produce compliant products, we understand that most manufacturers that intend to sell to California have already begu n research to develop new resin system(s). As the effective date of the ATCM is ab out two years into the future for Phase 1 and four years before Phase 2, we belie ve there is sufficient time for

manufacturers to conduct mill trials and make the n ecessary production changes for their new or modified resin systems.

Another manufacturer has commented that the Phase 1 standards for HWPW should be lower and required sooner, and the Phase 2 standards should also be effective sooner than staff is proposing. We are n ot proposing earlier compliance

dates because we believe that most HWPW manufacture rs will need the provided time to research alternatives, and as appr opriate, redesign their manufacturing operations. We are not proposing low er standards for Phase 1 because our intent is to set an industry cap to sto p the low-cost, high-emitting products from coming into California.ES-10

G. Other Formaldehyde Emission Standards

Presently, the U.S. trails the efforts undertaken i n Japan, Europe, and Australia to reduce formaldehyde emissions from composite woo d products. In Europe, concerns over the health effects of formaldehyde em issions from composite wood products led to a guideline to limit formaldeh yde emissions from particleboards, fiberboards, and plywood to 0.1 ppm , which is known as the E1 classification (Deutsches Institut fur Bautechnik, 1994). Australia has also adopted the E1 classification. In Japan, the Japan ese Building Standard Law (Takabatake, 2003) created a “sick house” regulatio n which regulates the amount of formaldehyde that can be emitted from building m aterials.

Staff believes that the proposed Phase 2 standards will limit formaldehyde as effectively or more effectively than those being ap plied elsewhere in Europe or Japan. In comparison to the proposed Phase 1 and P hase 2 standards, the E1 standard is an “average” standard that allows panel s to be produced with formaldehyde contents higher than the value of the standard. The proposed ATCM is a “cap” standard which does not allow for a ny products with emission levels above the cap to be sold to California. To ensure that the panels never exceed the standards, manufacturers will need to ro utinely operate below the “cap.” Moreover, in terms of formaldehyde contents , Europe and Japan allow multiple grades of panels to be sold for consumer u se. Therefore, not all panels in Europe and Japan meet a single standard. In Eur ope, a major portion is made to comply with less stringent standards than those proposed by staff, but in Japan, the F  and F  standards bracket the stringency of the proposed standards. In the proposed ATCM, all HWPW , PB, and MDF would be required to meet a single product-specific standard . The proposed ATCM would be the most stringent production standard in the wo rld.

Unlike Europe and Japan, the U.S. has no comprehens ive formaldehyde emission regulations for composite wood products. (The only standards are set by HUD, but apply only to manufactured homes.) Con sequently, the U.S. is a growing market for low-cost, high-emitting products from overseas that can no longer be sent to other markets. While U.S. manufa cturers have made progress toward lower formaldehyde emitting products since t he 1980’s, voluntary reduction efforts in the U.S. continue to lag far b ehind improvements being made in Europe and Japan. The proposed ATCM would apply to HWPW, PB, and MDF used in all other applications, there are no co mparable federal regulations at this time. Note, however, that the HUD standard preempts other standards where it applies. Therefore, the proposed ATCM wou ld not apply to

manufactured homes.ES-11

H. Environmental Impacts

The primary benefit of the proposed ATCM is a reduc tion in formaldehyde emissions, total public exposure, and excess cancer risk in California. In setting new formaldehyde emission standards for HWPW, PB, a nd MDF, reductions in statewide formaldehyde emissions of over 500 tons p er year would be expected to occur at all points along the product distributi on chain. In addition, we will request that the U.S. Environmental Protection Agen cy provide State Implementation Plan credits to California for the f ormaldehyde emission reductions from the ATCM. Formaldehyde is a volati le organic compound and a precursor to the formation of ozone. We anticipate no significant adverse environmental impacts from the implementation of th is ATCM.

I. Environmental Justice

The proposed ATCM would not cause significant adver se impacts in any community. Implementation of the proposed ATCM is aligned with the principle of pollution prevention, and would reduce exposures to formaldehyde in all communities, including low-income areas and ethnica lly diverse communities.

J. References

California Air Resources Board (CARB). 1992. Fina l Report on the Identification of Formaldehyde as a Toxic Air Contaminant. Part A, Exposure Assessment. Technical Support Document, Stationary Source Divis ion, Sacramento, CA. 89

pp.

Deutsches Institut fur Bautechnik (DIBt). Guidelin e on the classification and control of wood-panels with regard to formaldehyde emission. Guideline 100, DIBt, Berlin, Germany. (English Translation; Origi nal Not Seen)

Takabatake K. 2003. Japanese Sick House Regulatio ns. Accessed : 6 July

2006. From : http://strategis.ic.gc.ca/epic/site/imr-ri.nsf/en/g r116049e.htmlChapter I Page 1



### I. Introduction

The California Air Resources Board staff is proposi ng an Airborne Toxic Control Measure to reduce formaldehyde (HCHO) emissions fro m composite wood products. “Composite wood products” is a general t erm for wood-based panels made from wood plies, particles, or fibers that are bound together with a resin or adhesive. They include hardwood plywood (HWPW), pa rticleboard (PB) and medium density fiberboard (MDF), which emit HCHO be cause the resins typically

used to bond the wood materials contain HCHO. Emis sions from these products

result from the release of unreacted HCHO from the resins and from chemical degradation over time. This chapter discusses our regulatory authority and the need for reducing HCHO emissions from composite woo d products.

In the early 1980’s, the California Legislature app roved Assembly Bill (AB) 1807 [Tanner, 1983] – also known as “The Toxic Air Conta minant Identification and Control Act.” Pursuant to AB 1807, the California Air Resources Board (CARB) established a comprehensive program to identify and control toxic air contaminants (TAC) to reduce public exposures to ai r toxics. Subsequently, the Legislature approved AB 2588 [Connelly, 1987], comm only known as the “Air Toxics “Hot Spots” Information and Assessment Act.” This legislation called for the development of a statewide inventory of air tox ic emissions, requirements for notifying people exposed to significant air toxic-r elated health risks, and facility plans for reducing air toxic-related health risks.

In California’s TAC Identification and Control Prog ram, CARB is required to consider specific criteria in its efforts to priori tize compounds for identification as TACs and for reducing statewide emissions (cf. Heal th and Safety Code (H&SC) §39660(f)). Moreover, data gathered under the AB 2 588 “Hot Spots” program must also be evaluated. In 1992, CARB listed HCHO as a TAC without an identifiable threshold exposure level below which n o significant adverse health effects are anticipated.

Because HCHO is a TAC, CARB is required to prepare a report on the need and appropriate degree of regulation to reduce HCHO emi ssions (H&SC §39665). Regulations that bring about reductions in TAC emis sions are called airborne toxic control measures (ATCMs). State law requires that ATCMs be based on the use of the best available control technology (B ACT) or a more effective control method, in consideration of cost and human health risk (H&SC §39666) for substances having no identified safe threshold.

This Initial Statement of Reasons (ISOR) for the pr oposed ATCM to control emissions of HCHO from composite wood products prov ides information on:

• The purpose of the regulation and CARB’s regulator y authority;

• The process and data used to develop the regulatio n;

• Physical and chemical characteristics of HCHO;Chapter I Page 2

• Sources of HCHO;

• Annual average ambient HCHO concentrations, exposu re, atmospheric persistence, and health effects;

• The major types of composite wood products used in California;

• How composite wood products are manufactured; and

• The proposed ATCM and its health, economic, and en vironmental impacts.

The proposed ATCM is designed to reduce the emissio ns of HCHO from HWPW, PB, and MDF, and finished goods that are fabricated with those materials. As HCHO is a carcinogen with no safe threshold exposur e level, and because annual average ambient HCHO levels in California pr esently exceed the Office of Environmental Health Hazard Assessment’s (OEHHA) ch ronic reference exposure level for HCHO, the proposed ATCM would re duce HCHO emissions to ambient air where there are existent risks to publi c health. Secondarily, the proposed ATCM would also lower human exposures to H CHO in homes, schools, and workplaces, where indoor HCHO levels a re also known to reach concentrations that pose serious health risks to se nsitive individuals (e.g., children, the elderly, and people with pre-existing respiratory challenges).

A. Regulatory Authority

The Board’s regulatory authority to control air pol lution is set forth in Divisions 25.5 and 26 of the Health & Safety Code (H&SC). He alth & Safety Code §39903

identifies CARB as:

“... the state agency charged with coordinating efforts to attain and maintain ambient air quality standards, to conduct research into the causes of and solutions to air pollution, and to sy stematically attack the serious problem caused by motor vehicles, which is the major source of air pollution in many areas of the state. ”

Provisions in Division 26 of the H&SC authorize CAR B to control the emissions of criteria pollutants (and their precursor) from s pecific source categories. For example, H&SC §41712 directs CARB to adopt regulati ons to reduce VOC emissions from consumer products. There are air po llutants, such as HCHO, that are precursors to criteria pollutants and are also TACs. TACs are defined in H&SC §39655 as:

“... an air pollutant which may cause or contribute t o an increase in mortality or in serious illness, or which may pose a present or potential

hazard to human health.”

The Board’s authority to regulate TAC emissions is separately codified in H&SC §39650 et seq. (The “Tanner Act”), and in the case of compounds such as HCHO, the justification for pursuing emission reduc tions may derive from more than one provisions of the H&SC.Chapter I Page 3

For the proposed ATCM, the authority of CARB to reg ulate HCHO emissions from composite wood products principally derives fr om the Tanner Act (H&SC §39650 et seq.). The Tanner Act established a two- step process to (1) identify and (2) control TACs in California. In the first s tep, a substance is formally identified as a TAC based on reviews by CARB and OE HHA. In the second step, CARB adopts appropriate regulations, such as ATCMs, to control TAC emissions and to reduce human exposure. In 1992, CARB identi fied HCHO as a TAC with no identified “safe” threshold exposure level (titl e 17, California Code of Regulations §93000.) In situations where no safe t hreshold level has been identified for a TAC, the Tanner Act requires CARB to reduce emissions of the TAC to the lowest level achievable through applicat ion of BACT or a more effective control method (H&SC §39666(c)).

In addition to the authority granted to CARB under the Tanner Act, H&SC §41712 provides CARB with supplementary, independent, auth ority to regulate HCHO emissions from consumer products (i.e., PB and MDF panels) as defined in Health & Safety Code §41712(a)(1) as:

“... a chemically formulated product used by househol d and

institutional consumers ...”

By this definition, PB and MDF panels, but not HWPW panels or finished goods made with those materials, are consumer products be cause they are “chemically formulated” products that are produced by processin g wood waste (e.g., sawdust and other waste wood) to form particles or fibers, which are then combined with resins and other chemicals to produce a panel produ ct that is used by household

and institutional consumers. While wood waste is o ne of the raw materials in the panel product, the wood is highly processed and the panel product is created by applying heat and pressure to induce chemical react ions between the proteins in

wood and the resins and other chemicals added to th e mixture (see subsection IV.C.) As PB and MDF are consumer products, H&SC § 41712(b) requires CARB to adopt regulations to achieve the maximum feasibl e reductions in volatile organic compounds (VOCs) emitted by consumer produc ts. Because HCHO is both a TAC and a VOC, under H&SC §41712, CARB has t he authority to adopt

HCHO emission standards for PB and MDF as a VOC con trol measure for consumer products.

B. Formaldehyde in California

Formaldehyde is directly emitted from a variety of mobile, stationary, area-wide, and natural sources in California (see subsection I II.B.). Composite wood products (i.e., HWPW, PB, and MDF) are responsible for about 5% of these emissions, and the emissions from these products oc cur both outdoors and indoors. Formaldehyde is emitted to ambient, outdo or air from newly made and standing stocks of composite wood products stored a t manufacturing facilities, construction sites, and lumberyards, and during tra nsport of composite wood products by rail, truck, or ship. Indoor emissions come from composite woodChapter I Page 4

products used as structural components or amenities inside buildings. Over time, studies demonstrate that HCHO emissions produ ced indoors from an array of sources, including composite wood products (Batt elle, 1996), make their way outdoors through normal air exchange mechanisms (su bsection III.F.), and

contribute to concentrations measured in ambient ai r.

Ambient HCHO concentrations (i.e., outside) result from both direct HCHO emissions and from secondary HCHO formation in the atmosphere (see subsection III.C.). While the major mobile and sta tionary sources of direct HCHO emissions have previously been regulated by CARB or the U.S. Environmental Protection Agency (USEPA), composite wood products are an important source of HCHO emissions contributing to human exposure in California that have not yet been controlled. Presently, the statewide annu al average HCHO

concentration in ambient air exceeds the chronic re ference exposure level for HCHO that presents a known risk to public health (O EHHA, 2005). Thus, reducing ambient HCHO concentrations is of principa l concern from a public health perspective, requiring both reductions in di rectly emitted HCHO and in VOC emissions that contribute to secondary HCHO for mation. Since the 1970’s, CARB has adopted a suite of increasingly stringent VOC control measures for mobile sources as a means to substantially reduce V OC emissions, including HCHO, to achieve state and federal ambient air qual ity standards for ozone. Reducing VOC emissions has historically been a prim ary focus of state air quality regulators and reductions have been achieved from n early every significant source of VOC emissions (CARB, 2007). In spite of these efforts, there is a continuing need for additional VOC control measures to garner the remaining

VOC reductions needed to achieve state and federal ozone standards.

“Hot spots” are areas where concentrations of a TAC in ambient air, such as HCHO, are greater than regional or statewide averag e TAC concentrations. The elimination of “hot spots” has been the primary rat ionale for many of the ATCMs adopted by CARB in the past (e.g., CARB, 2006). In this regard, results from computer modeling analyses indicate that composite wood products may contribute to HCHO “hot spots” close to a range of sources where these products are present (subsection III.G.). The modeling resu lts indicate that maximum HCHO concentrations in these “hot spots” represent a health risk to proximate receptors. This risk would be reduced by controlli ng HCHO emissions from composite wood products.

In addition to the health risk posed by HCHO in the ambient air, an additional

health risk exists from indoor concentrations of HC HO. As indoor levels in many situations exceed outdoor levels, potential health risks to building occupants are likely to be greater. Although composite wood prod ucts contribute only a small percentage to the HCHO levels that occur in the amb ient air, these products are responsible for a large portion of HCHO exposure that occurs indoors. These combined outdoor and indoor exposures lead to subst antial total exposures to

HCHO for adults and children.Chapter I Page 5

C. Need for Reducing Formaldehyde Emissions from C omposite Wood

Products

Formaldehyde is an air pollutant that is both a TAC and a precursor to the formation of ozone. In choosing to control HCHO em issions from composite wood products, staff considered four factors. As m entioned previously, one factor is that composite wood products are an impor tant uncontrolled source of

HCHO emissions. While there are a number of other sources of HCHO, there is no identified safe threshold exposure level and thi s ATCM contributes to reducing ambient HCHO to the lowest level achievable. Also, with respect to ambient air, the second factor considered by staff is that emiss ions from composite wood products contribute to ambient HCHO “hot spots,” su ch as in proximity to a lumberyard.

The third factor considered by staff is that contro lling HCHO emissions from composite wood products will provide the greatest b enefit in terms of reducing

the total air pollution related health risk from HCHO. Reco gnizing that the Tanner Act requires CARB staff to consider all rele vant factors, including the potential exposure to a TAC in indoor environments, in deciding what sources of HCHO to prioritize for regulation (H&SC §39660.5 an d 39665), reducing HCHO emissions from composite wood products will dramati cally reduce indoor health risks, and thus significantly reduce total exposure and risks from HCHO emissions in California. Thus, it is appropriate f or the CARB staff to give priority to developing an ATCM for this source of HCHO.

The fourth factor considered by staff is that signi ficant VOC reductions that would be achieved in setting stringent HCHO emission stan dards for composite wood products. The reductions from this source category are part of the CARB’s

overall effort to establish VOC standards for numer ous categories of consumer products. Because California needs VOC emission re ductions to achieve state and federal ambient air quality standards, it has b een necessary to develop standards for products from which very low levels o f emissions reductions could be achieved (e.g., limits on contact adhesives effe cted 11 tons per year of VOC emission reductions) (CARB, 2004). As HCHO is also a VOC, the proposed ATCM would reduce HCHO emissions from HWPW, PB, and MDF by approximately 500 tons per year after adoption of t he Phase 2 standards in 2012. Moreover, HCHO is a highly reactive VOC, which mean s that any reduction in HCHO emissions will have an impact in reducing ozon e formation. Because of its high reactivity, the benefits of reducing HCHO emissions will be much greater

than for other VOCs that are less reactive.Chapter I Page 6

D. Regulations Applicable to Formaldehyde

1. Airborne Toxic Control Measures

No specific ATCM to control HCHO emissions has been adopted by CARB, since HCHO was identified as a TAC in 1992. However, HCH O emissions from mobile sources have been reduced as a result of regulation s that lower exhaust emissions of non-methane hydrocarbons from vehicles in light-duty, mediumduty, and heavy-duty weight classifications. In ad dition, exhaust emission standards limiting formaldehyde emissions have been established.

2. Comparable Federal Regulations

The USEPA identified HCHO as a hazardous air pollut ant (HAP) in the federal Clean Air Act Amendments of 1990. In 1992, CARB fo rmally identified HCHO as a TAC (CARB, 1992).

In 1985, the U.S. Department of Housing and Urban D evelopment (HUD)

established HCHO emission limits for PB and HWPW us ed to construct mobile homes (Newton et al., 1986). As the standards appl y only to PB and HWPW, and specifically when used in the manufacture of mo bile homes, they in effect apply to a niche product, and not to composite wood products for use in other applications. These standards were instrumental in actuating substantial HCHO

emission reductions in PB and HWPW which are bonded with urea-formaldehyde resins. However, exposures to HCHO in indoor setti ngs, including but not limited to mobile homes, can still be found at levels that posed significant health risks (CARB, 2005), even after the HUD requirement for th e use of lower-emitting composite wood products.

To control air toxic emissions in the USEPA’s Natio nal Emission Standards for Hazardous Air Pollutants Program, toxic emission li mits were established for plywood and other composite wood product manufactur ing facilities (USEPA, 2002). This rule applies to emissions generated at manufacturing facilities, but does not apply to emissions from the products thems elves.

While federal statutes have been enacted to control HCHO emissions from HWPW and PB for use in mobile homes and from compos ite wood product manufacturing facilities, there is no comparable, e xisting federal regulation to the proposed ATCM.

3. Safe Drinking Water and Toxic Enforcement Act o f 1986

Formaldehyde was listed as a carcinogen on January 1, 1988, under the Safe Drinking Water and Toxic Enforcement Act of 1986 (i .e., Proposition 65), which requires the State to publish a list of chemicals k nown to cause cancer, birthChapter I Page 7

defects, or other reproductive effects (OEHHA, 2005 ). The list is updated at least once a year, and currently includes over 750 chemic als.

E. Indoor Air Quality

With respect to air pollution, a principal responsi bility of state and federal environmental protection agencies is to protect pub lic health by ensuring the air is clean. Since the 1970’s, substantial reductions in ambient air pollutant levels have been realized through efforts aimed at lowerin g emissions from motor vehicles, stationary sources, and many other source s. While these efforts have been beneficial to public health in California and the rest of the nation, studies have found that people spend 90% or more of their t ime indoors (University of California, Berkeley, 1991), where less is known ab out the sources of indoor air pollution or the potential health risks that could be occurring.

In the early 1990’s, CARB released an indoor air qu ality guideline titled “Formaldehyde in the Home,” which identified the ma jor sources of HCHO in homes and what people could do to reduce indoor HCH O exposures (CARB, 1991). Composite wood products such as PB, HWPW, a nd MDF were listed as major sources of HCHO emissions in California homes , where average HCHO concentrations were reported to be 70 to 80 and 50 parts per billion (ppb) in mobile and conventional homes, respectively. Subse quent research confirmed the importance of composite wood products as a sour ce of HCHO in indoor environments (Battelle, 1996), which in combination with HCHO emissions from other consumer goods and products, allowed for inte rmittent exposures well

above levels determined to cause chronic health eff ects (OEHHA, 2005). These same concerns were reiterated in a recent report to the California Legislature titled “Indoor Air Pollution in California,” submit ted in response to the requirements of AB 1173 [Keeley, 2002] (CARB, 2005)

.

F. References

Battelle. 1996. Determination of Formaldehyde and Toluene Diisocyanate

Emissions from Indoor Residential Sources. Final R eport, CARB Contract No. 93-315, Sacramento, CA. 119 pp.

California Air Resources Board (CARB). 1991. Form aldehyde in the Home. Indoor Air Quality Guideline, Research Division, Sa cramento, CA. 5 pp.

CARB. 1992. Final Report on the Identification of Formaldehyde as a Toxic Air Contaminant. Part A, Exposure Assessment. Technic al Support Document, Stationary Source Division, Sacramento, CA. 89 pp.

CARB. 1993. The Identification of Federal Hazardo us Air Pollutants as Toxic Air Contaminants. Staff Report, Stationary Source Divi sion, Sacramento, CA. 8 pp.Chapter I Page 8

CARB. 2004. Initial Statement of Reasons for the Proposed Amendments to the California Aerosol Coating Products, Antiperspirant s and Deodorants, and Consumer Products Regulations, Test Method 310, and Airborne Toxic Control

Measure for Para-dichlorobenzene Solid Air Freshene r and Toilet/Urinal Care Products. Stationary Source Division, Sacramento, CA.

CARB. 2005. Indoor Air Pollution in California. Report to the Legislature, Pursuant to Health & Safety Code §39930. Research Division, Sacramento, CA. 248 pp.

CARB. 2006. Proposed Amendments to the Hexavalent Chromium Airborne Toxic Control Measure for Chrome Plating and Chromi c Acid Anodizing Operations. Stationary Source Division, Sacramento , CA. 125 pp.

CARB. 2007. Air Resources Board’s Proposed State Strategy for California’s 2007 State Implementation Plan. Draft Report, Plan ning & Technical Support Division, Sacramento, CA. From : http://www.arb.ca.gov/planning/sip/sip.htm

Accessed : 14 February 2007.

Newton LR, WH Anderson, HS Lagroon, and KA Stephens . 1986. Large-scale test chamber methodology for urea-formaldehyde bond ed wood products. In : B Meyer, BA Kottes Andrews, and RM Reinhardt (eds). Formaldehyde Release from Wood Products. ACS Symposium Series No. 316: 154-187.

OEHHA. 2005. Proposition 65 in Plain Language. A ccessed : 8 February 2007.

From : http://www.oehha.ca.gov/prop65/background/p65plain. html

U.S. Environmental Protection Agency (USEPA). 2002 . Regulatory Impact Analysis of the Proposed Plywood and Composite Wood Products NESHAP. Final Report, Office of Air Quality Planning and St andards, Research Triangle Park, NC.

University of California, Berkeley. 1991. Activit y Patterns of California Residents. Final Report, CARB Contract No. A6-177- 33, Research Division, Sacramento, CA. 63 pp.Chapter II Page 9



### II. Public Outreach

This chapter summarizes the numerous public meeting s held with stakeholders since fall 2001 when plans were announced to develo p an ATCM to reduce HCHO emissions from composite wood products.

A. Outreach Efforts

Table II-1 lists selected key public meetings, conf erence calls, or presentations to discuss various aspects of the proposed ATCM to red uce HCHO emissions from composite wood products. The meeting notices and r elated information are posted at: http://arb.ca.gov/toxics/compwood/workshops.htm

.

Table II-1. Selected ATCM-related Outreach Efforts

Date Purpose of Meeting/Activity Sep 2001 • Initial public meeting on proposed ATCM concept

Oct 2001 • Focused meeting with non-manufacturer groups

Nov 2001 • Public meeting on format and content of the produc t survey

Jan 2002 • Focused meeting to refine the product survey Apr 2003 • Distribute survey to U.S. manufacturers Apr 2004 • Stakeholder meeting to discuss survey results Aug 2004 • Public meeting on survey results and need for ATCM

Oct 2004 • Public meeting on ATCM data needs and enforcement May 2006 • Public meeting to release first draft regulation

Jun 2006 • Public meeting on enforcement and revised draft re gulation Aug 2006 • Site-visit to a particleboard manufacturing plant

• Site-visit to the Port of Oakland Sep 2006 • Presentation at National Green Building Conference

Oct 2006 • Site-visit to architectural plywood facilities

• Conference call – Finished Product Testing

• Public meeting to release second revision of draft regulation

Nov 2006 • Meeting with wood importing association

Dec 2006 • Site-visits to a testing lab and plywood manufactu ring plant

B. Public Involvement

Manufacturers, industry associations, government ag encies, researchers, and environmental organizations were contacted and aske d to provide input throughout the ATCM development process. In additi on to hosting public meetings, information (e.g., meeting notices, slide presentations) was posted on

ARB’s website at: http://www.arb.ca.gov/toxics/compwood/compwood.htm . A composite wood list-serve was developed to keep app roximately 540 stakeholders notified of progress being made with r espect to ATCMChapter II Page 10

development. In addition, as specified in Health & Safety Code §39665(c),

relevant comments on the ATCM have been included in the administrative

record. Comments are listed as a reference to the chapter, and are available from CARB staff upon request (Various, 2005-2007).

1. Industry

Manufacturers and industry associations have been a ctive participants throughout the ATCM development process. Their inv olvement has included:

• Contacting staff by telephone and email;

• Providing facility tours;

• Responding to the 2003 Composite Wood Survey; and

• Participating in conference calls and public meeti ngs.

In 2006, a major effort was initiated to open a dia logue with industry associations and individual manufacturers, fabricators, and reta ilers. In addition to the three public workshops (Table II-1), the outreach effort included over 30 face-to-face meetings, over 20 conference calls, approximately 1 0 facility site-visits, and two presentations at national conventions/conferences. Among the industry associations that were contacted and/or provided in put during the ATCM development process are:

• American Home Furnishings Alliance

• American Homeowners Association

• APA – The Engineered Wood Association

• Australian Wood Panels Association, Inc.

• Business & Industrial Furniture Manufacturers Asso ciation

• California Building Industry Association

• California Manufactured Housing Institute

• California Wood Industries Coalition

• Composite Panel Association

• Consulate General – People’s Republic of China

• Door & Access System Manufacturers Association

• Forintek Canada Corporation

• Formaldehyde Council, Inc.

• Formaldehyde-free Coalition

• Hardwood Plywood & Veneer Association

• Healthy Building Network

• International Wood Products Association

• Kitchen Cabinet Manufacturers Association

• National Retail Federation

• National Wood Flooring Association

• Window & Door Manufacturers Association

• Woodwork InstituteChapter II Page 11

In addition, meetings and conference calls with a n umber of individual companies were held throughout 2006. Through these contacts, it was learned that the proposed California regulations were being discusse d at international wood products meetings in Asia and Europe. While the pr oposed ATCM has the potential to impact many economic sectors, a concer ted effort was made to contact and solicit input from as many affected ind ustries as possible.

2. Government Agencies

In addition to consulting with CARB staff in the En forcement, Monitoring and Laboratory, Planning and Technical Support, and Res earch Divisions, input and cooperation was received from other State agencies and local air districts. Concerning issues related to health risk assessment , numerous meetings and

conference calls were held with the OEHHA to seek t heir input on the methodology used to assess health risks for the pro posed ATCM. Similarly, regular updates were provided to the California Air Pollution Control Officers Association’s (CAPCOA) Toxic Air Risk Managers Advi sory Committee on progress made on ATCM development. A separate pres entation was also made to CAPCOA’s Enforcement Managers.

Owing to the nature of the HCHO emission test proce dures used in the composite wood products industry, contacts were mad e with the California Department of Health Services, which is in the proc ess of developing a test facility in their San Francisco Bay Area Laboratory that would be comparable to test facilities operated by the Composite Panel Ass ociation and the Hardwood Plywood & Veneer Association, the principal industr y associations in the U.S. An agreement is being developed to utilize the test fa cility that will be operated by the Department of Health Services.

C. Survey of Products Manufactured in 2002

A survey was conducted in 2003 to gather data on co mposite wood products manufactured in 2002. In 2003, a survey package wa s sent to over 200 U.S. manufacturers (http://www.arb.ca.gov/toxics/compwoo d/survey2002.htm). Manufacturers were asked to provide information abo ut the range of products they produced, types of resins they used, amount of product sales in California, chemical composition of the resins used, and equipm ent used in manufacturing (CARB, 2003). Fifty-seven responses were received, and those data were analyzed and presented at a public meeting in Augus t 2004. Results of the survey are discussed in detail in Chapter V.Chapter II Page 12

D. References

California Air Resources Board. 2003. Composite W ood Survey Package.

From : http://www.arb.ca.gov/toxics/compwood/survey.htm Accessed : 8 February

2007.

Various. 2005-2007. Collection of Relevant Commen ts Concerning the Proposed ATCM to Control Formaldehyde Emissions fro m Composite Wood Products. Compiled by Stationary Source Division, Sacramento, CA.Chapter III Page 13



### III. Need for Regulation of Formaldehyde

Under Health and Safety Code Section 39665, ARB is required to prepare a report on the need and appropriate degree of regula tion for compounds identified as toxic air contaminants. This chapter meets the requirements of State Law and provides an overview of the physical and chemical p roperties of formaldehyde, sources, emissions, measured concentrations in vari ous environments, and atmospheric persistence.

A. Health Effects of Formaldehyde

Exposure to HCHO has both non-cancer and cancer hea lth effects. The noncancer health effects of HCHO are eye, nose, and/or throat irritation (OEHHA, 2005b). In 2004, the International Agency for Rese arch on Cancer conducted an evaluation of formaldehyde and concluded that there is sufficient evidence that HCHO causes nasopharyngeal cancer in humans (i.e., in the region of the throat behind the nose) (National Cancer Institute, Not Da ted). The risk from exposure to annual average HCHO concentrations in ambient ai r alone is about 20 to 24 excess cancer cases per million based on a 70 year lifetime exposure. The number of excess cancer cases per million rises con siderably when HCHO exposure from current total daily HCHO exposure is considered. A detailed, comprehensive review of the non-cancer and cancer h ealth effects of HCHO is contained in Chapter VII.

B. Physical and Chemical Properties

Formaldehyde (HCHO) is a colorless, volatile, flamm able gas at room temperature and pressure. It has a pungent, highly irritating, suffocating odor and may cause a burning sensation to the eyes, nose , and lungs at high

concentrations. Pure HCHO is not available commerc ially and is generally produced, sold and transported as water solutions ( formalin) with concentrations ranging from 25 to 56 weight percent (%) (Gerberich and Seaman, 1994). It is very soluble in water, alcohols and other polar sol vents (Lide, 1999). Table III-1 summarizes some of the physical and chemical proper ties of HCHO. Formaldehyde is also known as methanal, methylene o xide, oxymethylene, methylaldehyde, and oxomethane (USDHHS, 1999). The commercial forms of formaldehyde include paraformaldehyde, formalin sol utions, polymers, resins,

and other derivatives.

Formaldehyde is a member of the family of aldehydes , its simple structure is composed of two hydrogens directly attached to a ca rbonyl group (Wade, 1999). Formaldehyde exhibits most of the general chemical properties of aldehydes, except it is more reactive than longer chain aldehy des. Formaldehyde is a very strong electrophile. It can participate in electro philic aromatic substitution reactions with aromatic compounds and can undergo e lectrophilic addition reaction with alkenes. Compared to other carbonyl compounds, HCHO has goodChapter III Page 14

thermal stability and is able to undergo a broad ra nge of chemical reactions, many of which are useful in commercial processes (C ARB, 1992).

Formaldehyde gas can undergo slow polymerization to trimer, trioxane, and paraformaldehyde at temperatures below 80 oC (Canad ian Centre for Occupational Health & Safety, 2005; Reuss et al., 1 988). In aqueous solutions, HCHO reacts with water to form methylene glycol (CA RB, 1992). Traces of polar impurities, such as water, methanol, alkalies, and acids considerably speed up the polymerization process (Reuss et al., 1988; Wal ker, 1964).

When pure liquid HCHO is warmed to room temperature in a sealed container it undergoes rapid polymerization with evolution of he at (Gerberich and Seaman, 1994). In order to prevent polymerization of HCHO, methanol is generally added as a stabilizing agent (Merck, 1989). The uncataly zed decomposition of HCHO is slow (below 300 oC), which yields carbon monoxid e and hydrogen gas (Gerberich and Seaman, 1994). When catalyzed by me tals such as platinum, copper, chromia, and alumina, HCHO decomposition ca n produce methanol, methyl formate, formic acid, carbon dioxide, and me thane. Formic acid is formed when HCHO is oxidized via atmospheric oxygen. When stored, HCHO solutions should be kept tightly sealed in order to prevent f ormic acid formation.

Table III-1. Physical and Chemical Properties of Fo rmaldehyde 1

Chemical Formula: HCHO CAS Registry Number: 50-00-0 Molecular Weight: 30.03 Boiling Point: -19.5 oC Melting Point: -118 oC Vapor Pressure: 3284 mm Hg at 20 oC Vapor Density: 1.03 (aq); 1.08 (gas) Density/Specific Gravity: 1.067 (air = 1) Log Octanol/Water Partition

Coefficient: 0.35

Conversion Factor: 1 ppm = 1.23 mg/m3 Solubility in Water: Very soluble (40g/100mL at 20 oC)

(1) Sources : Canadian Centre for Occupational Health & Safety (2005); Merck (1989); Sax and Lewis (1989); Syracuse Research Corp. (2004).

C. Sources and Emissions of Formaldehyde

Formaldehyde gas is released into the environment f rom a variety of sources. There are directly emitted sources and there are in direct sources. Direct sources include motor vehicles, aircraft, boats, chemical p lants, and fireplaces (seeChapter III Page 15

subsection III.C.1). Indirect sources include atmo spheric photooxidation processes, which is the dominant source of HCHO in the lower atmosphere. The photochemical oxidation of hydrocarbons in polluted atmospheres that contain ozone and nitrogen oxides results in formation of H CHO. This is the largest source of HCHO in ambient air in California (CARB, 1992).

Formaldehyde is the most commercially important ald ehyde and it is an essential component of many resin technologies. More than ha lf of all HCHO is used primarily to make urea-, phenol-, melamine-formalde hyde and polyacetal resins (Formaldehyde Council, Inc., 2005). Formaldehyde-b ased resins are used as adhesives for composite wood products including HWP W, PB, and MDF. Formaldehyde is widely used in mobile and conventio nal home construction, and in the garment industry. It can be found in produc ts such as antimicrobial agents and it is also used in fumigants and soil disinfect ants (USDHHS, 1999). As a result, these activities emit significant amounts o f HCHO into surrounding air.

Some of the uses of HCHO are summarized in Table II I-2.

Table III-2. Product Distribution for Formaldehyde in the U.S. (2003) 1

Product Percentage of consumption Urea Formaldehyde Resins* 27

Phenolic Resins* 20 Polyacetal Resins* 11

Butanediol 9 Methylene Diisocyanate (MDI) 8 Pentaerythritol 4 Urea Formaldehyde Concentrates 3 Hexamethylenetetramine 2

Melamine Resins* 3

Miscellaneous 14

(1) Source : Global Insight, Inc. (2006). “*” indicates produ cts used in the manufacture of composite wood products. Note: Total may not add u p to 100% due to rounding.

With respect to composite wood products, HCHO is di rectly emitted from manufacturing plants during panel processing and fr om fabrication facilities that use these products to make furniture, cabinets, etc . As HCHO emissions from composite wood products occur over multiple year pe riods, and throughout their distribution and use, substantive amounts of emissi ons occur during:

• Truck, rail, and ship transportation during produc t distribution;

• Use in new home construction and remodeling constr uction;

• Stockpiles in lumberyards and wood product warehou ses; andChapter III Page 16

• Exchange processes from indoors to outdoors throug h windows, doors, and ventilation systems in homes and other building s.

1. Outdoor Sources

Among the principal, directly-emitted sources of HC HO is the combustion of fossil fuels from mobile sources, which comprises n early 76% of direct HCHO emissions (Table III-3). Of this total, nearly 26% of total statewide HCHO emissions originate from automotive exhaust (CARB, 2006a; Canadian Centre for Occupational Health & Safety, 2005). The remai ning 50% can be attributed to airplanes, recreational boats, construction, and mi ning equipment (CARB, 2006a). Stationary sources comprise approximately 13% and area-wide sources, such as wood burning add approximately 11% to the overall statewide HCHO emissions. Other important, direct outdoor so urces include power plants, agricultural burns, oil refineries, incinerators, a nd tobacco smoke.

Table III-3. Formaldehyde – 2005 Statewide Emission Inventory 1

Emission Source Tons/Year Percent of Total Stationary 2,474 12
Area-wide 2,014 10 On-Road Mobile 4,999 25

Gasoline 3,076 15

Diesel 1,922 10 Other Mobile 9,590 48

Gasoline 2,979 15

Diesel 4,526 23

Other 2,085 10 Composite Wood 900 5

Natural Sources 0 0 Total Statewide 19,978 100

(1) Source : CARB (2006a) for all tons/year values except “Composite Wood.” The tons/year value for composite wood is a preliminary estimate based on Appendix B. Note: Totals may not add up due to rounding.

Other anthropogenic sources of HCHO include industr ial releases of HCHO at any given stage of the production, use, storage, tr ansport, or disposal of products with residual HCHO (Liteplo et al., 2002).

2. Indoor Sources

Generally, indoor HCHO concentrations are higher th an outdoor concentrations due to the wide spectrum of building materials and consumer products inChapter III Page 17

workplaces and residential areas that emit HCHO (CA RB, 1992; USDHHS, 1999). Formaldehyde resins are used in many materi als and these resins slowly give off HCHO over time. Off-gassing from construc tion and building materials, especially composite wood products made with urea-f ormaldehyde (UF) resins and spray-on insulating foam are primary sources of indoor HCHO emissions. Other potentially significant sources of HCHO in in door areas are tobacco smoke, wood-burning stoves, fireplaces, and furnace s (CARB, 1992). Textile products, carpet, pads and tape, drapes, and a vast number of consumer products also contribute to indoor HCHO concentrati ons (CARB, 2005b). While these emissions originate in indoor environments, t he major portion of these emissions are removed to outside, ambient air by no rmal ventilation processes (e.g., when air moves through windows or doors, or mechanical ventilation systems), within a few hours.

a. Composite Wood Products

Newly manufactured composite wood products such as HWPW, PB, and MDF are the most significant sources of HCHO inside of homes (CARB, 2005b). Particleboard is used as sub-flooring, shelving mat erial, as well as in cabinetry and furniture. Hardwood plywood paneling is common ly utilized for decorative wall coverings. Hardwood plywood is used in cabine ts, furniture, and flooring. Medium density fiberboard is used for drawer fronts , cabinets, and furniture tops.

Emission rates of selected indoor sources of HCHO a re presented in Table III-4. The products tested were those used most commonly i n the California market. The results showed that bare urea-formaldehyde comp osite wood products were the highest dry product emitters. The adhesive com ponent of composite wood products (UF resin) is primarily responsible for th e off-gassing of HCHO into the air. When these wood products are pressed in the m anufacturing process, some unreacted UF resin and other volatiles are trapped within the boards, and released to air over time. Typically HCHO concentra tions in the core of a composite wood panel are twice as high as that at t he surface (USDHHS, 1999). Unreacted hydroxy-methyl groups that are inherently present in UF resins can also produce HCHO by hydrolytic cleavage.Chapter III Page 18 Table III-4. Emission Rates of Selected Indoor Sour ces of

Formaldehyde (μg/m 2 /hr) 1

Source of Formaldehyde Emission Rate Bare Urea-Formaldehyde Wood Products 8.6 to 1,580 Coated Urea-Formaldehyde Products < 2.7 to 460

Permanent Press Fabrics 42 to 215

Decorative Laminates 4 to 51 Fiberglass Products 16 to 32 Bare Phenol-Formaldehyde Wood Products 4.1 to 9.2 Paper Grocery Bags and Towels < 0.6

Latex Paint 502 Fingernail Hardener 215,500

Nail Polish 20,700 Base Coat Floor Finish 1,050,000 Top Coat Floor Finish 421,000

(1) Source : Battelle (1996). “μg/m 2 /hr” = microgram per square meter per hour. Values for wet products are average initial emissions.

Principally, the release of HCHO is highest from ne wly manufactured wood products; however, the emission is strongly depende nt on the nature of the material. As the products age, emissions of HCHO d ecrease over time to lower rates, thus older homes generally have lower indoor HCHO levels (CARB, 1992; Sexton et al., 1989). Formaldehyde emissions from composite wood materials

have been measured in mobile homes and found to be greater than in conventional homes as a result of higher loading ra tios (i.e., the ratio of the surface area of a source, such as a PB panel, to th e volume of the enclosed area where the source is present). Meyer and Hermanns ( 1985) found that mobile homes have minimal ventilation and poorly insulated features, and thus, experience elevated HCHO levels due to the higher a mbient temperatures where they are located.

b. Insulation Products

Urea-formaldehyde foam insulation (UFFI) previously was a major source of

HCHO emissions that was addressed in the 1980’s. I n the early 1970’s, UFFI was injected into wall cavities to improve the ener gy efficiency of older homes (Meek et al., 1985). Due to continuous health conc erns, adverse acute and chronic health problems arose from the HCHO emissio ns that occurred during this time, and the U.S. Consumer Products Safety Co mmission placed a ban on UFFI in 1982. Although this ban was overturned, th is action significantly

contributed to a reduction in HCHO emissions and th e residential use of UFFIChapter III Page 19

products. The California Energy Commission adopted insulation standards in 1982, which granted the use of UFFI only if its emi ssions were below 0.01 % by weight in a standard test protocol (CARB, 1992). T his rule effectively prohibits

the use of UFFI in California. Studies have shown that HCHO released from UFFI products decreased rapidly in the first few mo nths and progressively declines with time. Thus, HCHO concentrations in o lder homes from insulation materials are likely to be low after several decade s of product off-gassing.

c. Furnishings

There are many furnishing products that contain HCH O resins, and thus, have the potential to emit HCHO. Furniture constructed with PB and wood veneer emits HCHO. Formaldehyde polymers are used in the manufacture of floor coverings. Pre-pasted wall paper and papers that c onsist of fibers or layers that are bonded with HCHO resins also have HCHO-emitting potential (Gammage and Gupta, 1984). Formaldehyde-based resins are co mmonly used in the textile industry; they are used to produce crease-resistant and flame-retardant fabrics, and fabrics that withstand shrinking. Formaldehyde -releasing agents also provide dimensional stability and serve as binders in textile printing.

d. Cigarette Smoke

Sterling et al. (1987) measured HCHO in office buil dings where smoking was permitted and found levels to be as high as 0.60 pp m. In comparison, nonsmoking office buildings had levels as high as 0.22 ppm. Although composite wood products contribute to the majority of HCHO em issions in indoor air (Battelle, 1996), environmental tobacco smoke may a lso be a source of 10 to 25% of the noxious exposure (Sterling et al., 1987)

.

e. Consumer Products

Formaldehyde is also found in varying quantities in selected consumer products such as nail care products, adhesives, and paper pr oducts. Fabrics can be treated with HCHO-containing compounds, where it is used to add permanent press qualities to clothing and draperies. Paper p roducts, such as grocery bags, napkins, paper towels, and disposable sanitary prod ucts are often treated with HCHO-containing resins which improve strength and w ater resistance (Gammage and Gupta, 1984). These consumer products contribute minimally to

the HCHO concentrations of indoor air.

D. Emissions from Composite Wood Products

Prior to this rulemaking, HCHO emissions from compo site wood products were not specifically estimated due to a scarcity of inf ormation on HCHO emission rates, rates of decay in emissions over time, and t he amount of product sold each year into the California marketplace. Based o n efforts to quantify the extent of emissions from composite wood products in the st ate, staff identifiedChapter III Page 20

composite wood products as a separate category of a rea-wide sources of HCHO (Appendix B).

1. Emissions Inventory

Area-wide sources are source categories associated with human activity that take place over a wide geographic area (CARB, 2004) . For purposes of the statewide emissions inventory for toxic air contami nants, composite wood products (i.e., HWPW, PB, and MDF) were classified as an “aggregated point source,” which consists of many small point sources , which are not inventoried individually, but rather are estimated as a group a nd reported as a single source category. The emission estimation technique used t o develop the statewide HCHO emissions inventory for composite wood product s required knowledge of two fundamental elements: (1) rates of HCHO emissio n from HWPW, PB, and MDF, and (2) the amount of composite wood panels in use in California (CARB, 2006c). Rates of HCHO emission were estimated from measured air concentrations (Myers, 1984; Myers and Nagaoka, 198 1). For uncoated panels,

decreases in HCHO emission over time were estimated in consideration of published emission decay studies (e.g., Zinn et al. , 1990). Emissions of HCHO from uncoated panels were projected to occur over a n 11-year time period when emission rates stabilize to about 2% of a newly man ufactured panel. For coated panels, it was assumed that the initial rate of dec rease in HCHO emission would be moderated by the coating, and that it would take longer for unbound HCHO in the panel to be released to air (i.e., 20-years). Estimates of the total amount of composite wood products in California that could po tentially emit HCHO to air were developed from annual product summaries prepar ed by the USDA (e.g., Howard, 2004).

For 2002, total statewide HCHO emissions from PB, M DF, and HWPW were estimated to be about 450, 190, and 240 tons per ye ar, respectively. Thus, the

total amount of HCHO emissions from this area-wide source category was about 900 tons per year.

E. Natural Occurrences

Formaldehyde occurs naturally in the environment an d it is a product of many natural processes. The primary sources of release from natural sources include biomass combustion, such as forest and brush fires (Howard, 1989). Other natural sources of HCHO include animal wastes, micr obial by-products of biological systems, and plant volatiles (USDHHS, 19 99). Photochemical oxidation of naturally emitted hydrocarbon precurso rs also account for HCHO emissions (Zhang et al., 2004). In water, HCHO is also formed by the irradiation of humic substances by sunlight (Kieber et al., 199 0; WHO, 2001).

Formaldehyde is present as a metabolic intermediate and exists at low levels in most living organisms (WHO, 2001). The basic pathw ay for cellular metabolismChapter III Page 21

of HCHO involves formic acid formation, catalyzed b y formaldehyde dehydrogenase and glutathione, which is quickly rem oved by the supporting blood supply (Heck et al., 1982). The extent of ex posure to HCHO other than by inhalation is very small under normal circumstances . In California, HCHO is present in drinking water in very low amounts. Exc ept for accidental water contamination with HCHO, concentrations in drinking water are < 0.1 mg/L (WHO, 2001). Formaldehyde levels in food are highe r, but the majority of HCHO present in food is not absorbed; rather it is rapid ly converted to harmless metabolites in the body (CARB, 1992). Fruits and v egetables typically contain 3 to 60 mg/kg, milk and milk products approximately 1 mg/kg, meat and fish 6 to 20 mg/kg, and shellfish 1 to 100 mg/kg (WHO, 2001).

Reaction of HCHO with primary and secondary amines, thiols, hydroxyls and amides to form methylol derivatives is virtually in stantaneous (WHO, 2001). During chemical reactions, HCHO acts as an electrop hile and reacts with macromolecules, such as proteins, DNA, and RNA to f orm reversible adducts or

irreversible cross-links. When HCHO is absorbed it can be oxidized to formate (a salt or ester of formic acid) along three different pathways, and exhaled as carbon dioxide (USDHHS, 1999). In the human body, HCHO is produced in small quantities as a normal metabolite and as well as in the oxidative demethylation of xenobiotics (i.e., foreign materia ls to the body), thus it

accumulates in the liver. Removal of HCHO from blo od plasma occurs with a half-life of approximately 1 to 1.5 minutes, with m ost of it being converted to carbon dioxide and exhaled via the lungs. Smaller amounts of HCHO are

excreted in urine as formate salts and several othe r metabolites (WHO, 2001).

F. Measured Formaldehyde Concentrations

Formaldehyde concentrations range considerably depe nding on where measurements are made. This section provides an ov erview of measured and modeled concentrations in a range of microenvironme nts.

1. Outdoor Concentrations

Formaldehyde is the most common aldehyde in the env ironment and it is usually present in the highest concentration of all the maj or aldehydes and ketones in ambient air (Finlayson-Pitts and Pitts, 2000). Sin ce HCHO in outdoor air has the potential to enter buildings, schools, and resident ial areas, measured indoor concentrations must be gauged against outdoor level s of HCHO (3 to 4 μg/m 3 ; see Table III-5). The natural background concentrat ion of HCHO is < 1 μg/m 3 (1 ppb = 1.23 μg/m 3 ), with a mean = 0.5 μg/m 3 (IARC, 1995). Concentrations in unpopulated areas, rural-urban interfaces and large -urban areas are reported to range from 0.4 to 2.5, 0.1 to 12.3, and 1.2 to 73.8 μg/m 3 , respectively (FinlaysonPitts and Pitts, 2000).Chapter III Page 22

In late 1984, CARB established a statewide air toxi c monitoring network to facilitate the identification of air toxics which p ose an inhalation risk to the largest number of people in the state. Ambient levels of H CHO are routinely monitored in the CARB toxics network, and the data are used t o support human exposure and health risk assessments, assess temporal trends , changes in the environmental quality, and impacts on the environme nt.

The CARB’s HCHO sampling network encompasses 15 air basins across California, including the eight most populous, whic h reflect the highest priority locations in the state (Figure III-2 – labeled as F igure 10). The ambient monitoring network consists of 17 air monitoring st ations, where 24-hour samples are collected on a one day in 12 day schedule. For maldehyde is continuously extracted from ambient air to silica cartridges coa ted with acidified 2, 4- dinitrophenylhydrazine (DNPH) (CARB, 2001). An ozo ne scrubber is installed upstream from the sampling cartridge in order to el iminate interference by ozone. During sampling, HCHO reacts with DNPH to form hydr azone derivatives which are eluted from the cartridges and quantified by re verse-phase high performance liquid chromatography with ultraviolet absorption d etector at 360 nm.

Outdoor HCHO concentrations were obtained from the Annual Statewide Toxics Summary (Table III-6) for 1996 through 2005 (CARB, 2006b). The mean ambient HCHO concentration was 3.69 μg/m 3 and the maximum was 18.45 μg/m 3 . Trends for California have shown a steady mean l evel for the past decade, with annual HCHO concentrations ranging fro m 3.14 to 4.31 μg/m3. The highest mean values measured were 4.23 and 4.31 μg/ m3 in 1996 and 2002, respectively. Minimum HCHO concentrations ranged f rom 0.06 μg/m3 (recorded in multiple years) to 0.4 μg/m3 in 2002. Maximum v alues ranged from 9.7 μg/m3 in 2000 to 32.0 μg/m3 in 2001. While maximum value s have been fairly consistent in 2002-2005, minimum values are higher than in the late 1990’s.

Table III-5. Statewide Annual Average Formaldehyde Concentrations (μg/m3): 1996-2005 1

Year Range Mean (± SD)

2005 0.2 to 17.2 3.52 ± 2.52

2004 0.1 to 18.5 3.31 ± 2.35

2003 0.2 to 14.8 3.87 ± 2.46

2002 0.4 to 22.1 4.31 ± 2.80

2001 0.06 to 32.0 3.91 ± 3.51

2000 0.2 to 9.7 3.14 ± 1.82

1999 0.06 to 16.0 3.94 ± 2.61

1998 0.06 to 12.3 3.25 ± 2.19

1997 0.06 to 14.8 3.55 ± 2.03

1996 0.06 to 27.1 4.23 ± 2.85

(1) Source: CARB (2006b). “μg/m 3 ” = micrograms per cubic meter; “SD” = standard deviation. Detection limit = 0.123 μg/m 3

.Chapter III Page 23

The standard deviation in statewide annual average HCHO concentration has been fairly consistent from year-to-year (Figure II I-1). The maximum standard deviation was recorded in 2001 (3.51 μg/m3) and the lowest in 2000 (1.82 μg/m3). This is consistent with our understanding of region al-scale ambient HCHO concentrations which are largely determined by rate s of photochemical

processes.

Figure III-1. Annual Statewide Summary for Ambient Formaldehyde 1

Annual Statewide Toxics Summary of Formaldehyde

-4 -2 0 2 4 6 8 10 12

1996 1997 1998 1999 2000 2001 2002 2003 2004 2005

yearμg/m3

Mean

(1) Source : CARB (2006b).

The statewide characterization of ambient HCHO in 2 005-2006 was accomplished by measuring levels at selected locati ons across the state. Summary data for each of the monitoring sites is pr esented in Table III-7. These data were collected from January 2005 through April 2006; the most recent quality-assured data from the CARB network. Concen trations of HCHO varied across air basins, where in southern California, co ncentrations tended to be higher ( ≥ 4.0 μg/m 3 ) than in northern California (< 3.0 μg/m 3 ). Intermediate concentrations (2.0 to 2.9 μg/m 3 ), were observed in inland basins, South Central Coast, and the San Diego Basin.Chapter III Page 24

Figure III-2. Mean Ambient Formaldehyde Concentrati ons by Air Basin.Chapter III Page 25

At individual monitoring sites, mean annual concent rations ranged from 1.3 μg/m 3 (San Francisco) to 7.5 μg/m 3 (Los Angeles) (Table III-6), while basin averages ranged from 1.6 μg/m 3 in San Francisco Bay Area to 4.6 μg/m 3 in the

South Coast. The wide variation in HCHO concentrat ion may have been due to

a number of factors. Variations in ambient HCHO ma y be influenced by the number and types of sources located in a region, ar eas of heavy traffic, elements of climate, vegetation, varying terrain and geograp hical characteristics (near the coast versus inland), local meteorological patterns , and photochemical activity.

Table III-6. Summary of Ambient Formaldehyde Conce ntrations (μg/m 3 ): 1 January 2005 through 30 April 2006 1

Air Basin/Site Location Range Mean ± SD

A. Southern California

South Coast Air Basin

Azusa 0.5 to 8.4 4.1 ± 2.4

Burbank 0.5 to 9.1 4.9 ± 2.4 Los Angeles 2.5 to 17.2 7.5 ± 3.6 North Long Beach 0.5 to 7.5 3.1 ± 1.5

Riverside 0.9 to 8.0 3.6 ± 2.2

South Central Coast Air Basin Simi Valley 0.5 to 4.8 2.6 ± 1.6 San Diego Air Basin

Chula Vista 0.5 to 5.0 2.4 ± 1.0 El Cajon 0.6 to 6.2 3.0 ± 1.4

Salton Sea Air Basin

Calexico 0.5 to 12.5 4.0 ± 2.4

B. Northern California

San Francisco Bay Area Air Basin

Freemont 0.4 to 3.8 1.5 ± 0.9

San Francisco 0.4 to 3.1 1.3 ± 0.7

San Jose 0.5 to 5.2 2.0 ± 1.3

San Joaquin Valley Air Basin

Bakersfield 0.6 to 6.5 2.9 ± 1.7

Fresno 0.9 to 8.5 3.3 ± 2.2

Stockton 0.5 to 4.6 2.1 ± 1.2

Sacramento Valley Air Basin

Chico 0.4 to 12.3 3.5 ± 3.1

Roseville 0.7 to 5.9 2.3 ± 1.4

(1) Source : CARB (2006b).Chapter III Page 26

Table III-7 shows countywide HCHO emissions data (t ons/year) from the 2005 emissions inventory. The high ambient HCHO levels in the South Coast Air Basin follow from the presence of four of the top t en HCHO emitting counties, particularly Los Angeles County (CARB, 2006a). The six other counties in the state’s top ten accounted for approximately 25% of statewide HCHO emissions.

Table III-7. Formaldehyde Emissions in the Top Ten California Counties 1

Formaldehyde Emissions County Air Basin Tons/Year % of State Los Angeles South Coast 2,664 14 San Diego San Diego 1,240 6 Kern San Joaquin Valley 1,184 6 Orange South Coast 908 5 Alameda San Francisco Bay 711 4 Santa Clara San Francisco Bay 647 3

Santa Barbara South Central Coast 585 3 Fresno San Joaquin 558 3

Riverside South Coast 529 3

San Bernardino South Coast 522 3

(1) Source : CARB (2006b).

Urban environments, such as Los Angeles (and large cities within other major air basins), commonly experience unhealthy air quality and high HCHO emissions. The most dominant source of HCHO in the troposphere is the oxidation of biogenic and anthropogenic hydrocarbons. Formaldeh yde is also an important intermediate in the oxidation of hydrocarbons to ca rbon monoxide (CO); it is an ozone precursor and thus plays an important role in tropospheric ozone chemistry. Direct HCHO emissions also contribute t o ambient HCHO, which are primarily derived from motor vehicles (CARB, 2006a) . In future years, the adoption of increasingly stringent exhaust emission standards for motor vehicles will further reduce HCHO from this source category.

2. Indoor Concentrations

Generally, indoor HCHO concentrations are several t imes higher, and sometimes one or two orders of magnitude higher, than levels in ambient air, due to a higher concentration of sources in a confined space with r educed air mixing. As discussed, the major sources of HCHO are composite wood products in structural or finished product applications, perman ent press clothing, some consumer products, upholstery, combustion sources, and environmental tobacco smoke. Many factors influence indoor HCHO concentr ations, among them areChapter III Page 27

the emission rate and pattern, age of the sources, the ratio of source surface area to the indoor air volume, the indoor-outdoor a ir exchange rate, humidity, and temperature. Mobile homes contain significant amou nts of high-emitting materials in a relatively small air space, and newe r homes generally have greater amounts of new building materials that have the hig hest HCHO emission rates.

Table III-8. Measured Indoor Formaldehyde Concentra tions (μg/m 3 ) 1

Environment Average Maximum

Manufactured Homes 46 279 Classrooms (Inside) 22 135

Conventional Homes 17 285 Office Buildings 16 32

(1) Source : CARB (2005b). “Average” or “Maximum” values are the average or maximum values calculated from the data or reported in the one to four studies referenced for each

environment.

The current estimates of indoor HCHO levels in Cali fornia span a broad spectrum of values. Estimates of average HCHO concentration s are useful in order to illustrate relative levels among the different envi ronments, and to understand how Californian’s exposures compare to health benchmark s. Manufactured homes have the highest estimated average HCHO levels of 4 6 μg/m 3 (CARB, 2005b, based on Sexton et al. (1986) and others). As manu facturing practices have changed since the early 1980’s, HCHO emissions from new composite wood products are lower today than what they were, as ev idenced by an average reduction of about 50% measured by Kelly et al. (19 99) compared to Pickrell et al. (1983).

Data from the California Portable Classrooms Study collected in 2001 and 2002 were used to estimate school-year average and maxim um HCHO concentrations. A large statewide data set was collected across fou r seasons using both active and passive sampling methods. The calculated schoo l-year average HCHO concentration, including both warmer and cooler sea son values, was 22 μg/m 3
(CARB, 2005a). The statewide maximum mean was 135 μg/m 3 ; however, this value excluded extreme values measured in the study population. Results from the Portable Classrooms Study showed that HCHO conc entrations in 4% of California’s classrooms (i.e., 10,720 classrooms ho using 200,000 to 300,000 children) exceeded OEHHA’s 8 hour reference exposur e level for acute eye, nose, and lung irritation, and all of the classroom s in the study exceeded a one in

a million excess lifetime cancer risk level.Chapter III Page 28

Estimates for current conventional home concentrati ons of HCHO were estimated from two studies from the 1990’s (CARB, 2 005b). In the National Human Exposure Assessment Survey (NHEXAS) conducted in 189 Arizona homes over several years, HCHO levels were measured using passive badges (Gordon et al., 1999). The NHEXAS utilized a proba bility-based sampling scheme to obtain data representative of the entire state. The second study, conducted in southern California, examined a popula tion that resided in older homes in a mild climate (Avol, 1996). Results from the two studies were weighted by sample size to calculate estimates for conventional California homes. The estimated average HCHO concentration wa s 17 μg/m 3 and the maximum was 285 μg/m 3

.

The USEPA Building Assessment Survey and Evaluation (BASE) study, conducted in 100 large office buildings across the country from 1994 to 1998, found that pollutant levels in office buildings, in cluding HCHO, were variable. The average and 95 th percentile levels for HCHO were 16 and 32 μg/m 3 (USEPA, 2007).

All of these studies reflect the continuously eleva ted exposures that Californians experience throughout their day. Concentrations in all of these major indoor environments exceed acceptable health benchmarks fo r excess cancer risk, and even those for prevention of acute impacts.

a. Portion of Formaldehyde Emitted Indoors that Mo ves Outdoors

Nearly all HCHO directly emitted indoors from indoo r sources moves to the

outdoors. Most such indoor-emitted HCHO moves outd oors within hours, primarily through indoor-outdoor air exchange from mechanical and natural ventilation and building leakage. Some HCHO is rev ersibly sorbed onto surfaces in the indoor space at a rate dependent on the indo or air concentration (vapor pressure) of HCHO, the actual surface area of the i ndoor surfaces, air movement, and other factors, with subsequent desorp tion at a future time. A small portion may be irreversibly lost through oxid ative decomposition and other processes when uptake occurs in a surface water fil m, but this has not been quantified. A very low percentage of HCHO – from < 1% up to 7%, depending on the air exchange rate and other factors – is estima ted to be removed through homogeneous chemical reactions that result in perma nent removal of HCHO. Thus, a conservative estimate for the portion of HC HO emitted indoors that eventually makes its way outdoors is 90 to 100%, wi th the vast majority of the HCHO moving outdoors within hours of being released indoors.

i. Release to the Outdoors through Air Exchange

Formaldehyde is a very volatile chemical that is re adily transported to the outdoors as indoor air is replaced by outdoor air. All indoor spaces exchange air with the outdoors through mechanical or natural ven tilation, or both, as well asChapter III Page 29

through infiltration due to building leakage, such as through construction interfaces and utility penetrations. Most homes in California are ventilated by infiltration and through opening of windows and doo rs (natural ventilation). A small percent of newly constructed homes have mecha nical ventilation systems that actively draw outdoor air into the indoor spac e. Most medium and large public and commercial buildings are mechanically ve ntilated with a system that moves large quantities of air through the building over time in order to meet building ventilation requirements. Smaller public and commercial buildings are more variable in the type of ventilation they use; some have small mechanical systems that actively exchange air, while others ar e more similar to residential buildings and rely on natural ventilation and leaka ge for air exchange. Consequently, public and commercial buildings have a more variable range of air exchange rates than residences.

The air exchange rate (AER) of a building is typica lly expressed as the number of building volumes of air that enter each hour, also called air changes per hour. Due to airflow patterns, incomplete mixing of air i n some indoor spaces, and nonuniform distribution of indoor pollutant sources, v entilation efficiency is typically less than 100%. Ventilation efficiency generally r efers to the effectiveness of the ventilation system or conditions in reducing such a spects as air pollutant concentrations, odors, and excessive heat, relative to the feasible theoretical maximum reduction (Bearg, 1993). In indoor spaces with reasonably well-mixed air, the decrease in the concentration of an indoor contaminant can be expressed based on the time constant of the ventilation proce ss, or 1/N (in units of hours), where N is the air exchange rate (Bearg, 1993; Maro ni et al., 1995). For an AER of 0.5 per hour, then, 1/N = 1/0.5 = 2 hours. Afte r one time constant, or 2 hours, 63% of the original body of indoor air would be rel eased outdoors, based on an exponential decay function, and 37% would remain; a fter two time constants (4 hours in this example) only 13.5% of the original b ody of air would remain.

Air exchange rates (AERs) in California homes range from about 0.10 to 3.0 air changes per hour, averaging about 0.5 to 1 in the w inter, and about 1 to 3 in the summer (Ozkaynak et al., 1996; Sheldon et al., 1993 ; Wilson et al., 1993; Berkeley Solar Group and Xenergy, 1990; Pellizzari et al., 1989; Wilson et al., 1986; Koontz 1998; Pandian et al., 1993, 1998). In light of the various improvements in energy efficiency in California hom es required through regulation or encouraged through rebates and other utility programs over the past decade, current average air exchange rates are likely closer to the lower ends of these ranges, or about 0.5 AER in the winte r and 1 to 1.5 in the summer. Thus, based on the discussion above, the volume of air indoors is moved to the outdoors within a matter of hours under typical res idential conditions. This several hour residence time of HCHO indoors may all ow the opportunity for permanent loss of a very small portion of the HCHO through chemical reaction and some temporary loss through sorption onto surfa ces (discussed below). However, most of the HCHO emitted indoors would be lost to the outdoors within several hours due to the exchange with outdoor air.Chapter III Page 30

Air exchange rates in public and commercial buildin gs range from about 0.2 to 9, averaging about 1 to 2.5 (Grot, 1995; Persily, 1989 ; Turk et al., 1987). Based on the time constant discussion above, the volume of a ir in these buildings would typically be replaced within a few hours. Thus, wi th the exception of areas of poor air mixing in the building, nearly all of the HCHO in a building at a given point in time would be expected to be moved to the outdoors within several

hours.

ii. Sorption to Indoor Surfaces and Materials

Like other VOCs, HCHO displays sorption to and subs equent desorption from indoor materials (sink effects) such as carpet, wal ls, and furnishings. The rates of sorption and desorption are dependent on the air concentration (vapor pressure) in the room, temperature and humidity, th e actual surface area (“fleece factor” – accounting for roughness and porosity), t he indoor-outdoor air exchange rate and the efficiency of air mixing, and characte ristics of the pollutant and the specific surface material (Weschler, 2003; Zhang et al., 2002; Won et al., 2001; Van der Wal et al., 1997; Tichenor et al., 1991; Na zaroff and Cass, 1989).

However, sorption has generally been found to resul t in little or no permanent loss of HCHO and other very volatile compounds. Ma tthews et al. (1987) found that common gypsum board used for interior walls so rbed and released HCHO based on its vapor concentration in the air surroun ding the board, with sorption highest with high air concentrations and desorption highest with low air concentrations, and very little loss of HCHO. In a study of ventilation and VOC concentrations in a call center, Hodgson et al. (20 03) found that emissions of HCHO were elevated at higher ventilation rate condi tions; the authors speculated

that this association was attributable to re-emissi on from the indoor material sinks. Smedje and Norback (2001) found that after adjusting for season and air exchange rate, an increase in fleece factor of 0.1 m 2 /m 3 was associated with an increase in HCHO of 4 μg/m 3 , and they concluded that furnishings and textiles acted as significant pollutant reservoirs in the cl assrooms studied. Van der Wal et al. (1998) did not test HCHO but found that othe r very volatile compounds exhibited a weak sorption effect, even when tested with the strongest sink (woollen carpet).

Based on formaldehyde’s hydrophilic nature and poss ible reactivity with amino groups, a small portion of indoor-emitted HCHO may be permanently lost through oxidative decomposition and other processes when up take occurs in a surface water film, but this has not been quantified. The limited data on HCHO to date generally indicate higher levels of HCHO associated with increased ventilation rates, which is consistent with substantial re-emis sion of HCHO from indoor

sinks.Chapter III Page 31 iii. Estimated Reactivity Losses

Indoor HCHO reactions appear to differ from those o utdoors. The half-life of

HCHO in the outdoor environment is estimated to ran ge from about 4 to 10 hours (Kao, 1994; Atkinson, 1990). However, this relativ ely short lifespan is largely attributable to photolysis, which generally does no t occur in indoor environments (or is very much reduced) due to lack of sunlight, and to reactions with atmospheric chemical species not normally present i n large quantities indoors.

Indoor reactivity loss of HCHO is believed to be la rgely attributable to homogeneous decomposition dominated by attack by th e hydroxyl (OH) radical (Weschler and Shields 1996; Nazaroff, 2006). Ozon e/alkene reactions can produce hydroxyl radicals indoors, resulting in “ty pical” OH levels indoors

estimated at about 7 x 10 5 molecules/cm 3 (or 2.8 x 10 -5 ppb) by Weschler and Shields (1997). The reaction of hydroxyl with HCHO has a second order rate constant of 0.24 per ppb per second, or 860 per ppb per hour (Weschler and Shields, 1996). From this information, Nazaroff (20 06) has estimated a first order loss rate coefficient of 0.024 per hour (R), and a fractional degree of reduction in the indoor concentration of HCHO from homogeneous c hemical reaction equal to approximately 1 – [A/(A + R)], where A equals the A ER. Thus, for an AER of 0.5, the HCHO concentration would be reduced by 1 – [(0. 5)/(0.5 + 0.024)], or about 5%. For an air exchange rate of 3 it would be redu ced by about 0.8%, and for an AER of 0.3, it would be reduced by about 7.4%. The se results are consistent with Weschler and Shields (2000) who found that con centrations of products generated from reactions among indoor pollutants in creased as ventilation rates decreased. Thus, permanent loss due to reaction in doors might range from less than 1% up to 7%. However, because most buildings experience AERs of 0.5 and higher, the percent reduction in HCHO levels wo uld generally be very low,

less than 5%.

Few other indoor HCHO reactions have been reported or studied. Formaldehyde

loss from reaction with ozone indoors has been foun d to be negligible, due to the exceedingly low rate constant of this reaction (Wes chler 2000). Other reactions likely occur, but at levels too low to be readily e vident. Consequently, reactivity

losses indoors are estimated to total 1 to 7% of HC HO, but typically less than 5%, and total permanent loss of HCHO indoors due to any cause is estimated conservatively at no more than 10% total.

3. In-vehicle Concentrations

Pollutant concentrations were measured in-vehicles in simulated two-hour commutes in Los Angeles and Sacramento (Research Tr iangle Institute, 1998). The measured pollutants included particulate matter , metals, and selected organic compounds, including HCHO. In-vehicle HCHO levels were generally higher in Los Angeles than in Sacramento, where ave rage in-vehicle concentrations ranged from 10 to 22 μg/m 3 and 5 to 14 μg/m 3 , respectively. InChapter III Page 32

two “maximum concentration” commutes designed to ac hieve the highest invehicle pollutant concentration possible, concentra tions of 62 to 68 μg/m 3 were recorded. Compared to concentrations at roadside o r ambient air monitoring stations (i.e., 2 to 4 μg/m 3 in Sacramento and 7 to 19 μg/m 3 in Los Angeles), average in-vehicle HCHO levels were typically two t o four times higher. While factors such as roadway condition, congestion level , and time-of-day were found to variably influence in-vehicle pollutant levels, the effects of vehicle type and ventilation settings were found to be minimal.

G. Modeled Formaldehyde Concentrations

A near-source air dispersion modeling approach was used to estimate HCHO

concentrations in outdoor air in two scenarios. Th is section describes the HCHO concentrations that may result near a warehouse sto re or downwind of a PB plant and associated cancer risks.

1. Near-source Modeling

Near-source air dispersion modeling was conducted t o estimate the outdoor air concentrations of HCHO resulting from emissions of HCHO from composite wood products. Two scenarios were modeled: (1) a warehouse-size home repair store with a large amount of composite wood products stored inside, with emissions exiting the building through a large roll -up door, and (2) bundles of particleboard stacked outdoors under a pole barn. In both scenarios, the nearest receptor, a resident, was assumed to be located app roximately 30 meters from the point of emissions. Emissions were estimated f or the different types of composite wood products based on emission factors s ummarized in Appendix C that are based on studies conducted by Battelle (19 96). The USEPA Industrial Source Complex Short Term (ISCST3) air dispersion m odel was used to model HCHO concentrations downwind of the sites (USEPA, 1 995). Because meteorological conditions vary throughout Californi a, meteorological data from the following five cities were used: Burbank, Fres no, Oakland, Pasadena, and San Diego. An annual average air concentration was estimated for both

scenarios at a distance of 30 meters from the emiss ion source. The results of the modeling are contained in Appendix C.

Cancer risk estimates can be calculated by using mo deling results and the cancer unit risk factor for HCHO developed by the O ffice of Environmental Health Hazard Assessment (OEHHA, 2005) of 6.0 x 10 -6 per μ g/m 3 . The modeled annual average HCHO concentration for both scenario s corresponded to a cancer risk ranging from about 0.1 to 0.3 excess ca ncer cases per million people exposed, assuming a 70-year lifetime exposure. Thi s modeling analysis demonstrates that composite wood products contribut e to outdoor cancer risk.Chapter III Page 33

2. Near-source Modeling of a Particleboard Plant

Similar to the near-source modeling described in su bsection III.G. above, worstcase assumptions were made about what near-source H CHO concentrations could be downwind of a particleboard manufacturing plant. The Occupational Safety & Health Administration’s (OSHA) permissible 8-hour exposure level for

HCHO is 937.5 μ g/m 3 (0.75 ppm) (OSHA, Not Dated). This concentration was assumed to be uniform throughout a large manufactur ing plant of 100 meters by 100 meters with a 5 meter high ceiling. The follow ing calculation was used to

estimate an emission rate:

(937.5 μ g/m 3 )(100 m)(100 m)(5 m) = 5.86 x 10 6 μg/hr (8 hr)

This emission rate is 42-times higher than in the w arehouse-size home repair

store scenario described in subsection III.G.1. In air dispersion modeling, downwind concentrations are directly proportional t o the emission rate. Hence, the downwind air concentration could be as high as 42 times higher than downwind of the warehouse-size home repair store, o r as high as 0.0225 μg/m 3 x 42, for an estimated annual average concentration o f 0.94 μg/m 3 . This corresponds to a risk of about six excess cancer ca ses per million people exposed, assuming a 70-year lifetime exposure.

H. Atmospheric Persistence

Formaldehyde can be present in the atmosphere in tw o ways: it can be directly emitted into the atmosphere or it can be formed in the atmosphere from methane and non-methane hydrocarbons through photochemical degradation. In California, photochemical degradation is the larges t source of HCHO in ambient air (CARB, 2006a). The dominant atmospheric remova l process for HCHO in the lower troposphere occurs primarily by photolysis an d oxidation by hydroxyl radicals and by wet deposition, which leads to the incorporation of HCHO into the rain, cloud and fog water (CARB, 1992). In the abs ence of nitrogen dioxide, the

half-life of HCHO is estimated to be 50 minutes dur ing the daytime, but only 35 minutes when nitrogen dioxide is present (Bufalini et al., 1972). With photolysis as the principal removal mechanism, atmospheric lif etimes of approximately 7 and 4 to 10 hours, were calculated by Atkinson (199 0) and Kao (1994), respectively. Episodic removal by wet deposition ( e.g., rain, snow, or fog) can also occur, resulting in shorter atmospheric lifeti mes on an event-basis.

I. Risk Characterization

A “toxic air contaminant” is defined in H&SC §39655 (a) as:

“...an air pollutant which may cause or contribute to an increase in mortality or in serious illness, or which may pose a present or potential

hazard to human health.”Chapter III Page 34

Presently, there are approximately 200 compounds th at have been designated as top ten TACs in California (CARB, 1999), and HCH O is one of the most harmful TACs based on its potential public health r isk (CARB, 2006a). In terms of estimated chances per million of developing canc er over a 70-year lifetime (i.e., 20 chances per million), exposure to ambient annual average concentrations of HCHO rank third behind diesel par ticulate matter (540 chances per million) and benzene (43 chances per million). While statewide efforts to

control mobile source exhaust emissions have led to major reductions in emissions of diesel particulate matter, benzene, an d HCHO, efforts to reduce

other sources of HCHO have been limited.

Studies show that Californians spend close to 90% o f the day indoors (University of California, Berkeley, 1991), where HCHO concentr ations are reported to be four- to ten-times higher than outdoors (CARB, 2005 b). Estimates of the lifetime cancer risk from total daily exposure to HCHO are p rovided in section VII.D.

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Avol E. 1996. Residential Microenvironmental and Personal Sampling Project for Exposure Classification. Final Report, CARB Co ntract No. 92-317, Research Division, Sacramento, CA.

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### IV. Manufacturing of Composite Wood Products

This chapter describes how the composite wood produ cts subject to this ATCM are manufactured and the fundamental chemistry of c ommonly used formaldehyde-containing and no added HCHO resins (s ee Chapter V for details).

A. Background

Hardwood plywood is made by gluing together hardwoo d plies, and used to make paneling, flooring, cabinets and furniture. P articleboard is made of wood fragments or particles glued together, and used to make countertops, cabinets, and floor underlayments. Medium density fiberboard is made of wood fibers glued together, and used to make furniture, cabinet s, moldings, and door skins. While there are many other types of composite wood products (e.g., oriented strandboard, hardboard, etc.), the ATCM applies to HWPW, PB, and MDF.

B. Composite Wood Product Manufacturing Plants

1. Hardwood Plywood Plants

Plywood is made out of wood veneers and an inner co re, where the core may be a wood veneer, lumber, PB, MDF, or a combination of materials (Figure IV-1). The proposed ATCM would apply to HWPW made with eit her a veneer core or with a composite core composed of PB, MDF, or a com bination of PB, MDF, and wood veneers (e.g., combination core). The primary uses of HWPW are for interior wall panels, furniture, flooring, and cabi nets. In 2003, HWPW production

in the U.S. was estimated to be 1.9-million m 3 (Howard, 2005).

Figure IV-1. Types of Hardwood Plywood

Source : Cognard (2005).

Logs are steamed, then peeled to form a continuous ribbon of thin veneer. The

veneer is cut and dried. Processed veneers are sta cked onto a assembly line and adhesives applied. Stacked veneers are cold pr essed and then hot pressed. After the panels cool, they are trimmed, resized, o r sanded.Chapter IV Page 43

Figure IV-2. Plywood Manufacturing Process

Source : Cognard (2005).

Plywood panels of 3⁄8 ” or thinner typically contain one double glue-line ; panels with thicknesses of 1⁄2”, 5⁄8 ”, and 3⁄4” contain two double glue-lines (Spelter, 1 989). A single glue-line application rate is 30-40 lbs pe r 1,000 ft 2 (Industry Canada, 2005a; 2005b). As such, thicker panels require twi ce as much glue as thin panels. The glue used may contain HCHO.

2. Particleboard Plants

Particleboard (PB) is typically made in three layer s: two face layers and a core. The faces of the board consist of finer wood partic les than the core. This layered construction promotes more consistent heat transfer during the curing process. In 2003, PB production in the U.S. was 7.1-million m 3 (Composite Panel Association, 2006; Howard, 2005; Industry Canada, 2 005a). It is principally used in furniture manufacturing, underlayments, or subst rates for countertops.

The five main steps in PB manufacturing are: (1) fu rnish preparation (i.e., wood particles), (2) resin application, (3) mat formatio n, (4) hot pressing, and (5) finishing. The furnish is prepared by refining log s and other raw materials into small particles, and drying them to achieve a moist ure content of 2 to 7% (Cognard, 2005). Drying the furnish to a specific moisture content is key to ensuring that the proper amount of resin is added p rior to manufacturing, which is fundamental to controlling surface HCHO emissions a nd desired structural properties. As addition of the resin provides mois ture to the furnish, it is a critical step insofar as achieving an optimal moisture conte nt at the start of the manufacturing process.

During resin application, resin is mixed with the f urnish. In PB, the resin accounts for 5 to 12% of the total weight of the pa nel depending on the size of the wood particles and the required properties of t he panel (e.g., moisture resistance) (Cognard, 2005; Goldboard, 2000). Afte r a UF resin is thoroughly Log Yard Log Conditioning Peeling

Lay up Line (Cold Press) Apply

Adhesive (Hot Press) Panel Trimming & Sanding Finished

Panel DryingChapter IV Page 44

mixed with the furnish, the mixture is cold-pressed to form a mat, then hotpressed at cure temperatures ranging from 130 to 15 0 o C (Cognard, 2005). In comparison, PB made with PF resin requires hot-pres sing at temperatures ranging from 180 to 230 o C (Pizzi, 1994). In the finishing process, PB pane ls are trimmed, cut, and sanded to produce panels of a des ired thickness. Figure IV-3 depicts a typical production line for PB manufactur ing.

Figure IV-3: Schematic of a Particleboard Manufactu ring Line

Source : Wikipedia Contributors, 2006.

3. Medium Density Fiberboard (MDF) Plants

In 2003, MDF production was 2.7-million m 3 in the U.S., where it is primarily used in the manufacture of furniture, shelving, molding, and kitchen cabinets (Composite Panel Association, 2006; Howard, 2005). The manufacturing process for MDF is similar to that for PB, except t hat additional processing is required to prepare the fibers in the furnish (McCa llum, 1996; Tetlow, Not Dated). Logs used in the manufacture of MDF are debarked be fore being chipped with a disk chipper to produce chips of the desired size. After washing, the chips are compacted using a screwfeeder and then fed into a d efibrator (or digester) to produce a fine, light-weight pulp. From the defibr ator, the pulp enters a blowline, where it mixed with wax and resin before being stor ed for making panels. This is the main factor contributing to the difference in d ensity between MDF (600 to 800 kg m -3 ) and PB (160 to 450 kg m -3 ).Chapter IV Page 45

C. Resins Currently Used in Composite Wood Product s

1. General Properties of Resins

The role between resins and wood surfaces is a very complex interaction and entails many different theories regarding bond form ation and thermodynamic processes. First, we must define some terms in ord er to describe some of the interactions that occur (USDA, 1999):

• Adhesive is a substance capable of holding materials togeth er by surface

attachment.

• Adherend is a substrate held to another substrate by an adh esive.

• Adhesion is defined as “the state in which two surfaces are held together by interfacial forces, such as valence forces, inte rlocking action, or both.

o Valence forces are the interactions of atoms, ions, and molecules by the adhesive and the adherend.

o Interlocking action means surfaces are held together by an adhesive that has penetrated the porous wood surfac e.

The primary mechanism by which adhesives fasten to porous wood surfaces is mechanical interlocking (Frihart, 2004), which take s place below the surface of the wood. The adhesive penetrates beyond the damag ed fibers of the wood surface into the next two to six wood cell layers. The deeper the adhesive can penetrate into the wood, the more effective the mec hanical interlocking. Also, if

the adhesive is able to diffuse into the cell walls of the wood while curing takes place, the strength of the bond can exceed the stre ngth of the wood itself.

Three intermolecular attraction forces are importan t to the bond formation

between adhesive and the molecular structure of woo d (Vick, 1999). They are:

1. Dipole-dipole forces – positively and negatively charged polar molecule s that have powerful attractions toward other polar m olecules;

2. London forces – a weaker attraction of polar and non-polar molec ules. These forces are weaker than dipole-dipole forces b ut increase as the number of atoms or molecules increase; and 3. Hydrogen bonds – a strong attraction between a positively charged atom from a polar molecule and the electronegative atom of another molecule. Hydrogen bonds are usually stronger than dipole-dip ole forces. Hydrogen bonds are probably the most important intermolecula r force due to the number of hydroxyl groups on cellulosic surfaces.

Adhesion is nearly completed after the transformati on of the adhesive from liquid

to solid form. There are two mechanisms in which a n adhesive changes from liquid to a solid form (Connor, 2001). This transf ormation may be a physical change (thermoplastics) or a chemical change (therm osettings). In thermoplastics, the solid form may occur by a loss of solvent from the adhesiveChapter IV Page 46

through evaporation or diffusion into the wood, or cooling of molten adhesive on a cooler surface. For thermosets, the mechanism is through a chemical polymerization to form crosslinked structures.

2. Formaldehyde-containing Resins

The most prevalent types of resin used in composite wood products contain HCHO (Frihart, 2005). Compounds such as urea, phen ol, and melamine are combined with HCHO to develop different formulation s of resins for PB, MDF, plywood, and other composite wood products. The ch emical reaction involves a nucleophile (electron-rich compound), such as urea, phenol, and melamine, with an electrophile (electron-poor compound), such as H CHO. There are three reaction steps involved with HCHO adhesives (Frihar t, 2005):

1. Formaldehyde reacting with a nucleophile to form a hydroxymethyl derivative (Figure IV-4); 2. Condensation of two hydroxymethyl groups to form a bismethylene ether group, with loss of a water molecule; and 3. Elimination of HCHO from the bismethylene ether to form a methylene bridge.

The rate of reaction depends on the pH of the envir onment, the nucleophile, temperature, and the addition of catalysts or retar ders.

Figure IV-4. Reaction between a Nucleophile (Nu) a nd Formaldehyde

O H

H N u:

E le c tro p h ile

OH

N

N N

N H 2 NH 2 NH 2

NH 2 O

N H 2 Nucleophiles

Phenol Urea Melamine

The majority of formaldehyde-containing resins are waterborne. The amount of water in the resin is very critical for the polymer ization of the resin. Too much water hinders the reaction; too little water reduce s the mobility of the resin and limits the polymerization process. For resin formu lation, the mole ratio of HCHO needs to be greater than that of the co-reactant (F rihart, 2005), which is neededChapter IV Page 47

to bring about the required reactions to form a cro sslink-type solid. All formulations are also adjusted to decrease the amou nt of HCHO emissions and to insure good curing times and fast set rates.

a. Urea-Formaldehyde Resins

Urea-formaldehyde (UF) resins have been around sinc e the early 1920’s and have been the most dominant adhesive for PB, MDF, a nd HWPW (Meyer and Hermanns, 1986). In the U.S. alone, it is estimate d that the demand for UF resins will reach over 2.4 billion pounds in 2007. Approximately 89% of the UF produced in North America is used for wood adhesive s (Kennedy, 2005). Ureaformaldehyde resins are used for interior applicati ons and need a dry environment. They cure fast and are relatively ine xpensive. There are many advantages and disadvantages concerning the use of UF resins (Table IV-1).

Table IV-1. Advantages and Disadvantages of Urea-fo rmaldehyde Resins 1

Advantages Disadvantages

• Low cost

• Rapid cure rate

• Light color

• Non-flammable

• Resistant to microorganisms • Not water-resistant

• Continuation of HCHO

emissions

• Combination of moisture and heat depolymerizes resin

(1) Source : Frihart (2005).

i. Manufacturing Urea-formaldehyde (UF) Resins

Urea and HCHO are the building blocks for UF resins . Urea is synthesized by combining ammonia (NH 3 ) and carbon dioxide (CO 2 ) under heat and pressure. Formaldehyde, with the addition of a catalyst, is m anufactured from methanol (CH 3 OH) (Orica, 1999). There are two main steps involv ed in the manufacturing of UF resins (Connor, 1996). The first stage invol ves the addition of HCHO with urea. Under basic conditions (pH 8 to 9), urea is hydroxymethylated to form mono-, di-, and trihydroxymethylureas (Figure IV-5)

.Chapter IV Page 48

Figure IV-5. Addition of Urea and Formaldehyde to F orm Hydroxymethylureas

O

N H 2 NH 2 O

H H N HOH 2 C

CH 2 OH N

H O

CH 2 OH



## + 3 Addition

The second stage involves a condensation reaction u nder acidic conditions (about pH 5) to generate oligomers that will polyme rize until a target viscosity is obtained (Figure IV-6). Polymerization is slowed b y raising the pH and cooling the reaction. Water is then removed by vacuum dist illation to achieve a desired solids content (i.e., 60 to 65%). Urea is often ad ded to the resin to reduce HCHO emissions and obtain the desired formaldehyde-to-ur ea mole ratio.

Figure IV-6. Condensation Reaction and Polymerizati on of UF Resins

N HOH 2 C

CH

2 OH N H O

CH

2 OH

N HOH 2 C

CH 2 OH N H O

C H
2

O C H
2

N

CH 2 OH N H O

C H
2

O C H
2

N

CH 2 OH N H CH

2 OH O

n Condensation

acid

-H 2 O

The reactions that occur during UF resin synthesis are reversible. During the forward reaction, water is eliminated. However, if moisture interacts with the UF resin, depolymerization may occur, leading to hydro lysis or the release of HCHO.

ii. Curing Urea-formaldehyde (UF) Resins

During the hot pressing of a composite wood product , polymerization and condensation of the resin is completed and the rele ase of free HCHO occurs. Hot-press temperatures for UF resins usually range between 100 to 120 °C. This is a critical step in the manufacturing process sin ce too much heat can hydrolyze the UF resin into urea and HCHO, which degrades the bond and releases even more HCHO (Conner, 2001). Table IV-2 displays some of the characteristics of

UF resins:Chapter IV Page 49 Table IV-2. Characteristics of Urea-formaldehyde (U F) Resins 1

Category Summary Form Available as a dry powder or liquid(s)

Properties High in dry strength; moderately durable under damp conditions;

low resistance to temperatures > 49 °C; white or ta n in color

Preparation Liquid use as received; powder form mix with water; hardeners,

extenders, and fillers may be added; hot press at 1 00 to 120 °C.

Uses HWPW for interior use and furniture; interior PB an d MDF for

cabinets, underlayment, flush doors, and furniture core stock

(1) Source : Eckelman (1997).

b. Phenol-formaldehyde (PF) Resin

Phenol-formaldehyde (PF) resins were first introduc ed and commercially developed in the early 20 th century by Leo Baekeland (Society of the Plastics Industry, 1997). They are one of the oldest classe s of synthetic polymers used in composite wood products. Phenol-formaldehyde resin s are used mainly for exterior applications because of their high water r esistance and higher strength retention after water soaking. They also have outs tanding durability and high polymer strength due to good adhesion to wood surfa ces. Approximately 32% of

the total 1.78 metric tons of resin solids is consu med in North America (Zheng, 2002). The primary composite wood products that us e PF resins are oriented strandboard and softwood plywood, which are mainly used for exterior sidings. They may be unsuitable for decorative applications, such as paneling and furniture, because of the inherent dark color of th e resin. Although PF resins have many advantages, some of their disadvantages a re longer press times and higher press temperatures, which results in higher energy consumption and lower productivity. However, by altering reaction temperature, reaction time, catalyst type, and formaldehyde-to-phenol ratio, so me disadvantages may be overcome (Frihart, 2005).

There are two main types of phenolic resins: resol e and novolac. Novolac resins are produced using an acid catalyst and excess phen ol; whereas, resole resins are produced with a base catalyst and excess formal dehyde (Durez, Not Dated). Most wood adhesive applications use resole resins b ecause they provide a soluble adhesive that has good wetting properties a nd the cure is delayed until activated by heat, allowing additional time for pro duct assembly.Chapter IV Page 50 i. Phenol-formaldehyde (PF) Resin Chemistry

Phenolic resins are developed through a polycondens ation reaction of phenol and HCHO (Frihart, 2005). Phenols may react with H CHO in both the ortho- and para- positions of the hydroxyl group in either a b asic or acidic environment (Figure IV-7).

Figure IV-7. Addition Reaction for Phenol and Forma ldehyde

OH

O

H H OH

HOH 2 C CH 2 OH

CH 2 OH 

## + 3 Addition

base or acid

The second stage of resin development involves the formation of linear phenolformaldehyde oligomers through heat and condensatio n. The oligomers are created by reaction of the methylol groups with oth er phenol or methylol phenol compounds (Figure IV-8).

Figure IV-8. Phenol-formaldehyde (PF) Resin: Conden sation Reaction

OH

HOH 2 C

CH 2 OH

C H
2

CH 2 OH OH

C H
2

CH 2 OH OH

CH 2 OH

n OH

HOH 2 C CH 2 OH

CH 2 OH Condensation

heat

-H 2 O

After the formation of the linear oligomers, polyme rization occurs to create a phenol-formaldehyde crosslinked polymer network (Fi gure IV-9).Chapter IV Page 51

Figure IV-9. Phenol-Formaldehyde Cross-linked Polym er

Ch OH OH OH OH

Ch OH OH OH

Ch

Ch Ch

Phenol Form aldehyde Crosslinked Polym er

Unlike UF resins, PF reactions are not reversible a nd are pressed at a higher temperature (190 °C or higher) (Eckelman, 1997). T able IV-3 lists some of the

characteristics involved with PF resins.

Table IV-3. Characteristics of Phenol-formaldehyde (PF) Resins 1

Category Summary Form Available as a dry powder or liquid(s)

Properties High in dry and wet strength; very resistant to moi st conditions

and high temperatures; dark red color

Preparation Liquid form use as received; powder form mixed with alcohol or

water; extenders and fillers usually added to liqui d form; press temperatures are higher (up to 200 °C) Uses Exterior use in softwood plywood, OSB, hardboa rd

(1) Source : Eckelman (1997).

c. Melamine-containing Formaldehyde (MF) Resins

Like PF resins, melamine-formaldehyde (MF) and mela mine-urea-formaldehyde (MUF) resins are resistant to moist conditions (Mar ra, 1992). They are most commonly used for exterior and semi-exterior plywoo d and PB. In addition, MFChapter IV Page 52

is used for decorative laminates, paper treating, a nd paper coating. One drawback of MF resins is the cost of melamine (e.g. , $63 to $68 per pound) (ICIS Pricing, 2006). This contributed to the developmen t of MUF resins, which still have water resistance, but at a lower cost. The MU F resins can be viewed as a less expensive MF resin that has lower durability, or as a more expensive UF

resin that has better water resistance. The MF and MUF resins are also lighter in color compared to PF resins.

i. Melamine Chemistry

The formation of melamine-based resins is very simi lar to that of an UF resin (Frihart, 2005). However, the addition of HCHO to the amino groups of melamine is faster and more complete than to urea b ecause melamine is a stronger nucleophile than urea (Figure IV-10).

Figure IV-10. Addition Reaction for Formaldehyde an d Melamine

N

N N

NH 2 N H 2 NH 2
O

H H N

N N

NH N H N H CH 2 OH

CH 2 OH CH 2 OH 

## + 3 Addition

Melamine Formaldehyde Adduct

Melamine can potentially react with six HCHO molecu les to form two methylol groups on each exocyclic amine group. This condens ation reaction can occur under acidic, neutral, and slightly basic condition s (Figure IV-11).

Figure IV-11. Condensation Reaction of Hydroxymeth ylated Melamines

N

N N

NH N H N H CH 2 OH

CH 2 OH CH 2 OH N N N N H

N H N H CH 2 OH

CH 2 OH C

H 2 N H

N N N

N H CH 2 OH N H

C H 2 N H

N N N

N H N H

CH 2 OH n Condensation

heat

-H 2 O

Furthermore, the release of HCHO during the condens ation reaction is less prominent than for UF resins. During polymerizatio n, pH is lowered and temperature is raised to insure a complete reaction . In addition, melamineChapter IV Page 53

significantly reduces HCHO emissions (Dijkman, 2004 ). Table IV-4 lists some of the properties and uses for melamine-based resins.

Table IV-4. Summary of Melamine-based Resin Propert ies and Uses 1

Category Summary Form Powder with blended catalyst; may use up to 40 % melamine

with urea; white to tan; colorless bondline Properties High dry and wet strength; very resistan t to water and damp

conditions Preparation Powder mixed with water and applied at room temperature;

cured in hot press (120°C - 150°C) Uses Typically a fortifier in UF resins; used in HW PW and MDF

(1) Source : Eckelman (1997).

3. No added Formaldehyde Resins

For the past 70-years, HCHO has been an essential s olvent in composite wood product resins. In fact, greater than 95% of wood adhesives are formaldehydebased (Dunky, 2005). However, there are “no added” HCHO resins that are currently in the composite wood products market tha t are developing into a feasible option for manufacturers. Examples of “no added” HCHO resins are polydiphenylmethane diisocyanate (pMDI), soy-based, polyvinyl acetate (PVA),

and tannin resins.

a. Polydiphenylmethane Diisocyanate (pMDI) Resins

Isocyanate-based adhesives have been commercially a vailable since the 1940’s, but their use increased substantially in the 1970’s (Eckelman, 1997). Polydiphenylmethane diisocyanate (pMDI) is primaril y used in oriented strandboard production and applications for strawbo ard products, but has been commercially available for other wood composites, s uch as MDF and PB (Ecology Action, 2004). The cost of pMDI is consid erable; however, these resins have a high reactivity and efficiency in bonding to wood surfaces or adhering to difficult surfaces (Frihart, 2005). The chemical b onds in pMDI are stronger and

more stable than the condensation reactions of UF o r PF (Pizzi, 1994). There is even more demand for pMDI-bonded products where inc reased water resistance is required since pMDI resins are resistant to hydr olysis. Table IV-5 lists the advantages and disadvantages of pMDI.Chapter IV Page 54 Table IV-5. Advantages and Disadvantages of Polydi phenylmethane

Diisocyanate (pMDI) Resins 1

Advantages Disadvantages

• Tolerance for higher moisture

content in wood

• Less MDI is needed on a weight

basis to form bonded material

• Faster press cycles

• Lower press temperatures

• No formaldehyde emissions • Higher cost

• Use of mold releases for metal press platens

• Health risks to workers (isocyanates)

• Must be stored away from moisture to prevent precure

(1) Source : Marra (1992).

i. Polydiphenylmethane Diisocyanate (pMDI) Chemist ry

The first reaction for the polymerization of MDI th at occurs is the combination of the isocyanate and water to form a urethane bridge (Figure IV-12). Once isocyanate reacts with water, the rest of the proce ss proceeds rapidly if there is enough isocyanate for the reaction. The result is an unstable carbamic acid product that decomposes to form an amine and carbon dioxide (Pizzi, 1994).

Figure IV-12. Isocyanate and Water React to Produce a Urethane

N

H O

O N O H



### + R C R' R C 2 O

The amine formed by this reaction will react immedi ately with additional isocyanates to form a substituted urea compound (Fi gure IV-13).

Figure IV-13. Reaction of an Amine and Isocyanate t o Form a Substituted Urea

N O N N O

N R H 2 

## + C R R H C H RChapter IV Page 55

Cross-linking and hardening occur when amine groups from the urethane react with the substituted urea to form allophenate and b iuret bridges (Figure IV-14).

Figure IV-14. Urethane Bridge and Substituted Ureas React with Isocyanates to Produce Allophenate and Biuret Bridges

N O R C NH C O

N C O

O R

R R' N C O

O 

## +

allophenate R H R'

N O R C NH C O

N C O

NH R

R R N C O

N R H H 

## + R

biuret

This rapid polymerization and ability to form bonds in the presence of higher moisture content gives MDI advantages in several ap plications. When used in core areas that might have higher moisture contents , MDI bonds to wet lumber. Another use of MDI is the manufacturing of strawboa rd. Because of the low polarity of MDI, it is able to penetrate through th e waxy coating of straw and cure readily (Frihart, 2005). Table IV-6 lists some of the MDI resin characteristics.

Table IV-6. Characteristics of MDI Resins 1

Category Summary

Form Liquid resin or water emulsions; can create wide va riety of

adhesives; light brown liquid and clear bondline

Properties Excellent adhesion to wood and other materials, suc h as metals

and plastics; resistant to high moisture and temper atures; excellent chemical aging resistance

Preparation One-part adhesive cures by heat or moisture; two-pa rts resins

cure upon mixing; very rapid cure Uses Used mainly in OSB, PB, MDF or flakeboards

(1) Source : Eckelman (1997).Chapter IV Page 56 b. Soy-based Resins

Soy-based resins have been used in the manufacture of plywood for more than 70-years (United Soybean Board, 2004). However, ea rly soy resins had low solids, slow press times, and, most importantly, po or water resistance (Wescott et al., 2006). This limited the use of soy resins to only interior applications. Since the introduction of petroleum derived resins (e.g., UF or PF), soy-based resins rapidly diminished from the market because t hey were inferior in performance and more expensive. In the last 40-yea rs, UF and PF have been the most popular resins used in composite wood prod ucts. In recent years, environmental concerns from volatile organic compou nds, such as freeformaldehyde from UF resins and the constant increa se of petroleum prices, have revitalized interests in developing soy-based resins (Lorenz et al., 1999).

The primary ingredient in soy-based resins is soy f lour, which is produced by grinding the meal that remains after removing soybe an oil (Wescott and Frihart, 2004). Soy flour is high in protein and contains m any side-chain reactive amino acid groups and is believed to have the ability to react with other cross-linking agents to create a water-resistant resin.

i. Soy-based Resin Preparation

In a study by Wescott and Frihart (2004), soy resin s were prepared in a lowtemperature environment. They are formulated with water, sodium hydroxide (8% to 12%), and a solubilizing agent (e.g., a glyc ol), along with soy flour. The ingredients were combined and heated to 70 °C. Wat er durability was modified by the addition of a copolymer or synthetic resin t o engage the polymerization

process.

New soy resins are beginning to show promise in bot h performance and economics compared to the UF and PF resins. Soy re sins are also safer to

handle and reduce the amount of free HCHO that can be emitted from composite wood products. Chapter V describes a range of diff erent soy-based resins that are being explored today for composite wood product s.

c. Polyvinyl Acetates (PVA)

Polyvinyl acetate (PVA) is known throughout as your common “white glue” used mainly for HWPW veneers and wood bonding in furnitu re. This resin sets quickly at room temperature and has a high dry strength, bu t is less resistant to moisture, humidity, or high temperatures (Eckelman, 1997). Because PVA loses bonding capacity at temperatures over 70 °C, it is used mainly for interior applications. However, cross-linking agents, such as chromium complexes, may be added to the resin to withstand higher moisture contents and temperatures (Connor, 2001).Chapter IV Page 57

Polyvinyl acetate is a linear polymer that is flexi ble in nature and exhibits good flow on the surface of wood (Frihart, 2005). Since PVA has a high content of acetal groups, the resin is able to form hydrogen b onds with wood for a good interfacial adhesion. The polymer flexibility of P VA provides a conformable bond if the wood expands or contracts (Marra, 1992).

i. Polyvinyl Acetate (PVA) Chemistry

Polyvinyl acetate is a self-polymerizing resin that is initiated under free radical conditions of the monomer vinyl acetate. By adding ethylene, the polymer chains can be modified to form a PVA copolymer which creat es a more flexible resin (Figure IV-15).

Figure IV-15. Polymerization of PVA

C H 2 CH

CH 3

O

C H 2

CH

O Ch Ch

O

CH 3 n Free Radical

Homopolymerization

Poly(vinyl acetate) Homopolymer

Cross-linking PVA with other resin additives such a s glyoxal, HCHO resins, or isocyanates, can convert the PVA from a thermoplast ic to a thermoset (see subsection IV.C.1). This improves resistance to hi gh moisture and higher temperatures (Frihart, 2005). Table IV-7 lists som e characteristics of PVA.

Table IV-7. Characteristics of Polyvinyl Acetate (P VA) Resins 1

Category Summary Form Several brands available; vary in properties; sold in liquid forms

Properties High dry strength; low resistance to moisture and e levated

temperatures; white or yellow in color Preparation Ready to use liquid; applied at room te mperature Uses HWPW; furniture assembly

(1) Source : Eckelman (1997).Chapter IV Page 58 d. Tannin-based Resins

Attempts have been made to depart from the use of p etroleum derived products, such as phenol, to using natural resources instead of synthetic resins. Tannins, as a natural substitute for phenols, are a natural phenolic-type material that is extracted from the bark or heartwood of many plant species (Roffael et al., 2000) (Figure IV-16). Mangrove and mimosa bark contain c omparably high levels of extractives, while the amount from spruce bark is r elatively low. Commercially

available tannin extracts that are used in manufact uring include: Acacia sp. (wattle or mimosa), Schinopsis sp. (quebracho), Tsuga sp. (hemlock), Rhus sp. (sumac), and Pinus

sp. (Pizzi, 2006).

Figure IV-16. Average Yield of Extractives from Dif ferent Woods and Barks 1

0% 10% 20% 30% 40% 50% Chestnut Wood Oak Wood Oak Bark Spruce Bark Pinus radiata Bark

Sumach Valonea Quebracho Wood Mimosa Bark Mangrove Bark

Tannins

Non Tannins

(1) Source : Roffael et al., 2000.

Tannins are categorized as either hydrolyzable or c ondensed. Hydrolyzable tannins are used more for medicinal purposes and no t in adhesive research. Condensed tannins, which are used in the preparatio n of resin adhesives, constitute more than 90% of the total world product ion (Sellers and Miller, 2004). Tannins are more reactive than phenol resulting in water-resistant bonds when polymerized with HCHO (Santana et al., 1997). This reactivity is due to their “Aring,” which is resorcinolic in nature (Figure IV-1 7). The A-ring ensures the rate of reaction to be 10 to 50 times faster than phenol (Kim et al., 2003).Chapter IV Page 59

Figure IV-17. The A-Ring Unit of a Tannin Compound

O H

OH

Tannins have their limitations compared to synthetic resins. They have a high viscosity, restrictions on availability, and are highly reactive (F rihart, 2005). This causes a short pot-life for tannin resins. However, other ha rdeners may be added to prolong tannin pot-life (Trosa and Pizzi, 2001). R eactions involving tannin compounds are very complex, but studies have s hown that HCHO reacts with the free C6 and C8 sites on the A-ring to form the ad hesive (Kim et al., 2003). This characteristic results in HCHO emissions comparable to the wood

itself. Research in tannin adhesives has continued to disc over more lowformaldehyde resins.

D. References

Cognard P. 2005. Woodworking and furniture adhesives. P art 5: Applications

and end uses. Accessed : 20 September 2006. From : http://www.specialchem4adhesives.com/resources/articles/print article.aspx?id=1

235

Composite Panel Association (CPA). 2006. 2005 North Americ an Shipments Report: Particleboard, Medium Density Fiberboard, Hardboard. C PA, Gaithersburg, MD. 18 pp.

Connor AH. 1996. Urea-formaldehyde adhesive resins. In : Salamone JC (ed). Polymeric Materials Encyclopedia, Volume 11, T-Z, p. 8496-8501 . CRC Press, Inc., Boca Raton. ISBN: 0-8493-2470-X.

Connor AH. 2001. Wood: Adhesives. In : Buschow KHJ (ed). Encyclopedia of Materials: Science and Technology, p. 9583-9599. Elsevier S cience Ltd.,

Amsterdam. ISBN: 0-08-0431526.

Dijkman H. 2004. DSM Melamine: Growing a profitable busines s. From : http://www.dsm.com/en_US/downloads/invest/dijkman_24_se pt.pdf Accessed : 4 February 2007.

Dunky M. 2005. Resins for ultra low formaldehyde emissio n according to the Japanese F**** quality. From : http://www.forestprod.org/adhesives05dunky3.pdf

Accessed : 4 February 2007.Chapter IV Page 60

Durez Corporation. Not Dated. Phenolic molding composites. From : http://www.durez.com/product.pdfs/phen.mold.comp/pmc.t ech.overview.pdf

Accessed : 4 February 2007.

Eckelman CA. 1997. Brief survey of wood adhesives. FN R 154, Forestry & Natural Resources, Purdue University, Cooperative Extension S ervice, West Lafayette, IN. 10 pp.

Ecology Action. 2004. Wood panels: Plywood, OSB, MDF, and Ag Waste

Boards. Accessed : 2 February 2007. From : http://www.ecoact.org/Programs/Green_Building/green_Materials/ wood_panels.h

tm

Frihart CR. 2004. Adhesive interactions with wood. In : Forest Products Laboratory. Fundamentals of Composite Processing: Proceed ings of a Workshop. General Technical Report FPL-GTR-149, p. 29-38. USDA, Forest Service, Forest Products Laboratory, Madison, WI.

Frihart CR. 2005. Wood adhesion and adhesives. In : Rowell RM (ed). Handbook of Wood Chemistry and Wood Composites. Chapt er 9, p. 215-278. CRC Press, Inc., Boca Raton.

Goldboard Development Corporation. 2000. Gluing: Urea-forma ldehyde (UF)

resin. From : http://www.goldboard.com/products/gluing_uf.html Accessed : 12

December 2001.

Howard JL. 2005. U.S. Forest Products Annual Market Re view and Prospects, 2001-2005. Research Note FPL-RN-0299, USDA, Forest Servic e, Forest Products Laboratory, Madison, WI. 11 pp.

ICIS Pricing. 2006. Melamine (USA): 9 th August 2006. Accessed : 2 February

2007. From : http://www.icispricing.com/il_shared/Samples/SubPage1010004 3.asp

Industry Canada. 2005a. Wood-based panel products: Te chnology roadmap. I.

Introduction and overview. From : http://strategis.ic.gc.ca/epic/internet/infiif.nsf/en/oc01504e.html Accessed : 13 April 2006.

Industry Canada. 2005b. Wood-based panel products: Te chnology roadmap. II. Panels in perspective. From : http://strategis.ic.gc.ca/epic/internet/infiif.nsf/en/oc01505e.html Accessed : 13 April 2006.

Kennedy HJ. 2005. The North American Wood Adhesives M arket. Accessed : 4 February 2007. From : http://www.forestprod.org/adhesives05kennedy.pdfChapter IV Page 61

Kim S, Y-K Lee, H-J Kim, and HH Lee. 2003. Physico-mec hanical properties of particleboards bonded with pine and wattle tannin-based adhe sives. Journal of Adhesion Science & Technology, 17(14): 1863-1875.

Lorenz LF, AH Conner, and AW Christiansen. 1999. The e ffect of soy protein additions on the reactivity and formaldehyde emissions of urea-formaldehyde adhesive resins. Forest Products Journal, 49(3): 73-78.

Marra AA. 1992. Technology of Wood Bonding: Principles in Practice. Chapter 4, p. 61-101. Van Nostrand Reinhold Company, New York . 454 pp. ISBN:

0442007973.

McCallum D. 1996. The manufacturing process: Medium den sity fibreboard.

From : http://sres-associated.anu.edu.au/fpt/mdf/manufacture.h tml Accessed : 23 February 2007.

Meyer B and K Hermanns. 1986. Formaldehyde release from wood products:

An overview. In : Meyer B, BA Kottes Andrews, and RM Reinhardt (eds). Formaldehyde Release from Wood Products. ACS Symposium S eries, 316: 1-

16.

Orica Limited. 1999. Urea formaldehyde resin. Accessed : 4 February 2007.

From : http://www.pacia.org.au/_uploaditems/docs/3.urea_formaldeh yde_resin.pdf

Pizzi A. 1994. Advanced Wood Adhesives Technology. Chapter 8, p. 273-282. Marcel Dekker, Inc., New York.

Pizzi A. 2006. Recent developments in eco-efficient bio-b ased adhesives for wood bonding: Opportunities and issues. Journal of Adhesio n Science & Technology, 20(8): 829-846.

Roffael E, B Dix, and J Okum. 2000. Use of spruce ta nnin as a binder in particleboards and medium density fiberboards (MDF). Holz als Roh- und Werkstoff, 58: 301-305.

Santana MAE, MGD Baumann, and AH Connor. 1997. Utiliz ation of black wattle bark and tannin liquefied in phenol in the preparation of reso l-type adhesives.

From : http://www.fpl.fs.fed.us/documnts/pdf1997/santa97a.p df Accessed : 4 February 2007.

Sellers T Jr and GD Miller Jr. 2004. Laboratory manufacture of high moisture southern pine strandboard bonded with three tannin adhesiv e types. Forest Products Journal, 54(12): 296-301.Chapter IV Page 62

(The) Society of the Plastics Industry, Inc. 1997. The phenolic advantage.

From : http://www.phenolics.org/products/PhenolicNL.htm Accessed : 11 April

2001.

Spelter H. 1989. Plywood Manufacturing Cost Trends, Exc luding Wood, in Western U.S. Mills: 1975-1988. General Technical Report FPL-G TR-64. USDA, Forest Service, Forest Products Laboratory, Madison, WI. 1 2 pp.

Tetlow K. Not Dated. Composite Panels: Particleboard and Medium-density fiberboard. Accessed: 28 February 2007. From: http://archrecord.construction.com/resources/conteduc/arch ives/0512weyerhaeu ser-1.asp

Trosa A and A Pizzi. 2001. A no-aldehyde emission hardene r for tannin-based wood adhesives for exterior panels. Holz als Roh- und Werkst off, 59: 266-271.

United Soybean Board. 2004. Soy-based composites tech nical research. From : http://www.omnitechintl.com/pdf/Composites%20-%20T.pdf Accessed : 4 February 2007.

U.S. Department of Agriculture (USDA). 1999. Glossary. In : Forest Products Laboratory. Wood Handbook – Wood as an Engineering Mate rial. General Technical Report FPL-GTR-113. USDA, Forest Service, Fores t Products Laboratory, Madison, WI.

Vick CB. 1999. Adhesive bonding of wood materials. In : Forest Products Laboratory. Wood Handbook – Wood as an Engineering Mate rial. General Technical Report FPL-GTR-113, Chapter 9. USDA, Forest Se rvice, Forest Products Laboratory, Madison, WI.

Westcott JM and CR Frihart. 2004. Competitive soybean flour/phenolformaldehyde adhesives for oriented strandboard. In: Tichy RJ and V Yadama (eds). 38 th International Wood Composites Symposium Proceedings, p. 1 99-206. Washington State University, Pullman, WA.

Westcott JM, CR Frihart, and AE Traska. 2006. High-soy-c ontaining waterdurable adhesives. Journal of Adhesion Science & Technolog y, 20(8): 859-873.

Wikipedia contributors. 2006. Particle board. Accessed : 5 September 2006.

From : http://en.wikipedia.org/wiki/particle_board

Zheng J. 2002. Studies of PF Resole/Isocyanate Hy brid Adhesives. Ph.D. Dissertation, Virginia Polytechnic Institute and State Universit y, Blacksburg, VA. 213 pp. Accessed : 4 February 2007. From : http://scholar.lib.vt.edu/theses/available/etd-01072003- 200607/unrestricted/Jun_Zheng_Dissertation.pdfChapter V Page 63



### V. Assessment of Best Available Control Technolog y

In this chapter, the technical basis for the proposed Phas e 1 and Phase 2 standards for HWPW, PB, and MDF are presented in considera tion of BACT. For this ATCM, BACT is defined as HWPW, PB, and MDF me eting the proposed Phase 2 emission limits in Tables V-21, V-23, and V-25, respec tively, through a combination of process- and resin-related modifications. The candidate resin systems for meeting BACT are listed below:



### • HWPW -- Phase 2 Standard (0.05 ppm)



### ° UF (mole ratio ≈ 1.2 to 1.4) + 15% Melamine



### ° PVA



### ° PVA-Soy



### • PB -- Phase 2 Standard (0.09 ppm)



### ° UF (mole ratio ≈ 0.8 to 1.1) + 8% Melamine



### ° UF (mole ratio ≈ 0.8 to 1.1) + Scavengers



### ° PF



### • MDF – Phase 2 Standard (0.11 ppm)



### ° UF (mole ratio ≈ 0.9 to 1.2) + 12% Melamine



### ° UF (mole ratio ≈ 0.9 to 1.2) + Scavengers



### ° pMDI

The above resin systems reflect staff’s assessment of B ACT, which recognizes

that manufacturers that choose to use UF resins have o ne or more options for reducing their HCHO emissions to meet the proposed Phase 2 standards. In section C, we summarize the results of studies on resin s used to make HWPW, PB, and MDF. In section D, we summarize the resu lts of studies on candidate low-formaldehyde resin systems. In section E, the technical basis for the proposed Phase 2 limits is described. In general, staff projects that BACT will be based on reformulated UF resins. However, the prop osed regulation provides an incentive for panel manufacturers to convert to no added HCHO resins early by not having to comply with the requirement to perform quarterly emission tests of their products under a third party certificat ion program.

A. Introduction

The range of resin systems that may presently or with som e degree of modification be used to manufacture products that comply with the proposed

emission standards is discussed in the remainder of this ch apter.Chapter V Page 64

1. Legal Requirements

According to H&SC §39666, CARB is required to adopt ATCMs to reduce emissions of TACs. For TACs without a Board-specified thre shold exposure level, H&SC §39666 requires the ATCM to be designed to red uce emissions to the lowest level achievable through the application of BACT, or a more effective control method. With respect to BACT for the present A TCM, there are two elements identified in H&SC §39665(a)(4) and §39665(a)(6) that need to be

evaluated:

(4) The availability and technological feasibility of airborne toxic control

measures to reduce or eliminate emissions, the anti cipated effect of airborne toxic control measures on levels of exposu re, and the degree to which proposed airborne toxic control measures a re compatible with, or applicable to, recent technological improv ements or other actions, which emitting sources have implemented or taken in the recent past to reduce emissions.

(6) The availability, suitability, and relative eff icacy of substitute compounds of a less hazardous nature.

To determine BACT, staff evaluated the proposed control m easure and alternatives to the proposed control measure by gathering pe rtinent information from a variety or sources, as described in the following subse ctions. For this ATCM, BACT is defined as HWPW, PB, and MDF meeting th e proposed Phase 2 emission limits in Tables V-21, V-23, and V-25, respectively.

2. Best Available Control Technology Assessment Pr ocess

To ascertain BACT, staff collected information by exploring patents, scientific literature, consultations with academia, resin researchers and manufacturers, and examining the data collected in a CARB survey of comp osite wood products

manufactured in 2002.

a. Patents on Resins Used in Composite Wood Products

Staff researched the patents regarding resins used in compo site wood products listed on the U.S. Patent & Trademark Office website ( http://www.uspto.gov/ ) listed in 2001 through 2006, and found over 80 patents and 34 applications. Examples of resins included:

• Soybean flour and a cross-linking agent adhesive;

• Liquid melamine-urea-formaldehyde (MUF) resin that includes usi ng a catalyst, thickener, and hardener;

• Water resistant polyvinyl acetate (PVA) aqueous emulsion;

• Tannin-based resins;

• Protein-modified urea-formaldehyde (UF) resin;Chapter V Page 65

• Soy protein portion and modifying ingredient portion;

• Glutaraldehyde co-solvent urea resins;

• Formaldehyde-free lignocellulosic adhesive, and

• Hydrolyzates of soybeans as components of thermosett ing resins.

b. Scientific Literature

Several search engines were used to locate articles in the pe er-reviewed literature. The primary websites that were accessed include:

• Science Direct : lists handbooks, book series’, and journal collections -- over 6.75 million articles;

• APT Online : lists current and archived journals, issues, and authors;

• Thomson Scientific : provides access to complete bibliographic information from over 8,000 leading journals and more than 2,000 books; and

• Google : enables users to search the web, usenet, and images

.

c. Consultations

Through phone calls and emails, staff contacted resin rese archers, resin manufacturers, and academia to discuss resin technology u sed in manufacturing composite wood products. Table V-1 lists the contacts ma de to date relative to resin technology.

Table V-1. List of Researchers, Manufacturers, and Academ ia Contacted

Contact Affiliation Bailey, Mr. Chris Collins Company (Portland, OR) Gardner, Dr. Doug University of Maine (Orono, ME) Harmon, Dave Hexion Specialty Chemicals (Springfield, OR) Holloway, Tom Dynea Adhesives (Springfield, OR) Johns, Dr. William Washington State University (Pullman, WA) Kelly, Dr. Myron North Carolina State University (Raleigh, NC) Kim, Dr. Moon Mississippi State University (Starkville, MS) Li, Dr. Kaichang Oregon State University (Corvallis, OR)
Matuana, Dr. Laurent Michigan State University (East Lansing, MI) Moriarty, Mr. Chris Huntsman International, LLC (Salt Lake Cit y, UT) Odda, Mr. Ulf Akzo Nobel (Sweden) Pizzi, Dr. Antonio ENSTIB, University of Nancy I FR (Franc e) Rosengarth, Mr. T.J. Flakeboard Company, Ltd. (Canada) Shupe, Dr. Todd Louisiana Forest Prod. Dev. Ctr. (Baton R ouge, LA) Sun, Dr. Susan Kansas State University (Manhattan, KS) Tang, Dr. R.C. Auburn University (Auburn, AL) Taylor, Mr. Mike States Industries (Eugene, OR) Wescott, Dr. James Heartland Resource Technologies, LLC (Pasadena, CA) Wolcott, Dr. Michael Washington State University (Pullman, WA)Chapter V Page 66

In conjunction with public workshops and stakeholder meeting s held over the years, staff has also made contact with a number of U.S . and overseas manufacturers, including:

• Columbia Forest Products (Portland, OR)

• Flakeboard (Canada)

• Georgia-Pacific (Decatur, GA)

• Masisa (Chile)

• Roseburg Forest Products (Roseburg, OR)

• SierraPine, Ltd. (Roseville, CA)

• States Industries (Eugene, OR)

• Timber Products (Springfield, OR)

• Weyerhauser (Eugene, OR)

d. 2003 California Air Resources Board Survey

The CARB staff distributed a composite wood products surv ey to manufacturers across the U.S. in March 2003 to collect information regardin g engineered wood products, such as plywood, particleboard, fiberboard, and ot her composite wood products. The survey, hereafter referred to as the “2003 C ARB Survey”, consisted of four questionnaires pertaining to manufacturer, product, resin, and process information. Over 250 surveys were mailed out, in w hich respondents were asked to provide information pertaining to products manu factured in 2002. From the 250 surveys distributed, ARB received 57 response s. Staff categorized the responses by composite wood type and entered all info rmation into an

AccessTM database.

Based on an analysis of the survey results, the highest f ormaldehyde-emitting composite wood products were hardwood plywood, particleboa rd, and medium density fiberboard for interior applications. The majority of th ese products are made with urea-formaldehyde resins, which are inexpensive, a nd emit more HCHO than products made with other resins. For this ATCM, controlling the HCHO emissions from hardwood plywood, particleboard, and me dium density

fiberboard was the focus of this BACT assessment.

3. Overview of Existing Formaldehyde Standards and Regulations

During the 1970’s, HCHO emissions from PB and HWPW led t o numerous complaints in newly constructed homes. In 1985, the U. S. Housing and Urban Development Agency (HUD) implemented a regulation that limite d the HCHO concentration in mobile homes to 0.4 parts per million (ppm) (Spe lter, 1992). This would be achieved by lowering HCHO emissions from PB a nd HWPW to 0.3 and 0.2 ppm, respectively. This action triggered a need for many HWPW and PB manufacturers to modify their products in order to comply wit h the standard. However, absent any new regulations since 1985, industry h as continued toChapter V Page 67

produce products that comply with the HUD standard (Turne r et al., 1996) with modest reductions in average HCHO emissions. Products spe cifically covered under the HUD standard are not subject to the proposed A TCM.

Similar concerns relative to the health effects of HCHO emis sions from composite wood products and HCHO in indoor air were also bein g raised in Europe. This led to a guideline from the German health min istry in 1980 to limit HCHO emissions from particleboards, fiberboards, and plywood to 0.1 ppm in a steady state climate chamber test, which is also known a s the E1 classification (Deutsches Institut fur Bautechnik, 1994). In 2000, Aus tralia adopted the same standards as those used in Europe. Compliance with Europ ean regulations is based on the quantity of free-formaldehyde in a product rather than the actual emissions from the product; the presumption for this is that any freeformaldehyde in a wood product will be emitted at a later tim e. The E1 standard is an “average” standard that allows for panels to be produc ed with HCHO contents higher than the numerical value of the standard, so long as an equal amount of product is produced at a comparable HCHO con tent below the standard. In terms of HCHO contents, Europe allows multip le grades of panels to be sold for consumer use. As such, not all panels sold to Europe meet the E1 standard; a portion is made to comply with the E2 standard , which approximates the stringency of the 1985 HUD standards in the U.S.

The most stringent HCHO regulation implemented today is th e Japanese Building Standard Law (BSL) (Takabatake, 2003). The BSL ha s a “sick house” regulation which regulates the amount of chemical products, such as HCHO, that can be emitted from building materials. As noted above fo r Europe, multiple grades of products are allowed in Japan, in terms of HCHO c ontent. There are 15 kinds of HCHO-emitting building materials subject to the re gulation, which include plywood, PB, and MDF. The regulation requires supplie rs of building materials to determine HCHO emission levels from their produc ts and comply with applicable JIS (Japan Industrial Standards) or JAS (Japan Agriculture Standards), or obtain approval from the Ministry of Land, In frastructure and Transport (MLIT). All building materials are classified by HCHO em ission rate into four formaldehyde-emitting categories: Type I, F  , F  , and F 

. Table V-2 describes the four Japanese formaldehyde-emission standards for building materials. The emission standards are expressed as a n emission rate as determined by testing with the Japanese desiccator te st.Chapter V Page 68

Table V-2. Japanese Building Standard Law Classifications fo r Building Material Formaldehyde (HCHO) Emissions 1

Classification HCHO Emission Rate (mg/m 2 /hr) Board Usage Type I 0.12 < x Prohibited in use

F  0.02 < x < 0.12 Tighter area restriction

F  0.005 < x < 0.02 Area restriction

F  x < 0.005 No restrictions

(1) Source : Takabatake (2003). “mg/m 2 /hr” = milligrams HCHO per square meter per hour.

The use of Type 1 building materials as interior finishing materia ls in habitable rooms is prohibited. The use of F  and F  building materials in habitable rooms is limited, depending on total area of the room(s). Th e amount of F 

and F  building materials is adjusted based on the number of ventila tors and

floor area of each habitable room. Use of F  building materials is without any limitations.

To meet these demanding HCHO standards, resins must be modified to reduce HCHO emissions levels to a significant extent. Low HCHO resins have been developed by engaging one or more technological methods, such as:

• Lowering the formaldehyde:urea (F:U) ratio of the UF resin;

• Adding formaldehyde-scavenger materials directly to the UF resin;

• Post-treating panels with a formaldehyde scavenger; or

• Changing to a new resin system.

From this list of options, the primary method used to decrea se HCHO emissions is by lowering the F:U ratio. In the 1980’s, F:U ratios w ere generally between 1.4 to 1.6. Today, F:U ratios in resins used in the U.S. ran ge from 1.05 to 1.2 (Bauman, 1997). To an extent, the results of the CARB 2003 survey suggest that more stringent HCHO emission standards in Europe and Japan have prompted U.S. manufacturers to lower the F:U ratios in the resins that they use.

Some UF resins with F:U ratios of 0.8 to 0.9 have been d eveloped. However, complications in the mechanical and physical performance o f wood panels may arise when HCHO levels are lowered. This is usually compensat ed for by adding a substitute compound in place of HCHO, or by fortificati on with chemicals intended to reinforce the glue bonds.

Another option to significantly lower HCHO emissions is addin g HCHO scavengers directly to UF resins before press time. These s cavengers are usually nitrogen-based compounds that bind to free-formaldeh yde in the resin. Urea scavengers have been used for many years and are ve ry effective in reducing HCHO emissions without influencing the physical ch aracteristics of theChapter V Page 69

wood panel. Another type of scavenger is a scavenger wa x emulsion, which reduces HCHO emissions in two ways: it scavenges free-fo rmaldehyde and also hinders water absorption by the wood panel. Most HCHO s cavengers are cost effective and widely used in North American plants.

There are also a variety of post-pressing board treatments u sed to reduce HCHO emissions from UF resins (Myers, 1986). While post-pressing treatments are used to a lesser extent than pre-pressing treatments, bot h are very effective. The most common post-pressing treatment used to reduce H CHO emissions is to fumigate wood panels with anhydrous ammonia. Significan t HCHO emission reductions, two to 10 times less, can be achieved by exp osure to anhydrous ammonia. Other post-press treatments include adding liquid ammonia or

ammonia salt solutions to the board surface. Ammonium b icarbonate and ammonium carbonate have been used as solid powders, while solutions of ammonium salts, alkali metal salts, and other compounds hav ing amine functionality have been found to be effective.

Breakthroughs in resin chemistry have led to the development of new resin systems that are either low-emitting or zero-added HCHO, to m eet the more stringent European E1 and Japan F  standards. Table V-3 compares the different HCHO emission standards for composite wood produ cts in the U.S., Europe, and Japan. In the U.S., separate standards a re established for PB, plywood, and MDF (i.e., voluntary standards set by ANSI) b ased on surface HCHO emissions (ASTM E1333). In Europe, the standards fo r PB and plywood are based on surface HCHO emissions (EN 717-1), but complia nce with the standard is determined by the amount of free-formaldehy de in PB (EN 120) or by the HCHO emission rate in plywood (EN 717-2). In Japan, all building materials subject to the Building Standard Law are based on HCHO em ission rate (JIS A1901). Because these various standards are applied dif ferently, target different health related goals, and tested using different analytical methods, they are not directly comparable to the proposed Phase 1 and Phase 2 s tandards developed by staff. An analysis of the relative stringency of the s tandards in the proposed ATCM is contained in Appendix H. In Appendix H, the ap proximate ASTM E1333-equivalent values for E1 products are estimated to be 0.14 ppm for HWPW and PB, and 0.10 ppm for MDF. For the F  and F  , the approximate ASTM E1333-equivalent values are estimated to be 0.07 and 0.04 ppm, respectively.Chapter V Page 70

Table V-3. Formaldehyde (HCHO) Emission Standards for Compo site Wood

Products in the U.S., Europe, and Japan 1

Standard Product HCHO Limit Test Method

Particleboard 0.30 ppm Med. Density Fiberboard 0.30 ppm Plywood Wall Panels 0.20 ppm U.S.

Industrial Plywood 0.30 ppm ASTM

E1333

Particleboard, Plywood 0.10 ppm EN 717-1 Particleboard 6 to 10 mg/100 g EN 120 Europe – E1 Plywood ≤ 3.5 mg/m 2 /hr EN 717-2

All Products -- F  0.02 to 0.12 mg/m 2 /hr

All Products -- F  0.005 to 0.02 mg/m 2 /hr Japan – F

Standards

All Products -- F  ≤ 0.005 mg/m 2 /hr JIS A1901

(1) Sources : ASTM (1996); Building Center of Japan (2004); Gro ah et al. (1991); National Particleboard Association (1994). The U.S. standar d for MDF is the voluntary ANSI standard. “ANSI” = American National Standards Institute; “pp m” = parts per million; “mg/100g” = milligrams per 100 grams of dry board; “mg/m 2 /hr” = milligrams per square meter per hour; “ASTM E1333” = American Large Chamber Test Method; “EN 717-1” = Eu ropean Institute Large Chamber Test Method; “EN 120” = European Perforator Test; “EN 71 7-2” = European Gas Analysis Method; “JIS A1901” = Japanese Small Chamber Test.

B. Product Descriptions and Survey Results

This section provides information on how the selected produ cts are manufactured, the results of analyses of the “CARB 2003 Survey,” and for HWPW, an evaluation of supplemental data submitted by th e Hardwood Plywood

& Veneer Association to CARB.

1. Hardwood Plywood

a. Description and Properties

Hardwood plywood (HWPW) consists of thin wood veneers (or p lies) glued together so that the grain direction of each layer of vene er is perpendicular to that of its adjacent layers (Youngquist, 1999). This cross-la mination provides excellent two-way strength for a suite of stiffness (e.g. , dry shear test) and water resistance properties (e.g., three-cycle soak test) (American N ational Standards Institute, 2000). Hardwood plywood is always constructed with an odd number of plies, where the outside and inside plies are referred to as t he faces and core,Chapter V Page 71

respectively. There are several types of HWPW differentiat ed by the thickness and composition of the core, which is commonly made with e ither veneer, lumber, MDF, or PB. The outermost layer or face layer is finely finished wood surface made from a hardwood species such as oak or ma ple.

With respect to water resistance, there are four grades of HWPW: Technical, Type I, Type II, and Type III, where Technical grade H WPW is the most waterresistant and Type III the least (Youngquist, 1999). To our knowledge, in order to produce HWPW for exterior applications (i.e., Technical or Type 1), resins other than urea-formaldehyde (UF) resins are used (e.g., phenol-f ormaldehyde), which typically have HCHO emission rates that are 90% or more bel ow that of HWPW made with a UF resin (Battelle, 1996). In comparison, HWPW designated as either Type II or III are interior-grade products that are large ly used as decorative wall paneling, and the construction of cabinets and furniture (Norbord Inc., Not Dated). The resin most commonly used in these products is UF resin, which has been found to produce HWPW with ASTM E1333 values rang ing from 0.05 to 0.19 ppm (Hardwood Plywood & Veneer Association, 2006).

b. Analysis of Responses to the CARB 2003 Survey

To learn more about the HCHO emission characteristics of HWP W produced in the U.S., a survey (CARB, 2003) was mailed to domestic ma nufacturers. The intent of the CARB 2003 Survey was to learn about the t ypes of equipment used to manufacture composite wood products and to determine the characteristics of HWPW, PB, and MDF produced in the U.S. in 2002. A to tal of 10 responses were received with information on HWPW, representing approxim ately 73% of total U.S. production (in 2002, total U.S. production was estimated to be approximately 1.5 x 10 9 ft 2 , based on 3⁄8 ” thickness). The range of reported ASTM E1333 values from the 10 respondents was 0.07 to 0.75 ppm, and the production-weighted grand mean was 0.09 ppm. All 10 comp anies reported using an ammonia-UF resin to manufacture their HWPW, where t he lowest ASTM E1333 values were achieved by manufacturers that a dded catalysts (e.g., ammonium chloride or hexamethylentetramine (hexamine)). The HW PW that was reported to have an ASTM E1333 value of 0.75 ppm w as an architectural plywood product, which is produced in very low volumes for h ighly specialized applications (e.g., curved objects).

c. Supplemental Data from the Hardwood Plywood & Venee r Association

In fall 2006, various stakeholders in the HWPW industry as ked if consideration had been given to establishing separate HCHO emission stan dards for HWPW made with a veneer core (HWPW-VC) vs. HWPW made with a c omposite core (HWPW-CC) (i.e., core material is either PB or MDF). As this dist inction had not been specified previously, there were no plans at the tim e to establish separate standards for the two products. To clarify the need for separate standards and to supplement analyses of the CARB 2003 Survey data, the Hardwood Plywood &Chapter V Page 72

Veneer Association (HPVA) offered to submit HCHO emission d ata from HWPWVC and HWPW-CC manufactured in 2001-06 from several compan ies (Note: Statutes governing manufacturer confidentiality prohibit the disclosure of actual company names). The HCHO emission data for HWPW-VC from six companies, measured using either ASTM D5582 (desiccator test) or ASTM E 1333 (large chamber test) were provided for two to five years of product ion (Table V-4).

Table V-4. Measured or Estimated ASTM E1333 Average Data for Hardwood

Plywood-Veneer Core from Selected U.S. Manufacturers 1

Company Year No. Samples ASTM E1333 (ppm)

HPVA #1 2004-05 20 0.12

HPVA #2 2001-05 40 0.13

HPVA #3 N/A 11 0.10*

HPVA #4 – Mill F 2003-05 18 0.12*

HPVA #4 – Mill G 2001-05 56 0.09*

HPVA #4 – Mill H 2001-04 15 0.09*

HPVA #4 – Mill I 2001-05 103 0.13*

HPVA #4 – Mill J 2004-05 6 0.15*

HPVA #5 – Mill A 2001-05 6 0.17

HPVA #5 – Mill B “ 11 0.08

HPVA #5 – Mill C “ 16 0.09

HPVA #5 – Mill D “ 6 0.19

HPVA #5 – Mill E “ 9 0.10

HPVA #6 2004-06 32 0.09 Grand Mean (n = 14) ----- ----- 0.12

(1) Data provided by the Hardwood Plywood & Veneer Ass ociation; ASTM E1333 data followed by an asterisk indicate values estimated by multiplyin g measured ASTM D5582 data by 0.4.

In consideration of the variation in numbers of samples, rep orted years, and company/mill information, multiple-year means were calculated for each mill that could be identified. For data that could not be assigned to a specific mill, data for the entire company were averaged. In 2001-06, facility me an ASTM E1333 values ranged from 0.09 to 0.19 ppm, and the grand mean was 0.12 ppm (n = 14). Relative to the data from the CARB 2003 Survey, th e range of reported ASTM E1333 values was smaller, but the grand mean was 25 % higher (i.e., 0.12 ppm vs. 0.09 ppm in the CARB 2003 Survey).

Less data were provided for HWPW-CC (i.e., three companies vs. six for HWPWVC) (Table V-5), which in part reflects lower production volume s for HWPW-CC than HWPW-VC. As for the HWPW-VC data, multiple-year mea ns were calculated for each company, and the company means ave raged to calculate a grand mean. Compared to HWPW-VC, the range in ASTM E1 333 values wasChapter V Page 73

smaller, as was the grand mean (0.08 ppm for HWPW-CC vs. 0.12 for HWPWVC), which may have been influenced by the difference in sample sizes. These data, in light of the lower grand mean and inter-company ran ge in ASTM E1333 values for HWPW-CC, does not support the need for emission standards with

different ASTM E1333 values for HWPW-VC and HWPW-CC at this time.

Table V-5. Measured or Estimated ASTM E1333 Data for Hard wood PlywoodComposite Core from Selected U.S. Manufacturers 1

Company Core Year No. Samples ASTM E1333 (ppm)

HPVA “A” PB 2005 1 0.05

HPVA “B” PB 2001-04 11 0.08

HPVA “C” PB NA 8 0.10*

HPVA “B” MDF 2001-03 5 0.09

HPVA “C” MDF NA 9 0.09* Grand Mean (n = 5) ----- ----- ----- 0.08

(1) Data provided by the Hardwood Plywood & Veneer Ass ociation; ASTM E1333 data with an asterisk indicate values estimated by multiplying A STM D5582 data by 0.4. NA = not available.

2. Particleboard

a. Description and Properties

Particleboard is made of wood fragments, such as chips or s havings, that are dried and mechanically pressed with heat into sheet form, a nd bonded together with resin (Youngquist, 1999). There are typically three layers in a PB panel -- the two outer faces of the board, which consist of fine ly ground wood particles,

and the core which consists of more coarse material. Part icleboard (85% or more) is used for furniture, flooring systems, underlayment, ma nufactured housing, and other products in conventional homes (e.g., c abinets) (Milton, 2006).

b. Analysis of Responses to the CARB 2003 Survey

A total of 20 responses were received with information on PB, representing approximately 53% of total U.S. production (in 2002, total U .S. production was estimated to be approximately 2.9 x 10 9 ft 2 , based on 3⁄4” thickness). The range of reported ASTM E1333 values from the 20 respondents w as 0.13 to 0.24 ppm, and the production-weighted grand mean was 0.18 ppm. I n all, the 20 respondents reported using two UF and one phenol-formalde hyde (PF) resin to manufacture the products they offered for sale in 2002. One of the UF resins, used in approximately 51% of reported production volume, wa s a straight UFChapter V Page 74

polymer with a F:U mole ratio of 1.1 to 1.3 (Note: For UF re sins, the mole amount of HCHO is typically greater than for urea. As such, if a UF resin is reported to have a mole ratio greater than 1, this reflects the F:U mo le ratio and not the U:F mole ratio).

To reduce surface emissions of HCHO from PB made with a UF resin of this kind, manufacturers may include one or more additives to the resin such as catalysts (sodium chloride, sodium sulfate, ammonium sulf ate), scavengers (low mole ratio urea solution), and/or wax emulsions (for moisture retention). The other UF resin was a methanol-UF resin that was used to p roduce approximately 48% of the reported volume of production. As for the stra ight polymer UF resin, surface emissions of HCHO may be reduced by use of the same additives mentioned above, as well as magnesium chloride-hexahydrate. The remaining 1% of reported production was manufactured with a blended PF-UF resin.

3. Medium Density Fiberboard (MDF)

a. Description and Properties

Medium density fiberboard (MDF) is made of wood fibers and ha s stronger physical properties than PB (Youngquist, 1999). Fiberboard is classified by board density -- MDF has a specific gravity of 0.5 to 0. 8 or a density of 31 to 50

lbs/ft 3 (Keidel Supply Co., Inc., 2001-06). The surfaces of MDF are smooth, uniform, and free of knots, and it can undergo a variet y of finishing steps depending on the final product. The primary uses for MDF include furniture, cabinets, molding, door skins, and industrial packaging (Mithra, 2007).

b. Analysis of Responses to the CARB 2003 Survey

A total of 12 responses were received with information on MDF, representing approximately 83% of total U.S. production (in 2002, total U .S. production was estimated to be approximately 1.6 x 10 9 ft 2 , based on 3⁄4” thickness). The range of reported ASTM E1333 values from the 12 respondents w as 0.03 to 0.31 ppm, and the production-weighted grand mean was 0.25 ppm. I n all, the 12 respondents reported using three UF and one methylene diiso cyanate (MDI) resin to manufacture the products offered for sale in 2002 . Similar to PB, a major portion of manufacturers reported using a straight polymer UF (approximately 40% of reported production) or methanol-UF resin (approximately 20%), while others used a melamine-UF resin (approximately 39%) with sodium chloride as a catalyst. Although the same additives listed for PB may b e used to control surface emissions of HCHO from MDF (i.e., catalysts, scave ngers, and wax emulsions), the specific additives used to manufacture MD F are considered to be proprietary information. Of the reported volume of productio n, approximately 1% was made using a MDI resin.Chapter V Page 75

C. Present-day Resin Technologies

In this BACT assessment of present-day resin technologies , an evaluation of currently used and laboratory tested resins, and production processes that may

be used to achieve the maximum feasible HCHO emission redu ctions from HWPW, PB, and MDF was conducted. Staff’s review of t he literature concludes that generally speaking, resin technologies can be applied to all three regulated products (HWPW, PB, and MDF), although adjustments in resin s may be necessary to accommodate the different manufacturing pro cesses. In addition,

the assessment also considers the results of the CARB 20 03 Survey, patent searches, a literature review, and consultations with resin su ppliers, panel manufacturers, and academia. In this analysis, resin syste ms were evaluated in consideration of the need to meet selected structural prop erties.

1. Urea-formaldehyde (UF) Resins

Presently, UF resins are the most widely used adhesives in the manufacture of HWPW, PB, and MDF, which produces boards with the highes t HCHO surface emissions (i.e., ASTM E1333 values). The basic chemical reac tion in UF resins involves bond formation between amine and hydroxyl groups on the resin components. New technologies seek to find alternative c omponents that are

able to form irreversible bonds with HCHO to reduce the amoun t of free HCHO that remains in the final product. To produce HWPW, PB, and MDF with a UF resin that would achieve lower HCHO emissions, manufacturers may choose to use resins with lower F:U mole ratios (i.e., less than 1.0), ad d different amounts or mixtures of scavengers and hardeners, and/or apply decrea sed press times and temperatures (Wolcott et al., 1996). Limited studies indicate the potential to

meet the F  standards, but it is not clear as to how low an ASTM E1 333 value can be achieved using a UF resin, as efforts made t o date to lower surface HCHO emissions from HWPW, PB, and MDF are not well docum ented in the open literature.

2. Melamine-urea-formaldehyde (MUF) Resins

The most widely used approach for decreasing surface HCHO emissions from

boards made with a UF resin is to lower the F:U mole ratio o f the base resin. Presently, mole ratios are reported to range from 1.05 to 1.2 , depending on the specific formulation of the resin (Baumann, 1997). Howev er, when the F:U mole ratio is lowered below 1.0 (i.e., more moles of urea than HC HO), adjustments must be made to the resin to moderate unwanted changes in the physical and structural properties of the board. The addition of melamine during resin synthesis is often used to improve the durability and stab ility of a board, and its addition can also decrease surface HCHO emissions by act ing as cross-linking agent.

Cremonini and Pizzi (1999) measured the effects of adding me lamine acetate (Mac) on the tensile strength of plywood made with a UF re sin (F:U mole ratio =Chapter V Page 76

1.5). Measurements of tensile strength were made before a nd two-years after exposure to the weather in northern Italy (Table V-6). While p lywood made with a “UF + 15% Mac” resin had a lower initial tensile strength tha n plywood made with commercially available Phenol-MUF resin, it had a higher t ensile strength after two-years of weather exposure (1.27 vs. 1.05 N/mm 2 ). In comparison, plywood made with commercially available MUF resin exhibited bot h higher initial and post-exposure tensile strength than plywood made with PMUF or any “UF + Mac” resin combinations. Overall, the durability of plywood ma de with 15% or more Mac would allow manufacturers to produce panels that c omply with European tensile strength requirements, comparable to plywood made with a MUF resin with 33 to 40% melamine. This suggests that th e addition of Mac to UF resins may be equally as effective in maintaining plywood tensile strength as MUF resins with higher melamine contents. Pizzi (2000) also re ported that equivalent tensile strengths were measured in plywood bonde d with a 40:60 weight ratio MUF resin and plywood bonded with a 10:90 we ight ratio melaminesalt UF resin.

Table V-6. Effect of Melamine Acetate (Mac) on Plywood T ensile Strength 1

---------- Tensile Strength (N/mm 2 ) ---------- Resin (M:U weight ratio) Initial Post-exposure PMUF Control (33:66) 1.48 1.05 MUF Control (47:53) 2.07 1.91 UF + 10% Mac (7:93) 0.52 0 UF + 15% Mac (10:90) 1.33 1.27 UF + 20% Mac (13:87) 1.10 1.07 EN 314 Requirement > 1.0 NA

(1) Source : Cremonini and Pizzi (1999). PMUF = phenol melami ne urea-formaldehdye; MUF = melamine urea-formaldehyde; UF = urea-formaldehyde. The bas e UF resin had a F:U mole ratio of 1.5. Postexposure tensile strength is the value after two-ye ars of weather-exposure in northern Italy. NA = no t applicable.

Relative to lowering HCHO emissions, Dunky (1995) developed a MUF resin using a very low mole ratio UF resin (F:U = 0.75 to 0.90) and adding 15 to 23% melamine by weight to achieve very low HCHO concentrations . With respect to HCHO content, the panels exhibited DIN EN 120 values le ss than 2.0 mg/100 g (approximate ATSM E1333 value of 0.025 ppm).

Akzo Nobel (2005; 2006) is currently conducting laboratory t rials on a MUF resin made with a low mole ratio UF resin (F:U = 1.05 to 1.15), me lamine, and a “catcher” compound. The catcher is specifically formulated t o decrease HCHO emissions from PB produced with the MUF resin. Particleboard , ranging in thickness from 16 to 28 mm, has been produced at a p ress temperature of 185 °C and a 10.8 s/mm press time. While the resin system is still in laboratory trials, it has shown good success in terms of producing PB with lo w JIS A1460 (Japanese desiccator test) values (less than 0.3 mg/L ≈ ASTM E1333 value ofChapter V Page 77

0.04 ppm) and improving durability when applied at a 10% by weight resin dosage. This resin system has the potential to be used to make PB with very low

HCHO emissions.

3. Melamine-formaldehyde (MF) Resins

Melamine-formaldehyde resins are excellent exterior wood adhesiv es because of their water resistance. Frihart and Chandler (2006) found tha t MF resins could reduce wood swelling by entering into the walls of wood cells and strengthening

them.

Kim and Kim (2005) conducted a range of HCHO emission test s (e.g., DIN EN 120, JIS A1460) on 8-mm MDF made from Korean pine (4% m oisture content)

and bonded with a MF resin. The resin had a F:M mole rat io of 1.75. Before the MDF was pressed, three-parts (to resin) of 25% ammonium chlo ride (hardener) and 13 parts of 44% wax solution (for waterproofing) were a dded to the base MF resin. The MDF made with the MF resin displayed a JIS A1 460 value of 0.6 ppm and a DIN EN 120 value of 2.88 mg/100 g dry board, whic h complies with the Japanese F  and nearly the F  standard.

Pizzi et al. (1996) examined the strength and HCHO emission properties of PB made under laboratory conditions with either a 0.5 or 1.1 mo le ratio MF resin containing ammonium chloride (i.e., 15-parts by weight of a 20% solution). Hexamine (i.e., 38-parts by weight of a 40% solution) was added to the 0.5 mole

ratio MF resin to determine if hexamine addition could com pensate for the resin’s lower melamine content. Observed differences in dry internal bond strength and

DIN EN 120 results are shown in Table V-7 for PB made with the two MF resins.

These results confirm that the addition of hexamine to a lo w mole ratio MF resin allows for the production of PB with similar internal bond stren gths as PB made with higher mole ratio MF resins. In addition, the DIN EN 1 20 value of the PB made with the hexamine-hardened MF resin was approximately 50% lower than the value of the higher mole ratio MF resin without hexamin e. Overall, it appears that adding hexamine as a hardener to MF resins may be an effective way to lower HCHO emissions and maintain internal bond strength in PB. Further research is needed to identify the optimal amount of hex amine to add to MF resins for the manufacture of PB with acceptable internal bo nd strengths and low

HCHO emissions.

The findings from these studies demonstrate the potential for using MF resins to produce PB or MDF with low HCHO emission properties.Chapter V Page 78

Table V-7. Comparison of Strength and HCHO Emission Propert ies of Particleboard Made with Two Melamine-formaldehyde (MF) Resins 1

-------------------- Resin -------------------- Resin or Particleboard Parameter MF Alone MF + Hexamine MF Mole Ratio (Parts by Weight) 1.1 (174) 0.5 (154) Dry Internal Bond Pressure (MPa) 0.77 0.65 DIN EN 120 (mg HCHO/100 g) 6.9 3.5

(1) Source : Pizzi et al. (1996). MPa = megapascals; mg = mil ligrams; g = grams. DIN EN 120 refers to the European perforator test. The press time for PB made with either resin was 4-

minutes.

4. Phenol-formaldehyde (PF) Resins

Phenol-formaldehyde resins are commonly used in PB for exte rior applications

that must be durable under wet and/or humid conditions. T hey typically exhibit low HCHO emission rates (Battelle, 1996), and selected comme rcially available products would likely comply with the proposed Phase 2 stan dards that would take affect in 2011 to 2012 (Appendix A). Industry repre sentatives have expressed concern over the longer press times and higher pre ss temperatures required for producing products with PF versus UF resins, as t hese changes result in higher energy consumption and decreased productiv ity. However, recent studies have shown that adding compounds such a s esters, lactones, or organic carbonates to PF resins can reduce cure times (Conne r et al., 2002; Lorenz and Conner, 2000; Pizzi et al., 1997).

5. Methlylene Diisocyanate (MDI) Resins

Since the 1970’s, MDI has been increasingly used in the manufacture of MDF (Eckelman, 1997). As a non-polar, low viscosity liquid that wets the wood surface and penetrates deep into the wood structure, MD I resins penetrate further than PF resins, thus creating one of the most dura ble adhesive networks. While more expensive than any other resin discussed in this section, there are no HCHO emissions associated with its use, enabling PB and MD F made with this adhesive to meet the proposed Phase 2 standards that w ould take effect in 2011 to 2012. A number of other properties that make MDI a desirable adhesive for composite wood products include:

• Fast polymerization rate (making it suitable for use as core resin) and ability to form bonds with wood with a high moisture content , including green wood (Connor, 2001; Frihart, 2005);

• Low volatility – less resin is used to manufacture products with comparable structural properties (Marra, 1992); andChapter V Page 79

• Lower energy-related production costs due to the use of lower press temperatures, faster press cycles, and shorter drying times (C onnor, 2001).

At the industrial-scale, research on isocyanates is presently focused on their use as a copolymerization agent in existing resins, which have led to the creation of hybrid resin systems (e.g., UF-MDI, PF-MDI, PUF-MDI, PMUF-MD I, and PUFTMDI) that outperform traditional wood resins (Lei et al., 20 06).

6. Methylene Diisocyanate (MDI) Hybrid Resins

a. Urea-formaldehyde-MDI (UF-MDI) Resins

Composite wood products made with UF resins are only used for interior applications because they have very low water resistance p roperties. However, researchers working with MDI hybrids have recently created an exterior-grade UF-MDI hybrid resin for use in a range of applications (Mansou ri et al., 2006). By using a UF-MDI resin made by adding MDI (10 to 15% by weig ht) to a UF resin, the water resistance of plywood was substantially upgraded. Wieland et al. (2006) found that adding ammonium sulfate (approximately 2 % by weight) could further accelerate plywood curing times. In plywood, the strength of the bondlines made with a UF/MDI hybrid resin are much improved relative to those made with a UF resin due to the greater number of urethane cross links that form between isocyanate and UF methylol groups.

Mansouri et al. (2006) examined the changes to structural pro perties in plywood made with UF-MDI hybrid resins ranging from 5 to 15% MDI by weight (Table V8). The test material was a three-layer beech veneer plywood bonded with a base UF resin (F:U mole ratio = 1.6 to 1.8) that was modif ied by the addition of ammonium sulfate (2% solution), wheat flour (30% by weight), and MDI. The results show that as the amount of MDI is increased, the boiling water performance of the plywood improved (e.g., after 11-minute s the tensile strength of the control was four- to five-times lower than the plyw ood made with any of the UF-MDI hybrid resins). While the selected measures of tensile strength were all improved by the addition of MDI to the UF resin, the ext ent of improvement is much greater when 10 to 15% MDI is added vs. only 5%. To produce plywood with exterior-grade properties using a UF resin, greater amou nts of MDI would need to be added to achieve the required level of water res istance. Nevertheless, the tensile strength and water resistance pro perties of plywood made with a UF resin can be considerably improved by the ad dition of 10 to 15% MDI by weight.Chapter V Page 80

Table V-8. Selected Measures of Tensile Strength (N/mm 2 ) in Plywood Made with Urea-formaldehyde (UF) and UF-Methylene Diisocyanate (UF-MD I) Hybrid

Resins 1

------------ Tensile Strength (N/mm 2 ) ------------ Test UF UF-MDI (5%) UF-MDI (10%) UF-MDI (15%) Dry Internal Bond 2.00 2.07 2.13 1.89

24-hour Cold Soak 1.91 2.00 2.00 2.26 Boiling Water: 3-min 2.27 2.88 2.49 2.57 Boiling Water: 5-min 1.96 2.41 2.52 2.32 Boiling Water: 7-min 1.87 2.02 2.21 2.18 Boiling Water: 11-min 0.42 1.84 1.70 1.90 Boiling Water: 15-min 0 0 1.28 1.95 Boiling Water: 19-min 0 0 1.25 1.49 Boiling Water: 23-min 0 0 0 0.71 Boiling Water: 27-min 0 0 0 0.61 Boiling Water: 30-min 0 0 0 0

(1) Source : Mansouri et al. (2006). For the UF-MDI headings, values in parentheses indicate the amount of MDI in the resin on a weight-basis. “min ” = minutes. Glue-spread = 300-320 g/m 2 ; press time = 5 min; press temperature = 120 °C; pre ss pressure = 11 kg/cm 2

.

b. Phenol-formaldehyde-MDI (PF-MDI) Resins

Phenol-formaldehyde and MDI resins have been used to ma nufacture plywood and oriented strand board (OSB) for exterior applications outside the U.S. because of their excellent water resistance. Presently, PF resins dominate the market for exterior and marine-grade plywood (Pizzi et al., 1995); however, PF

resins are less effective when used to bind wood veneers w ith high moisture contents. This limitation may be overcome by adding MDI to a PF resin (as in a PF-MDI hybrid), as it raises the moisture tolerance of the resin , promotes resin curing, and enables a stronger bond-line to develop between the plywood veneers (Figure V-1). When used alone, full curing of a MDI re sin requires veneer moisture contents to be above 10% and curing time is not affected until the veneer moisture content is greater than 18% (Zheng, 20 02). Compared to PF resins, MDI resins have a faster cure rate at lower press temperature and better resin network stability at lower adhesive spread levels (C onner, 2001), and are currently used in industrial applications to upgrade the per formance of traditional wood resins (Lei et al., 2006).Chapter V Page 81

Figure V-1. Polyurethane Cross-linking in a PF-MDI Hybrid Resin

OH

CH 2 CH 2 OH

n n CH 2 OH

CH 2 O NH NH O

O

C O OH

CH 2 CH 2 R C

c. Phenol-urea-formaldehyde-MDI (PUF-MDI) Resins

Phenol-urea-formaldehyde (PUF) resins have been used for ex terior applications since the early 1990’s (Pizzi, 1994). To reduce resin cost, increasing amounts of urea have been added, which affects a number of structu ral properties in PB, especially water resistance (Osman et al., 2005). To counte rbalance the effects of urea, MDI can be added to improve the performance of the board and to accelerate the curing process.

Table V-9. Effect of MDI and/or Urea Additions on Select ed Resin and Panel Properties in Particleboard Made with Phenol-urea-formaldehyde (P UF) Resins 1

-------------------- PUF Resin --------------------

Resin or Panel Property Control 10% MDI 10% MDI

+ 15% Urea 10% MDI

+ 20%

Urea Viscosity (MPa

· s) 570 570 210 164 Board Density (kg/m 3 ) 693 706 708 705 Wet Internal Bond (MPa) 0.16 0.25 0.19 0.16

(1) Source : Osman et al. (2005). “MPa

· s” = megapascals-second; “g/cm 3 ” = grams per cubic centimeter; “MPa” = megapascals. Particleboard pre ss temperature = 195°C, press time = 11 s/mm, and pressure = 28 kg/cm 2 . Wet internal bond strength was measured after th e PB was

boiled in water for two-hours and dried for 16-hour s (DIN 68763).

Osman et al. (2005) examined the properties of 16-mm PB mad e with four PUF resins, to evaluate the changes resulting from additions of MDI and urea. The

control PUF resin had a solids content of 59% and containe d approximately 40% urea by weight. The test resins were “PUF + 10% MDI,” “PUF + 10% MDI + 15% urea,” and “PUF + 10% MDI + 20% urea.” With respect to resin viscosity,

addition of MDI alone had no effect relative to the PUF c ontrol, but urea additions resulted in sizable reductions (Table V-9). While only minor cha nges were observed in PB density (i.e., 1 to 2% higher than the PUF control), the addition of 10% MDI to the PUF resin dramatically increased the wet int ernal bond strengthChapter V Page 82

of PB compared to the PUF control, except with addition of 20% urea. With further research, it is conceivable that a cost-competitive PU F-MDI hybrid resin may be developed to allow manufacturers to produce PB with the desired structural properties and low HCHO surface emissions.

d. Phenol-melamine-urea-formaldehyde-MDI (PMUF-MDI) Resins

Phenol-melamine-urea-formaldehyde (PMUF) resin is used to manu facture exterior-grade composite wood panels. The resin is made by co-reaction of a PMUF resin with 5 to 10% phenol (Cremonini et al., 1996).

Lei et al. (2006) evaluated the effects of adding small incre ments of MDI to a PMUF resin on PB performance. The base PMUF resin had P :M:U:F mole ratio of 0.11 phenol, 0.33 melamine, 1.18 urea, and 2.15 forma ldehyde, plus ammonium sulfate (3% by weight). Small additions of MDI d id not appear to affect PB dry internal bond strength, as the value for PB made with 100% MDI was only 14% higher than for the PB made with 100% PMUF resin (Table V-10).

Table V-10. Dry and Wet Internal Bond (IB) Strength and De nsity in Particleboard Made Phenol-melamine-urea-formaldehyde (PMUF)-MDI Resins 1

PMUF Resin --------------- Internal Bond (IB) or Density ---------------

% MDI Added Dry IB

(MPa) Dry Density

(kg/m 3 ) Wet IB

(MPa) Wet Density

(kg/m 3 )

0 1.00 711 0.09 727

5 0.95 693 0.21 675

10 1.05 726 0.23 713

15 1.08 697 0.29 720

25 0.94 701 0.46 714

50 1.00 702 0.48 694

75 1.01 702 0.46 689

85 1.02 681 0.36 708

90 1.05 698 0.45 674

95 0.98 681 0.48 700

100 1.14 653 0.58 660

(1) Source : Lei et al. (2006). “MPa” = megapascals; “kg/m 3 ” = kilograms per cubic meter. The

total resin solid content of the PB was 10%. Parti cleboard press temperature = 195 oC, press time = 11 s/mm, and maximum pressure = 33 kg/cm 2 . Wet internal bond strength was measured

after the PB was boiled in water for two-hours and dried for 16-hours.

Far greater changes were observed in wet internal bond streng th where additions of 5 or 10% MDI raised values by more than two fold (i.e., 0.21 to 0.23 vs. 0.09 MPa). When the amount of MDI was 25% or more, wet inte rnal bond strength was increased by four or five fold relative to the PMUF con trol. Densities of theChapter V Page 83

PB ranged from 653 to 727 kg/m 3 in measurements made before or after the wet

internal bond test. While lower densities were measured in PB made with 85% or more MDI before the wet internal bond test, the reductio ns were not consistently observed after the wet internal bond test. A t lower MDI additions (e.g., 10 to 25%), PB density appeared to be consistently higher relative to PB

made with the PMUF resin without added MDI. In conclus ion, as for the other MDI hybrid resins discussed previously (e.g., UF-MDI, PF-MDI, PUF-MDI) adding

small amounts of MDI to a PMUF resin was also found to d ramatically increase the performance of PB. For PMUF resins, the largest impr ovement was observed for wet internal bond strength, where additions of 5 to 10% MDI are likely to result in only a small increase in resin cost.

D. Candidate Low-formaldehyde Resin Systems

In this section, the resin systems that have been used to produce panels with low-formaldehyde emissions are discussed. While interior-grade HWPW, PB, and MDF are all presently being made with UF resins, in future years, it may be necessary to consider an array of low HCHO resins given the manufacturing differences between HWPW, PB, and MDF. This is partly du e to the stringency of present HWPW, PB, and MDF emission standards in the U.S., which have not kept pace with efforts in Europe and Japan, where the b ulk of the research concerning low-formaldehyde resin technology is occurring.

While the commercial viability of soy resins for HWPW has been demonstrated in the U.S., staff expects that manufacturers will opt to use UF resins because of its low cost and versatility. To date, domestic efforts to low er HCHO emissions have been a consequence of work aimed at improving wate r resistance in composite wood products. As such, despite not being dis cussed in detail here, modified UF resins are likely to be the primary choice of ma nufacturers to achieve low HCHO emissions. Following optimization of plant-lev el operations and wood preparation, it is projected that the use of addit ives such as hexamine and melamine will be examined closely. Should these options prove to be too costly, the use of cost-effective non-UF resins might the n be considered.

1. Hardwood Plywood (HWPW) Resins

a. Soy-based Resins for Low-formaldehyde Hardwood Plywood

Soy-based resins have been used since the early 20 th Century (United Soybean Board, 2004), and research efforts have continuously focu sed on the development of resins with near-zero HCHO emissions, comp etitive pricing, and improved water resistance. In recent years, the use of so ybeans (which are approximately 40% protein and approximately 34% carbohydrate ), as a component in adhesives for plywood has grown, due in part to the abundance of key functional groups that all resins must have (Li et al., 2 004). Proteins provide amine and amide functional groups, and carbohydrates provide hydroxyl groupsChapter V Page 84

for high reactivity with a range of cross-linking agents (Heartlan d Resource Technologies, Not Dated).

Figure V-2. Cationic Polyamidoamine-epichlorohydrin (PAE)

N

O H

N

O H + - Cl

Li et al. (2004) prepared a soy-based resin for plywood by co mbining soy protein isolate (SPI) with Kymene ® 557H, a commercially available cationic polyamidoamine-epichlorohydrin (PAE) resin used in the paper ind ustry (Figure V-2). Soy protein isolate is a soy product with a higher prote in (86% vs. 40% by weight) and lower carbohydrate (14% vs. 34% by weight) co ntent than soybeans. A plywood adhesive was prepared by mixing SPI and Kymene ® at a dry weight ratio of 1.33:1. The maximum shear strength and water res istance were then determined on 1 x 10 cm plywood strips. Measurements of shear strength were made on dry plywood and plywood subject to a water-soak ing-and-drying (WSAD) test, where the test materials were soaked in water at room temperature for 24-hours, and dried for 24-hours, prior to being measured (F igure V-3). No significant differences were observed in dry and WSAD shea r strength at any reaction time. This indicated that plywood shear strength was not reduced after a WSAD test, and none of the plywood samples delamina ted.Chapter V Page 85

Figure V-3. Effect of Reaction Time on the Dry and Water -Soaking-and Drying (WSAD) Shear Strength of Plywood Made with a Soy Protein Isolate-Kymene ®

Resin 1



### 0 1 2 3 4 5 6 7 8 9

5 30 60 90 120 150

Reaction Time (min)Shear Strength (MPa)



### Dry

WSAD

(1) Source : Li et al. (2004). Shear strengths are the mean o f 10 or more replicate measurements. Plywood was made with 1 x 10 cm strips of sugar map le veneer; press temperature = 120 °C, press time = 5 min; press pressure = 200 psi.

The SPI-Kymene ®

adhesive developed by Li et al. (2004) produced plywood wit h comparable shear strength properties to plywood made with a PF resin. However, SPI is very expensive, and at present-day prices, is not costcompetitive with PF. In comparison, soy flour is an inexpen sive alternative that may have utility for plywood made for interior applications, whic h have lower interior strength and water-resistance requirements than exterio r-grade plywood. As such, soy flour-Kymene ® adhesives may be a cost-competitive no added HCHO replacement for UF resins in interior grade plywood. The use of a soybased adhesive for HWPW was initiated by Columbia Forest P roducts, which

markets its trademark Purebond TM product line as HWPW made with a no added HCHO resin (Columbia Forest Products, 2005). In 2006, Colum bia Forest Products began converting their HWPW-VC plants, which previo usly made HWPW-VC with a UF resin, to manufacturing Purebond TM . Columbia Forest

Products has stated that the use of Purebond TM is cost-neutral to UF resin and

meets the F  standard, and its utility as a resin for PB and MDF is currently being tested.

Heartland Resource Technologies has also developed a promisin g soy-based adhesive for HWPW called Soyad ® . In this resin formulation, soy flour is combined with a PF resin (Heartland Resource Technologies, N ot Dated). In their resin, soy flour is denatured in an alkaline environment to expose allChapter V Page 86

available amine and hydroxyl functional groups to make them accessible to crosslinking with the PF resin. When the soy flour is added to the PF resin for crosslinking, the bonds formed with HCHO are irreversible. In t heir experience, the manufacturing process is more user-friendly with soy-based resins, since no vacuum processing or high-pressure steps are involved (Westc ott and Frihart, 2004). Heartland Resource Technologies has overcome many o f the difficulties that were encountered in other efforts to develop a soy a dhesive for HWPW (Table V-11).

Table V-11. Soy-based Adhesives: Problems and Solutions 1

Problems Solutions

Biologically Unstable Proper denaturing and copolymerizing with small amount of reactant improves product biological stability.

Low Solids A new method for denaturing and copolymerizing with viable crosslinking agents was developed, allowing for soy resins with solids contents ranging from 30 to 45%.

Slow Press Times Copolymerizing with reactive crosslinking agents allows for tailoring cure rates to meet a variety of applications.

Poor Water

Resistance Soy resins become water-resistant thermoset resins after copolymerizing with reactive crosslinking agents.

Very Short Shelf Life Through innovative processing, the soy resin shelf life ranges from two weeks (similar to PF) to one year.

(1) Source : Wescott and Frihart (2004).

Wescott and Frihart (2004) examined the properties of oriented strand board (OSB) made with a commercially available PF resin and soy-PF resin s. Table V12 lists the physical properties of the resins that were tes ted. The soy-PF resins were made using a soy:phenol ratio of either a 1:1 or 3.4: 1 by weight. While the viscosity of the soy-PF resins were three- to four-times highe r than the PF resin, the soy-PF resins could still be applied as a spray. This is because the soy-PF resins are thixotropic; their viscosity lowers when stress or high shear is applied, such as in the spraying process. As such, the viscosity of these soy-PF resins is lowered when it is sprayed, then it returns to its original visco sity after pressing and cooling. This property makes the resins easier to work into the manufacturing process and may have applications to PB and MDF. While the soy-PF resins had lower solids contents than the PF resin, v alues for percent extractables were similar for the 1:1 soy-PF resins and higher for the 3.4:1 soyPF resin.Chapter V Page 87

Table V-12. Physical Properties of Phenol-formaldehyde (PF) a nd Soy-PF

Resins 1

----------------------------- Resin ------------------------------ Property PF Soy-PF 1 Soy-PF 2 Soy-PF 3 Soy-PF 4 Soy:Phenol 0:1 1:1 1:1 1:1 3.4:1 Viscosity (mPa·s) 244 1,200 1,100 750 1,100 pH 11.2 10.2 11.3 11.3 10.3

% Solids 53.3 39.0 34.4 39.5 35

% Extractable 24 16 22 22 32

(1) Source : Westcott and Frihart (2004). “mPa·s ” = millipas cal-second.

In their OSB study, Westcott and Frihart (2004) used the s oy-PF resins as a face resin, which they applied by air atomization. The 7 / 16 ” OSB was formed on a 16” x 16” mat from yellow poplar strands with 5.6% moisture con tent to a target density of 42 lbs/ft 3 (674 kg/m 3 ). The OSB made with a 1:1 soy:phenol ratio (i.e., Soy-PF 1-3), displayed dry internal bond strengths that were c omparable to OSB made with the PF resin (Figure V-4). The OSB made with soy-P F 4 required a longer press time due to its higher soy content (data not shown). Further research is needed to optimize the crosslinking in soy-PF resin s at soy:phenol ratios greater than 1:1.

Figure V-4. Dry Internal Bond Strengths for Oriented Strand B oard made with PF and Soy-PF Resins 1

0 10 20 30 40 50 60 70 80 90 100

PF Control Soy 1 Soy 2 Soy 3Internal Bond (lb./in2)

210 sec

150 sec

(1) Source : Westcott and Frihart (2004). Oriented Strand Boa rd press temperature = 200 o C.Chapter V Page 88

Wet internal bond strength was evaluated after applying th e aggressive 2-hour boil test, where OSB is boiled for 2-hours and then oven-dried (Westcott and Frihart, 2004). As for the results of the dry internal bond t est, OSB made with the 1:1 soy:phenol resins exhibited comparable results to OSB ma de with a PF resin (Figure V-5), indicating that soy resins can used to produce O SB with excellent durability.

Figure V-5. Wet Internal Bond Strengths for Oriented Strand Board Made with Phenol-formaldehyde (PF) and Soy-PF Resins 1



### 0 1 2 3 4 5 6 7 8 9 10

PF Soy 1 Soy 2 Soy 3Internal Bond (lb./in2)



### 210 sec

150 sec

(1) Source : Westcott and Frihart (2004).

In conclusion, soy resins are an option for HWPW, and there are other researchers working to develop soy-based resins. For example, at Kansas State University, Dr. X. Susan Sun is developing a HCHO-free soy re sin that is water resistant (K-State Media Relations & Marketing, 1998). The United Soybean Board is currently involved with soy binder research for large ma nufacturers of composite wood products (United Soybean Board, 2004).

b. Polyvinyl Acetate (PVA) Resins for Low-formaldehyde Hardwo od Plywood

Polyvinyl acetate (PVA) is used to manufacture HWPW-VC fo r internal applications. It is a water-soluble adhesive that does not contain HCHO, and is one of the more flexible resins used to make plywood. Ply wood made with PVA cures at lower temperatures than UF resins, thus allowing f or reduced product cycle times (Steenbergen, 2000). The pot-life for PVA ranges from two to threeChapter V Page 89

days after mixing compared to three or four hours for UF resin s (Steenbergen, 2000). Under high moisture settings, PVA it does not bind as well as UF (Frihart, 2005).

Franklin International (1999), among others, sells PVA that meets the requirements for the Hardwood Plywood & Veneer Association ’s HP-1 Type I and Type II plywood under several brand names (e.g., Multibond ® , Titebond ®

, Advantage ® ). Polyvinyl acetate adhesives can be obtained as either o ne-part systems that come pre-mixed, or as a two-part system that utilizes a catalyst. Because PVA is a no added HCHO resin (i.e., does not use HCHO as part of the cross-linking structure), it could be used to make HWPW tha t would achieve low

HCHO emission levels.

c. Tannin-based Resins for Low-formaldehyde Hardwood Plywo od

The use of tannins, as a substitute for petroleum-based re sins, has been studied for quite some time. Tannins are naturally phenolic and have been used commercially as a replacement for phenol or resorcinol in PF or p henolresorcinol-formaldehyde (PRF) resins in Brazil, South Africa, and A ustralia (Santana et al., 1996). Different hardwood tannins, such as wattle and quebracho, have been produced and used commercially (Li and Maplesden, 1998). As a naturally occurring compound in trees, there is a real potential for tannins to be used in an aldehyde-free and no added HC HO adhesive for plywood, PB, and MDF. Three new tannin-based technologie s, tannin-hexamine hardening, tannin autocondensation, and methylolated nitro paraffin hardening, are ready for use at the industrial-scale, and are presently b eing considered for use by a number of international manufacturers (Pizzi, 2006).

Hexamine (Figure V-6) is a nitrogen-containing compound that c an be used as a tannin hardener (Kamoun et al., 2003). It readily reacts w ith the nucleophilic sites on tannins, resorcinol, and melamine. Under alkaline co nditions, hexamine intermediates react with tannins before decomposition to HC HO. Tanninhexamine resins are environmental-friendly; composite wood prod ucts made with

these resins exhibit near-zero HCHO concentrations when mea sured using the JIS A5908 desiccator test (Pichelin et al., 2006). Pizzi et al. (1994) found that faster press times for products made with tannin-hexamine re sins could be achieved by adding accelerators, such as zinc salts.Chapter V Page 90

Figure V-6. Chemical Structure of Hexamine

N N

N N CH 2 CH 2

CH 2

CH 2 CH 2 CH 2

Tannin autocondensation is a reaction that takes pl ace between polyflavonoid

tannins that consist of 5 to 11 monoflavonoid units . Monoflavonoid units consist of two phenolic rings joined by a heterocyclic ring (i.e., one or more atoms in the ring are atoms other than carbon) (Figure V-7). Un der alkaline or acidic conditions, polyflavonoid tannins can autocondense in the absence of HCHO – the functional groups on a monoflavonoid in a tanni n molecule can react with

another monoflavonoid unit on a different tannin mo lecule. While the viscosity of the tannin increases, gelling does not occur (Pizzi , 2006). In order to control viscosity, increase pot-life, and avert gelation in tannins, methanol is usually added. Overall, tannin autocondensation reactions improve the dry strength of composite wood panels with little or no HCHO emissi ons.

Figure V-7. Chemical Structure of a Monoflavonoid Unit

O O O

O O

H H

H

H

Trosa and Pizzi (2001) compared the breaking loads and HCHO contents of plywood made with a quebracho tannin-based resin am ended with a methylolated nitroparaffin (i.e., tris(hydroxymethy l)nitromethane or TN). The 10- mm plywood (5-ply okoume veneer) had an initial moi sture content of 4%. Compared to plywood made with a MUF resin (M:U = 1) , breaking loads in plywood made with tannin-TN resins were 22 to 67% l ower (Table V-13).Chapter V Page 91

However, when TN additions were 8% by weight or hig her, measured breaking loads exceeded the minimum requirement of European Norm EN 314 Method 5.5.3. for exterior-grade plywood. In terms of HCH O content, the plywood made

with the tannin-based resin with 10% TN had a DIN E N 120 value of 0.5 mg/100 g dry board, well below the European E1 standard of 8 mg/100 g dry board. These results show that the addition of TN, and pot entially other methylolated nitroparaffins, to tannin-based resins, can both im prove plywood strength and

lower HCHO content.

Table V-13. Effect of Tris(hydroxymethyl)nitrometha ne (TN) Addition on the Breaking Loads and Formaldehyde Contents of Plywood Made with Quebracho

Tannin Resin 1

Resin or Standard Breaking Load (MPa) HCHO Emissions

(mg/100 g panel)

MUF Control 2.7 6

Quebracho + 6% TN 0.9 NA

Quebracho + 8% TN 1.7 NA

Quebracho + 10% TN 2.1 0.5

EN 314 Standard > 1.0 < 6.5

(1) Source : Trosa and Pizzi (2001). “MPa” = megapascals; “mg” = milligram(s); “g” = gram(s); “NA” = not available. Plywood press temperature = 120 °C; total press time = 6 minutes; press pressure = 8 kg/cm 2 ; glue spread = 250 g/m 2 . EN 314 Standard refers to the European Standard for Class 3, Marine-grade plywood.

Tannin-based adhesives have also been used to manuf acture various grades of HWPW in Brazil and China. To produce exterior-grad e plywood, adhesives are fortified with other polymer systems, such as PF, R F, PRF, and MDI (Santana et al., 1997). Copolymerization with resol PF may als o provide cost savings (approximately 20 to 40%) in that industrial applic ations allow for the use of 250 g/m 2 adhesive instead of 400 g/m 2 , as required for PF resin.

d. Phenol-urea-formaldehyde-Tannin (PUFT) Resins f or Lowformaldehyde Hardwood Plywood

Tannins, which are phenolic in nature, can be used to replace phenol in PF resins. Vasquez et al. (2004) created a PUFT resin using PUF prepolymers and Pinus pinaster

bark tannins, and compared the chemical characteri stics of the resulting PUF and PUFT adhesives. The PUF and PUFT resins were prepared in two stages. The first stage involved reacting H CHO and phenol under acidic conditions for one or two hours, and the second inv olved reacting HCHO with

urea under alkaline conditions for 40 or 80-minutes . The two-stage synthesis allowed the viscosity of the resin to be comparable to PUF resins used in commercial plywood facilities (1,300 to 3,000 mPa·s ); however, the viscosity ofChapter V Page 92

the PUFT resins increased over the 16 to 18 hour pe riod between resin synthesis and chemical analysis. The PUFT resins displayed l ower free-phenol contents than the PUF prepolymers and longer pot-lifes (4 to 7 days) than other tanninmodified adhesive systems that were deemed unsuitab le for use in plywood manufacturing. For the PUF resins, lower free-form aldehyde:phenol ratios were observed in resins with 80-minute stage two reactio n times (Figure V-8). The PUFT resins, containing 5 to 17% tannin by weight, had 40 to 65% lower ratios of free-formaldehyde:phenol than comparable PUF resins . The PUFT resins with the highest tannin concentrations exhibited the low est free-formaldehyde:phenol ratios. Spectral data indicated that the decrease in free-formaldehyde was due to methylolation reactions between Pinus pinasterbark tannin and freeformaldehyde in the resin.

Figure V-8. Mole Ratios of Free Formaldehyde:Pheno l in Phenol-ureaformaldehyde (PUF) and PUF-Tannin Resins 1

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

PUF (1,40) PUFT

(1,40)

17% PUF

(1,80) PUFT

(1,80)

5% PUF (2,40) PUFT

(2,40)

17% PUF

(2,80) PUFT

(2,80)

10%Moles Free-HCHO/mol phenol

(1) Source : Vasquez et al. (2004). The numbers in parentheses are the number of hours and minutes required for stage 1 and stage 2 resin synthesis, respectively. For PUFT resins, the % value is the tannin concentration on a weight basis.

2. Particleboard (PB) Resins

a. Phenol-urea-formaldehyde (PUF) Resins for Low-f ormaldehyde

Particleboard

For the past 40-years, PB manufacturers have primar ily used UF and PF resins.

The use of low-cost UF resins has been dominant for interior applications, while PF resins are principally used to make exterior-gra de products. The development of PUF resins was undertaken as a cost- control approach toChapter V Page 93

improving the durability and reducing HCHO emission s from interior-grade products (Tomita and Hse, 1998).

Zhao et al. (1999) examined the gel times for PF re sins co-reacted with urea (up to 42%) under alkaline conditions, which promotes r eactions between the hydroxyl groups on PF resins and amine groups on ur ea, as shown in the following:

PF–CH 2 OH + NH 2 CONH 2 ↔ PF–CH 2 –NHCONH 2

Tests were conducted on samples of PB prepared in t heir laboratory made with a 9% PF resin solids content. The gel times of the P F resins with different F:P mole ratios and mole percentages of co-reacted urea are displayed in Table V14. These results indicate that at the F:P mole ra tios tested, increasing the amount of urea leads to faster gel times. The decr ease in gel times with urea addition was thought to be due to an increase in mo lecular size of the polymer.

Table V-14. Gel Times (minutes) for Particleboard Made with Phenolformaldehyde (PF) Resins Co-reacted with Urea 1

-------------------- Urea (Mole % of Phenol) ---- ---------------- F:P Mole

Ratio 0 6 12 18 24

1.5 64.9 53.4 46.1 37.2 29.5

1.7 46 35.5 30.2 23.4 21.5

2.5 25.4 23.3 19.5 18.1 18.0

(1) Source : Zhao et al. (1999). Particleboard press temperature = 190 to 195 °C; maximum pressure = 28 kg/cm 2

.

These workers also examined the effects of urea add ition on dry and wet internal bond strength of softwood PB bonded with a PF resin (F:P mole ratio = 1.7) (Table V-15). Their results showed that the dry an d wet internal bond strengths are highest for softwood PB made a PUF resin with 1 2 to 24 mole-percent urea (i.e., dry strength > 1 MPa and wet strength ≥ 0.27 MPa). Spectral data confirmed that the greatest proportion of urea co-r eaction with phenol occurs at 18 mole-percent urea, and that at urea mole-percent ages greater than 12, there is virtually no free-formaldehyde in the PB.Chapter V Page 94

Table V-15. Effect of Urea Addition on Dry and Wet Internal Bond Strengths in Softwood Particleboard Bonded Phenol-formaldehyde ( PF) Resin 1

Resin Dry Internal Bond (MPa) Wet Internal Bond (MP a)

PF Control 0.88 0.20

+ 6% urea 0.91 0.26

+ 12% urea 1.07 0.30

+ 18% urea 1.09 0.31

+ 24% urea 1.12 0.28

+ 30% urea 0.98 0.25

+ 36% urea 0.94 0.24

+ 42% urea 0.96 0.25

(1) Source : Zhao et al. (1999). Wet internal bond strength was measured after the particleboard

was boiled for two-hours and dried. The F:P mole ratio of the PF control resin = 1.7.

The process throughput of PB made with PF resins is typically slower than that for PB made with UF resins, where the fastest press times for PB made with a commercial PF resin is reported to be 12 to 13 s/mm at a press temperature of 190 °C (Zhao et al., 1999). To achieve faster pres s times, manufacturers can either use higher press temperatures or add carbona te accelerators. The effectiveness of glycerol triacetate or triacetin ( Figure V-9) has been tested in

PUF resins as an means to accelerate PUF resin cros slinking and increase the board strength.

Figure V-9. Chemical Structure of Triacetin



### O

O

O O O



### O

Zhao et al. (1999) found that the press time for ha rdwood PB bonded with a PUF resin (i.e., F:P mole ratio = 1.7, urea = 24 mole-p ercent) could be reduced from 21.4 to 8.5 s/mm without decreasing dry or wet int ernal bond strength, by addition of triacetin (Table V-16). The press time s they achieved were comparable to those of a catalyzed UF resin. The h ardwood PB made using an 8.5 s/mm press time, exhibited dry and wet internal bond strengths that wouldChapter V Page 95

readily comply with the European Norm (EN 300, 1996 ) or German DIN standards (DIN 68763) of 0.35 MPa or greater and 0. 15 MPa or greater, respectively. At a 7.1 s/mm press time, dry and we t internal bonds were markedly lower than at 21.4 s/mm, but the resulting dry and wet internal bond strengths would still comply with European and Germ an standards. Similar reductions in press times may also be achieved by r aising press temperatures to 200 to 220 °C without reducing internal bond streng th to levels below the standard(s). Board densities ranged only slightly, from 729 to 753 kg/m 3 , over the range of press times tested.

Table V-16. Effect of Press Time on Dry and Wet In ternal Bond Strength in

Hardwood Particleboard Bonded with a Phenol-urea-fo rmaldehyde (PUF) Resin

with Triacetin 1

Press Time (s) Press Time

(s/mm) Dry Internal

Bond (MPa) Board Density

(kg/m 3 ) Wet Internal

Bond (MPa)

300 21.4 0.85 753 0.23

240 17.1 0.93 758 0.28

180 12.9 0.95 729 0.29

150 10.7 0.95 732 0.30

120 8.5 0.81 751 0.22

100 7.1 0.52 735 0.15

90 6.4 0.49 741 0.11

(1) Source : Zhao et al. (1999). Wet internal bond strength was measured after the PB was boiled for two-hours and dried. Particleboard was bonded with PUF resin with a F:P mole ratio = 1.7; 24 mole-percent urea, and 10% triacetin by weight. “s” = seconds; “s/mm” = seconds per millimeter; “MPa” = megapascals; “kg/m 3 ” = kilograms per cubic meter.

b. Tannin-based Resins for Low-formaldehyde Partic leboard

The effort to decrease or eliminate surface HCHO em issions from PB using tannin-based resins is a work-in-progress. There a re tannin technologies that are viable for commercial use in Australia, New Zea land, Chile, Brazil, Argentina, and South Africa (Frihart, 2005). Interest in usin g tannin-based resins is growing in Japan and Europe. In this regard, tannin autoco ndensation, an environmentalfriendly technology previously described subsection IV.A.3. for HWPW, can also be used for manufacturing PB.

Pizzi et al. (1995) measured the HCHO content of PB made with resin produced by pecan nut ( Carya illinoensis ) tannin autocondensation. Over a range of press times from 10 to 37.5 s/mm, HCHO contents in PB ran ged from 0.01 to 0.03 mg/100 g dry board (by the DIN EN 120 test). These data demonstrate the potential utility of tannin-based resins for produc ing PB with low HCHO contents. To determine if the structural properties of PB mad e with tannin-based resinsChapter V Page 96

were adversely affected, these workers measured the internal bond strength of

PB made with four commercial flavonoid tannin-based resins (i.e., pecan nut ( C.

illinoensis ), pine bark ( Pinus radiata ), mimosa bark ( Acacia mollissima ), and quebracho wood ( Schinopsis balansae )). The 12-mm PB used in the study was made by pressing wood particles with 3% moisture co ntent for 7.5 minutes at

190 o C. Board densities ranged from 680 to 700 kg/m 3 . While the internal bond strengths for PB made with pine and pecan resins we re as high as 0.8 MPa, the values for PB made with mimosa or quebracho resins were 0.3 MPa or less. However, when pecan nut tannin (40% by weight) was added to the mimosa or quebracho resins, internal bond strengths increased by four- to five-fold. The increase in internal bond strength was thought to b e due the presence of more reactive tannin “A-rings” in pecan nut and pine bar k than in mimosa bark or quebracho wood. Press times could also be improved by the addition of finely powdered silica.

In comparison, Kim et al. (2003) measured the mecha nical and physical properties of PB made with two tannin-hexamine resi ns (subsection IV.A.3.). Ttwo other hardeners besides hexamine were tested, but only the results for

hexamine are discussed here. Commercial tannin ext racts from wattle (or mimosa ( Acacia mearnsii )), and radiata pine ( Pinus radiata ) were provided by Bondtite (New South Wales, Australia) and DITECO (P unta Arenas, Chile), respectively. Hexamine (i.e., 6.5, 8, and 10% by w eight of dry tannin extract) was added to each tannin extract. The PB was press ed a temperatures ranging

from 160 to 190 o C for 5-minutes at a pressure of 30 kg/cm 2 , and released in (two) one-minute steps. The 8-mm PB was preconditi oned at 25 °C and 65% relative humidity for two weeks before testing. Th e HCHO contents of the PB were measured by the DIN EN 120 test. Particleboar d produced with either tannin-hexamine resin had very low HCHO content; th e values for wattle and pine were 0.85 and 1.75 mg HCHO/100 g dry board, re spectively. By extrapolation, PB with these DIN EN 120 values woul d have ASTM E1333 values less than 0.03 ppm, which may meet the Japanese F  standard. In comparison, the proposed Phase 2 standard for PB is 0.08 ppm.

Kim et al. (2003) also examined changes in bending (modulus of rupture) and internal bond strength in PB made with the wattle a nd pine tannin-hexamine resins. The two tannins differ with respect to the ir A-ring reactivity, which affect their curing properties. The resin made with wattl e tannin is more of a thermosetting resin, in which functional group cros s-linking increases with press temperature, whereas the resin made with pine tanni n is fast-reacting, and cures at lower press temperatures. As projected, PB mad e with the wattle tanninhexamine resin exhibited a stronger modulus of rupt ure and internal bond strength as press temperature was raised from 160 t o 190 °C, while the responses of PB made with the pine tannin-hexamine resin decreased with increasing press temperature. Overall, PB made wit h either tannin-hexamine resin exhibited strength properties that exceeded t he minimum requirements for Grade M-3 industrial or shelving PB (Table V-17; AN SI, 1999).Chapter V Page 97

Table V-17. Minimum American National Standards In stitute (ANSI) Strength Requirements for Medium (M) Industrial and Shelving Grade Particleboard 1

------------ Minimum Strength Requirement (MPa) - ---------- Grade Modulus of

Rupture Modulus of Elasticity Internal Bond

M1 11.0 1,725 0.40 MS 12.5 1,900 0.40
M2 14.5 2,250 0.45
M3 16.5 2,750 0.55

(1) Source : ANSI (1999). Listed values are those specified for the ANSI A208.1 standard.

In other studies to identify additives that would b oth lower HCHO contents and strengthen the physical properties of PB, Trosa and Pizzi (2001) added a methylolated nitroparaffin (i.e., tris(hydroxymethy l)nitromethane or TN) to a tannin-based resin and produced PB with satisfactor y structural properties for dry internal bond and 2-hour boil test strengths, and l ow HCHO emissions (DIN EN 120 = 0.3 to 0.6 mg/100 g dry board). Ballerini et al. (2005) used a tannin-glyoxal adhesive to produce PB with very low HCHO contents (i.e., DIN EN 120 = 0.6 mg/100 g dry board). Glyoxal is a simple di-aldehy de that has a low toxicity and

can be substituted for HCHO. Either of the above a dditives, TN or glyoxal, could be used to produce PB that would comply with the pr oposed Phase 2 standard (0.08 ppm).

c. Cashew Nut Shell Liquid (CNSL) Resins for Low-f ormaldehyde

Particleboard

Cashew nut shell liquid (CNSL) is a naturally occur ring product that chemically has phenolic nuclei with unsaturated fatty acid cha ins (Figure V-10), and has potential utility as an additive for improving wate r-resistance in PB, and possibly other composite wood products (Pizzi, 2006). Prese ntly, the major source continents of CNSL are South America and Asia; howe ver, there are a number of cashew plantations in Mozambique (Kanji et al., 200 4). At BC (formerly the BioComposites Center, Bangor, Wales), reactive alde hyde monomers were prepared by ozonolysis of CNSL. As an additive to PB resin, the aldehyde monomers react with the aromatic groups of cardanol (i.e., anacardic acid) and produce a phenol/aldehyde crosslinking network. As these monomers are very reactive, self-condensation occurs and no crosslink ing agent needs to be added

to the mixture.Chapter V Page 98

Figure V-10. Chemical Composition of Cashew Nut Sh ell Liquid

O H

R 1

R 2 R 3

C 15 H 31-n R 1 = H or CH 3

R 2 = H or OH

R 3 = H or COOH

Anacardic acid (R 1 = H, R 2 = H, R 3 = COOH)

Cardanol (R 1 = H, R 2 = H, R 3 = H)
Cardol (R 1 = H, R 2 = OH, R 3 = H) Methyl cardol (R 1 = CH 3 , R 2 = OH, R 3 = H)

The CNSL-based resin technology is in early stages of development, thus, it is difficult to evaluate its economical feasibility. However, strength tests of PB made in a laboratory with CNSL-based resins are pro mising (Table V-18). Compared to PB made with PF resin, PB made with a C NSL-based resin had higher lap-shear bond and dry internal bond strengt hs. These findings provide support for the use of CNSL-based resins in PB manu facturing (Pizzi, 2006), but additional information on press time and board dens ity is needed to fully assess its cost-effectiveness in industrial applications.

Table V-18. Strength Responses in Particleboard Ma de with Phenolformaldehyde (PF) and Cashew Shell Nut Liquid (CNSL ) Resins 1

-------------------- Strength (MPa) ------------- ------- Resin Lap-shear Bond Dry Internal Bond Wet Internal Bond

PF Control 5.55 0.69 NR

CNSL 6.77 1.05 0.58

(1) Source : Pizzi (2000). “MPa” = megapascals; “NR” = not reported. Wet internal bond strength was measured after the particleboard was boiled for two-hours and dried.

d. Soy-based Resins

Work continues to develop soy resins that can be us ed to produce PB (Heartland Resource Technologies, Not Dated). Recently, Colum bia Forest Products announced the availability of a PurebondTM PB, which is being used as the platform for its composite core plywood products.Chapter V Page 99

3. Medium Density Fiberboard (MDF) Resins

a. Tannin-based Resins for Low-formaldehyde Medium Density

Fiberboard

Three tannin-based technologies (i.e., hexamine add ition, autocondensation, and methylolated nitroparaffin addition; see subsection IV.A.3.) that have potential utility in the manufacture of HWPW and PB, have als o been found to be applicable to MDF.

Trosa and Pizzi (2001) found that exterior/marine-g rade HWPW, PB, and MDF, with very low HCHO emissions, could be made with a tannin-based resin by adding an inexpensive methylolated nitroparaffin (i .e., tris(hydroxymethyl)- nitromethane or TN). In their study, the addition of TN prolonged the pot-life of the tannin-based resin, and HCHO emissions only occ urred when the wood was heated – at lower temperatures, the resin appeared to depress HCHO emissions originating from wood used to make the boards. Com parison of HCHO content and measures of strength and swell were conducted o n 3-mm MDF made from pine wood fibers in plant trials with either UF or quebracho tannin-based resin (i.e., total tannin solids, TN, and wax emulsion co ntents were 14%, 16%, and 2%, respectively). Relative to the MDF made with UF re sin, the MDF made with the tannin-based resin had a higher bending strength an d lower free-HCHO content (Table V-19), but no differences were observed in c old water swell, board density, or dry internal bond strength. The free-H CHO content of the MDF was low enough to meet the requirement for E0 boards, w hich is lower than the proposed Phase 2 standard for MDF of 0.08 ppm. Sim ilar results were also

obtained for HWPW and PB made with the tannin-based resin. As an additive to tannin-based resins, TN could be added with other H CHO-based resin hardeners (e.g., methylolureas, paraformaldehyde) over a broa d range without loss of

effectiveness.

Table V-19. Density, Swell, Strength, and Formalde hyde Content in Medium Density Fiberboard Made with Urea-formaldehyde (UF) and Quebracho Tanninbased Resins 1

-------------------- Resin -------------------- Parameter Quebracho Tannin UF Control Density (kg/m 3 ) 870 870 Cold Water Swell (20 °C for 24-hours) 14% 14% Bending Strength (MPa) 38 30 Dry Internal Bond Strength (MPa) 1.8 1.8 HCHO Content (mg/100 g dry board) 0.0 0.9

(1) Source : Trosa and Pizzi (2001). “kg/m 3 ” = kilograms per cubic meter; “ o C” = degrees Celsius; “MPa” = megapascals; “mg” = milligrams. Medium density fib erboard (3-mm thickness) press temperature = 180 °C

, press time = 22 s/mm; maximum press pressure = 170 Bar. The quebracho tannin-based resin contained 16% tris(hydroxymethyl)nitromethane and 2% wax emul sion by weight.Chapter V Page 100 b. Phenol-urea-formaldehyde-Tannin (PUFT) Resins f or Lowformaldehyde Medium Density Fiberboard

As the cost of petrochemical-based resin components rise (e.g., phenol), the search for lower cost alternatives is of increasing concern to resin manufacturers. For HWPW and MDF, phenol-urea-formaldehyde-tannin ( PUFT) resins have been tested with promising results, in which increa sing amounts of tannins can be added in place of phenol.

Lopez-Suevos and Riedl (2003) measured the dry and wet internal bond strengths of MDF made with three PUFT resins. The PUFT resins were made by adding 35% Pinus pinaster bark tannin solution to a PUF resin (40% solids content by weight). Three PUFT resins were prepare d: PUFT-10, PUFT-12, and PUFT-15 (the numbers indicate the % tannin content by weight). The MDF was made with 90% black spruce and 10% Douglas-fir fibe rs with an initial moisture content of 3%. Relative to dry or wet internal bon d strength, only MDF made with PUFT-10 had values comparable to MDF made with a PF resin (Table V-20). The MDF made with PUFT-15 or PUFT-12, even when pre ssed for 8.83 minutes, exhibited markedly lower dry and wet internal bond strengths, that may be due to a higher degree of resin condensation (i.e., when l arger resin molecules form, which do not bond as tightly to wood fibers as smal ler molecules). While all of the MDF tested exhibited dry internal bond strength s above the European standard for interior-grade MDF (0.6 MPa; EN 319), only the MDF made with the PF or PUFT-10 resins would comply with the dry and wet internal bond strength standards for exterior-grade MDF (0.8 and 0.15 MPa, respectively). The PUFT10 resin, which has a 44% phenol replacement by tan nins, could conceivably be a cost-competitive resin for MDF, which may also ha ve a low HCHO content.

Table V-20. Dry and Wet Internal Bond Strengths of Medium Density Fiberboard Made with Phenol-formaldehyde (PF) and Phenol-urea- formaldehyde-tannin (PUFT) Resins 1

--------------- Strength (MPa) --------------- Resin (Press Time) Density (kg/m 3 ) Dry Internal Bond Wet Internal Bond PF Control (5.33 min) 727 1.18 0.58 PUFT-15 (5.33 min) 771 0.74 0.09 PUFT-15 (6.83 min) 706 0.62 0.07 PUFT-15 (8.83 min) 710 0.68 0.08 PUFT-12 (5.33 min) 734 0.72 0.13 PUFT-10 (5.33 min) 732 1.10 0.20 PUFT-10 (8.83 min) 728 1.42 0.44

(1) Source : Lopez-Suevos and Riedl (2003). “MPa” = megapascals; “kg/m 3 ” = kilograms per cubic meter. Medium density fiberboard press temperature = 215 oC.Chapter V Page 101

E. Technical Basis for the Proposed Emission Stand ards

1. Proposed Emission Standards for Hardwood Plywoo d

Appendix A contains the regulation order for the pr oposed ATCM. For HWPW, made with a veneer core (HWPW-VC) or with a composi te core (HWPW-CC), the numerical values of the proposed Phase 1 and 2 HCHO emission standards are based on analyses of manufacturer responses to the CARB 2003 Survey, data supplied by the Hardwood Plywood & Veneer Associati on (HPVA), reports or articles in the open literature, commercial brochur es, and other published materials or websites, and stakeholder meetings, co ncerning resin technologies that are either commercially available or laborator y tested to display low or nearzero HCHO emissions. The proposed standards and ef fective dates for HWPWVC and HWPW-CC are shown in Table V-21.

Table V-21. Proposed Phase 1 (P1) and Phase 2 (P2) Formaldehyde (HCHO) Emission Standards for Hardwood Plywood 1

HCHO Emission Standard Effective Date HWPW-VC HWPW-CC January 1, 2009 P1: 0.08 ppm ----- July 1, 2009 ----- P1: 0.08 ppm January 1, 2011 P2: 0.05 ppm ----- July 1, 2012 ----- P2: 0.05 ppm

(1) “ppm” = parts per million; “HWPW-VC” = hardwood plywood with a veneer core; “HWPW-CC” = hardwood plywood with a composite core. Compliance with the HCHO Emission Standards is demonstrated by producing HWPW-VC and HWPW-CC with an ASTM E1333 test value less than or equal to the listed P1 or P2 HCHO concentration in ppm.

From the CARB 2003 Survey, approximately 20% of the HWPW-VC or HWPWCC produced for sale in 2002 achieved, on average, an ASTM E1333 test value that would meet the proposed Phase 1 standard of 0. 08 ppm. However, as the survey respondents did not distinguish if the infor mation they provided was for decorative wall panels or industrial panels, indust ry representatives are concerned that the above estimate may not be accura te. Note that the survey

was conducted before Columbia Forest Products switc hed to using PurebondTM

and now about 40% of the HWPW in the U.S. meets the Phase 2 standard. In the ASTM E1333 test, decorative wall panels are tes ted at a higher loading rate (0.29 ft 2 /ft 3 ) than industrial panels (0.13 ft 2 /ft 3 ). Thus, unless it can be determined which type of HWPW-VC or HWPW-CC was measured, an a ccurate analysis of industrial panel emissions cannot be made with cert ainty. From the survey, all of

the HWPW-VC or HWPW-CC that achieved an ASTM E1333 value of 0.08 ppmChapter V Page 102

was made with an ammonia-UF (AUF) resin with added catalysts or hardeners to

reduce surface HCHO emissions. These AUF resins we re reported to have high F:U mole F:U ratios ranging from 1.7 to 1.98. Abse nt clear information regarding the need to develop a new standard for decorative w all panels, no change is proposed with respect to the loading rates presentl y used for ASTM E1333 testing.

To produce HWPW-VC or HWPW-CC that would meet the p roposed Phase 1 emission standard (a 0.08 ppm cap), manufacturers t hat choose to use UF resins could use resins with lower F:U mole ratios (e.g., 1.05 to 1.20; Baumann, 1997) to lower their emissions below their present ASTM E 1333 levels. Further reductions could be achieved through the use of add itives such as ammonium chloride or hexamine, which act as hardeners or cat alysts, in amounts ranging from 1 to 4% by weight. The combined use of a lowe r F:U mole ratio resin and

addition of hardeners should enable manufacturers t o produce HWPW-VC or HWPW-CC that complies with the proposed Phase 1 sta ndard. However, as none of the reported HWPW-VC or HWPW-CC was able to comply, on average, with the proposed Phase 2 standard (a 0.05 ppm cap) , manufacturers may need to utilize a reformulated resin system or another r esin system than UF. While laboratory studies indicate that reductions in HCHO emissions can be achieved by the addition of melamine and/or MDI, it will be up to manufacturers to

determine how best to manufacture HWPW-VC or HWPW-C C that meets the proposed Phase 2 standard.

From analysis of the data provided by the Hardwood Plywood & Veneer Association, the issue of whether to establish sepa rate HCHO emission

standards for HWPW-VC and HWPW-CC was clarified. P reviously, stakeholders requested that CARB staff consider setting separate standards because the core material in HWPW-CC was typically either PB or MDF, which has higher allowable emissions than HWPW. In calculating mean ASTM E1333 values for HWPW-VC and HWPW-CC from the data provided by the H PVA, the means for HWPW-VC and HWPW-CC were 0.12 ppm (n = 14) and 0.08 ppm (n = 5), respectively (Tables V-4 and V-5). Moreover, the r ange in ASTM E1333 values for HWPW-VC was 0.08 to 0.19 ppm vs. 0.05 to 0.10 p pm for HWPW-CC. As this was counterintuitive to the justification offe red by stakeholders from the HWPW industry for separate standards, the numerical values of the proposed Phase 1 and Phase 2 standards, which apply to HWPW- VC and HWPW-CC, are the same. Additional time is provided for HWPW-CC to allow for the availability and use of lower emitting core materials.

In evaluating BACT for HWPW, an internet search unc overed products from three U.S. sources, either HWPW panels or resin use d to manufacture HWPW, that could be used immediately to produce HWPW that complies with the proposed Phase 2 standard (Table V-22).Chapter V Page 103

Table V-22. Low-formaldehyde Hardwood Plywood (HWP W) or HWPW-Resins 1

Product Company HCHO Emissions Resin System

Purebond TM Columbia Forest Products Near-zero Soy-based

Multibond ®

Franklin Adhesives Near-zero PVA

Purekor

® Collins Pine Company Near-zero MDI

(1) “Near-zero” emissions indicates measured ASTM E1333 test values = 0.03 ppm or less.

From the literature and stakeholder discussions, th ere are resins that have the potential to be used to manufacture HWPW to meet th e proposed Phase 1 and Phase 2 standards, such as soy-based, PVA, MUF, PUF , PUF-tannin, and several MDI hybrid systems, and the resin preparati on and application methods are well documented. As such, staff proposes that the numerical value of the Phase 1 standard for HWPW, regardless of core compo sition, be a cap of 0.08 ppm measured by the ASTM E1333 test, with effective dates of January 1, 2009 for HWPW-VC and July 1, 2009 for HWPW-CC. For Phas e 2, the proposed standard would be a cap of 0.05 ppm measured by the ASTM E1333 test, regardless of core composition, with effective date s of January 1, 2011 for HWPW-VC and July 1, 2012 for HWPW-CC.

For Phase 2, careful consideration was given to the absolute value of the proposed standard, requirements of the present ASTM E1333 test and the potential for higher emitting products in core mate rials (e.g., PB or MDF) to raise

measured HCHO concentrations in the ASTM E1333 test

.

2. Proposed Emission Standards for Particleboard

As for HWPW, the numerical values for the proposed Phase 1 and Phase 2 HCHO emission standards are also based on analyses of the CARB 2003 Survey. In addition, a review of the literature an d expert opinions provided by industry and stakeholders on the range of resin and wood preparation technologies that could be used to manufacture PB w ith low to near-zero surface HCHO emissions were considered. The proposed stand ards and effective dates

for PB are shown in Table V-23.Chapter V Page 104 Table V-23. Proposed Phase 1 (P1) and 2 (P2) Emiss ion

Standards for Particleboard 1

Effective Date HCHO Emission Standard January 1, 2009 P1: 0.18 ppm January 1, 2011 P2: 0.09 ppm

(1) “ppm” = parts per million. Compliance with the HCHO Emission Standards is demonstrated by producing particleboard with an ASTM E1333 test value less than or equal to the listed P1 or P2 HCHO concentration in ppm.

Analysis of the CARB 2003 Survey data for PB found that approximately 55% of the PB produced in 2002, on average, would comply w ith the proposed Phase 1 standard of 0.18 ppm. The predominant resins used were UF or methanol-UF resins, and PB manufacturers that reported the lowe st average ASTM E1333 values (i.e., less than 0.18 ppm) achieved those le vels by adding low mole ratio urea solutions (which act as a HCHO scavenger) and/ or a variety of catalysts, such as ammonium sulfate, sodium chloride, and sodi um sulfate.

Table V-24. Low-formaldehyde Particleboard (PB) an d PB-Resin Systems 1

Product Company ASTM E1333

Value Resin Chemistry

Low-formaldehyde Particleboard

Purekor

® Collins Pine Near-zero MDI Skyblend ®

Roseburg < 0.01 ppm PF

Low-formaldehyde Particleboard Resin Systems

Ecobind ®

Hexion ≤ 0.03 ppm MUF + Co-reactants

PF Soy/PVA blend

Kenocatch ®

Akzo Nobel ≤ 0.03 ppm MUF + catcher

Rubinate ®

Huntsman Near-zero Polyurethane

(1) “MDI” = methylene diisocyanate; “PF” = phenol-formaldehyde; “MUF” = melamine-ureaformaldehyde; “PVA” = polyvinyl acetate; “ppm” = parts per million. “Near-zero” refers to an extrapolated ASTM E1333 value less than 0.03 ppm.

No manufacturer reported producing PB with an avera ge ASTM E1333 value that would meet the proposed Phase 2 standard of 0.09 pp m, although after an internet search, a short-list of commercially avail able low-formaldehyde PB orChapter V Page 105

resins used to manufacture PB was developed (Table V-24). Both PB products are made for niche markets (e.g., Green Building Pr ograms) that specify the use of low- or no added HCHO materials. These resin sy stems, if used in combination with additives or low-formaldehyde resi ns developed outside the U.S., may potentially be used meet the proposed Pha se 2 standard.

3. Proposed Emission Standards for Medium Density Fiberboard

As for HWPW and PB, analysis of the data from the C ARB 2003 Survey, information in the open literature and expert opini ons on low- and no added HCHO resin technologies, were the main data conside red with respect to selecting the numerical values of the proposed Phas e 1 and 2 emission standards for MDF. The proposed standards and thei r effective dates are shown

in Table V-25 for MDF.

Table V-25. Proposed Phase 1 (P1) and Phase 2 (P2) Standards for

Medium Density Fiberboard 1

Effective Date HCHO Emission Standard January 1, 2009 P1: 0.21 ppm January 1, 2011 P2: 0.11 ppm

(1) “ppm” = parts per million. Compliance with the HCHO Emission Standards is demonstrated by producing MDF with an ASTM E1333-96 test value less than or equal to the listed P1 or P2 HCHO concentration in ppm. (2) Thin MDF Phase 1 standard is 0.21 ppm (January 1, 2009), and Phase 2 standard is 0.13 ppm (January 1, 2012)

From the CARB 2003 Survey, approximately 25% of MDF reported for sale in 2002, on average, would comply with the proposed Ph ase 1 standard (0.21 ppm). All of the manufacturers that reported produ cing MDF at an average ASTM E1333-96 of 0.21 ppm or less made their produc ts with a UF resin. In our view, MDF manufacturers would be able to consistent ly meet the Phase 1 standard by using low mole ratio urea solutions (wh ich act as a scavenger), and/or a variety of catalysts, such as melamine, am monium sulfate, sodium chloride, and sodium sulfate, or proprietary scaven gers. Making MDF with a MDI resin would also be a viable approach for meeting t he Phase 1 and 2 standards, but at present, MDI use is typically limited to the production of products for niche applications (e.g., hospitals). These resin system s are just a few of the ways that MDF manufacturers could meet the proposed Phase 2 s tandard (0.11 ppm cap) (Table V-26).Chapter V Page 106

Table V-26. Available Low-formaldehyde Medium Dens ity Fiberboard (MDF) or

MDF-resins 1

Product Company HCHO

Emissions Resin Chemistry

Low-formaldehyde Medium Density Fiberboard

• Arreis ®

• Medite II ®

• Medex

® Sierra Pine ≤ 0.05 ppm MDI

Purekor

® Collins Pine Near-zero MDI

Low-formaldehyde MDF-resins

Ecobind ®

Hexion ≤ 0.03 • MUF + Coreactants

• PF

• Soy/PVA Blend

Kenocatch ®

Akzo Nobel ≤ 0.03 MUF + Catcher

Rubinate ®

Huntsman Near-zero Polyurethane

(1) “MDI” = methylene diisocyanate; “PF” = phenol-formaldehyde; “MUF” = melamine-ureaformaldehyde; “PVA” = polyvinyl acetate; “ppm” = parts per million. “Near-zero” refers to an extrapolated ASTM E1333 value less than 0.03 ppm.

4. Thin Medium Density Fiberboard (MDF) (Thickness ≤ 8-mm)

“Thin MDF” is defined as MDF with thicknesses of 8 mm ( ≈ 5 / 16 inch) or less. While the amount of thin MDF production is not know n with certainty, to our knowledge, it represents a small percentage of tota l MDF production in the U.S. Thin MDF, at thicknesses starting at 1.8 mm, is bei ng manufactured and used as a substitute for hardboard and thin plywood due to its being smooth on both surfaces and free from the grain features of plywoo d substrates (European Panel Federation, Not Dated). Fabricators use these mate rials in furniture (e.g., drawer bottoms, cabinet backs, and center panels in framed doors) and as wall and ceiling panels, skins in flush doors, partitioning, lightweight doors, and exhibition paneling for inside-building applications (e.g., of fices, reception areas, classrooms, and exhibition displays).

From CARB’s 2003 Survey, only two MDF manufacturers listed thin MDF as a product that they offer for sale. One manufacturer reported ASTM E1333 values ranging from 0.17 to 2.5 ppm for MDF ranging in thi ckness from 8 mm to 5⁄8 ”; however, none of the reported ASTM E1333 values cou ld be specifically assigned to thin MDF. The second manufacturer repo rted ASTM E1333 valuesChapter V Page 107

ranging from 0.20 to 0.37 ppm for their thin MDF ma de with a UF resin (exact thickness was not provided). A web-search for manu facturers of thin MDF found

Fibrex

® manufactured by Flakeboard Company Limited (Flakeb oard, 2005), which is described as a high density, thin MDF. As the average ASTM E1333 values for this product were reported to be less th an 0.2 ppm, it would presently comply with the proposed Phase 1 standard for MDF ( i.e., 0.21 ppm). From the Composite Panel Association (CPA) website (CPA, 200 6), one other manufacturer indicated the availability of thin MDF , that presumably complies with the HUD standard (0.3 ppm).

Recently, a U.S. manufacturer reported that the thi n MDF they produce exhibited ASTM E1333 values of 0.7 ppm or higher, consistent with one of the manufacturers that responded to the CARB 2003 Surve y. As such, they contend that it is unlikely that thin MDF can be made to co mply with the proposed Phase 1 (0.21 ppm) and Phase 2 standards (0.11 ppm), and consideration be given to setting a separate standard for MDF of thicknesses less than 8 mm. While the specific application for the 0.7 ppm product is not known, given the existence of

Flakeboard’s Fibrex ® and the prospects for a full range of no added ure aformaldehyde MDF products from CalAg (Sustainable D esign Resources, 2003), there is a reasonable basis for projecting that thi n MDF could be manufactured to comply with the proposed Phase 1 standard of 0.21 p pm for thin MDF in January 2009 and the proposed Phase 2 standard of 0.13 ppm in January 2012.

5. ASTM E1333 Background Concentration

The large chamber test method (ASTM E1333) is the i ndustry recognized test method for measuring surface emissions of HCHO from composite wood products in the U.S. In the ASTM E1333 test, board s are pre-conditioned for approximately seven days in a controlled chamber pr ior to emission testing. The test chamber is purged of HCHO by running tests wit hout boards or with the use of filters designed to lower the background HCHO co ncentration in air, or both. To run an emission test, the test material is place d inside the conditioned chamber at 25 °C, 50% relative humidity, and an air exchange of 0.5/hr. The sample remains in the chamber for 16 to 20 hours pr ior to measuring the HCHO

concentration of the air in the chamber. In consid eration of the proposed numerical values of the Phase 2 standards, manufact urers will likely need to ensure the use of intake air with very low HCHO lev els and use the DNPH method to accurately measure HCHO levels in quality control testing.

6. Technical Basis for Consumer Products

Health & Safety Code §41712 requires all consumer p roduct regulations adopted by the Board to be technologically and commercially feasible. Also, 1996 revisions to H&SC §41712 added a constraint that co nsumer product regulations not eliminate a product form. These statutory crit eria were followed in setting the proposed limits for PB and MDF. As discussed in Ch apter 1, PB and MDF meet the statutory definition of a “consumer product” un der H&SC §41712.Chapter V Page 108

For PB and MDF, there are products already on the m arket that would comply with the proposed Phase 1 and Phase 2 standards. I n this regard, the proposed

emission standards for PB and MDF are considered to be technologically feasible as the limit is already being met by at le ast one product designated as PB or MDF, and that the limit can reasonably be exp ected to be met in the time frame provided in the proposed ATCM through additio nal development efforts.

In setting the proposed limits for PB and MDF, staf f made an effort, wherever possible, to ensure that multiple resin technologie s exist or are anticipated to exist through additional development efforts, which would allow products to comply by the proposed effective dates.

The term “commercially feasible” is not defined in State law. In interpreting this term, staff has utilized the reasoning employed by the U.S. Court of Appeals for the District of Columbia in interpreting the federa l Clean Air Act. In the leading case of International Harvester Company v. Ruckelsh aus , (D.C. Cir. 1973) 478 F. 2d 615, the Court held that the USEPA could promulg ate technology-forcing motor vehicle emission limits which might result in fewer models and more limited choice of engine types for consumers so long as as the basic market demand for new passenger automobiles could be generally met.

Following this reasoning, staff has concluded that a regulation is “commercially feasible” as long as the “basic market demand” for a particular consumer product can be met. “Basic market demand” is the underlyin g need of consumers for a product to fulfill a basic, necessary function. Ap plying this reasoning to the proposed Phase 2 standards for PB and MDF allows fo r the basic market demand to be met for each product.

In meeting the criteria for technological and comme rcial feasibility, we believe that the proposed standards for PB and MDF meet the requirements of H&SC §41712.

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### VI. Proposed Airborne Toxic Control Measure (ATCM)

This chapter describes the proposed ATCM and its ba sis, including a discussion of alternatives to the proposed ATCM. The staff’s proposed regulation order is found in Appendix A.

A. Summary of the Proposed Airborne Toxic Control Measure (ATCM)

The proposed ATCM would reduce HCHO emissions from HWPW, PB, MDF, and finished goods containing those materials, that are sold, offered for sale, supplied, used, or manufactured for sale in Califor nia. This would be achieved by requiring manufacturers for the HWPW, PB, and MD F products they produce for use in California, to meet new stringent HCHO e mission standards introduced in two phases. The measure applies not only to man ufacturers, but also to distributors, importers, fabricators, and retailers that sell or supply HWPW, PB, or MDF, or finished goods containing those materials, for use in California. The proposed ATCM does not apply to composite wood prod ucts and finished goods that are manufactured or sold for shipment and use outside of California.

The proposed ATCM also does not apply to PB and HWP W installed in manufactured homes used as dwelling units. Formald ehyde emission standards for PB and plywood installed in manufactured homes have been promulgated by the U.S. Department of Housing and Urban Developmen t (24 Code of Federal Regulations section 3280 et seq., section 3280.308) . Federal law generally preempts State and local regulations regarding cons truction and safety standards for manufactured homes, such as the formaldehyde st andards specified in the HUD regulations (see 42 U.S. C.A section 94503(d)). To comply with federal law, the proposed ATCM exempts products covered by the HUD regulations. The HUD regulations do not apply to plywood and par ticleboard used in applications other than manufactured homes (e.g., r esidential and office buildings, furniture, etc.) and finished products m ade with these materials. The HUD regulations also do not apply to MDF used in ma nufactured homes, which would be covered by the proposed ATCM.

Furthermore, the proposed ATCM would not apply to a rchitectural plywood, military specification plywood used in airplane con struction, or composite wood products used in motor vehicles. Military plywood and composite wood use in motor vehicles is very limited and inclusion in the regulation would create difficult compliance issues for these mobile sources. Finall y, the proposed ATCM also exempts finished windows containing less than five volume percent of HWPW,

PB or MDF combined in relation to the total volume of the finished window product.

On January 1, 2009, the proposed ATCM establishes a suite of new emission standards that would take effect, beginning with th e Phase 1 (P1) emission standards for HWPW made with a veneer core (HWPW-VC ), PB, MDF, and thinChapter VI Page 117

MDF (Table VI-1). Subsequently, on July 1, 2009, t he remaining P1 standard for HWPW made with a composite core (HWPW-CC) would bec ome effective. The Phase 2 (P2) standards for HWPW-VC, PB, MDF, thin M DF, and HWPW-CC become effective in the 2011-2012 timeframe, as spe cified in the following table.

Table VI-1. Proposed Phase 1 and Phase 2 Standards for Hardwood Plywood (HWPW), Particleboard (PB), and Medium Density Fibe rboard (MDF) 1 Error!

Bookmark not defined.

-------------------- ASTM E1333-96 Value (ppm) -- ------------------ Effective Date HWPW-VC HWPW-CC PB MDF tMDF January 2009 P1: 0.08 ----- P1: 0.18 P1: 0.21 P1: 0 .21 July 2009 ----- P1: 0.08 ----- ----- ----- January 2011 P2: 0.05 ----- P2: 0.09 P2: 0.11 ---- - January 2012 ----- ----- ----- ----- P2: 0.13 July 2012 ----- P2: 0.05 ----- ----- -----

(1) Abbreviations: P1 = Phase 1, P2 = Phase 2, HWPW-VC = HWPW with a veneer core, HWPWCC = HWPW with a composite core, PB = particleboard, MDF = medium density fiberboard;

tMDF = thin MDF.

Finally, the proposed ATCM contains “sell-through” provisions that allow noncomplying products manufactured before the effec tive dates of the Phase 1

and Phase 2 emission standards to be sold for certa in specified time periods after these effective dates. Differing sell-throug h periods apply depending on whether the product is sold by a manufacturer, dist ributor, importer, fabricator, or retailer. All of the sell-through provisions of th e ATCM are contained in Appendix 1 of section 93120.12.

1. Section 93120.3- Requirements for Manufacturers of Composite

Wood Products

The requirements for manufacturers are contained in section 93120.3 and Appendix 2 of section 93120.12. In general, manufa cturers of HWPW-VC, HWPW-CC, PB, MDF, or thin MDF, whether foreign or d omestic, would be required to:

• Meet the applicable emission standards;

• Provide independent verification of the emissions performance of the composite wood product they manufacture;

• Have quality assurance programs;

• Comply with labeling and recordkeeping requirement s.

To independently verify the emissions performance o f their composite wood products, manufacturers using formaldehyde based re sin systems would beChapter VI Page 118

required to be monitored by independent groups know n as “third party certifiers.” Manufacturers would work with third party certifier s to initiate quality control and emission testing programs in order to demonstrate o ngoing compliance with the applicable emission standards in Table VI-1. All t esting will be correlated to product emission tests using the “large chamber tes t method,” hereafter referred

to as ASTM E1333-96.

Under the provisions of section 93120.12, Appendix 2, manufacturers would also be required to develop and follow a quality assuran ce program. Basic elements of the quality assurance program include developmen t of a quality control manual, verification of quality control personnel, establishment of a correlation between the manufacturing plant test method and AST M E1333-96, and ongoing quarterly emissions correlation verification testin g. In addition, Appendix 2 also provides guidance on the disposition of manufacture d panels that do not meet the regulatory emission standards.

Generally speaking, the proposed regulation primari ly affects composite wood products made with formaldehyde based resin systems . As mentioned throughout this staff report, however, several exam ples exist today of alternative resin systems that contain no added formaldehyde an d result in only de minimus formaldehyde emissions from composite wood products . Therefore, under section 93120.3(b) manufacturers using these resins would be allowed to follow an alternative compliance option that does not requ ire third party certification.

To qualify for the “no added formaldehyde resin” co mpliance option, manufacturers must apply to and obtain written appr oval from CARB. The application must contain the resin chemical formula tion, a demonstration of the emissions performance of the candidate “no added fo rmaldehyde” resin system,

and a statement to indicate the manufacturer’s inte nt to use the candidate resin exclusively in the manufacturing of identified prod ucts. Upon approval, CARB will notify the manufacturer in writing. CARB appr oval would exempt the manufacturer only from the third party certificatio n requirements of the proposed ATCM; all other ATCM requirements would still apply

.

Because composite wood panels are a commonly traded commodity, there are many potential distribution routes within commerce. So, to facilitate enforcement of the emission standards the proposed ATCM require s all manufacturers that supply products for sale or use in California to la bel these products in a manner that clearly identifies their third party certifier , the name of their company, product lot number or batch produced, and a marking to deno te that the product meets the applicable Phase 1 or Phase 2 emission standard . Manufacturers are also required to maintain records for two years so compo site wood products can be traced back to individual manufacturers and to spec ific emissions performance tests under third party certification program.Chapter VI Page 119

Because manufacturers are the only group who can de termine the formaldehyde levels in composite wood products, it is vital that downstream customers have some way of knowing whether the products they purch ase are legal to sell in California. Therefore, the proposed ATCM specifie s the information that must be passed from manufacturers to downstream customer s. In addition to the labeling requirements discussed above, manufacturer s are required to state on the product bill of lading or invoice that the prod uct complies with the applicable

Phase 1 or Phase 2 emission standard. Manufacturer s are also required to maintain specified records at their production faci lities. These records will allow individual panels sold in commerce to be traced bac k to specific lot or batch of product that was manufactured.

The proposed ATCM allows a one-month sell-through p eriod for noncomplying products manufactured before the effective dates of the Phase 1 and Phase 2 standards. The specific sell-through dates for manu facturers are set forth in the following table (Table VI-2):

Table VI-2. Schedule of Composite Wood Product Sell -through for

Manufacturers 1

Event HWPWVC HWPWCC PB MDF tMDF

Effective Date: P1 Jan ‘09 Jul ‘09 Jan ’09 Jan ’09 Jan ’09 Date When Only P1

Products Can Be Sold Feb ‘09 Aug ‘09 Feb ‘09 Feb ‘09 Feb ‘09

Effective Date: P2 Jan ‘11 Jul ‘12 Jan ‘11 Jan ‘11 Jan ‘12 Date When Only P2

Products Can Be Sold Feb ‘11 Aug ‘12 Feb ‘11 Feb ‘11 Feb ‘12

(1) All effective dates begin on the 1 st day of the specified month-year. Manufacturers have a onemonth sell-through period following the effective date of the applicable P1 or P2 standard.Abbreviations: P1 = Phase 1, P2 = Phase 2, HWPW-VC = HWPW with a veneer core, HWPWCC = HWPW with a composite core, PB = particleboard, MDF = medium density fiberboard,

tMDF = thin MDF.

Relative to enforcement, section 93120.3(f) notifie s manufacturers that they may be inspected by CARB or local air district personne l (as well as third party certifiers as specified in Appendices 2 and 3 of se ction 93120.12). Inspections would be focused on facility inspections, auditing of records, and securing of samples for enforcement testing.Chapter VI Page 120

2. Section 93120.4- Requirements for Third Party C ertifiers

Third party certifiers have an important role in en suring that manufacturers of composite wood products can demonstrate that their production facilities are producing products that comply with the applicable emission standards in Table VI-1. Requirements for third party certifier s are contained in section 93120.12, Appendix 3. The application process to b ecome an ARB-approved third party certifier is specified in section 93120 .4.

The proposed ATCM requires routine quality assuranc e emissions testing by manufacturers of newly produced composite wood prod ucts. The quality assurance manufacturing testing program is develope d in collaboration with, and is independently validated by, third party certifie rs. All third party certifiers are required to be approved by CARB as provided in sect ion 93120.4.

To be approved as a third party certifier, an organ ization must submit an application in writing to the Executive Officer for approval. Applicants must demonstrate that they have actual field experience in the certification of laboratories and wood products, have the ability to train and supervise inspectors, possess product inspection agency certi fication, and large chamber ASTM E1333-96 certification by the International Ac creditation Service or by another signatory to the International Laboratory A ccreditation Cooperation Mutual Recognition Arrangement, and must list which products they are qualified to certify. If the criteria specified in the ATCM are met, the Executive Officer will issue an executive order approving them as an third party certifier. The Executive Officer will also assign an identifying n umber to each third party certifier. As described previously, manufacturers will display this number on each panel or bundle of composite wood products.

The proposed ATCM requires third party certifiers t o take part in quarterly

validation of correlations between manufacturers’ s mall scale testing and the ASTM E1333-96 large chamber. All large chambers mu st be certified by the International Accreditation Service, Inc., or by an other signatory to the International Laboratory Accreditation Cooperation Mutual Recognition Arrangement. Third party certifiers must also cond uct periodic inspections of manufacturing facilities and maintain records for t wo years, including a list of manufacturers certified by the third party certifie r, results of inspection audits, and proof of certification for ASTM E1333-96 large chambers used.

Third party certifiers are also subject to enforcem ent audits by CARB. Executive orders granted to third party certifiers will conta in conditions allowing CARB to verify that third party certifiers are complying wi th all regulatory requirements. A provision is also included whereby the Executive Of ficer may review and, for good cause, modify or revoke an executive order app roving a third party certifier. In order to provide due process protections, an exe cutive order cannot beChapter VI Page 121

modified or revoked unless the third party certifie r is first provided an opportunity for a hearing.

3. Section 93120.5- Requirements for Distributors

Distributors are the “goods movers” within the mark etplace supply chain. The proposed ATCM requires that all products and finish ed goods sold by distributors must comply with the applicable emission standards. The proposed ATCM also requires that distributors must take reasonable pru dent precautions to ensure that the composite wood products and finished goods they acquire are in compliance with the applicable emission standards i n Table VI-1. To accomplish this, distributors would need to establish a procur ement policy that requires them to obtain and keep a record of written documentatio n from their suppliers that the products they acquire meet the applicable emission standards. Records must be kept for a minimum of two years for enforcement pur poses.

Typically distributors only sell products in commer ce and do not modify the products they sell. But, if a distributor modifies the composite wood products or finished goods that they acquire, then the regulati on requires distributors to follow the labeling and sell-through requirements for fabr icators (see section VI.A.5).

Under section 93120.5(d), distributors are also req uired to provide a written statement on the bill of lading or invoice that sta tes that the composite wood product or finished goods they sell meet the emissi on standards.

Because distributors may purchase HWPW-VC, HWPW-CC, PB, MDF or tMDF panels from manufacturers during the sell-through p eriods in Table VI-2, an additional period of time is provided to distributo rs to sell-through products that do not comply with the new standards. In total, d istributors would have a sellthrough period of five-months after the effective d ate of the applicable Phase 1 or Phase 2 standards in Table VI-1 (see Table VI-3). The sell-through period for finished goods would be the same as that for compos ite wood products.

Table VI-3. Schedule of Composite Wood Product Sell -through for Distributors 1

Event HWPWVC HWPWCC PB MDF tMDF

Effective Date: P1 Jan ‘09 Jul ‘09 Jan ‘09 Jan ‘09 Jan ‘09 Date When Only P1

Products Can Be Sold Jun ‘09 Dec ‘09 Jun ‘09 Jun ‘09 Jun ‘09

Effective Date: P2 Jan ‘11 Jul ‘12 Jan ‘11 Jan ‘11 Jan ‘12 Date When Only P2

Products Can Be Sold Jun ‘11 Dec ‘12 Jun ‘11 Jun ‘11 Jun ‘12

(1) All effective dates begin on the 1 st day of the specified month-year. Distributors hav e a five-month sellthrough period following the effective date of the applicable P1 or P2 standard. Abbreviations: P1 = Phase 1, P2 = Phase 2, HWPW-VC = HWPW with a veneer core, HWPW-CC = HWPW with a composite core, PB = particleboard, MDF = medium density fiberboard , tMDF = thin MDF.Chapter VI Page 122

Regarding enforcement, section 93120.5(e) notifies distributors that they may be inspected by CARB or local air district personnel. Inspections would be focused on facility inspections, auditing of records, and s ecuring of samples for enforcement testing.

4. Section 93120.6- Requirements for Importers

The proposed ATCM requires that all products and fi nished goods sold by importers must comply with the applicable emission standards. The proposed ATCM also requires that importers must take reasona ble prudent precautions to ensure that the composite wood products and finishe d goods they acquire are in compliance with the applicable emission standards i n Table VI-1. To accomplish this, importers would need to establish a procureme nt policy that requires them to obtain and keep a record of written documentatio n from their suppliers that the products they acquire meet the applicable emission standards. Records must be kept for a minimum of two years for enforcement pur poses.

Typically, importers do not modify goods they marke t, so for unmodified composite wood products or finished goods, no addit ional labeling would be required on the part of importers. However, if an importer modifies the composite wood products or finished goods that they purchase, they would subject to the labeling and sell-through requirements for fabricat ors (see section VI.A.5).

Under section 93120.6(d), importers are also requir ed to provide a written statement on the bill of lading or invoice that sta tes that the composite wood product or composite wood products contained in fin ished goods comply with the

emission standards in Table VI-1.

Because importers may purchase HWPW-VC, HWPW-CC, PB , MDF, or tMDF panels and finished goods from an overseas manufact urer during the sellthrough periods allowed for manufacturers, an addit ional period of time is provided to importers to sell-through products that do not comply with the new standards. In total, importers would have a sell- through period of five months (the same as distributors) after the effective date of the applicable Phase 1 or Phase 2 standards in Table VI-1 (see Table VI-3). The sell-through period for finished goods would be the same as that for compos ite wood products.Chapter VI Page 123

Table VI-4. Schedule of Composite Wood Product Sell -through for Importers 1

Event HWPWVC HWPWCC PB MDF tMDF

Effective Date: P1 Jan ‘09 Jul ‘09 Jan ‘09 Jan ‘09 Jan ‘09 Date When Only P1

Products Can Be Sold Jun ‘09 Dec ‘09 Jun ‘09 Jun ‘09 Jun ‘09

Effective Date: P2 Jan ‘11 Jul ‘12 Jan ‘11 Jan ‘11 Jan ‘12 Date When Only P2

Products Can Be Sold Jun ‘11 Dec ‘12 Jun ‘11 Jun ‘11 Jun ‘12

(1) All effective dates begin on the 1 st day of the specified month-year. Importers have a fivemonth sell-through period following the effective date of the applicable P1 or P2 standard.Abbreviations: P1 = Phase 1, P2 = Phase 2, HWPW-VC = HWPW with a veneer core, HWPWCC = HWPW with a composite core, PB = particleboard, MDF = medium density fiberboard,

tMDF = thin MDF.

Regarding enforcement, section 93120.6(e) notifies importers that they may be inspected by CARB or local air district personnel. Inspections would be focused on facility inspections, auditing of records, and s ecuring of samples for enforcement testing.

5. Section 93120.7- Requirements for Fabricators

The proposed ATCM defines “fabricator” as any perso n that uses composite wood products to make finished goods. Examples of fabricators are companies that use composite wood panels to produce furniture or cabinets. While such companies might be referred to as “manufacturers” i n ordinary conversation, they are not “manufacturers” under the ATCM. The propos ed ATCM uses the term “manufacturer” to refer only to persons who manufac turer or produce the actual composite wood products (i.e., HWPW, PB or MDF), as opposed to persons who use panels of HWPW, PB or MDF to make finished good s. A person can be both a “fabricator” and a “manufacturer” if they produce both composite wood products and make finished goods from these products. Such a person would have to comply with both the provisions of the ATCM that ap ply to manufacturers (for the HWPW, PB or MDF that they produce) and the provisio ns that apply to fabricators (for the finished goods that they produ ce).

Like distributors and importers, the proposed ATCM requires that all products and finished goods sold by fabricators must comply with the applicable emission standards. The proposed ATCM also requires that fa bricators must take reasonable prudent precautions to ensure that the c omposite wood products and finished good components they acquire are in compli ance with the applicable emission standards in Table VI-1. To accomplish th is, fabricators would need toChapter VI Page 124

establish a procurement policy that requires them t o obtain and keep a record of written documentation from their suppliers that the products they acquire meet the applicable emission standards. Records must be kept for a minimum of two years for enforcement purposes.

Among finished goods produced with composite wood p roducts, window assemblies typically utilize only small amounts of HWPW, PB or MDF. Therefore, exposure from composite wood products us ed in windows is expected to be insignificant and enforcement testing would a lso be complex and expensive. Therefore, section 93120.7(b) provides an exemption for windows. The exemption applies only to windows that contain more than five percent by volume of any composite wood product.

To denote that the finished goods produced by a fab ricator for the California market were made with complying products, fabricato rs must label every finished good, or on every box containing finished goods. F abricators may label finished goods with a stamp, tag, sticker, or bar code. Und er the proposal, fabricators would also be required to designate their goods as being made with HWPW, PB or MDF in compliance with the emission standards on the bill of lading or invoice provided to retailers or other entities that sell t hose composite wood products or finished goods to the public.

Because fabricators may purchase HWPW-VC, HWPW-CC, PB, MDF, or tMDF from distributors and importers during the sell-thr ough periods allowed for these entities, an additional period of time is provided to fabricators to sell-through products that do not comply with the new standards. In total, fabricators would have a sell-through period of 12 months after the e ffective date of the applicable Phase 1 or Phase 2 standards (see Table VI-5). The longer sell-through period

reflects that fact that it takes time for fabricato rs to produce finished goods from the composite wood products they purchase.

Table VI-5. Schedule of Composite Wood Product Sell -through for Fabricators 1

Event HWPWVC HWPWCC PB MDF tMDF

Effective Date: P1 Jan ‘09 Jul ‘09 Jan ‘09 Jan ‘09 Jan ‘09 Date When Only P1

Products Can Be Sold Jan ‘10 Jul ‘10 Jan ‘10 Jan ‘10 Jan ‘10

Effective Date: P2 Jan ‘11 Jul ‘12 Jan ‘11 Jan ‘11 Jan ‘12 Date When Only P2

Products Can Be Sold Jan ‘12 Jul ‘13 Jan ‘12 Jan ‘12 Jan ‘13

(1) All dates begin on the 1 st day of the specified month-year. Fabricators are provided a 12- month sell-through period following the effective date of the applicable P1 or P2 standard.Abbreviations: P1 = Phase 1, P2 = Phase 2, HWPW-VC = HWPW with a veneer core, HWPWCC = HWPW with a composite core, PB = particleboard, MDF = medium density fiberboard,

tMDF = thin MDF.Chapter VI Page 125

Regarding enforcement, section 93120.7(e) notifies fabricators that they may be inspected by CARB or local air district personnel. Inspections would be focused on facility inspections, auditing of records, and s ecuring of samples for enforcement testing.

6. Section 93120.8- Requirements for Retailers

The proposed ATCM requires that all products and fi nished goods sold by retailers must comply with the applicable emission standards. The proposed ATCM also requires that retailers must take reasona ble prudent precautions (such as communicating with their suppliers) to ens ure that the composite wood products and finished goods they purchase are in co mpliance with the applicable emission standards in Table VI-1. To accomplish th is, retailers would need to establish a procurement policy that requires them t o obtain and keep a record of written documentation from their suppliers that the products they acquire meet the applicable emission standards. Records must be kept for a minimum of two years for enforcement purposes.

Because retailers may purchase HWPW-VC, HWPW-CC, PB , MDF or tMDF products or finished goods from manufacturers, impo rters, distributors, or fabricators during the sell-through periods for the se entities, an additional period of time is provided to retailers to sell-through pr oducts that do not comply with the new standards. In total, retailers would have sell -through periods of 12 months and 18 months, after the effective date of the appl icable Phase 1 or Phase 2 standards in Table VI-1 (see Table VI-6), for HWPW- VC, HWPW-CC, PB, MDF, and tMDF panels and finished goods containing those products, respectively.Chapter VI Page 126

Table VI-6. Schedule of Composite Wood Panel Sell-t hrough for Retailers 1

Event HWPWVC HWPWCC PB MDF tMDF

A. Composite Wood Products

Effective Date: P1 Jan ‘09 Jul ‘09 Jan ‘09 Jan ‘09 Jan ‘09 Date When Only P1

Products Can Be Sold Jan ‘10 Jul ‘10 Jan ‘10 Jan ‘10 Jan ‘10

Effective Date: P2 Jan ‘11 Jul ‘12 Jan ‘11 Jan ‘11 Jan ‘12 Date When Only P2

Products Can Be Sold Jan ‘12 Jul ‘13 Jan ‘12 Jan ‘12 Jan ‘13

B. Finished Goods

Effective Date: P1 Jan ‘09 Jul ‘09 Jan ‘09 Jan ‘09 Jan ‘09 Date When Only P1

Products Can Be Sold Jul ‘10 Jan ‘11 Jul ‘10 Jul ‘10 Jul ‘10

Effective Date: P2 Jan ‘11 Jul ‘12 Jan ‘11 Jan ‘11 Jan ‘12 Date When Only P2

Products Can Be Sold Jul ‘12 Jan ‘14 Jul ‘12 Jul ‘12 Jul ‘13

(1) All effective dates begin on the 1 st day of the specified month-year. Retailers have a 12- month or 18-month sell-through period following the effective date of the applicable P1 or P2 standard for panels or finished products, respectively. Abbreviations: P1 = Phase 1, P2 = Phase 2, HWPW-VC = HWPW with a veneer core, HWPW-CC = HWPW with a composite core, PB = particleboard, MDF = medium density fiberboard, tMDF = thin MDF.

Regarding enforcement, section 93120.8(c) notifies retailers that they may be inspected by CARB or local air district personnel. Inspections would be focused on facility inspections, auditing of records, and s ecuring of samples for enforcement testing..

7. Section 93120.9- Test Methods

The regulation includes various test methods to be used to demonstrate compliance with the emissions standards specified i n section 93120.2.

Under section 93120.9(a), the emission standards wi ll be based on the industry standard large chamber test method, as specified in American Standards for Testing and Materials (ASTM) E1333-96. The ASTM E1 333-96 test method was developed by the ASTM through a consensus process a nd is recognized as the “gold standard” among formaldehyde test methods. F urthermore, the current federal HUD standards regarding particleboard and p lywood in manufactured homes specify the ASTM E1333-96 as the applicable t est method.Chapter VI Page 127

Sections 93120.9(a)(1)-(3) allows for the use of eq uivalent alternate test methods in lieu of ASTM E1333-96, if approved by the Execut ive Officer. An application process is also specified for obtaining ARB approva l. This section allows alternative test methods to be used that may prove to be more applicable to particular products.

Sections 93120.9(b) and (c) describe the test metho d to be used for enforcement purposes. These provisions reference the use of AS TM D6007-02 for testing of HWPW, PB or MDF, or finished goods made from these materials. The ASTM D6007-02 is a standardized small chamber industry-d eveloped test method. When properly calibrated, test results from a small chamber are known to have a very high correlation to large chamber test results . The use of the small chamber is included in the regulation to allow CARB to cond uct compliance verification testing using smaller sample sizes and to obtain fa ster results.

The small chamber method will also allow CARB to te st pieces of composite wood products in finished goods that are bare or pa rtially covered (e.g. one side laminated). To test fully covered or laminated fi nished products, CARB will follow the method development plan shown in Table V I-7.

Table VI-7. Development Plan for Fully Covered Fini shed Products

Timeframe Action/Activity

Spring 2007 • Purchase lab equipment

• Purchase/build small testing chambers

• Begin evaluating field equipment

Summer 2007 • Develop draft lab analytical methods and begin testing composite wood samples, starting with raw

boards

• Begin certification process for small chambers

Fall 2007 • Begin evaluating finished product sample preparati on

approaches

Late 2007 • Complete certification of small chambers against a

large chamber

• Begin round robin testing with other labs

Spring 2008 • Complete round robin testing, make refinements to lab methods as necessary

Summer 2008 • Complete lab analytical protocols, including finis hed product testing (sampling, preparation and analysisChapter VI Page 128

B. Alternatives to the Proposed Airborne Toxic Con trol Measure Error!

Bookmark not defined.

1. Alternative 1: No Action

Taking no action would allow the continued sale of high HCHO-emitting composite wood products that have detrimental impac ts on public health.

Without stricter HCHO emission limits it will conti nue to be legal for high HCHOemitting composite wood products and finished goods to be sold in California that cannot currently be sold to many other countries. Because there is no safe threshold for exposure to HCHO, taking no action pe rpetuates the existing public health risks described in this staff report.

2. Alternative 2: Establish Less Stringent Emissio n Limits

a. Applicability

The principal entities that would be affected by th is alternative are manufacturers of HWPW-VC, HWPW-CC, PB, MDF, and tMDF, resin manuf acturers,
businesses that use those materials to fabricate ot her products, distributors, importers and retailers of HWPW-VC, HWPW-CC, PB, MD F, tMDF, or finished goods containing those materials.

b. Effectiveness

This alternative would not provide as great a publi c health benefit as the proposed ATCM. For example, if emission standards equal to the 1985 HUD standards are promulgated, there would be no public health benefit relative to current conditions because the major portion of U.S . manufacturers already produce composite wood products in voluntary compli ance with the HUD standard. Some reductions may be achieved with res pect to emissions from MDF, which is currently an unregulated product.

c. Enforceability

This alternative would require the same level of en forcement as the proposed

ATCM.

d. Resource Considerations

Minor modifications may be needed to incorporate a greater compliance margin to ensure that only products meeting an emission st andard equal to the HUD standard are distributed to California. Tighter to lerances on manufacturing lines may need to be established by some manufacturers in order to avoid potential violations resulting from the sale of non-complying products.Chapter VI Page 129

3. Alternative 3: Establish More Stringent Emissio n Limits – Zero

Emission Products

This alternative would require composite wood manuf acturers to use no added HCHO resins in the production of HWPW-VC, HWPW-CC, PB, MDF, and thin

MDF.

a. Applicability

Manufacturers of HWPW-VC, HWPW-CC, PB, MDF, thin MD F; resin producers; businesses that use composite wood products to fabr icate other products; distributors; importers; and retailers of HWPW-VC, HWPW-CC, PB, MDF, thin MDF, or finished goods containing those materials, would be the principal entities

affected.

b. Effectiveness

This alternative is not feasible at present, as we believe that cost-effective, no added HCHO resins would not be commercially availab le for all three products in the 2011-2012 timeframe. Setting a “zero emission” cap standard is also technically impractical because some HCHO is emitte d from wood itself, and the air used to measure HCHO emissions from composite w ood panels also contains trace amounts of HCHO. As such, even if the produc t were made with a no added HCHO resin, there could be enough HCHO emitte d from wood or present

in the test intake air to result in a non-zero emis sion test value.

c. Enforceability

This alternative would require the same level of en forcement as the proposed

ATCM.

d. Resource Considerations

Major breakthroughs in manufacturing and resin tech nology would be needed to consistently produce HWPW, PB, and MDF that would c omply with a zero emission standard. The costs for developing these products would far exceed the estimated cost increases resulting from the pro posed ATCM, possibly as much as 135% higher in the case of zero emission M DF made with pMDI.

C. Conclusion

We evaluated each of the alternatives and determine d that the alternatives did not meet the objective of H&SC §39666 to reduce emi ssions to the lowest level achievable through the application of BACT, or a mo re effective control method, in consideration of cost, health risk, and environm ental impacts.Chapter VII Page 130

VII. Health Impacts of the Proposed Airborne Toxic Control Measure

This chapter presents an overview of the health ris k assessment process, potential health impacts from exposure to HCHO in s elected scenarios, information on alternative wood adhesives, and the benefits of the proposed ATCM in terms of reducing statewide emissions and p otential health impacts.

A. Overview of the Health Risk Assessment

A health risk assessment (HRA) is a report prepared by a risk assessor that describes the potential for an individual or popula tion to experience adverse health impacts as a result of being exposed to the emissions released from a pollution-generating facility. Adverse health effe cts may include cancer, developmental effects, and/or respiratory illness. In a HRA, estimates of total pollutant exposure are calculated by cumulating pol lutant uptake via inhalation of gaseous and/or particulate compounds, ingestion of contaminated water and food, and dermal absorption. For HCHO emitted by b uilding materials and consumer products, the principal pollutant uptake p athway is inhalation of gaseous HCHO. In the following HRA, HCHO uptake vi a inhalation was the only exposure pathway evaluated to assess potential canc er or non-cancer health impacts.

The following four steps are followed to prepare a HRA:

• Step 1 -- Hazard Identification

First, a determination is made as to whether or not a hazard exists. If a hazard is deemed to exist, an analysis is performed to identi fy which pollutant(s) is/are involved and what types of health effects may resul t (i.e., cancer or non-cancer).

As HCHO has been identified as a toxic air contamin ant (CARB, 1992), there is no threshold exposure level below which adverse hea lth effects are not anticipated.

• Step 2 -- Dose-response Assessment

Next, the relationship, if any, between an individu al’s exposure to a pollutant and

the incidence of adverse health effects is characte rized. For cancer and noncancer effects, OEHHA provides cancer potency or un it risk factors (URF) and reference exposure levels (REL), respectively. The following citations contain

lists of the URFs or RELs used in California:

OEHHA. 2005a. Appendix A: Hot Spots Unit Risk and Cancer Potency Values.

In : OEHHA. Air Toxics Hot Spots Program Risk Assessm ent Guidelines. Part II. Technical Support Document for Describing Available Cancer Potency Factors.Chapter VII Page 131

OEHHA. 2000. All acute reference exposure levels adopted by OEHHA as of May 2000. From : http://www.oehha.ca.gov/air/acute_rels/allacrels.ht ml

OEHHA. 2005b. All chronic reference exposure leve ls adopted by OEHHA as of February 2005. From : http:// www.oehha.ca.gov/air/chronic_rels/allchrels.html

• Step 3 – Exposure Assessment

Public exposure is estimated by evaluating represen tative and elevated exposure scenarios, relevant exposure pathways (e.g., inhala tion), and the magnitude of exposure. For exposure to HCHO, daily time-weighte d average exposures were calculated for children and adults, by estimating t he time spent either outdoors, indoors, or and in-vehicles, and multiplying by an applicable representative or

elevated HCHO concentration from the literature.

• Step 4 – Risk Characterization

To calculate potential cancer risk in adults and ch ildren, the Hot Spots Program equation (OEHHA, 2003) was used to determine an inh alation dose (Dose inh ) for

HCHO:

Dose inh = [(C air ) x (DBR) x (A) x (EF) x (ED) x 10 -6 ] ÷ AT

Where :

Dose inh = Dose through inhalation (mg/kg body weight-day)

C air = HCHO concentration in air ( μ g/m 3 ) DBR = Daily breathing rate (liter/kg body weight-d ay) A = Inhalation absorption factor (dimensionless ad justment) EF = Exposure frequency (days/year) ED = Exposure duration (years)

10 -6 = Constant: (10 -3 x 10 -3 ) for ( μ g to mg) and (liter to m 3 ), respectively AT = Averaging time period (70-years) in days (25, 550 days)

The numerical values of the components in the above equation were chosen based on OEHHA (2003), except for the calculation o f C air . For this component, a daily time-weighted average (TWA) formaldehyde co ncentration was calculated, consistent with the scenario-based guid elines for exposure assessment developed by USEPA (Federal Register, 19 92). A daily TWA formaldehyde concentration was calculated separatel y for adults and children. In general terms, daily TWA HCHO concentration is:

Daily TWA = [(T ind x C ind ) + (T out x C out ) + (T inv x C inv )] ÷ 24Chapter VII Page 132

Where :

Daily TWA = Daily time-weighted average HCHO concen tration ( μ g/m 3 )

T ind = Time spent indoors (hr)

C ind = Indoor HCHO concentration ( μ g/m 3 )

T out = Time spent outdoors (hr)

C out = Outdoor HCHO concentration ( μ g/m 3 )

T inv = Time spent in-vehicles (hr)

C inv = In-vehicle HCHO concentration ( μ g/m 3 ) 24 = Constant (24 hr/day)

A reference exposure level or “REL” is used as an i ndicator of the potential for a compound to cause adverse, non-cancer health effect s (e.g., respiratory illness). For a given TAC, its REL is the pollutant concentra tion at or below which no adverse health effects are anticipated. To incorpo rate a margin of safety into RELs, they are designed to protect the most sensiti ve individuals in a population from acute and chronic exposures to a TAC. An acut e exposure is defined as one or a series of short-term exposures generally l asting less than 24 hours (i.e., a one hour exposure is used to assess acute non-can cer impacts). Chronic exposures are defined as exposures lasting from one year to an entire lifetime.

B. Total Daily Formaldehyde Exposure as the Basis for Risk

Assessment

To assess the potential health impacts of HCHO emis sions from composite wood products, quality assured data are needed on HCHO c oncentrations that people are exposed to, and health effect values (i.e., URF s and RELs). For this rulemaking, a persons’ total daily exposure to HCHO was estimated; this is a measure of cumulative HCHO exposure from the air th ey breathe in indoor, outdoor, and in-vehicle microenvironments, rather t han outdoor air alone. This requires estimates to be calculated of average HCHO concentrations in three microenvironments that people spend time in. As st udies have found that Californians spend 90% or more of their time indoor s, a principal focus was the development of estimates for HCHO concentrations in new and existing homes. Brief descriptions are provided in the following su bchapters concerning the

estimates of indoor HCHO concentrations and health effects values.

1. Average and Elevated Formaldehyde Concentrations

Average and elevated HCHO concentration data were p rimarily obtained from a CARB report prepared for the Legislature on indoor air pollution in California (CARB, 2005). In Appendix III of the report, avera ge and maximum HCHO

concentrations in selected indoor and outdoor micro environments were estimated (Table VII-1) and served as the principal basis for calculating daily

TWA concentrations of HCHO. For conventional homes , the elevated concentration represents the average concentration measured in newly builtChapter VII Page 133

homes (Sherman and Hodgson, 2003). The average and elevated HCHO concentrations for time spent in vehicles were esti mated from the data in Research Triangle Institute (1998).

Table VII-1. Average and Elevated Formaldehyde Con centrations ( μ g/m 3 )

in Selected Indoor and Outdoor Microenvironments

Microenvironment Average ( μ g/m 3 ) Elevated ( μ g/m 3 )

Conventional Home 17.2 46.7

In-vehicle 9.6 12.0

Outdoors 3.7 15.0

(1) Sources : CARB (2005); Research Triangle Institute (1998); Sherman and Hodgson (2003).

2. Health Effects Values for Formaldehyde

Pollutant exposure-response relationships are chara cterized by a variety of

health effects values that describe the incidence o f adverse health effects relative to the degree of pollutant exposure. A unit risk f actor or “URF” is used as an estimate of potential cancer risk, and RELs are use d as estimates of potential non-cancer impacts. The health values for HCHO, de termined by OEHHA, are listed in Table VII-2. For non-cancer effects, the RELs (acute and chronic) were established to protect against eye irritation, and associated impacts to the respiratory and immune systems (OEHHA, 1999; 2000).

Table VII-2. Health Effects Values for Formaldehyd e 1

Unit Risk Factor (μg/m 3 ) -1 Acute Reference

Exposure Level (μg/m 3 ) Chronic Reference Exposure Level (μg/m 3 )

6 x 10 -6 94 3

(1) Sources : OEHHA (2000); (2005a); (2005b).

a. Health Effects in Humans

Numerous acute controlled human exposure studies, a s well as observational studies in occupational settings, have been conduct ed to investigate formaldehyde’s irritative and pulmonary effects (Sh eppard et al., 1984; Sauder et al., 1986; Schachter et al., 1986; Kulle et al., 19 87; Sauder et al., 1987; Schachter et al., 1987; Witek et al., 1987; Uba et al., 1989; Harving et al., 1990; Akbar-Khanzadeh et al., 1994). Both irritation and significant decrements in pulmonary function have been observed in occupation al studies of carpentry,Chapter VII Page 134

wood and wood product, chemical plant, and formalde hyde production plant workers exposed to formaldehyde (Alexandersson et a l., 1982; Alexandersson and Hedenstierna, 1988; Holmstrom and Wilhelmsson, 1988; Horvath et al., 1988; Alexandersson and Hedenstierna, 1989; Malaka and Kodama, 1990; Wilhelmsson and Holmstrom, 1992). Formaldehyde exp osures in the home and

school environment have also been associated with i rritation and pulmonary function effects in children (Wantke et al., 1996; Smedje et al., 1997; Garrett et al., 1999; Smedje and Norback, 2001a; 2001b; Delfin o et al., 2003).

i. Respiratory Effects and Irritation – Acute Expo sure

Formaldehyde vapor produces immediate local irritat ion in mucous membranes, including eyes, nose, and the upper respiratory tra ct (Arts et al., 2006). Formaldehyde exposures of 0.25-1.39 ppm (1 ppm = 1. 24 mg/m 3 ) evoked numerous complaints of upper respiratory tract and eye irritation among embalmers at different funeral homes (Kerfoot and M ooney, 1975). Anatomy class students exposed to an average of 1.1 ppm (st andard deviation = 0.56 ppm) for 2 hours per week over 14 weeks experienced eye, nose and throat irritation (Kriebel et al., 2001). Exposure to low or moderate levels of formaldehyde (<1-3 ppm) can result in eye and upper respiratory tract irritation, headache, and rhinitis (inflammation of the mucous membrane of the nose) (Weber-Tschopp et al., 1977; Kulle et al., 1987). This has been observed in occupants of houses insulated with urea-formaldehyd e foam insulation (UFFI), residents of mobile homes, and employees of mobile day-care centers (Olsen and Dossing, 1982; Ritchie and Lehnen, 1987), and n oted in occupational settings.

Most people cannot tolerate exposures to more than 5 ppm formaldehyde in air, and above 10-20 ppm symptoms become severe and shor tness of breath occurs. For example, 13.9 ppm formaldehyde for 30 minutes c aused considerable nasal and eye irritation and continued mild lacrimation ( abnormal or excessive secretion of tears) in human volunteer subjects (Si m and Pattle, 1957).

High concentrations of formaldehyde may result in s evere mucous membrane irritation, burning, and lacrimation, nasal obstruc tion, choking, labored breathing, and chest tightness (Porter, 1975; Solomons and Coc hrane, 1984a). Inhalation exposures to high concentrations can cause signific ant inflammation of the lower respiratory tract, resulting in swelling of the thr oat, inflammation of the windpipe and bronchi, narrowing of the bronchi, inflammation of the lungs, and accumulation of fluid in the lungs. Pulmonary inju ry may continue to worsen for 12 hours or more after exposure.

Rhinitis and a wide range of asthma-like conditions can result from exposure to formaldehyde. Even fairly low concentrations of fo rmaldehyde can produce rapid onset of nose and throat irritation, causing coughi ng, chest pain, shortness of breath, and wheezing. Persons who are sensitized t o formaldehyde may alsoChapter VII Page 135

experience headaches, minor eye and airway irritati on, asthma, and dermatitis (inflammation of the skin), even at very low doses. Previously sensitized individuals can develop severe constriction of the bronchi at very low concentrations (e.g. 0.3 ppm). Bronchial constrict ion may begin immediately or can be delayed for 3 to 4 hours; effects may worsen for up to 20 hours after exposure and can persist for several days. Lower r espiratory effects can include bronchitis (acute or chronic inflammation of the br onchial tubes), pulmonary edema (abnormal accumulation of fluid in the lungs) , or pneumonia.

Exposure to 3 ppm formaldehyde for 1 hour in a cont rolled exposure study resulted in clinically significant reductions in re spiratory rates in both asthmatic and normal subjects (Green et al., 1987). Exposure to formaldehyde adversely affects pulmonary functioning with decreases in pea k expiratory flow (PEF) of 1% per ppm of formaldehyde (Kriebel et al., 2001). Th e effects of formaldehyde on asthmatics may be dependent on previous, repeated e xposure in worker studies (Burge et al., 1985). Some studies indicate that a sthmatics may not be more sensitive than non-asthmatics to the respiratory ef fects of formaldehyde unless specifically sensitized to formaldehyde, such as oc curs in occupational settings. However, as noted below, chronic low level exposure may be associated with asthma development in children.

Formaldehyde provocation of human subjects occupati onally exposed to formaldehyde at concentrations of 1.5 to 20.6 ppm a nd suffering from asthmalike symptoms such as wheezing, shortness of breath , or rhinitis, also resulted in pulmonary function decrements consistent with immed iate and/or delayed bronchoconstriction (constriction of the bronchial air passages) (Hendrick and Lane, 1977; Wallenstein et al., 1978; Burge et al., 1985; Nordman et al., 1985). Workers exposed to low concentrations may develop s evere prolonged asthma attacks after prior exposure; this suggests that th ey may have become sensitized (Feinman, 1988). Histology technicians exposed to formaldehyde volatilized from formalin at concentrations of 0.2 to 1.9 ppm were shown to have reduced pulmonary function, compared with controls (Kilburn et al., 1989). Furthermore, 3 out of 15 occupationally exposed workers challeng ed with formaldehyde vapors at concentrations from 1.5 ppm to 20.6 ppm for a br ief duration, exhibited late asthmatic reactions (Burge et al., 1985). Six othe r subjects had immediate asthmatic reactions likely due to irritant effects. Asthmatic responses were also observed in 12 occupationally-exposed workers chall enged with 1.67 ppm formaldehyde (Nordman et al., 1985).Chapter VII Page 136 ii. Chronic Human Exposure

Formaldehyde exposure primarily affects the mucous membranes of the upper airways and eyes. Chronically exposed populations that have been studied include embalmers, residents in houses insulated wi th urea-formaldehyde foam, anatomy class students, histology technicians, wood and pulp mill workers, and asthmatics. The literature describing these effect s is briefly summarized below.

iii. Exposure to Residents

Occupants of houses insulated with urea formaldehyd e foam insulation (UFFI) (1726 subjects) were compared with control subjects (720 subjects) for subjective measures of irritation, pulmonary functi on (FVC, FEV 1 , FEF 25-75 , FEF 50 ), nasal airway resistance, odor threshold for pyri dine, nasal cytology, and hypersensitivity skin-patch testing (Broder et al., 1988). The mean length of time of exposure to UFFI was 4.6 years. A significant i ncrease in symptoms of eye, nose and throat irritation was observed in subjects from UFFI homes (average exposure 0.043 ppm), compared with controls (averag e exposure 0.035 ppm).

No other differences from control measurements were observed (Broder et al., 1988).

Doctor-diagnosed asthma and chronic bronchitis have been found to be more prevalent in houses with elevated formaldehyde (Krz yzanowski et al., 1990). Compared with children exposed in their homes to le ss than 8 ppb, children in homes with formaldehyde levels greater than 49 ppb had a 39% higher risk of asthma after adjusting for common asthma risk facto rs (Rumchev et al., 2002). Exposure concentrations as low as 0.09 ppm formalde hyde exacerbated chronic respiratory and allergy problems in residents livin g in mobile homes (Liu et al., 1991).

Ritchie and Lehnen (1987) reported a dose-dependent increase in health complaints (eye and throat irritation, and headache s) in 2000 residents living in 397 mobile and 494 conventional homes, that was dem onstrated by logistic regression. Complaints of symptoms of irritation w ere noted at concentrations of 0.1 ppm formaldehyde or above. Similarly, Liu et a l. (1991) found that exposure to 0.09 ppm (0.135 mg/m 3 ) formaldehyde exacerbated chronic respiratory and allergy problems in residents living in mobile home s.

Employees of mobile day-care centers (66 subjects) reported increased incidence of eye, nose and throat irritation, unnat ural thirst, headaches, abnormal tiredness, menstrual disorders, and increased use o f analgesics as compared to control workers (Olsen and Dossing, 1982). The mea n formaldehyde concentration in these mobile units was 0.29 ppm (0 .43 mg/m 3 ) (range = 0.24 - 0.55 mg/m 3 ). The exposed workers were exposed in these units a minimum of 3 months. A control group of 26 subjects in differen t institutions was exposed to a mean concentration of 0.05 ppm (0.08 mg/m 3 ) formaldehyde.Chapter VII Page 137 iv. Occupational Exposures

Kerfoot and Mooney (1975) reported that estimated f ormaldehyde exposures of 0.25-1.39 ppm evoked numerous complaints of upper r espiratory tract and eye irritation among seven embalmers at six different f uneral homes. Three of the seven embalmers in this study reportedly had asthma . Levine et al

. (1984)

examined the death certificates of 1477 Ontario und ertakers. Exposure measurements taken from a group of West Virginia em balmers were used as exposure estimates for the embalming process, rangi ng from 0.3-0.9 ppm (average 1-hour exposure) and 0.4-2.1 ppm (peak 30- minute exposure). Mortality due to non-malignant diseases was signifi cantly elevated due to a twofold excess of deaths related to the digestive syst em. The authors suggest

increased alcoholism could have contributed to this increase.

An increase in severity of nasal epithelial histolo gical lesions, including loss of cilia and goblet cell hyperplasia (11%), squamous m etaplasia (78%), and mild dysplasia (8%), was observed in 75 wood products wo rkers exposed to between 0.1 and 1.1 mg/m 3 (0.08-0.89 ppm) formaldehyde for a mean duration o f 10.5 years (range = 1 - 39 years), compared to an equal number of control subjects (Edling et al

. , 1988). Only three exposed men had normal mucosa. A high frequency of symptoms relating to the eyes and uppe r airways was reported in exposed workers. Nasal symptoms included mostly a runny nose and crusting. The histological grading showed a significantly hig her score for nasal lesions when compared with the referents (2.9 versus 1.8). Exposed smokers had a higher, but non-significant, score than ex-smokers and non-smokers. When relating the histological score to duration of expo sure, the mean histological score was about the same regardless of years of emp loyment. In addition, no difference in the histological scores was found bet ween workers exposed only to formaldehyde and those exposed to formaldehyde and wood dust.

Chronic occupational exposure to formaldehyde conce ntrations estimated to be 0.025 ppm for greater than six years resulted in co mplaints by 22 exposed workers of respiratory, gastrointestinal, musculosk eletal, and cardiovascular problems, a higher incidence of abnormal chest x-ra ys, and elevated formic acid excretion in the urine (Srivastava et al., 1992). A control group of 27 workers unexposed to formaldehyde was used for comparison. A significantly higher incidence of abnormal chest x-rays was observed in formaldehyde-exposed workers compared with controls.

Alexandersson et al

. (1982) compared the irritant symptoms and pulmonar y function of 47 carpentry workers exposed to a mean concentration of formaldehyde of 0.36 ppm (range = 0.04 - 1.25 ppm) with 20 unexposed controls. The average length of employment for the exposed wo rkers was 5.9 years. Symptoms of eye and throat irritation as well as ai rway obstruction were more common in exposed workers. In addition, a signific ant reduction in FEV 1 ,Chapter VII Page 138

FEV 1 /FVC, and MMF was observed in exposed workers, as c ompared with

controls.

Alexandersson and colleagues studied workers (38 to tal) exposed for a mean duration of 7.8 years to 0.11 - 2.12 ppm (mean = 0. 33 ppm) formaldehyde for symptomatology, lung function, and total IgG and Ig E levels in the serum (Alexandersson and Hedenstierna, 1989). The contro l group consisted of 18 unexposed individuals. Significant decrements in p ulmonary function (FVC and

FEV 1 ) were observed, compared with the controls. Eye, nose, and throat irritation was also reported more frequently by the exposed group, compared with the control group. No correlation was found betwee n duration of exposure, or formaldehyde concentration, and the presence of IgE and IgG antibodies.

Chemical plant workers (70 subjects) exposed to a m ean of 0.17 ppm (0.26 mg/m 3 ) formaldehyde for an unspecified duration were com pared with 36 control workers not exposed to formaldehyde (Holmstrom and Wilhelmsson, 1988). The exposed subjects exhibited a higher frequency of ey e, nose, and deep airway discomfort. In addition, the exposed subjects had diminished olfactory ability, delayed mucociliary clearance, and decreased FVC.

Horvath et al

. (1988) compared subjective irritation and pulmonar y function in 109 workers exposed to formaldehyde with similar me asures in a control group of 254 subjects. The formaldehyde concentrations for the exposed and control groups were 0.69 ppm (1.04 mg/m 3 ) and 0.05 ppm (0.08 mg/m 3 ), respectively. Mean formaldehyde concentration in the pre-shift te sting facility and the state (Wisconsin) ambient outdoor - formaldehyde level we re both 0.04 ppm (0.06 mg/m 3 ). Duration of formaldehyde exposure was not state d. Subjects were evaluated pre- and post work-shift and compare d with control subjects. Significant differences in symptoms of irritation, FEV 1 , FEV 1 /FVC ratio, FEF 50 , FEF 25 , and FEF 75 were found when comparing exposed subjects’ pre- a nd post work-shift values. However, the pre-workshift valu es were not different from

controls.

Significant increase in symptoms of irritation were reported for 66 workers exposed for 1 - 36 years (mean = 10 years) to a mea n concentration of 0.17 ppm (0.26 mg/m 3 ) formaldehyde (Wilhelmsson and Holmstrom, 1992). Controls (36 subjects) consisted of office workers in a governme nt office and were exposed to a mean concentration of 0.06 ppm (0.09 mg/m 3 ) formaldehyde. The significant increase in symptoms of irritation in exposed worke rs did not correlate with total serum IgE antibody levels. However, two exposed wo rkers, who complained of nasal discomfort, had elevated IgE levels.

v. Immunological Effects in Humans

The binding of formaldehyde to endogenous proteins creates haptens that can elicit an immune response. This underlies sensitiz ation of formaldehyde exposedChapter VII Page 139

individuals and may explain the induction of asthma in occupationally exposed

individuals as well as the indications of increased asthma in children exposed at home. Chronic exposure to formaldehyde has been as sociated with immunological hypersensitivity as measured by eleva ted circulating IgG and IgE auto-antibodies to human serum albumin (Thrasher et al., 1987). In addition, a decrease in the proportion of T-cells was observed, indicating altered immunity. Thrasher et al. (1990) later found that long-term e xposure to formaldehyde was associated with auto-antibodies, immune activation, and formaldehyde-albumin adducts in patients occupationally exposed, or resi dents of mobile homes and homes containing particleboard sub-flooring (Thrash er et al., 1990).

Gorski et al

. 1992 evaluated the production of active oxygen species b y neutrophils in 18 persons exposed to 0.5 mg/m 3 (0.3 ppm) formaldehyde for two hours (Gorski et al., 1992). All 13 subjects who h ad allergic contact dermatitis (tested positive to formaldehyde in skin patch) exh ibited significantly higher chemiluminescence of granulocytes isolated from who le blood 30 minutes and 24 hours post-exposure than the individuals who were n ot formaldehyde sensitive. Thus, the immune cellular response of skin-sensitiz ed individuals to an inhalation exposure to formaldehyde indicates increased produc tion of active oxygen species, and demonstrates that inhalation exposures can elicit immune and inflammatory reactions in sensitized individuals.

vi. Reproductive and Developmental Effects in Huma ns

There are no conclusive data showing that formaldeh yde is toxic to the reproductive system or to developing fetuses in hum ans. Epidemiological studies of occupationally exposed individuals showe d no clear evidence of either maternal or paternal inhalation exposure to formald ehyde associated with increased risk of spontaneous abortion (Hemminki et al., 1985; Lindbohm et al., 1991; John et al., 1994; Taskinen et al., 1994).

In humans there are few data on the association of teratogenicity or adverse reproductive effects with formaldehyde exposure. E xisting data do not suggest that formaldehyde, by inhalation or oral routes, pr oduces significant teratogenic or reproductive effects (ATSDR, 1999).

vii. Infants and Children

There are a number of physiological and behavioral factors that influence response to toxicants and differ between children a nd adults (OEHHA, 2001).

Pharmacokinetic differences between children and ad ults include factors that influence absorption, distribution, metabolism, and excretion of toxicants. In addition, infants and children may have qualitative ly different responses due to different target tissue sensitivities during window s of susceptibility in the developmental process.Chapter VII Page 140

There is evidence that following acute exposure to formaldehyde, asthmatics and others previously sensitized to formaldehyde may be more likely to show asthmalike symptoms such as wheezing, shortness of breath , rhinitis, and/or decrements in pulmonary function consistent with im mediate and/or delayed bronchoconstriction (Hendrick and Lane, 1977; Walle nstein et al., 1978; Burge et al., 1985; Nordman et al., 1985). Furthermore, som e asthmatics may respond with significant reductions in lung function due to the irritant effects on asthma, sensitized or not. The potential association betwe en formaldehyde exposure and asthma is of special concern for children because t hey have higher prevalence rates of asthma than adults, and their asthma episo des can be more severe due to their smaller airways, which may result in more hospitalizations of children, especially for the first four years of life (Mannin o et al., 1998). In several studies, asthma symptoms in secondary school children were m ore common in schools with higher concentrations of formaldehyde (Harving et al., 1990; Smedje et al., 1997; Smedje and Norback, 2001b). In addition, the incidence of new asthma diagnosis was more common in children whose classro oms had higher concentrations of formaldehyde (Smedje and Norback, 2001a). Thus children, particularly asthmatic children, may be at greater risk from acute exposure to formaldehyde.

There are few chronic studies that compare the effe cts of formaldehyde on children versus adults. Among those that do, there is evidence that children are more susceptible to the adverse effects of chronic formaldehyde exposure. Krzyzanowski et al. (1990) assessed chronic pulmona ry symptoms and function in 298 children (6-15 years of age) and 613 adults (> 15 years of age) in relation to measured formaldehyde levels in their homes (Krz yzanowski et al., 1990). Information on pulmonary symptoms and doctor-diagno sed asthma and chronic bronchitis was collected by questionnaire. Pulmona ry function was assessed as peak expiratory flow rates (PEF) measured up to fou r times a day. The prevalence of chronic respiratory symptoms in child ren was not related to formaldehyde levels measured in tertiles (< 40, 41- 60, > 60 ppb). However, doctor-diagnosed asthma and chronic bronchitis were more prevalent in houses with elevated formaldehyde (p for trend < 0.02). T his effect was driven by the high disease prevalence observed in homes with kitc hen formaldehyde levels >60 ppb, and was especially pronounced among childr en with concomitant exposure to environmental tobacco smoke. By compar ison, in adults, while the prevalence rates of chronic cough and wheeze were s omewhat higher in houses with higher formaldehyde, none of the respiratory s ymptoms or diseases was significantly related to formaldehyde levels (Krzyz anowski et al., 1990).

In a random effects model, Krzyzanowski et al. (199 0) found that lung function (measured as peak expiratory flow (PEF) in children , but not adults, was significantly decreased by formaldehyde (coefficien t for household mean formaldehyde ± SE: -1.28 ± 0.46 vs 0.09 ± 0.27) (Kr zyzanowski et al., 1990). Measurements of PEF in the morning suggested that c hildren with asthma were more severely affected than healthy children (coeff icient ± SE: 1.45 ± 0.53 pChapter VII Page 141

<0.05) vs 0.09 ± 0.15 (p >0.10)). The authors note no threshold was found for formaldehyde effects on ventilatory function in the children, and that a 10% decrease in PEF was associated with exposures as lo w as 30 ppb in nonasthmatic children with an even larger effect in as thmatic children at 30 ppb. Compared to children, the effects of formaldehyde o n pulmonary function in adults were smaller, transient, limited to morning measurements, and generally most pronounced among smokers exposed to the higher levels of formaldehyde. These studies suggest that children may be more sus ceptible to the effects of chronic formaldehyde exposure on lung function than are adults.

Among studies of children only, a case-control stud y examined risk factors for asthma among young children (6 mo- 3 yr) (Rumchev e t al., 2002). Cases included children with clinically-diagnosed asthma, and controls were children of the same age group without such a diagnosis. Forma ldehyde levels were measured in the homes, once in summer and once in w inter. Questionnaires were used to assess potential risk factors for asth ma and collect parental reports of respiratory symptoms characteristic of asthma (c ough, shortness of breath, wheeze, runny nose, trouble breathing, and hay feve r in their children) (Rumchev et al., 2002). Formaldehyde levels were higher in the homes of children exhibiting asthma symptoms. Estimates of the relat ive risk for asthma (odds ratios) were adjusted for measured indoor air pollu tants, relative humidity, temperature, atopy (hereditary allergy), family his tory of asthma, age, gender, socioeconomic status, pets, smoke exposure, air con ditioning, and gas appliances. Compared with children exposed to < 8 ppb, children in homes with formaldehyde levels > 49 ppb had a 39% higher risk of asthma (p < 0.05) after adjusting for common asthma risk factors (Rumchev e t al., 2002).

Franklin et al

. (2000) measured exhaled nitric oxide levels in 224 children 6-13 years of age as an indicator of inflammation of the lower airways following chronic low-level formaldehyde exposure in the home (Kitaeva et al., 1990; Franklin et al., 2000). While there was no effect of formaldehyde on lung function measured by spirometry, eNO was significantly highe r in children from homes with average formaldehyde levels ≥ 50 ppb compared with those from homes

with levels ≤ 50 ppb (15.5 ppb eNO vs 8.7; p = 0.02) (Franklin e t al., 2000).

Garrett et al

. (1999) examined the association between formaldehyd e levels at home (median 15.8 μg/m 3 ; maximum 139 μg/m 3 ) and atopy and allergic sensitization in 148 children, 7-14 years of age (G arrett et al., 1999). The risk of atopy increased by 40% with each 10 μg/m 3 increase in formaldehyde measured in the bedroom. Two measures of allergic sensitiza tion to 12 common environmental allergens, the number of positive ski n prick tests and maximum wheal size, both showed linear associations with in creasing maximum formaldehyde exposure levels. After adjusting for parental asthma and allergy,

there was no evidence of an association between ast hma in the children and formaldehyde levels. However, these data do sugges t that formaldehyde levelsChapter VII Page 142

commonly found in homes can enhance sensitization o f children to common aeroallergens (Garrett et al., 1999).

Of the numerous, primarily occupational, studies in adults, the NOAEL and

LOAEL are 32 μ g/m 3 (26 ppb) and 92 μ g/m 3 (75 ppb), respectively, after adjustment for exposure continuity to formaldehyde. These data are based on nasal and eye irritation observed in Wilhelmsson an d Holstrom (1992), and histological lesions in the nasal cavity documented in Edling et al. (1988). However, studies in children, including the Krzyzan owski study above, indicate adverse health impacts in children at concentration s as low as 30 ppb.

Wantke et al

. (1996) reported that formaldehyde-specific IgE and respiratory symptoms were reduced when children transferred fro m schools with formaldehyde concentrations of 43 to 75 ppb to scho ols with concentrations of 23 to 29 ppb (Wantke et al., 1996). However, the prev alence of IgE sensitization in Japanese school children was not significant whethe r or not they had asthma (Doi et al., 2003). Formaldehyde in indoor air was significantly related to bacterial-specific IgG among Hungarian asthmatic ch ildren (Erdei et al., 2003). While these human studies are not entirely consiste nt with each other, and there is potential for confounding in each, nevertheless, taken together, they suggest that children are more sensitive to formaldehyde to xicity than adults. Findings by Delfino et al. (2003) also support the view that to xic air contaminants, such as formaldehyde, in communities in proximity to major emission sources, including both industrial and traffic sources, have adverse e ffects on asthma in children (Delfino et al., 2003). The odds ratio for more se vere asthma symptoms per interquartile range (3.16 ppb formaldehyde) were 1. 37 (95% CI 1.04-1.80).

b. Health Effects in Experimental Animals

i. Acute Animal Studies

Studies of the acute effects of formaldehyde exposu re in experimental animals with exposure durations ranging from 30 minutes to 10 hours resulted in irritation, decrements in respiratory functioning, respiratory distress, and lethality. In rats exposed to formaldehyde vapor 500-1,400 ppm (1 ppm = 1.24 mg/m 3 ) for 30 minutes, the lethal concentration to 50% of the exp osure group (LC 50 ) was 800 ppm (Skog, 1950). The first deaths did not occur u ntil 6 hours after cessation of exposure; respiratory difficulty lasted several day s after exposure; and several died after 15 days of bronchitis and diffuse bronch opneumonia. Three weeks following exposure, histological examinations of th e surviving animals revealed bronchitis, pulmonary micro-hemorrhages, and edema. The report stated that formaldehyde exposure resulted in delayed lethality (Skog, 1950).

Exposure of mice to high concentrations of formalde hyde (726 ppm) for 2 hours, resulted in deaths from massive pulmonary hemorrhag e and edema, but 2-hr exposure to 113 ppm did not produce signs of “subst antial distress” (Horton etChapter VII Page 143

al., 1963). Alarie (1981) determined the 10-minute LC 50 for formaldehyde in mice to be 2,162 ppm (95% CI, 1,687-2,770 ppm) (Alarie, 1981). In an acute lethality study , 125 or 250 ppm formaldehyde for 4 hours res ulted in deaths of albino rats (Carpenter et al., 1949). In another lethality study, the LC 50 in rats and mice for a 4-hour formaldehyde exposure was 474 ppm and 407 pp m, respectively (Nagornyi et al., 1979). A multi-species study sh owed that a 10-hr exposure to 15.4 ppm formaldehyde vapor killed 3 of 5 rabbits, 8 of 20 guinea pigs, and 17 of 50 mice (Salem and Cullumbine, 1960).

Amdur notes that exposure of guinea pigs to formald ehyde for one hour increases resistance and decreases compliance relat ive to the control level at 0.31 ppm and above (p<0.05) (Amdur, 1960).

Swiecechowski et al. exposed guinea pigs to 0.86, 3 .4, 9.4, or 31.1 ppm formaldehyde for 2 hours, or to 0.11, 0.31, 0.59, o r 1.05 ppm formaldehyde for 8 hours (Swiecichowski et al., 1993). An 8-hour expo sure to > 0.3 ppm formaldehyde was sufficient to produce a significan t increase in airway reactivity. Similar effects occurred after > 9 ppm (>11 mg/m3) formaldehyde for the 2-hour exposure group. Formaldehyde exposure also heighte ned airway smooth muscle responsiveness to acetylcholine (or carbacho l) ex vivo

.

Riedel et al

. studied the influence of formaldehyde exposure on allergic sensitization in the guinea pig (Riedel et al., 199 6). Exposure to formaldehyde concentrations (0.13 and 0.25 ppm) over 5 consecuti ve days, followed by sensitization to ovalbumin (OA) resulted in enhance d sensitization relative to filtered air controls (P < 0.01). Furthermore, com pressed air measurements of specific bronchial provocation were significantly h igher in the 0.25 ppm formaldehyde group than in controls (p< 0.01), indi cating increased bronchial obstruction. Histological examination found edema of the bronchial mucosa, but there was no sign of inflammation of the lower airw ays in formaldehyde-exposed guinea pigs. The investigators concluded that shor t-term exposure to a low concentration of formaldehyde (0.25 ppm) can signif icantly enhance sensitization to inhaled allergens in the guinea pig.

Mice exposed to 0.2 to 13 ppm formaldehyde showed a concentration-dependent decrease in respiratory rate, which was attributabl e to sensory irritation at 0.3 to 4.0 ppm, and, above 4 ppm, also to bronchoconstrict ion (Nielsen et al., 1999).

Taken together, these acute animal studies show tha t formaldehyde is a respiratory irritant at low exposures, and can aggr avate asthma-like conditions.

ii. Reproductive and Developmental Toxicity

A developmental toxicity study on formaldehyde was conducted on pregnant rats (25 per group) that were exposed to 0, 2, 5, or 10 ppm formaldehyde for 6 hours/day, during days 6-15 of gestation (Martin, 1 990). Although exposure toChapter VII Page 144

10 ppm formaldehyde resulted in reduced food consum ption and body weight gain in the maternal rats, no effects on the number , viability or normal development of the fetuses were seen. In addition, pregnant rats (25 per group) were exposed to 0, 5, 10, 20, or 40 ppm formaldehyd e from days 6 - 20 of gestation (Saillenfait et al., 1989). Maternal wei ght gain and fetal weight were significantly reduced in the 40 ppm exposure group. No significant fetotoxicity or teratogenic defects were observed at formaldehyde l evels that were not also maternally toxic (Saillenfait et al., 1989).

Evidence of embryotoxicity was reported in embryos of rats that had been exposed to formaldehyde by inhalation 4 h/d, 5 d/wk for 4 months (Kitaeva et al., 1990). At 1.5 mg/m 3 , but not at 0.5 mg/m 3 , there was a significant increase in the proportion of degenerate embryos. By comparison, t he bone marrow cells of the mothers appeared to be more sensitive to formaldehy de as shown by significant increases in the numbers of cells with aberrations, and the numbers of chromosomes with aberrations and aneuploidy at both dose levels (Kitaeva et al., 1990).

iii. Sub-chronic Animal Studies

Sub-chronic studies in rats and mice exposed to for maldehyde have shown histopathological changes (tissue changes character istic of disease) in the nasal respiratory epithelium and nasal lesions in a dose- dependent manner (MonteiroRiviere and Popp, 1986). In the nasal respiratory epithelium of adult male rats with exposure to 0.5 or 2 ppm formaldehyde, effects were limited to altered cilia (minute short hair-like processes, capable of lashi ng movement) with occasional wing-like projections on the ends of the ciliary sh afts. Loss of microvilli (microscopic projections of tissues, cells, or cell organelles) in ciliated cells was noted at all exposure concentrations (Monteiro-Rivi ere and Popp, 1986). Intermittent exposures (8 hours/day, 5 days/week) o f rats to 4 ppm formaldehyde for 13 weeks resulted in significant histological c hanges in the nasal septum and turbinates; however, 2 ppm did not produce signific ant lesions (Wilmer et al., 1989). This study revealed the concentration-depen dent nature of the nasal lesions caused by formaldehyde exposure.

When male and female Wistar rats were exposed to 0. 3 to 3 ppm formaldehyde vapor (6 hours/day, 5 days/week) for 13 weeks, hist opathological nasal changes varying from epithelial disarrangement to epithelia l hyperplasia (abnormal or unusual increase in epithelial cells composing a ti ssue) and squamous metaplasia (abnormal replacement of cells of one ty pe by cells of another) were found in the 3 ppm group, and were restricted to a small area of the anterior respiratory epithelium (Zwart et al., 1988). In an other subchronic study, rats were exposed to formaldehyde 0 to 20 ppm (6 hours/d ay, 5 days/week) for 13 weeks (Woutersen et al., 1989). Rats exposed to 20 ppm displayed retarded growth, yellowing of the fur, and significant histo logical lesions in the respiratory epithelium. Exposure to 10 ppm did not affect grow th, but resulted in significantChapter VII Page 145

histological lesions in the respiratory tract. No significant adverse effects were seen at the 1.0 ppm exposure level (Woutersen et al ., 1989).

Mice exposed subchronically to 0 to 40 ppm formalde hyde (6 hours/day, 5 days/week) for 13 weeks had histological lesions in the upper respiratory epithelium ( ≥ 10 ppm) and exposure to 40 ppm was lethal (Maronpot et al., 1986).

iv. Chronic Animal Studies

Nasal lesions of the respiratory and olfactory epit helium have been observed after chronic inhalation exposure of mice and rats to formaldehyde (Kerns et al., 1983; Rusch et al., 1983; Appelman et al., 1988; Wo utersen et al., 1989; Kamata et al., 1997; Kimbell et al., 1997). Fischer-344 r ats and B6C3F1 mice were exposed to 0 to 14.3 ppm formaldehyde vapor (6 hour s/day, 5 days/week) for 24 months (Kerns et al., 1983). The exposure period w as followed-up by 6 months of non-exposure with interim sacrifices conducted a t 6, 12, 18, 24, 27, and 30

months. Both male and female rats in the 5.6 and 1 4.3 ppm groups demonstrated decreased body weights over the 2-year period. At the 6 month sacrifice, the rats exposed to 14.3 ppm formaldehyd e had non-neoplastic lesions of epithelial dysplasia (abnormal growth or develop ment) in the nasal septum and turbinates (Kerns et al., 1983). As the study prog ressed, epithelial dysplasia, squamous dysplasia, mucopurulent discharge (contain ing mucus and pus), and rhinitis increased in severity and distribution in all exposure groups (Kerns et al., 1983). In B6C3F1 mice, cumulative survival decreas ed in males from 6 months to the end of the study. Serous rhinitis was detec ted at 6 months in the 14.3 ppm group of mice. Metaplastic and dysplastic changes were noted at 18 months in most rats in the 14.3 ppm group and in a few mice i n the 5.6 ppm exposure group. By 24-months, the majority of mice in the 1 4.3 ppm group had metaplastic and dysplastic changes associated with serous rhinitis, in contrast to a few mice in the 5.6 ppm group and a few in the 2 ppm group (Kerns et al., 1983).

At a similar dose of 10 ppm, compound-related nasal lesions of the respiratory and olfactory epithelium in male Wistar rats expose d 6 hours/day, 5 days/week to 0 to 10 ppm formaldehyde vapor for 28 months were o bserved (Woutersen et al., 1989). In the respiratory epithelium, the lesions consisted of rhinitis, squamous metaplasia and basal cell/pseudoepithelial hyperpla sia. In the olfactory region, the lesions included epithelial degeneration and rh initis. In a parallel study, male Wistar rats were exposed to 0 to 10 ppm formaldehyd e for 3 months followed by a 25-month observation period. As with the previou s studies, compound-related histopathological changes were found in the noses o f the 10 ppm group and were comprised of increased incidences of squamous metaplasia of the respiratory epithelium and rhinitis (Woutersen et a l., 1989).

Similar results were observed when male F-344 rats were exposed to formaldehyde vapor at 0 to 15 ppm (6 hours/day, 5 d ays/week) for up to 28Chapter VII Page 146

weeks (Kamata et al., 1997). Animals from each gro up were randomly selected at the end of 12, 18, and 24 months, and surviving animals at 28 months were sacrificed for full pathological evaluation. Behav ioral effects related to sensory irritation were evident in the 15 ppm group. Abnor mal histopathological findings were confined to the nasal cavity. Inflammatory ce ll infiltration, erosion or edema of the nasal cavity was evident in all groups, incl uding controls. Significantly increased incidence of non-proliferative (squamous cell metaplasia without epithelial cell hyperplasia) and proliferative lesi ons (epithelial cell hyperplasia with squamous cell metaplasia) were observed in the nasal cavities beginning at 2 ppm. In the 0.3 ppm group, a non-significant inc rease in proliferative nasal

lesions was observed in rats that were either sacri ficed or died following the 18 th
month of exposure. Note that respiratory tract les ions also occur in occupationally exposed workers at lower formaldehyd e concentrations.

Also using male F-344 rats exposed to 0 to 15 ppm f ormaldehyde (6 hours/day, 5 days/week) for up to 6 months, squamous metaplasia was not observed in any regions of the nasal cavity in the control, 0.7, or 2 ppm groups (Kimbell et al., 1997). However, the extent and incidence of squamo us metaplasia in the nasal cavity increased with increasing dose beginning at 6 ppm (Kimbell et al., 1997). In a different study, significant nasal lesions wer e found in rats exposed to 10 ppm formaldehyde (6 hours/day, 5 days/week) for 52 weeks, but exposure to 1.0 ppm or less for this period did not result in nasal histological lesions (Appelman et al., 1988). However, Apfelbach and Weiler deter mined that rats (5 exposed, 10 controls) exposed to 0.25 ppm (0.38 mg/m 3 ) formaldehyde for 130 days lost the olfactory ability to detect ethyl acetate odor (Apfelbach and Weiler, 1991).

Groups of 6 male cynomolgus monkeys, 20 male or fem ale rats, and 10 male or female hamsters were exposed to 0 to 3.0 ppm formal dehyde vapor (22 hours/day, 7 days/week) for 26 weeks (Rusch et al., 1983). There was no treatment-related mortality during the study. In m onkeys, the most significant findings were hoarseness, congestion and squamous m etaplasia of the nasal turbinates in 6/6 monkeys exposed to 2.95 ppm. The re were no signs of toxicity in the lower exposure groups (0.19 and 0.98 ppm). In the rat, squamous metaplasia and basal cell hyperplasia of the nasal epithelia were significantly increased in rats exposed to 2.95 ppm. The same gr oup exhibited decreased body weights and decreased liver weights. In contr ast to monkeys and rats, hamsters did not show any signs of response to expo sure, even at 2.95 ppm.

More than 90% of inhaled formaldehyde gas is absorb ed in the upper respiratory tract of rats and monkeys (Conolly et al., 2002). In rats, it is absorbed in the nasal passages; in monkeys, it is also absorbed in the nasopharynx, trachea and proximal regions of the major bronchi. In mice exp osed to high concentrations of formaldehyde, minute ventilation is decreased by 50 % throughout exposure, resulting in a lower effective dose. This occurs o nly transiently in rats, as the minute ventilation is rapidly restored.Chapter VII Page 147

Acute or subacute exposure of rats to a concentrati on of 2 ppm appears to cause no detectable damage to the nasal epithelium and do es not significantly increase

rates of cell turnover. Cell turnover rates in rat nose during subchronic or chronic exposures to formaldehyde do not increase at 2 ppm, increase marginally at concentrations of 3 to 6 ppm and increase substanti ally at concentrations of 10- 15 ppm. Therefore, concentration is more important than length of exposure in determining the cytotoxicity of formaldehyde (Conol ly et al., 2002). In a different study rats were exposed for six months to 0, 0.5, 3 , and 15 ppm formaldehyde, which resulted in significantly elevated total lung cytochrome P450 in all formaldehyde-exposed groups (Dallas et al., 1989). The degree of P450 induction was highest after 4 days exposure and dec reased slightly over the course of the experiment.

c. Human Carcinogenicity

i. Genotoxicity

Formaldehyde is genotoxic (damaging to genetic mate rial) to humans. Increased numbers of DNA–protein crosslinks have been found i n peripheral blood lymphocytes of exposed workers (Shaham et al., 1997 ; Shaham et al., 2002; Shaham et al., 2003). Formaldehyde induces DNA-pro tein crosslinks, DNA single-strand breaks, chromosomal aberrations, sist er chromatid exchanges and gene mutations in human cells in vitro (Grafstrom et al., 1984; U.S.EPA, 1987; Shaham et al., 1996; IARC, 2004a; 2004b).

ii. Nasopharyngeal Cancer

Many studies in the epidemiological literature supp ort a link between formaldehyde and elevated risk of cancers of the up per respiratory tract in workers and in the general population. According t o the International Agency for the Research on Cancer (IARC), nasopharyngeal cance r mortality was statistically significantly increased in a cohort s tudy of United States industrial workers exposed to formaldehyde in comparison with the U.S. national population, with statistically significant exposure –response relationships for peak and cumulative exposure (IARC, 2004a; 2004b). The individual studies used as

the basis of this conclusion are described in furth er detail below.

Among the industrial cohort studies, Stayner et al. (1988) reported a relative risk of 3.4 (90% CI: 1.2-7.9) for buccal cancer (Stayner et al., 1988), and Blair et al

. (1986) reported a relative risk of 3.00 (90% CI: 1. 30-5.92) for nasopharyngeal cancer (Blair et al., 1986). Among industrial prop ortional mortality studies, Liebling et al

. (1984) reported a relative risk of 8.70 (90% CI: 1. 50-27.33) for buccal/pharyngeal cancer (Liebling et al., 1984) an d Stayner et al

. (1985) reported a relative risk of 7.5 (90% CI: 2.0-19) fo r buccal cancer (Stayner et al., 1985). In all of these studies the elevated risk w as statistically significant. The population-based case control studies reported stat istically significantChapter VII Page 148

relationships between formaldehyde exposure and upp er respiratory cancers in three studies (Olsen and Dossing, 1982; Hayes et al ., 1986; Vaughan et al., 2000), although these cancers can appear in any of several sites. Studies of embalmers, who used formaldehyde, have shown increa sed rates of nasopharyngeal cancer, brain cancer and leukemia. A significant incidence of nasopharyngeal cancer was found among workers in fi berboard plants and among book binders, both being subject to formaldeh yde exposure (Malker et al., 1990).

IARC (2004) has reviewed available cohort studies i ncluding those of embalmers, industrial workers, and British chemical workers (IARC, 2004a; 2004b). An excess of nasopharyngeal cancer was obs erved in a proportionate mortality analysis for the largest U.S. cohort of e mbalmers (Hayes et al., 1990) and in a Danish study of proportionate cancer incid ence among workers at companies which used or manufactured formaldehyde ( Hansen and Olsen, 1995).

In a more recent study, evidence of an exposure-res ponse relationship with mortality from nasopharyngeal cancer was found in a large cohort of formaldehyde-exposed workers, but not for cancers o f the pancreas, brain, lung, or prostate (Hauptmann et al., 2004).

The relation of nasopharyngeal cancer with exposure to formaldehyde has also been investigated in seven case control studies (Ol sen et al., 1984; Vaughan et al., 1986a; 1986b; Roush et al., 1987; West et al., 1993; Armstrong et al., 2000; Vaughan et al., 2000; Hildesheim et al., 2001), fiv e of which found elevations of risk for overall exposure to formaldehyde, or in hi gher exposure categories, including one in which the increase in risk was sta tistically significant, and three that found higher risks in subjects with the highes t probability, level or duration of exposure. The Working Group considered it improbab le that all of the positive findings for nasopharyngeal cancer that were report ed from the epidemiological studies, and particularly from the large study of i ndustrial workers in the USA, could be explained by bias or unrecognized confound ing effects. The Working Group concluded that these studies provide “suffici ent epidemiological evidence that formaldehyde causes nasopharyngeal cancer in h umans” (IARC, 2004a; 2004b).

Blair et al

. (1987) presented further analysis resulting in a significa nt association between nasopharyngeal cancer and simultaneous expo sure to formaldehyde and to particulate, indicating that such exposure m ay be a risk factor (Blair et al., 1987).

Recent occupational studies have investigated the r elationship of formaldehyde exposure to histological changes, some of which are potentially precancerous lesions, in the nasal mucosa. Holmstrom et al

. (1989) found that workers exposed to well-defined levels of formaldehyde deve loped significant changes inChapter VII Page 149

the middle turbinate, while those exposed to both f ormaldehyde and wood dust did not (Holmstrom et al., 1989). Boysen et al

. (1990) found in nasal biopses that workers exposed to formaldehyde showed a significan tly higher degree of metaplastic alterations (Boysen et al., 1990). Edl ing et al

. (1988) found significant histological differences in the nasal mucosa of for maldehyde workers compared to unexposed workers, but found no histological dif ferences between those exposed to formaldehyde and those exposed to formal dehyde and wood dust (Edling et al., 1988). Berke (1987) found no stati stical relationship between exfoliated nasal cells in formaldehyde-exposed work ers and control groups. Thus, these studies provide some indication of poss ible histological changes due to formaldehyde exposure in humans, consistent with results in animals.

iii. Leukemia

Leukemia mortality, primarily of the myeloid-type, was increased in six of seven cohorts of embalmers, funeral-parlor workers, patho logists, and anatomists (Walrath and Fraumeni, 1983; Levine et al., 1984; W alrath and Fraumeni, 1984; Logue et al., 1986; Stroup et al., 1986; Hayes et a l., 1990; Hall et al., 1991) as reviewed by IARC 2004a; IARC 2004b. Recent evidenc e indicates a greater

incidence of leukemia in two cohorts of U.S. indust rial workers and U.S. garment workers, but not in a third cohort of United Kingdo m chemical workers. Therefore, IARC concluded that there is “strong but not sufficient evidence for a causal association between leukemia and occupationa l exposure to formaldehyde” (IARC, 2004a; 2004b).

Until recently, the findings for leukemia in studie s of professional workers appeared to be contradicted by the lack of such fin dings among industrial workers. However, some evidence for an excess of l eukemia has been reported in the recent updates of two of the three major coh ort studies of industrial workers. A statistically significant exposure–resp onse relationship was observed between peak exposures to formaldehyde and mortalit y from leukemia in the study of industrial workers in the USA (Blair et al ., 1990; Hauptmann et al., 2003). A recent meta-analysis found that, overall the relative risk for leukemia in these workers was increased and did not vary signif icantly among studies (Collins and Lineker, 2004).

Mortality from leukemia was also found to be in exc ess in the recent update of the study of garment workers exposed to formaldehyd e in the U.S. (Pinkerton et al., 2004). A small and statistically non-signific ant excess was observed for the entire cohort in comparison with rates from the gen eral population. This excess was somewhat stronger for myeloid leukemia, which i s consistent with the findings from the study of industrial workers in th e U.S. and several of the studies of medical professionals and embalmers. In contras t, the updated study of

industrial workers in the U.K. did not find excess mortality from leukemia (Coggon et al., 2003).Chapter VII Page 150

Linos et al

. reported elevated rates of follicular non-Hodgkin’ s lymphoma and of acute myeloid leukemia among embalmers and funeral directors in a populationbased case control (Linos et al., 1990). The exces s was also stronger among workers with long duration of exposure and long fol low-up, and who had been employed early in the study period when exposures t o formaldehyde were believed to be the highest. This pattern of findin gs is generally consistent with what might be expected if, in fact, exposure to for maldehyde were causally

associated with risk for leukemia.

The IARC Working Group concluded, “In summary, ther e is strong but not

sufficient evidence for a causal association betwee n leukemia and occupational exposure to formaldehyde.” This conclusion, falling between sufficient and limited evidence, was based on a consistently increased ris k in studies of embalmers, funeral parlor workers, pathologists, and anatomist s and was present in two of

the three most informative studies of industrial wo rkers (IARC, 2004a; 2004b).

iv. Lung Cancer

The three largest - and therefore potentially most sensitive - industrial cohort studies reported an elevated rate of lung cancer. The largest study with 26,561 U.S. workers, reported a statistically elevated dea th rate due to lung cancer, equivalent to 35% above the national average (Blair et al., 1986). Several other studies reported elevated death rates due to lung c ancer (Acheson et al., 1984a; 1984b; 1984c) in 7,680 British male workers, mostly young, and in 11,030 US workers, mostly female (Stayner et al., 1988). Som e of the categories in the Acheson study showed statistically significant incr eases of lung cancer (Acheson et al., 1984a; 1984b). The Stayner (1988) study fo und lung cancer to be elevated 14% overall, which was not statistically s ignificant, but the exposures

were well below those of the other two studies.

In Blair et al. (1986), the investigators concluded that a causal relationship between formaldehyde exposure and lung cancer was u nlikely because of a lack of dose gradient for those tumors. Sterling and We inkam (1988; 1989) performed a reanalysis on the basis that Blair et a l

. (1986) failed to account for a “healthy-worker” effect in the original report. Th ese corrected results showed that lung cancer was related to formaldehyde exposu re in a dose-dependent manner which was statistically significant (Sterlin g and Weinkam, 1988; 1989).

Recent epidemiological studies contribute to the co nclusions only marginally.
Gerin et al

. (1989) presented the results of a large case contro l study with 3,726 cancer patients (Gerin et al., 1989). The odds rat io for the highest exposure group with adenocarcinoma of the lung was nearly si gnificant at the 95% confidence level, and there was an apparent trend o f incidence of this cancer with exposure. Bertazzi et al. (1989) presented an extension of a previous study (Bertazzi et al., 1986), that had detected elevated lung cancer among 1,332 workers in a resin B-289 manufacturing plant subjec t to formaldehyde exposureChapter VII Page 151

(Bertazzi et al., 1989 as cited in IARC, 2004a; 200 4b). In the extended study with more accurate estimates of exposure, the lung cancer rate was not elevated above expected for those exposed to formaldehyde (B ertazzi et al., 1989 as cited in IARC, 2004a; 2004b). Coggon et al

. (2003) noted an increase in the risk of lung cancer, but not a significant association with mortality (Coggon et al., 2003). Based on the current data alone, a definitive relat ionship between formaldehyde exposure and lung cancer mortality could not be mad e by the IARC Working Group (IARC, 2004a; 2004b).

v. Sinonasal Cancer

The association between exposure to formaldehyde an d risk for sinonasal cancer

has been evaluated in six case–control studies with a primary focus on formaldehyde. Four of these studies also contribut ed to a pooled analysis that collated occupational data from 12 case–control inv estigations. After adjustment for known occupational confounders, this analysis s howed an increased risk for adenocarcinoma in both men and women and also (alth ough on the basis of only a small number of exposed cases) in the subset of s ubjects who were thought never to have been occupationally exposed to wood o r leather dust. Moreover, there was a dose–response trend in relation to an i ndex of cumulative exposure (Luce et al., 2002). One other case-control study (Olsen and Asnaes, 1986) and a proportionate incidence study (Hansen and Olsen, 1995) showed an increased risk of sinonasal cancer, particularly squamous cel l carcinoma. Against these largely positive findings, the three most informati ve cohort studies of industrial and garment workers showed no excess of sinonasal c ancer (Coggon et al., 2003; Hauptmann et al., 2004; Pinkerton et al., 200 4).

The IARC Working Group noted that most of the epide miological studies did not distinguish tumors as originating in the nose or si nuses, thus an increased risk of

nasal cancer would be diluted if there were no corr esponding effect on the sinuses. In the case-control studies, the Working Group also noted the potential for confounding by wood dust exposure, which is ass ociated with nasopharyngeal adenocarcinoma. The Working Group c oncluded that there is limited evidence that formaldehyde causes sinonasal cancer in humans (IARC, 2004a; 2004b).

vi. Cancer at Other Sites

A number of studies have found associations between exposure to formaldehyde and cancer at other sites, including the oral cavit y, oro- and hypopharynx, pancreas, larynx, lung and brain. However, the IAR C 2004 Working Group considered that the overall balance of epidemiologi cal evidence did not support a causal role for formaldehyde in relation to these o ther cancers (IARC, 2004a, IARC 2004b).Chapter VII Page 152 d. Animal Carcinogenicity

i. Genotoxicity

Formaldehyde is comprehensively genotoxic in a vari ety of experimental systems, ranging from bacteria to rodents, in vivo . Administration of formaldehyde in the diet to Drosophila melanogaster induced lethal and visible mutations, deficiencies, duplications, inversions, translocations and crossing-over in spermatogonia (Auerbach et al., 1977; Swenberg e t al., 1983).

In rodent cells in vitro , formaldehyde induced cell transformation, chromos omal aberrations, sister chromatid exchange, DNA strand breaks, DNA-protein crosslinks and gene mutation (Cosma et al., 1988; C asanova et al., 1994; Merk and Speit, 1998; Speit and Merk, 2002). Inhalation of formaldehyde leads to the formation of DNA-protein cross-links in the nasal r espiratory mucosa of rats and monkeys (Conaway et al., 1996). The formation of D NA-protein cross-links is a sublinear function of the formaldehyde concentratio n in inhaled air from 0.69 to 15 ppm, and the yield of DNA-protein cross-links at a given inhaled concentration is approximately an order of magnitude lower in mon keys than in rats. About 50% of formaldehyde-induced tumors in the nasal muc osa of rats have a point

mutation in the p53 tumor suppressor gene.

ii. Nasopharyngeal Cancer

In experimental animals, several studies have shown that inhalation exposure induces squamous cell carcinomas of the nasal cavit ies in rats (Albert et al., 1982; Kerns et al., 1983; Sellakumar et al., 1985; Morgan et al., 1986; Feron et al., 1988; Woutersen et al., 1989; Monticello et al ., 1996; Kamata et al., 1997), although single studies in mice (Kerns et al., 1983 ) and hamsters (Dalbey, 1982) showed no carcinogenic effects. Several studies in which formaldehyde was administered to rats by inhalation showed evidence of carcinogenicity, particularly induction of squamous-cell carcinomas of the nasal cavities, usually only at the highest exposure. A chronic exposure s tudy that primarily investigated aspects of nasal tumor development, ex amined rat nasal cavities following exposure to 0 - 15 ppm of formaldehyde fo r 6 hours/day, 5 days/week for 24 months (Monticello et al., 1996). Nasal les ions developed at 6, 10, and 15 ppm. The two highest doses included epithelial hyp ertrophy and hyperplasia, squamous metaplasia, and a mixed inflammatory cell infiltrate, but the lesions of the 6 ppm group were minimal to absent and limited to focal squamous metaplasia in the anterior regions of the nasal cav ity (Monticello et al., 1996).

A study sponsored by the Chemical Industry Institut e for Toxicology (CIIT) has provided the most quantitatively useful evidence fo r the carcinogenicity of formaldehyde (Swenberg et al., 1980a; Swenberg et a l., 1980b; Kerns et al., 1983). This study used 120 male and 120 female Fis cher-344 rats in each dose group, including a clean air group. The adjusted t umor incidences (adjusted forChapter VII Page 153

competing causes of death, including scheduled inte rim sacrifices) for squamous cell carcinomas in the nasal passages of males and females combined, when exposed to 0 to 14.3 ppm formaldehyde (6 hours/day, 5 days/week) for up to 24 months, were 0/156, 0/159, 2/153 and 94/140 for the highest dose group (14.3 ppm) (USEPA, 1987).

In an analogous study on mice, two mice in the high dose group (14.3 ppm) developed squamous cell carcinomas, a finding that was not statistically significant, but was thought to be biologically sig nificant due to the absence of

this tumor in control animals and due to concurrenc e with the rat studies. Kerns

et al

. (1983) also reported benign tumors, including polyp oid adenomas and squamous cell papillomas (Kerns et al., 1983). Swenberg et al

. (1980) described

a number of additional lesions in the nasal turbina tes of rats exposed to formaldehyde for 18 months, including rhinitis, epi thelial dysplasia and hyperplasia, squamous hyperplasia, and cellular aty pia that occurred in a doserelated manner (Swenberg et al., 1980a; Swenberg et al., 1980b). Other inhalation studies (Albert et al., 1982; Tobe et al ., 1985) have also provided positive evidence for the carcinogenicity of formal dehyde.

iii. Leukemia

The IARC Working Group concluded, “The current data indicate that both genotoxicity and cytotoxicity play important roles in the carcinogenesis of formaldehyde in nasal tissues.” On the other hand, with respect to the potential for formaldehyde to induce leukemia, the Working Gr oup was not aware of any good rodent models for acute myeloid leukemia in hu mans (IARC, 2004a; IARC 2004b). Several possible mechanisms were considere d, such as clastogenic damage to circulating stem cells. There is a singl e study reporting cytogenetic abnormalities in the bone marrow of rats inhaling f ormaldehyde (Kitaeva et al., 1990). The Working Group concluded, “Based on the data available at this time, it was not possible to identify a mechanism for the induction of myeloid leukemia in humans” (IARC 2004a; IARC 2004b).

iv. Other Routes of Exposure

Four studies of formaldehyde administered to rats i n drinking-water gave varying

results: one showed an increased incidence of fores tomach papillomas in male rats (Takahashi et al., 1986), a second showed an i ncreased incidence of gastrointestinal leiomyosarcomas in female rats and in both sexes combined (Soffritti et al., 1989), a third showed increased incidences of total malignant tumors, lymphomas and leukemias, and testicular int erstitial-cell adenomas in male rats (Soffritti et al., 2002), while a fourth did not show a carcinogenic effect (Til et al., 1989).Chapter VII Page 154

Recent investigations of chronic toxicity have show n formaldehyde administered orally for 24 months to be carcinogenic in Sprague- Dawley rats. Six exposure groups each of 50 male and 50 female Sprague-Dawley rats, with drinking water concentration of 8 ppm to 1210 ppm formaldehyde, re ported increases in the percent of B-290 animals bearing leukemias and gast rointestinal neoplasias at the higher exposures. Til et al

. (1989), using three exposure groups, of 70 male and 70 female Wistar rats each, with drinking water concentrations of 16 to1 532 ppm, reported numerous pathological changes at the highest exposure level, but no evidence of carcinogenicity at any level. Tobe et al. (1989), using three exposure groups, of 20 male and 20 female Wistar ra ts each, with drinking water concentrations of 161 to 4032 ppm, also reported pa thological changes at the highest exposures level but no significant increase s in the incidence of any tumor in these small treatment groups (Tobe et al., 1989) . In a letter to the editor,

Feron et al

. (1990) questioned the conclusions and some methods of Soffritti et

al

. (1989) (Feron et al., 1990).

Other types of exposures have produced a spectrum o f results. Watanabe et al. (1954) presented a brief preliminary report of expe rimentally inducing sarcomas by repeated injections of an aqueous solution of fo rmaldehyde in rats (Watanabe et al., 1954 as cited in IARC (2004)). Muller et a l. (1978) induced a preneoplastic lesion of the oral mucosa by repeated exposure to f ormalin solution in rabbits

. (Muller et al., 1978). Homma et al. (1986) found that formalin solution repeatedly administered in transplanted rat bladders did not p romote the formation of tumors (Homma et al., 1986). Takahashi et al. (1986) found that formalin solution in the diet promoted stomach tumors in Wistar rats (Takaha shi et al., 1986). Iversen et

al. (1988) found that topical skin application of forma ldehyde solution in mice did not promote the formation of skin tumors (Iversen e t al., 1988).

v. Co-carcinogenicity

Formaldehyde has shown co-carcinogenic effects by i nhalation, ingestion, and dermal exposure to rodents (Dalbey, 1982; Takahashi et al., 1986; Iversen et al., 1988). In additional studies in mice, rats and ham sters, modification of the carcinogenicity of known carcinogens was tested by administration of formaldehyde in drinking-water, by application on t he skin or by inhalation. Oral administration of formaldehyde concomitantly with N -nitrosodimethylamine to

mice increased the incidence of tumors at various s ites. Exposure of hamsters to formaldehyde by inhalation increased the multiplici ty of tracheal tumors induced by subcutaneous injections of N -nitrosodiethylamine (Morgan et al., 1986). Skin application of formaldehyde concomitantly with 7,12 -dimethylbenz[ a ]anthracene reduced the latency of skin tumors in mice (Homma e t al., 1986). In rats, concomitant administration of formaldehyde and N -methyl- N  ́-nitro- Nnitrosoguanidine in the drinking-water increased th e incidence of adenocarcinoma of the glandular stomach (Tobe et al ., 1989).Chapter VII Page 155 vi. Overall IARC Conclusion

The IARC Working Group concluded that formaldehyde is carcinogenic to humans (Group 1) , on the basis of sufficient evidence in humans and sufficient

evidence in experimental animals. Based on the information now available, this classification is higher than those of earlier IARC evaluations (IARC 1982, 1987, 1995)(IARC 2004a; IARC 2004b).

C. Factors that Affect the Outcome of a Health Ris k Assessment

Estimates of the potential health effects of HCHO e missions from composite wood products could be affected by:

• HCHO concentrations in indoor microenvironments;

• Rate of decrease in product-specific HCHO emission s with time;

• Initial product-specific HCHO emission rates;

• Air exchange rates in indoor microenvironments;

• Product-specific HCHO compensation points;

• Number and total surface area of HCHO-emitting pro ducts; and

• Practices utilized, if any, to reduce indoor HCHO exposure.

Variations in the numerical value of these factors will have substantive impacts on estimates of potential cancer risk and extent of non-cancer effects. For example, maintaining high air exchange rates and us ing air filtration systems could greatly reduce indoor exposures in homes, sch ools, and workplaces.

D. Summary of Potential Health Impacts

In this chapter, the results of the total daily HCH O exposure analyses are presented. As Californians spend 90% or more of th eir day indoors (University of California, Berkeley, 1991a), total daily HCHO expo sure is predominantly determined by indoor air quality. Based on the exp osure analysis, significant reductions in lifetime cancer risk may be realized by reducing HCHO emissions from composite wood products used as building mater ials and to fabricate finished products, such as furniture.

To calculate total daily exposure to HCHO requires data on activity patterns (i.e., time spent in different microenvironments; Table VI I-3) and typical HCHO concentrations ( μ g/m 3 ) in the selected microenvironments (Table VII-1). A daily TWA was calculated for an average and elevated expo sure for adults and children (i.e., four scenarios – current-average an d current-elevated for children and adults).Chapter VII Page 156

Table VII-3. Age-group Specific and Average Child and Adult Activity Patterns 1

Age T ind (hr) T out (hr) T inv (hr) T total (hr)

0-2 21.43 1.57 1.01 24.00

3-5 20.47 2.38 1.15 23.99

6-8 20.34 2.83 0.83 24.00

9-11 19.69 3.28 1.03 24.01

12-17 21.23 1.00 1.78 23.99

18-24 20.55 1.23 2.22 24.01

25-34 20.98 1.21 1.83 23.99

35-44 20.65 1.36 1.98 23.96

45-54 20.95 0.98 2.03 23.96

55-64 20.64 1.73 1.63 23.99

65 + 21.57 1.15 1.3 24.02 Child – Average 20.55 2.45 1.00 24.00 Adult – Average 20.82 1.47 1.71 24.00

(1) Sources : University of California, Berkeley, 1991a and 1991b. T ind = time spent indoors; T out = time spent outdoors, T inv = time spent in-vehicles, and T total = (T ind + T out + T inv ). Averages for children and adults are the average from age 0-9 and 0-70 years, respectively.

Summary data in two technical reports were used to calculate the average time spent indoors, outdoors, or in a vehicle (Universit y of California, Berkeley, 1991a; 1991b). For children from age 0-11, average time s pent was calculated as the mean for boys and girls for age groups 0-2, 3-5, 6- 8, and 9-11 (University of California, Berkeley, 1991b). Activity patterns fo r adolescents and adults were calculated as the mean for men and women for age gr oups 12-17, 18-24, 25-34, 35-44, 45-54, 55-64, and 65 + (University of California, Berkeley, 1991a). Over a conceptual 70-year lifetime, the standard exposure duration for health risk assessments (OEHHA, 2003), T ind ranged from 19.69 to 21.57 hr/day, T out from 0.98 to 3.28 hr/day, and T inv from 0.83 to 2.22 hr/day (Table VII-3).

Using the data in Tables VII-1 and VII-3, estimates of total daily HCHO exposure ( μ g/m 3 -hr) and daily time-weighted average HCHO concentra tion ( μ g/m 3 ) were calculated (Table VII-4). Although adults spend mo re time indoors or in-vehicles, there are only slight differences in exposure and d aily TWA compared to

children.Chapter VII Page 157

Table VII-4. Estimates of Total Formaldehyde (HCHO) Exposure and Daily Timeweighted Average (TWA) Formaldehyde Concentration 1

----- HCHO ( μ g/m 3 ) ----- Exposure ( μ g/m 3 -hr) Environment Time (hr) Average Elevated Average Elevated

Child: Total Exposure and Daily TWA

Indoors 20.65 17.2 46.7 355 964

In-vehicle 1.25 9.6 12 12 15

Outdoors 2.10 3.7 15 8 32
Total 24 ----- ----- 375 1,011 Daily TWA ----- ----- ----- 15.6 42.1

Adult: Total Exposure and Daily TWA

Indoors 20.82 17.2 46.7 358 972

In-vehicle 1.71 9.6 12 16 21

Outdoors 1.47 3.7 15 6 22
Total 24 ----- ----- 380 1,015 Daily TWA ----- ----- ----- 15.8 42.3

(1) Sources: Refer to Tables VII-1 and VII-3. “HCHO” = formaldehyde; “ μ g/m 3 ” = micrograms per cubic meter; “ μ g/m 3 -hr” = μ g/m 3 )-hour. Exposure was calculated by multiplying “time” by average or elevated HCHO concentration. Daily TWA was calculated by dividing “Exposure” by 24 -hours.

E. Multi-pathway Health Risk Assessment

To evaluate the potential health effects of a TAC a ll the routes by which an individual may be exposed to the TAC need to be ide ntified. The pathways or routes of pollutant exposure may include inhalation , dermal exposure, and ingestion of soil particles and food. For purposes of this HRA and rulemaking, inhalation is the principal pathway of HCHO exposur e (95% or more), with small amounts of uptake by dermal exposure from disinfect ant use. Therefore, analysis of impacts is based on exposure via inhala tion only.

F. Statewide Emission and Risk Reduction Benefits

The proposed ATCM would reduce emissions of HCHO fr om HWPW, PB, and MDF by approximately 20% in Phase 1 and approximate ly 57% in Phase 2, resulting in an estimated annual statewide emission s reduction of 180 and 500 tons per year, respectively. Because these emissio ns would substantially reduce indoor HCHO exposures, where HCHO levels are highes t and where people spend approximately 90% of their time, the reductio n in potential excess cancerChapter VII Page 158

cases in children is estimated to range from 3 to 9 after Phase 1, and 9 to 26 after Phase 2 (Table VII-5).

Table VII-5. Estimated Cancer Risk in Children and Adults After Implementation

of the Phase 1 and Phase 2 Emission Standards 1

Childhood Exposure: 9-year Exposure to Formaldehyde (HCHO)

Exposure Scenario TWA HCHO ( μ g/m 3 ) Cancer Risk

Per Million Cancer Cases

Reduced Current-average 16 23 -----

• Post Phase 1 13 20 3

• Post Phase 2 9 14 9

Current-elevated 42 63 -----

• Post Phase 1 36 54 9

• Post Phase 2 25 37 26

Lifetime Exposure: 70-year Exposure to Formaldehyde (HCHO)

Exposure Scenario TWA HCHO ( μ g/m 3 ) Cancer Risk

Per Million Cancer Cases

Reduced Current-average 16 86 -----

• Post Phase 1 14 74 12

• Post Phase 2 9 51 35

Current-elevated 42 231 -----

• Post Phase 1 36 196 35

• Post Phase 2 25 134 97

(1) “TWA HCHO” = Daily time-weighted average HCHO concentration. Changes in Phase 1 and

Phase 2 TWA HCHO levels were calculated based on 16% and 44% reductions in HCHO levels in a home (Appendix E). Cancer risk was calculated according to OEHHA (2005c).

For adults, reductions in cancer risk, based on a 7 0-year lifetime exposure, would be reduced by 12 to 35, and 35 to 97, after Phase 1 and Phase 2, respectively (Table VII-5).

Non-cancer chronic inhalation impacts were calculat ed by dividing the daily TWA exposure concentrations by the chronic inhalation R EL for HCHO (i.e., 3 μ g/m 3
for eye irritation) to derive a hazard quotient (OE HHA, 2003). Thus the hazard quotient based on the current-average TWA exposure concentration (15.8 μ g/m 3 ) would be 5.3 -- after Phase 1 and Phase 2, the haza rd quotient would decreaseChapter VII Page 159

to 4.5 and 3.1, respectively. As all of these valu es are greater than one, there is a probability of adverse eye irritation effects fro m HCHO at current- and future daily TWA exposure concentrations. The current ave rage, post-Phase 1, and post-Phase 2 hazard quotients for children were 5.2 , 4.4, and 3.1, respectively. For the current-elevated scenario, hazard quotients were approximately 2.7 times higher than for the current-average scenario in all time frames.

G. Potential Adverse Health Effects from Replaceme nt Compounds

It is anticipated that most manufacturers will achi eve the required emission reductions by lowering the amount of HCHO used in t he UF resin systems that they presently use. However, greater use of existi ng low-formaldehyde or formaldehyde-free adhesives may be considered (i.e. , phenol-formaldehyde, melamine-formaldehyde and isocyanates) in selected products. One HWPW manufacturer began the exclusive use of a soy flour -based adhesive in 2006.

1. Methylene Diphenyl Isocyanate (CAS No. 101-68-8 )

Methylene diphenyl isocyanate (MDI) is used in exis ting wood adhesives (Forest Products Laboratory, 1999). In consideration of po tential respiratory effects, the

chronic REL for MDI is 0.7 μ g/m 3 in California (OEHHA, 2000). Workplaces are the primary source of exposure to MDI, where it is handled by workers using respirators (Massachusetts Toxics Use Reduction Ins titute, Not Dated; NIOSH, 2005). The USEPA (Not Dated) reported that there i s inadequate data to classify MDI as a human carcinogen, consistent with a not cl assifiable designation by IARC (Massachusetts Toxics Use Reduction Institute, Not Dated). The USEPA (Not Dated) also reported that there was only limit ed data regarding animal carcinogenicity. It should be noted that panels ma de with MDI, once reacted in the production facility, do not continue to emit as do the current UF resin products.

2. Melamine (CAS No. 108-78-1)

Presently, melamine-HCHO resins are used in the man ufacture of HWPW, and HCHO emissions from these products were found to be intermediate to those of products bonded with urea-formaldehyde (high) and p henol-formaldehyde (low) (CARB 2003 Survey, unpublished data). Toxicity to mammals is low – it is not irritating to skin or eyes (OECD, 1998). Although one study found that melamine exposure produced urinary bladder tumors in male ra ts, it has not been classified as a carcinogen by IARC.

3. Phenol (CAS No. 108-95-2)

Phenol is a hazardous air pollutant that was identi fied as TAC under AB 2728 (CARB, 1993). To a limited extent, manufacturers m ay choose to utilize phenolHCHO resin in place of urea-formaldehyde for select ed applications. WoodChapter VII Page 160

products made with phenol-formaldehyde resins have very low HCHO emissions, and are exempt from the U.S. Housing and Urban Deve lopment standards for building materials used in mobile home construction (PFS Research Foundation, 2001). Phenol is a common industrial chemical used in a variety of manufacturing processes and household products (CAR B, 1997c). While phenol is a strong eye and respiratory irritant, there are limited data concerning its chronic health effects in humans resulting from inh alation or oral exposure. Moreover, due to a lack of data, phenol has not bee n classified as a carcinogen by either USEPA or IARC.

4. Soy Flour

A soy flour based resin is scheduled for use in the manufacture of HWPW by Columbia Forest Products beginning in 2006 (McIsaac , 2005). Soy flour is a high protein powder generally made from dehulled, heat-p rocessed soybeans or soybean flakes (Wikipedia Contributors, 2007). Soy flour is already being used in preparation and manufacture of a number of food products sold throughout the world, and its use as a wood adhesive is not expect ed to cause adverse noncancer or cancer health effects.

H. Workplace Exposure

Formaldehyde is a TAC (CARB, 1992) that is classifi ed as a known human carcinogen by IARC, and is an irritant to the eyes and the respiratory system. At concentrations ranging from 0.5 to 1.0 ppm, most in dividuals will experience eye, nose, and/or throat irritation. At concentrations greater than 1.0 ppm, HCHO causes extreme discomfort (OEHHA, 1999). Various w orkplace standards have been developed in consideration of these findings:

• U.S. Department of Labor’s Occupational Safety & H ealth Administration (OSHA) adopted “Permissible Exposure Limits” (PEL) in 1992 of 0.75-ppm for an 8-hr workday, and a 2-ppm Short-term Exposur e Limit (STEL) (Formaldehyde Council Inc., 2005);

• Australia “Worksafe Standards” are 1.0 ppm “time-w eighted average” (TWA) for an 8-hr workday, and a 2 ppm STEL for 15- min as safe levels for occupational exposure (Plywood Association of A ustralasia, 2004); and

• New Zealand’s “Occupational Exposure Limit” (OEL) is 1.0 ppm, not to be exceeded (Plywood Association of Australasia, 2004)

. Lowering the amount of HCHO used in the manufacture of MDF, PB, and HWPW serves to reduce workplace HCHO exposures for worke rs in raw board manufacturing and resin plants. Moreover, end-user exposure would also be

lowered due to the reduced HCHO content of raw boar ds.Chapter VII Page 161

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### VIII. Economic Impacts of the Proposed Airborne To xic Control

Measure

This chapter presents the estimated costs and econo mic impacts associated with the implementation of the proposed ATCM to control HCHO emissions from HWPW, PB, MDF, and finished goods that contain thos e materials. An overview of composite wood manufacturing in the U.S. is prov ided as a basis for assessing the financial ability of manufacturers to produce p roducts that comply with the proposed emission standards. An explanation of the cost-basis is then presented where estimates of the least-costly (i.e. , use of “drop-in” technology) and most-costly (i.e., outdated plants) options are presented, along with projected impacts to small producers.

The total cost of compliance to the composite wood manufacturing industry was estimated by multiplying the projected per panel in creases in HWPW, PB, and MDF by the amount sold to California. These costs would be borne by those manufacturers that currently do not produce product s that comply with the proposed Phase 1 or Phase 2 standards and plan to c ontinue to sell products into the California market. The projected impacts to downstream businesses such as distributors, importers, fabricators, and r etailers are also discussed.

A. Background

1. Composite Wood Product Manufacturing in the U.S

.

a. Particleboard

In North America (U.S. and Canada), PB manufacturin g is a billion-plus dollar industry (Composite Panel Association, 2006). In 2 005, North American PB shipments ( ≈ production) of industrial and flooring products we re approximately

6-billion ft 2 (approximately 10-million m 3 ) with an estimated value of $1.65 billion (i.e., the average cost of PB was $311 per thousand ft 2 ).

In North America, the interests of PB and MDF manuf acturers are largely represented by the Composite Panel Association (Gai thersburg, Maryland). An affiliated organization, the 180-plus member Compos ite Wood Council, brings together PB and MDF panel producers, furniture and cabinet manufacturers, distributors, suppliers, and others to disseminate to a broader audience, the attributes of composite wood products. The Composi te Panel Association’s current membership includes 37 of the leading U.S., Canadian, and Mexican manufacturers, collectively representing over 95% o f total North American manufacturing capacity (Table VIII-1) (Composite Pa nel Association, Not Dated).

This number is consistent with estimates for 1997-9 8, when the number of U.S. mills was thought to be 45 to 51 (Sellers, 2001; US EPA, 2002), which may account for the small percentage of manufacturers t hat are not members of the Composite Panel Association. Seven companies that manufacture PB in NorthChapter VIII Page 179

America also operate MDF mills (i.e., ATC Panels, F lakeboard, Georgia-Pacific, SierraPine, Temple-Inland, Uniboard, Weyerhaeuser).

In the CARB 2003 Survey, responses were received fr om 20-mills regarding the manufacture of PB (CARB, 2003). The range in repor ted annual production

amounts was 36- to 350-million ft 2 , where the median annual production of the

20-mills was 130-million ft 2 . In an attempt to classify the mills as either sm all, mid-size, or large, for purposes of this report, sm all manufacturers were designated as mills that produced less than 110-mil lion ft 2 (17%), mid-size

manufacturers between 110- to 170-million ft 2 (37%), and large manufacturers

more than 170-million ft 2 (46%). Regardless of whether a mill was small, mi dsize, or large, these facilities represent enterpri ses with a minimum of 50 or more employees. Similar distinctions were made for the 56-companies subject to the

USEPA’s National Emission Standard for Hazardous Ai r Pollutants rulemaking for composite wood product manufacturing: 23% of fa cilities had less than 100- employees, 54% had between 100- to 249-employees, a nd 23% had more than 250-employees (USEPA, 2002).

Besides number of employees, questions arise with r espect to mill age and the vintage of equipment being used at present, which w ill likely determine the extent of modification needed to produce PB that complies with proposed Phase 1 and

Phase 2 standards in 2009 to 2012. It is not clear what portion of the industry has already expended resources to upgrade their fac ilities over the past 10- years. Seemingly, as this is an industry that is m ade up principally of mid-size and large companies, those that choose to make the necessary improvements to produce low-emission PB for the California market w ill do so after careful consideration of the potential economic impacts.

Table VIII-1. Particleboard Manufacturers in the C omposite Panel Association

No. Company (No. Mills) Mill Location(s) 1 ATC Panels, Inc. (2) Franklin, VA; Moncure, NC 2 Boise Cascade Corp. (1) La Grande, OR 3 CanPar Industries (1) Grand Forks, British Columb ia 4 Collins Products, LLC (1) Klamath Falls, OR 5 Columbia Forest Products (1) Hearst, Ontario 6 Duraplay de Parral, S.A. de C.V. (1) Parral, Chih uahua 7 Fibratech Mfg., Inc. (1) Atikokan, Ontario 8 Flakeboard Co., Ltd. (1) St. Stephen, New Brunswi ck 9 Florida Plywoods, Inc. (1) Greenville, Florida

10 Georgia-Pacific Corp. (5) Gaylord, MI; Louisville, MS; Russellville, SC; Taylorsville, MS; Vienna, GA 11 GreenTech Panels, LLC (1) Minden, LAChapter VIII Page 180 Table VIII-1. Continued

No. Company (No. Mills) Mill Location(s) 12 Marshfield Door Systems, Inc. (1) Marshfield, WI 13 Merillat Industries, Inc. (1) Rapid City, SD 14 No. Engineered Wood Products (1) Smithers, Brit ish Columbia 15 Panolam Industries International (1) Huntsville, Ontario 16 Potlatch Forest Products, Corp. (1) Post Falls, ID

17 Rexcel S.A. de C.V. (2) Chihuahua, Chihuahua; Zitacuaro, Michoacan 18 Roseburg Forest Products Co. (2) Dillard, OR; M issoula, MT

19 SierraPine, Ltd. (3) Adel, GA; Martell, CA; Springfield,

OR 20 Tafisa Canada & Co., Ltd. (1) Lac-Megantic, Queb ec

21 Temple-Inland (4) Diboll, TX; Hope, AR; Monroeville, AL; Thomson, GA 22 Timber Products Co. (1) Medford, OR

23 Uniboard Canada, Inc. (2) Sayabec, Quebec; Val d’Or,
Quebec 24 Webb Furniture Enterprises, Inc. (1) Galax, VA

25 Weyerhaeuser Co. (3) Albany, OR; Bennetsville, SC; Simsboro, LA

Source : Composite Panel Association (Not Dated).

b. Medium Density Fiberboard

In terms of total North American production, the am ount of MDF produced in 2005 was less than half of the amount of PB product ion (i.e., 2.6-billion vs. 5.6-

billion ft 2 ) (Composite Panel Association, 2006). The total v alue of the MDF was estimated to be $1-billion, about 63% of the value of PB production. Per

thousand ft 2 , the average cost of MDF was about 40% higher than PB (i.e., $435 vs. $311) in 2005. The Composite Panel Association currently lists 26-mills among its member companies (Table VIII-2) (Composit e Panel Association, Not Dated).

In the CARB 2003 Survey, responses were received fr om 12-mills regarding MDF production volume (CARB, 2003). The range in r eported annual production

amounts was 18- to 204-million ft 2 , where the median annual production of the

12-mills was 107-million ft 2 . For the MDF cost analysis we classified the MDF mills as either small, mid-size, or large; in this case, small manufacturers were designated as mills that produced less than 100-mil lion ft 2 (18%), mid-size

manufacturers between 100- to 125-million ft 2 (38%), and large manufacturers

more than 125-million ft 2 (43%). Like PB-mills, small, mid-size, and large MDFmills appear to be fairly substantive facilities re quiring 50-plus employees.Chapter VIII Page 181

Table VIII-2. Medium Density Fiberboard Manufactur ers in the Composite

Panel Association

No. Company (No. Mills) Mill(s) 1 ATC Panels, Inc. (2) Clarion, PA; Pembroke, Onta rio 2 Basset Fiberboard (1) Bassett, VA 3 CMI/CraftMaster Mfg., Inc. (1) Towanda, PA 4 Del-Tin Fiber, LLC (1) El Dorado, AR

5 Flakeboard Co., Ltd. (2) St. Stephen, New Brunswick; Sault Ste. Marie, Ontario 6 Georgia-Pacific Corp. (2) Holly Hill, SC; Montic ello, GA 7 Great Lakes MDF, LLC (1) Lackawanna, NY 8 Langboard, Inc. (1) Willacochee, GA 9 Norbord Industries, Inc. (1) Deposit, NY 10 Pan Pacific Products, Inc. (1) Broken Bow, OK 11 Plum Creek MDF, Inc. (1) Columbia Falls, MT 12 Sacopan, Inc. (1) Sacre-Coeur, Quebec 13 SierraPine, Ltd. (2) Medford, OR; Rocklin, CA 14 Temple-Inland (1) Mt. Jewett, PA

15 Uniboard Canada, Inc. (2) La Bale, Quebec; Mont-Laurier,
Quebec 16 Unilin US MDF (1) Mt. Gilead, NC

17 West Fraser Mills Ltd. (2) Quesnel, British Columbia; White Court, Alberta

18 Weyerhaeuser Co. (3) Bennettsville, SC; Eugene, OR; Malvern, AR

Source : Composite Panel Association (Not Dated).

c. Hardwood Plywood

Statistics compiled by the U.S. Department of Comme rce report that hardwood veneer products accounted for nearly 25% of the ind ustry’s output in the early 1990’s (Answers.com, Not Dated). In the late 1990’ s, North American shipments (i.e., production) of hardwood veneer products were worth approximately $1 billion. The U.S. Department of Commerce report ed that approximately 50% of the plywood and veneer output in the 1990’s was mainly consumed in residential construction, and 25% was utilized in o ther lumber and wood products industries, while 11% was used in furniture and fix tures. The U.S. Census

Bureau estimated that there were 332 facilities in the U.S. that made hardwood veneer and plywood in the late 1990’s. Hardwood pl ywood production in 2000

was estimated to be 2.04 million m 3 (including core material such as softwood plywood and OSB), in 2000 these firms shipped $3.3- billion worth of goods andChapter VIII Page 182

employed approximately 24,000 workers (Encyclopedia of American Industries, 2007).

In North America, Indiana, North Carolina, Wisconsi n, and Michigan had the largest product shipments in this segment (Answers. com, Not Dated). One of the principal industry leaders in this category is Ply Gem Industries Inc., with 4,079 employees, followed by two Oregon, based companies; Roseburg Forest Products Co., with 3,975 employees and Columbia For est Products Inc. had 3,500 employees.

In North America, the interest of hardwood plywood manufacturers are largely represented by the Hardwood Plywood and Veneer Asso ciation (HPVA), based in Reston, VA (Table VIII-3). Member companies of HPVA produce 90% of the HWPW stock panels and hardwood veneer manufactured in North America. The HPVA is an international trade association, current ly representing more than 150 wood industry companies in the U.S., Canada, and ab road.

Table. VIII-3. Hardwood Plywood Facilities in Nort h America

No. Company (No. Mills) Mill(s) 1 Atlantic Veneer Corp. (1) Beaufort, NC 2 Autumn House (1) Granite Falls, NC 3 Besse Forest Products (1) Matoon, WI 4 Birchland Plywood, Ltd (1) Thessalon, Ontario 5 Buffalo Veneer & Plywood (1) Buffalo, MN 6 Chesapeake Hardwood Prod. (1) Chesapeake, VA

7 Columbia Forest Products (7) Trumann, AR; Old Fort, NC; Klamath Falls, OR; Chatham, VA; Hearst, Ontario; St. Casimir,
Quebec 8 Commonwealth Plywood Co. (1) Ste-Therese, Ontario 9 Darlington Veneer Co., Inc. (1) Darlington, SC 10 Duraply De Parral (1) Parral, Chihuahua, Mexico 11 European Panel Products (1) San Diego, CA 12 Florida Plywoods Inc (1) Greenville, FL 13 G/L Veneer Co., Inc. (1) Huntington Park, CA 14 General Veneer Manufacturing (1) South Gate, CA 15 Howell Plywood Corp (1) Dothan, AL 16 K & L Woodworking, Inc (1) Reading, PA 17 Mt Baker Products, Inc. (1) Bellingham, WA 18 Murphy Plywood Co. (1) Eugene, OR 19 Navy Island Plywood (1) West St. Paul, MN 20 Norbord Industries (2) Toronto and Cochrane, Ont arioChapter VIII Page 183 Table VIII-3. Continued

No. Company (No. Mills) Mill(s) 21 Nova Wood lamination Inc. (1) Kitchener, ON, Can ada 22 Panoply Corp (1) Lexington, TN 23 PanTim Wood Products, Inc. (1) Portland, ME 24 Panel Source International, Inc. (1) St. Albert, Alberta, Canada 25 Pavco Industries, Inc. (1) Pascagoula, MS 26 Perfecta Plywood Ltd. (1) St-Hyacinth, QC Canad a 27 Pittsburgh Forest Products (2) McMurray, PA; Tol edo, OH 28 Pluswood (1) Oshkosh, WI 29 Plywood Mfg. of California, Inc. (1) Torrance, C A 30 Pro-Ply Custom Plywood, Inc. (1) Mississauga, ON Canada 31 Roseburg Forest Products Co. (1) Roseburg, OR 32 States Industries, Inc. (2) Eugene, OR; Mocksvil le, NC 33 South West Panel Products (1) Katy, TX

34 Timber Products Company (4) Springfield, OR; Corinth, MS; Medford, OR; Grants Pass, OR 35 Veneer One Inc. (1) Oceanside, NY 36 Vermont Plywood (1) Hancock, VT 37 Western Panel Mfg., Inc. (1) Eugene, OR 38 The Wood Gallery, Inc. (1) Dallas, TX 39 Greenline Plywood Prod., Ltd. (1) Stouffville, O ntario

Source : Hardwood Plywood and Veneer Association (2007)

In the CARB 2003 Survey, responses were received fr om ten-mills regarding HWPW production volume (CARB, 2003). The range in reported annual production amounts was 300-thousand to 218-million ft 2 , where the median annual production of the ten-mills was 69-million f t 2 . For the HWPW cost analysis we classified the mills as either small, m id-size, or large manufacturers; in this case, small manufacturers were designated a s mills that produced less

than 25-million ft 2 (3%), mid-size manufacturers between 25- to 100-mi llion ft 2
(44%), and large manufacturers more than 100-millio n ft 2 (53%). Unlike PB and MDF mills, which appear to be fairly substantial si ze fairly, small HWPW mills may be operated by 10- to 15-employees.

The extent of modification necessary to produce har dwood plywood that complies with the proposed Phase 1 and Phase 2 stan dards in 2009 to 2012 will largely depend on the age of the industry (mills), equipment being used, wood species, and type of plywood being made. Approxima tely 40 to 50 percent of the hardwood plywood products sold in California are pr oduced by companies that already expended resources to upgrade their facilit ies in the past several years. A two-tiered structure has emerged that includes pl ants that are newer, larger, and operate at low-cost while there are many older, specialized, smaller, high-Chapter VIII Page 184

cost plants that try to survive, however, it is no t clear what portion of the industry is comprised by the latter.

2. Legal Mandates

Government Code §11346.3 requires state agencies to assess the potential for adverse economic impacts on California businesses a nd individuals when proposing to adopt or amend any regulation, such as the proposed ATCM. The assessment must include an evaluation of the impact of the proposed regulation on jobs, business expansion, elimination, or creati on, and the ability of California businesses to compete with comparable entities in o ther states. In addition, Government Code §11357 and guidelines adopted by th e Department of Finance (DOF) require CARB and other state agencies to esti mate the associated cost or savings to any local, state, or federal agency from the proposed ATCM. The agency proposing a regulation is also required to d etermine whether, as a result of the regulation, any cost to local agencies or sc hool districts is reimbursable by

the state.

Health & Safety Code §57005 further requires CARB t o perform an economic impact analysis of submitted alternatives to a prop osed regulation before the adoption of any major regulation. A “major regulat ion” is defined as a regulation that would potentially cost California businesses m ore than $10-million per year.

3. Affected Businesses

Any business that manufactures or markets HWPW, PB, or MDF for sale or supply, or finished goods containing those material s for sale or supply in California would potentially be affected by the pro posed ATCM. This would also include businesses that supply or manufacture resin s used in the aforementioned commodities and surface treatments. In this regard , the proposed ATCM is anticipated to directly and indirectly affect a wid e range of businesses in California, the U.S., and other countries. The dir ectly affected businesses include the following Standard Industrial Classific ation (SIC) codes (U.S. Census Bureau, 2003):

2435: Hardwood Veneer and Plywood Manufacturing, an d 2493: Medium Density Fiberboard and Particleboard M anufacturing.

Presently, the U.S. Census Bureau is revising the S IC coding system to the North American Industry Classification System (NAIC S). In this system, “Wood Product Manufacturing” is assigned to NAICS code nu mber 321, under which manufacturers of HWPW are assigned to category numb er 321211, and MDF

and PB manufacturers to 321219.

To our knowledge, the major manufacturers of HWPW, PB, or MDF are member companies of the Composite Wood Council and/or Comp osite Panel Association.Chapter VIII Page 185

The Composite Wood Council membership also includes panel and finished good/product distributors, home furnishing and cabi net manufacturers, equipment manufacturers, suppliers, secondary manuf acturers (including laminators, cut-to-size operations, and component m anufacturers), transporters, and trade magazines in California. The Composite P anel Association represents over 95% of the North American manufacturing capaci ty for PB, MDF, hardboard, and other compatible products (Composite Panel Asso ciation, 2007).

While manufacturers of HWPW, PB, or MDF are example s of directly impacted businesses, wood furniture and cabinet makers would be examples of indirectly impacted businesses. As the proposed ATCM will req uire downstream entities to purchase and use the Phase 1- and Phase 2-compliant HWPW, PB, or MDF in finished goods, compliance with the proposed ATCM w ill present different challenges to the various entities in the distribut ion chain from manufacturers to

retailers.

There will not be an impact on any local government agency or school district because the proposed ATCM specifically excludes the m from the fabricator definition and, therefore, the fabricator requireme nts.

4. Ability to Comply with the ATCM

a. Potential Business Impact

This portion of the economic impact analysis is bas ed on a comparison of the return on owners’ equity (ROE) for affected busines ses before and after inclusion of the cost to comply with the proposed requirement s. The data used in this analysis are obtained from publicly available sourc es, the 2003 CARB Survey, the Dun and Bradstreet financial data website, and the staff’s cost analysis discussed later in this chapter.

i. Affected Manufacturers

The survey identifies 25 mills nationwide that pote ntially will be affected by the Phase 2 standards of the proposed ATCM. Only nine mills owned by three companies are located in California. Of the 25 mil ls, there are 10 that manufacture PB which are owned by eight companies. There are nine that manufacture MDF owned by three companies, and six t hat manufacture HWPW that are owned by six companies. Table VIII-4 prov ides a range of cost per plant for these mills by product type.Chapter VIII Page 186 Table VIII-4. Cost per Plant by Type of Affected Pr oduct

Product Companies Mills Cost per Plant PB 8 10 $0.12 to 17.8 million MDF 3 9 $0 to 15.9 million HWPW 6 6 $0 to 6.6 million Total 17 25 $127 million

ii. Study Approach

This study covers 14 affected companies because thr ee of the above companies manufacture both PB and MDF. The approach used in evaluating the potential economic impact is outlined as follows:

• Compliance cost was estimated for each of these bu sinesses.

• Estimated cost was adjusted for federal and state taxes.

• The three-year average ROE was calculated, where d ata were available, for each of these businesses by averaging their ROE s for 2003 through 2005. ROE is calculated by dividing the net profit by the net worth. The adjusted cost was then subtracted from net profit d ata. The results were used to calculate an adjusted three-year average RO E. The adjusted ROE was then compared with the ROE before subtracti on of the adjusted cost to determine the potential impact on profitabi lity of the business. A reduction of more than 10% in profitability is cons idered to indicate a potential for significant adverse economic impacts.

The threshold value of 10% has been used consistent ly by CARB staff to determine impact severity. This threshold is consi stent with the thresholds used by USEPA and others.

iii. Assumptions

Calculations of ROEs before and after subtraction o f the adjusted compliance costs were based on the following assumptions:

• All affected businesses were subject to the highes t federal and state corporate tax rates of 35% and 9.3%, respectively; and

• Affected businesses are not able to increase the p rices of their products, nor can they lower their costs of doing business th rough short-term costcutting measures.

We understand that this last assumption is too cons ervative and it is unlikely to occur. This assumption is made to assess the sever ity of impacts using static measures of profit. According to USEPA (2004), ply wood and reconstitutedChapter VIII Page 187

wood products that are used in the construction ind ustry have a price elasticity of demand ranging from -0.10 to -0.27. This implies t hat for every 10% change in the price of these products, the quantity demanded for these products would decline from 1 to 2.7%. In other words, the affect ed manufacturers have a great ability to pass on their compliance costs to consum ers. Thus, it is likely that most

manufacturers will be able to recover the bulk of c ompliance costs through higher prices for their wood products.

iv. Results

These businesses are affected by the proposed ATCM to the extent that the additional costs imposed by the proposed requiremen ts would change their profitability. A detailed discussion and analysis of these costs is provided in the cost section of this report. According to the staf f’s cost analysis, the costs of manufacturing a 4’ x 8’ compliant wood panel board will range from about 3 to $6. The Phase 2 standards of the proposed ATCM wil l affect about 1.2 billion ft 2
of wood panel board used in California, thereby imp osing approximately 127 million in costs on composite wood manufacturers.

Using ROE to measure profitability, we found that t he average ROE of affected businesses declined by about 12% as shown in Table VIII-5. This represents a significant change in the average profitability of these businesses if they absorbed the entire cost of compliance. However, a s stated above, these businesses are most likely to be able to recover th e bulk of the cost increase

from consumers because of inelastic demand for thei r products. In such a case, the maximum price increase of a 4’ x 8’ compliant w ood panel to consumers would range from approximately $3.60 to $7.20 if ma nufacturers are able to recover the entire compliance cost of the proposed ATCM.

Table VIII-5. Change in Return on Owner’s Equity ( ROEs) for Typical Manufacturers in the Composite Wood Products Indust ry 1

Product Manufactured ∆ ROE

Particleboard 1.0% Medium Density Fiberboard 1.1% Hardwood Plywood 64.1%

Average 11.6%

(1) “ ∆ ” = change; all ∆ ROEs shown are negative (i.e., shows a decline in profitability).

As shown in Table VIII-5, the projected change in p rofitability of typical businesses in composite wood industry varies widely . The predicted decline in profitability of these businesses ranged from a hig h of about 64% for a HWPW

manufacturer to a low of 1.0% for a PB manufacturer . This variation in theChapter VIII Page 188

impact of the proposed ATCM can be attributed mainl y to the following factors. First, some manufacturers incur higher costs due to the quantity of noncompliant wood products they manufacture or market. For inst ance, the estimated annual costs for affected businesses ranged from a high of about $55 million to a low of about $112,000. Second, some manufacturers operate multiple mills of different sizes, others operate only one mill. Finally, the performance of manufacturers may differ from year to year. Hence, the average 2 003 through 2005 financial data used may not be representative of an average-y ear performance for some

manufacturers.

The estimated changes to ROEs may be high for the f ollowing reasons. First, annual costs of compliance are estimated using, in part, the current prices of raw materials. Raw material prices usually tend to fal l as higher demand for these materials induces economy of scale production in th e long run. Second, as stated above affected manufacturers probably would not absorb all of the increase in their costs of doing business. They wo uld be able to pass some of the cost on to consumers in the form of higher pric es. Also, they might be able to improve their operational efficiency, thus reducing their costs.

b. Potential Impact on Employment

The proposed ATCM is not expected to cause a notice able change in California employment and payroll. According to the 2004 U.S. Census Bureau (U.S. Census Bureau, 2006a; 2006b), California employment in the composite wood product industry (NAICS 321211/SIC 2435 and NAICS 3 21219/2493, which includes establishments engaged in manufacturing ha rdwood veneer and plywood, and reconstituted wood products) was 1,449 in 2004, or about 3.5% of the national employment in the industry. This repr esents about 0.1% of the total manufacturing jobs in California in 2004. These em ployees working in 38 establishments generated about $49 million in payro ll (Table VIII-6), accounting

for less than 0.1% of total California manufacturin g payroll in 2004. Six establishments had 100 employees or more; the other 32 had less than 100 employees each.

Table VIII-6. Establishments, Employees, and Payro ll by Industry

NAICS SIC Establishments Employees Annual Payroll 321211 2435 18 570 $13,794,000 321219 2493 20 879 $34,971,000 Total 38 1,449 $48,765,000

The employment in the composite wood products indus try accounts for a small portion of the California economy. The employment in the industry is unlikely to change significantly as a result of the proposed AT CM. This is because demand for affected products is price inelastic; implying that affected manufacturers orChapter VIII Page 189

marketers would be able to pass on the bulk of the cost increase to consumers in terms of higher prices for their products. In addi tion, strict enforcement of the proposed ATCM may enable domestic manufacturers to expand their California market share. Overseas manufacturers that produce low cost high emitting products are likely to lose some of their current p rice advantages over domestic manufacturers when the proposed ATCM goes into effe ct. Thus, most domestic manufacturers are likely to maintain their current profitability and as a result, no noticeable change is expected in their employment.

B. Cost of Compliance

1. Price Trends

In the U.S., the housing sector largely determines the demand for wood products (lumber and composite panels) (U.S. Department of A griculture, Not Dated). It is estimated that over 55% of the engineered wood prod ucts (e.g., PB, MDF, plywood, oriented strand board) manufactured in the U.S. is sold to residential house builders, and an additional 18% to commercial and industrial buildings (Global Wood Trade Network, 2005). The furniture i ndustry consumes a 22% share, mostly PB and MDF. Only 4% is exported (est imated valued = $1.2- billion), with nearly 50% of exports sold to Canada

.

a. Particleboard

From 1995 to 2005, unit prices of industrial PB ($/ thousand square feet ($/MSF)) ranged from $250 in 2003 to $328 in 2004 (Table VII I-7) (Composite Panel Association, 2006). Comparable unit prices were re ported in Random Lengths (2006) for Eastern PB, where prices ranged from $21 4 to $291. Relative to PB production, the decrease in unit price coincides wi th a drop in production volume in 2001, just prior to the start of a strong upturn in housing starts in 2003 (Random Lengths, 2006). As the number of housing s tarts remained high in 2004 and 2005, there was an increase in PB producti on to meet demand, and unit prices remained above $300 per MSF. Using hou sing starts as an indicator of wood product demand in the housing sector, the f luctuations in the unit price of PB from 2002 to 2005 can be explained, in part, by the sufficiency of PB supplies (and lower prices) in 2002 and 2003, followed by te mporary shortages leading to increased production and higher costs in 2004 and 2 005.Chapter VIII Page 190 Table VIII-7. Unit Cost of Industrial Particleboard : 1995-2005 1

------ Industrial Particleboard ($/MSF) -----

Year Composite Panel

Association Random Lengths --

East Production

(MSF)

1995 306 289 4,199,735
1996 287 285 4,367,662
1997 288 274 5,553,339
1998 274 269 5,836,159
1999 297 282 6,148,748
2000 321 286 6,113,097
2001 279 250 5,582,154
2002 263 214 6,016,915
2003 250 222 5,585,105
2004 328 291 5,851,270
2005 311 283 5,626,080

Mean 291 268 -----

(1) Source: Composite Panel Association (2006); Random Lengths (2006a). “$/MSF” = Dollars per million square feet. Data for industrial particleboard are estimated on a 3⁄4” basis.

Some of the demand for PB during 2004 and 2005 may have been met by increasing the amount of imports or by reducing exp orts (Figure VIII-1). In 2002, total U.S. imports of PB from China were valued at approximately $56,000 (U.S. Department of Agriculture, Not Dated (a)). Over th e ensuing four-years, the value of Chinese imports has risen nearly 100-fold to approximately $5-million. At a unit price of $300 per MSF, the represents abo ut 16,500 MSF, less than 0.5% of total U.S. production in 2005 (Composite Pa nel Association, 2006).Chapter VIII Page 191

Figure VIII-1. Value ($) of U.S. Imports of Particl eboard from China: 1997 to

2006 1

0

500 1000 1500 2000 2500 3000 3500 4000 4500 5000

1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

Year Particleboard Imported from China - Values in 1000 Dollars

(1) Source: U.S. Department of Agriculture (Not Dated (a)).

b. Medium Density Fiberboard

In 1995 to 2005, unit prices ($/MSF) of MDF ranged from $340 in 1999 to $442 per MSF in 1995; the 10-year mean was $380 per MSF (Table VIII-8) (Composite Panel Association, 2006). Similar findings were re ported by Random Lengths (2006a) for western MDF; unit prices ranged from $3 37 to $416 per MSF. In contrast to PB, MDF production has increased steadi ly over this period from 1.1-

million MSF in 1995 to 2.6-million MSF in 2005. Ho wever, similar to PB, unit prices rose substantially in 2004 and 2005, possibl y due to an increased demand for MDF in the housing sector.Chapter VIII Page 192 Table VIII-8. Unit Cost of Medium Density Fiberboar d: 1995-2005 1

------ Medium Density Fiberboard ($/MSF) -----

Year Composite Panel

Association Random Lengths --

West Production

(MSF)

1995 442 ----- 1,106,827
1996 387 411 1,200,700
1997 350 362 1,715,842
1998 337 342 1,900,486
1999 340 344 2,199,102
2000 366 358 2,193,398
2001 365 369 2,125,431
2002 389 366 2,386,843
2003 373 337 2,284,945
2004 399 415 2,554,629
2005 435 416 2,647,575

Mean 380 372 -----

(1) Source: Composite Panel Association (2006); Random Lengths (2006a). “$/MSF” = Dollars per million square feet. Data for medium density fiberboard are estimated on a 3⁄4” basis.

Imports of MDF from China, as for PB, have risen su bstantially since the late 1990’s (Figure VIII-2). In 2002, total U.S. import s from China were valued at approximately $500,000 and in 2006, were in excess of $17-million (U.S. Department of Agriculture, Not Dated (a)). At a un it price of $400 per MSF, the present amount of imported MDF from China represent s approximately 43,500 MSF or 1 to 2% of total U.S. production.Chapter VIII Page 193

Figure VIII-2. Value ($) of U.S. Imports of Medium Density Fiberboard from

China: 1997 to 2006 1

0 2000 4000 6000 8000 10000 12000 14000 16000 18000

1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

Year MDF Panel Imported from China- Values in 1000 Dolla rs

(1) Source: U.S. Department of Agriculture (Not Dated).

c. Hardwood Plywood

For HWPW, we were not able to find historical unit price data for panels. However, as shown in Table VIII-9, we found that wh olesale panel prices vary considerably depending on the type of face species and core used in the panel.

Table VIII-9. Unit Cost of Hardwood Plywood 1

Face Species Core Price per MSF Price per Piece White Maple Particleboard $375 $12 Nat. Birch Veneer $312 $10 Cherry Particleboard $375 $12 Hickory Veneer $469 $15 White Maple Veneer $469 $15 Luxcell Veneer $469 $15 White Birch Veneer $500 $16 Red Oak Veneer $500 $16 Red Oak Particleboard $375 $12

(1) Source : Pittsburgh Forest Products Company (2007).Chapter VIII Page 194

Currently, the HWPW industry has been experiencing strong competition from foreign producers. Imports of veneer, plywood and engineered wood products exceed exports by a wide margin (Global Wood, 2005) . In 2004, imported products were valued at approximately $9-billion, w hich represents nearly 25% of domestic demand. The growth in 2004 was estimated to be 51%, in spite of the weakening U.S. dollar. The U.S. trade deficit in v eneer, plywood, and engineered wood products is $7.8-billion.

Imports of HWPW from China, as for PB and MDF, have risen substantially since the late 1990’s (Figure VIII-3). In 2002, total U. S. imports from China were valued at approximately $64-million and in 2006, we re in excess of $730-million (U.S. Department of Agriculture, Not Dated (a)).

Figure VIII-3. Value ($) of U.S. Imports of Hardwo od Plywood from China: 1997

to 2006 1

0

100000 200000 300000 400000 500000 600000 700000 800000

1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

Year Hardwood Plywood Imported from China - Values in 10 00 Dollars

(1) Source: U.S. Department of Agriculture (Not Dated (a)).

According to Wood Based Panels International (2006) , the major plywood suppliers to the U.S. are Brazil, with 1.6-million m 3 (30.4% market share), China

with 1.3 million m 3 (24.2%), and Canada with 700,000 m 3 in 2005 (13.4%). Brazil, China, and Canada account for a combined ma rket share of approximately 67%.

2. Effect of Imports

The U.S. is the world’s leading importer of wood pr oducts ($23.3 billion), followed by the EU-25 ($13.2-billion), and Japan ($11.8-bill ion) (Global Trade Atlas, Not Dated), where in 2004, the major U.S. suppliers wer e Canada (61%), China, and Brazil. The market leader for engineered wood prod ucts in the U.S. is Weyerhaeuser (10% market share); Georgia-Pacific, B oise Cascade, andChapter VIII Page 195

Louisiana-Pacific are the next largest U.S. produce rs, and the combined U.S. market share of these four companies is approximate ly 30% (Global Wood Trade Network, 2005).

As the demand for low-cost composite wood products continues to remain high in the U.S., the demand is increasingly being met by i mports, due in part to higher costs for labor, energy, raw materials, and environ mental compliance in the U.S. In addition to panel manufacturers, furniture compa nies in the U.S., Europe, and Mexico have also commented about the increasing amo unt of furniture coming from China, where labor costs are lower (i.e., Chin ese furniture exports in 1999 and 2005 were $5-billion and $22-billion, respectiv ely) (Bowersheim, Not dated). Although Canada is the leading source of imported w ood products to the U.S., products from China are increasing in market share and may continue to rise in light of reported plans for production line improve ments (U.S. Department of Agriculture, Not Dated (b)). Presently, a typical Chinese production line is relatively small, producing less than 50,000 m 3 per year vs. 170,000 m 3 per year in other countries (i.e., 50,000 m 3 ≈ 29,000 MSF). While China has made regular purchases of four to six presses each year, it was reported that the Shanghai Wood-based Panel Machinery Co., Ltd. has recently d eveloped a continuous plat press with an annual output capacity of 200,000 m 3 that may be put into production beginning in 2007 (Global Wood Trade Net work, 2007).

3. Factors to Consider for Regulatory Compliance

Currently, the major centers of composite panel man ufacturing in the U.S. are located in the Pacific Northwest, Northeast, and So utheast (USEPA, 2002). For the most part, large manufacturers with customers t hroughout the country operate mills in each of these regions in order to deliver their products in a timely and cost-competitive manner. It is estimated that California consumes roughly 11% of the composite wood products manufactured in the U.S., and thus, manufacturers could choose whether or not to supply products to meet this sector of the U.S. Presumably, in consideration of the present way composite wood products are supplied to customers, the major portion of products for the California market would be supplied by mills in the Pacific Northwest. However, as a major portion of the U.S. furniture and cabine t industry is located on the eastern seaboard, some portion of manufacturers may choose to produce CARBcompliant products for finished goods that will be sold to California.

Since the proposed Phase 1 and Phase 2 standards ar e based on emissions performance, several resin systems could be used. If a company determines that major upgrades are needed to produce CARB-comp liant products at one of their mills, they would have the option to make “49 -state” products at that mill for

sale in other states or countries. Given the absen ce of HCHO emission standards for wood products of equal stringency to the proposed ATCM when it is fully implemented, in other states, Europe, and selected parts of Asia,Chapter VIII Page 196

manufacturers with multiple mills would not be requ ired to convert their entire operation to producing CARB-compliant composite woo d products.

In the following subsections, the projected increas e in the cost of PB, MDF, and HWPW manufactured to comply with proposed Phase 2 s tandard is described. Understanding the incremental increase in cost on a panel-basis is fundamental to evaluating costs downstream, in that the costs o f storing and redistributing the products are passed on from one level to the next. The analysis in this section serves to establish the incremental production cost to manufacturers, as a basis for assessing downstream cost to consumers.

4. Particleboard: Estimated Increase in Panel Cost

The five main steps in PB manufacturing are: (1) pr eparation of the furnish (i.e., wood particles), (2) resin application, (3) mat for mation, (4) hot pressing, and (5) finishing. The furnish is prepared by refining log s and other raw materials into small particles, and drying them to achieve a moist ure content of 2 to 7% (Cognard, 2005). To control HCHO emissions, it is projected that selected manufacturers using PF resins may need to upgrade o r purchase new dryers to more precisely control the moisture contents of the PB furnish that they use to make panels compliant with the proposed Phase 1 and Phase 2 standards. To optimize their drying operations, these manufacture rs may incur a one-time capital investment for a new dryer. Depending on t he size and energy rating of the new dryer, energy costs may increase, but some of these costs may be offset by savings due to more precise resin use.

During resin application, resin is mixed with the f urnish. In PB made with a UF resin, the resin accounts for 5 to 12% of the total weight of the panel depending on the size of the wood particles and the required properties of the panel (e.g., moisture resistance) (Cognard, 2005; Goldboard, 200 0). Projected cost impacts during resin application will depend on the type of resin that manufacturers choose to produce panels compliant with the propose d Phase 1 and Phase 2 standards, as the use of a new resin may require ch anges in mixing or application equipment, as well as the cost of the n ew additives, if any.

After a UF resin is thoroughly mixed with the furni sh, the mixture is cold-pressed to form a mat, then hot-pressed at cure temperature s ranging from 130 to 150 o C (Cognard, 2005). In comparison, PB made with PF re sin requires hot-pressing at temperatures ranging from 180 to 230 o C (Pizzi, 1994). As greater energy costs will be incurred from the use of higher hot-press t emperatures and longer press times, the increase cost per panel is expected to r ange on a case-by-case basis. The range of changes that a manufacturer chooses to make will determine the extent of the cost increase that they incur.Chapter VIII Page 197

In the finishing process, PB panels are trimmed, cu t, and sanded to produce panels of a desired thickness. Staff expects that any changes in the costs associated with the finishing process would be insi gnificant.

To maintain a competitive board price, optimization of the manufacturing process may provide cost savings to varying degrees. For e xample, optimizing resin distribution and application systems could reduce r esin waste, and lower manufacturing costs as well as surface HCHO emissio ns from the board.

a. Drop-in Approach: Modified UF or Alternate Resi n

In this subsection, the estimated cost of manufactu ring a PB panel with a modified or alternate resin system, which does not require an upgrade to the existing equipment in a mill, is discussed. It is projected that to manufacture PB that complies with the proposed Phase 1 and Phase 2 standards, manufacturers will need to modify their existing UF resins or use an alternative resin system, which could have a measurable impact on the resin c ost portion (30%) of the total cost of manufacturing a PB panel (Table VIII- 10).

The cost of manufacturing PB can be apportioned int o six categories: adhesive, energy, labor, wax, wood, and miscellaneous costs ( Table VIII-10). Among the six categories, the cost of the adhesive and wood a mounts to over 50% of the total cost of manufacturing a panel. In future yea rs, the cost of wood particles may rise significantly due to the shortage of harve stable forests in the U.S. and the inability to produce PB entirely from furnish m ade with urban wood waste. Moreover, the future cost of petroleum-based adhesi ve components (e.g., HCHO) is uncertain given the volatility in supply a nd demand that has occurred over the last 10-years.

Table VIII-10. Breakdown of Costs in Particleboard

Manufacturing 1

Category Percent (%) of Panel Cost

Adhesive 30 Electricity 9

Labor 19

Wax 3

Wood Particles 24

Miscellaneous 15

(1) Source: Industry Canada (2005a; 2005b).

Selected measures of the cost of PB and an estimate of the cost for the resin used to bind the furnish in PB ranging in thickness from 3⁄8 ” to 3⁄4” is presented inChapter VIII Page 198

Table VIII-11. Over this range of PB thickness, th e present cost of the UF resin used to manufacture a PB panel ranges from $2.74 to $3.57.

Table VIII-11. Estimated Cost of UF Resin in Parti cleboard of Varying

Thickness 1

------------ Board Thickness (Inches) ----------- - Measure of Cost 3⁄8 ” 1⁄2” 5⁄8 ” 3⁄4” 1,000 ft 2 $286 $299 $333 $372 4’ x 8’ Panel $9.15 $9.57 $10.66 $11.90 Estimated Resin Cost $2.74 $2.81 $3.20 $3.57

(1) Sources: Random Lengths (2006b); Industry Canada (2005a; 2005b).

Urea-formaldehyde (UF) is the most commonly used re sin for manufacturing interior grade PB in the U.S., largely because of i ts relatively fast curing speed

and low cost. As the cost of the resin used to bin d the wood particles in PB typically accounts for approximately 30% of the pri ce of a PB panel (Industry Canada, 2005b), assuming that manufacturers may cho ose to use an alternate resin system to lower their HCHO emissions, our ana lyses indicate that the most likely alternates would include MF, MUF, PUF, pMDI, and PF. As the prices for these resins are higher than for UF resin, the cost of a PB panel compliant with the proposed Phase 1 or Phase 2 standards is expect ed to increase (Table VIII-12). In calculating a “final cost,” fa ctors such as press conditions (e.g., press temperature, curing rate and applicati on rate) and the use of additives (e.g., extenders, hardeners, scavengers), which may increase or decrease the final cost, were considered.

Efficient application of extenders may reduce overa ll resin costs by up to 10% (Marutzky, 1989; Frihart, 2005) – extenders or fill ers (e.g, walnut shell flour), can be added to resins to reduce adhesive cost by limit ing the amount of resin overpenetration into wood particles. Hardeners or curi ng agents can be added to a resin to accelerate the hardening process, and coul d increase total production rates by up to 10%. Scavengers may also be added t o reduce HCHO emissions during or after production. Commonly added scaveng ers include urea alone, or in combination with ammonium chloride or with organ ic amines. Panel manufacturers report that the application of scaven gers could increase board prices by 1 to 5%.Chapter VIII Page 199

Table VIII-12. Estimated Price Increase in Particl eboard Made to Comply with

the Phase 2 Standard with an Alternate Resin 1

Resin Type Cost

($ lbs -1 ) Cure

Temp. Cure

Rate HCHO

(ppm) Price

Increase (%)

UF 0.24-0.27 NA NA 0.3 NA MF 0.72-0.81 Higher Slower < 0.09 60 to 70 MUF (<12%) 0.31-0.46 Higher Slower < 0.09 10 to 30 MUF (>12%) 0.48-0.68 Higher Slower < 0.09 30 to 55

MUF + Catcher 0.24-0.27 Similar Similar < 0.09 < 5 PF 0.48-0.68 Higher Slower < 0.09 30 to 55 pMDI 0.96-1.35 Lower Slower Trace 90 to 140

(1) “Cure Temp.” = cure temperature; “ppm” = parts per million; “NA” = not available; “UF” = ureaformaldehyde; “MF” = melamine-formaldehyde; “MUF” = melamine-UF; “PF” = phenolformaldehyde; “pMDI” = polymeric diphenylmethane diisocyanate. Cure rate and temperature are relative to production conditions for manufacturing particleboard (PB) with a UF resin. Values f or “Price Increase” are relative to the cost of PB made with a UF resin; effects of cure temperature and rate were not considered. Resin costs are based on price information supplied at public workshops or in stakeholder meetings.

Melamine-formaldehyde (MF) resin is presently used as an adhesive in exterior and semi-exterior grade plywood and PB, decorative laminates, paper treating and coating (Pizzi, 1994; Youngquist, 1999). As an alternative to UF resin, the use of MF resin may be cost-prohibitive in the 2010 to 2012 timeframe. It is estimated that PB made with a MF resin that complie s with the proposed Phase 2 standard could cost up to 60 to 70% more th an PB made with UF resin.

Melamine Urea-formaldehyde (MUF) resin has been sho wn to improve the moisture resistance of PB while lowering surface HC HO emissions. Typically, a

MUF resin with a melamine content of 12% or less is used to lower thickness

swell as well as surface HCHO emissions. Conceivab ly, the use of a MUF resin with lower melamine contents could result in PB pro duction costs comparable to the use of a UF resin. According to one major resi n manufacturer, a 1% increase

in the melamine content of a resin raises the cost of the resin by as much as $25 to $30 per ton (1.2 to 1.5¢ per pound). While the cost of manufacturing PB with a MUF resin is expected to be higher, its superior mo isture resistance may allow it to command a higher price than PB made with a UF re sin having lesser moisture resistance properties, thus moderating the extent o f the overall impact of the projected cost increase (10 to 30%). Akzo Nobel (2 005) has developed a “catcher” which has been used in Europe to produce panels meeting the E1 standard, and has the potential to be used as an ad ditive that would minimally increase the manufacturing cost of PB made with a U F resin.Chapter VIII Page 200

Phenol-formaldehyde (PF) resin is principally used in the manufacture of exteriorgrade plywood and PB, where superior water resistan ce is required. Blends of PF resins with resorcinol (i.e., PRF resins) are kn own to provide advantages insofar as lower cure temperature (Frihart, 2005). However, resorcinol is very expensive to use, and PRF resins would not be a cos t-competitive alternative to UF resin. At present, it is projected that at resi n application rates currently used to manufacture exterior-grade PB, the cost of a PB panel compliant with the proposed Phase 2 standard would be 30 to 55% higher due to higher resin costs and higher press temperatures. Further resin devel opment to allow faster cure speeds could significantly lower production costs.

Polymeric diphenylmethane diisocyanate (pMDI) resin has a low viscosity (Marutzky, 1989), which typically is mixed with a r eleasing agent to prevent panels from sticking to metal surfaces during hot p ressing. Although pMDI resin is more expensive than UF resin (Table VIII-9), the re are production cost-savings that partially offset the higher resin cost, such a s the ability to use furnish with a higher moisture content and lower resin spread rate (Zheng, 2002). Analogous to MUF resins, higher prices could be afforded to P B made with pMDI owing to its superior water resistance relative to PB made w ith a UF resin. Further costsavings may also be achieved through the use of agr icultural residues, such as wheat or rice straw in place of wood particles. At the plant-level, conversion of existing UF or PF facilities to pMDI should not req uire substantial manufacturing process-related capital investment (Goldboard, 2000 ).

Despite its high cost, Osman et al. (1994) reported making PB with a phenolurea-formaldehyde (PUF) resin to which they added M DI alone, or in combination with urea. Of the three components, the cost of MD I (approximately $2,200 per ton) was approximately twice that of PUF (approxima tely $1,000 per ton) and ten-times more than urea (approximately $200 per to n). These workers reported making PB with PUF-MDI-urea resins that were compar able in cost and internal bond strength to PB made with the PUF resin.

b. Plant Upgrade: New Equipment

Sellers (2001) reported on a suite of technologies being developed to improve productivity in the panel manufacturing process. T he list included:

• Radio-frequency curing – to provide more precise c ontrol over adhesiverelated processes, increase production, and uniform ity of curing;

• Steam injection – to accelerate cure rates for pMD I and PF resins;

• Foam extruders – to reduce adhesive use, trim loss , and clean-up;

• Continuous presses – to increase production and co ntrol product surface roughness over that achieved by batch platen presse s; and

• Resin additives to reduce tool wear.Chapter VIII Page 201

In discussions with industry representatives, the c ost of equipment replacement is a multi-million dollar undertaking, in that equi pment such as presses or dryers have $1-million or more price tags. As such, shoul d a manufacturer elect to upgrade a plant to produce CARB-compliant products, it would likely involve an investment of $200,000 to $300,000 per year for ten or more years. Given the amount that it would cost to upgrade a plant, manuf acturers would need to be reasonably certain of being able to recover their c ost of investment. As they would have the option of producing products for mar kets other than California, it is not likely that manufacturers will make a major investment of this kind. Thus, in our view, unless manufacturers can produce CARB- compliant PB with “dropin” technology, it is more likely that the plant wi ll be dedicated to the production of “49-state” wood products.

c. Small Producers

Based on the CARB 2003 Survey, a small PB producer manufactures less than

110-million ft 2 , and would be operated by less than 100-employees. For this size of facility, in addition to higher resin costs, con sideration must also be given to potential cost increases due to quality control tes ting and documenting chain-ofcustody. If the producer is already a member of th e Composite Panel Association or the Hardwood Plywood & Veneer Associ ation, no additional costs may be anticipated for quality control testing and only minimal increases would be projected for labeling and chain-of-custody rela ted activities. Likewise, compliance testing is tied to production volume, an d therefore, smaller producers would conduct fewer tests over time than large prod ucers, since they produce less product.

5. Medium Density Fiberboard: Estimated Increase i n Panel Cost

In 2003, MDF production was 2.7-million m 3 in the U.S., where it is primarily used in the manufacture of furniture, shelving, molding, and kitchen cabinets (Composite Panel Association, 2006; Howard, 2005). Manufacturing processes for MDF are similar to that for PB, except that add itional processing is required to prepare the fibers in the MDF furnish.

a. Drop-in Approach: Modified Urea-formaldehyde or Alternate Resin

The most promising alternative resins for making MD F that complies with the proposed Phase 1 and Phase 2 standards are similar to those for PB (Table VIII-12). For MDF, the cost of resin typica lly accounts for 27% of the cost of a panel (Industry Canada, 2005a). Estimates of the cost of resin in MDF of varying thickness are shown in Table VIII-13. For the most common thicknesses, the estimated cost of UF resin alone ranges from $3 to $4 per panel.Chapter VIII Page 202 Table VIII-13. Estimated Cost of Urea-formaldehyde (UF) Resin in Medium Density Fiberboard (MDF) of Varying Thicknes s 1

---------- Board Thickness ---------- Measure of Cost 3⁄8 ” 1⁄2” 5⁄8 ” 3⁄4” 1,000 ft 2 $309 $344 $402 $454 4’ x 8’ Panel $9.89 $11.01 $12.86 $14.53 Estimated Resin Cost $2.67 $2.97 $3.48 $3.92

(1) Source: Random Lengths (2006b). Estimated resin cost is based on the resin accounting for 27% of the cost of a MDF panel.

The estimated price increases for MDF made with an alternate resin are slightly less on a percentage basis than for PB. The most p romising option at this time appears to be the addition of melamine to a UF resi n (i.e., MUF), which could raise the price of a panel by 10 to 50% (Table VIII -14). While some manufacturers presently produce MDF with pMDI for s pecialty applications,

unless the cost of the furnish material can be decr eased significantly (e.g., fibers from rice straw instead of wood), the use of pMDI r epresents a higher cost option.

Table VIII-14. Estimated Price Increase in Medium Density Fiberboard Made to

Comply with the Phase 2 Standard with an Alternate Resin 1

Resin Type Cost

($/lbs) Cure

Temp. Cure

Rate HCHO

(ppm) Price

Increase (%)

UF 0.24-0.27 NA NA 0.3 NA MF 0.72-0.81 Higher Slower <0.08 55 to 65 MUF (<12%) 0.31-0.46 Higher Slower <0.08 10 to 25 MUF (>12%) 0.48-0.68 Higher Slower <0.08 30 to 50 pMDI 0.96-1.35 Lower Slower Trace 80 to 125

(1) “Cure Temp.” = cure temperature; “ppm” = parts per million; “NA” = not available; “UF” = ureaformaldehyde; “MF” = melamine-formaldehyde; “MUF” = melamine-UF; “pMDI” = poly meric diphenylmethane diisocyanate. Cure rate and temperature are relative to production conditions for manufacturing medium density fiberboard (MDF) with a UF resin. Values for “Price Increas e” are relative to the cost of MDF made with a UF resin; effects of cure temperature and rate were not considered. Resin costs are based on price information supplied at public workshops or in stakeholder meetings.Chapter VIII Page 203 b. Plant Upgrade: New Equipment

As noted for PB, the cost of equipment replacement is a multi-million dollar undertaking, where presses or dryers cost $1-millio n a piece or more. As such, if a manufacturer chooses to upgrade a plant to produc e CARB-compliant MDF, it could entail an investment of $200,000 to $300,000 per year for ten or more years. Given the cost to upgrade a plant, it is no t likely that manufacturers will make a major investment of this kind, especially si nce they have the option to produce MDF for customers outside of California. T hus, in our view, unless manufacturers can produce CARB-compliant MDF with “ drop-in” technology, it is more likely that a plant will be dedicated to the p roduction of “non-California” wood products.

c. Small Producers

Based on the CARB 2003 Survey, a small MDF producer manufactures less than

100-million ft 2 , and would be operated by less than 100-employees. For this size of facility, in addition to higher resin costs, con sideration must also be given to potential cost increases due to quality control tes ting and documenting chain-ofcustody. If the producer is a member of the Compos ite Panel Association, no additional costs would be anticipated for quality c ontrol testing and only minimal increases would be projected for labeling and chain -of-custody related activities.

6. Hardwood Plywood (HWPW): Estimated Increase in Panel Cost

Plywood is made out of wood veneers and an inner co re, where the core may be a wood veneer, lumber, PB, MDF, or a combination of materials. In 2003, HWPW production in the U.S. was estimated to be 1.9 -million m 3 (Howard, 2005). The primary uses of HWPW are for interior w all panels, furniture, flooring,

and cabinets.

a. Drop-in Approach: Modified Urea-formaldehyde or Alternate Resin

In a plywood panel, the cost of the resin is estima ted to be about 5% of the total cost of the panel (Industry Canada, 2005b). In com parison, the cost of the resin

accounts for 30% or 27% of the cost of a PB or MDF panel, respectively. For HWPW, the wood components (i.e., veneer and core ma terials) account for 50% or more of the cost the panel. Depending on the sp ecies and cut grade of the veneer, prices may range from $0.89 to $8.99 per ft 2 for selected oak veneers (Oakwood Veneer Company, 2006a, 2006b). For this p rice range, a 4’ x 8’ panel would cost $29 to $288. To control costs, some HWP W manufacturers import lower-cost cores from overseas suppliers. Dependin g on panel thickness, the cost of the UF resin in a panel can be approximatel y $2 (Table VIII-15).Chapter VIII Page 204 Table VIII-15. Estimated Cost of the Urea-formaldeh yde (UF) Resin in

Hardwood Plywood of Varying Board Thickness 1

---------- Board Thickness (Inches) ---------- Measure of Cost 1⁄2” Birch 3⁄4” Birch 3⁄4” Oak 3⁄4” Maple 4’ x 8’ Panel $33.95 $39.99 $42.99 $38.00 Estimated Resin Cost $1.70 $2.00 $2.15 $1.90

(1) Sources: Home Depot (2006); Industry Canada (2005b).

The estimated price increases for HWPW made with an alternate resin are considerably less on a percentage basis than for PB and MDF, due to the lower

amount of resin used to manufacture HWPW. While th e use of proprietary soy or “MUF + Catcher” resins are essentially cost-neutral , use of PVA or a PVA/soy resins could raise the price of a panel by 10 to 30 % (Table VIII-16).

Table VIII-16. Estimated Price Increases in Hardwo od Plywood Made with

Alternate Resins 1

Resin Type Cost

($ lbs -1 ) Cure

Temp. Cure

Rate HCHO

(ppm) Price

Increase (%)

UF 0.24-0.27 NA NA 0.3 NA

MUF + Catcher 0.24-0.27 Similar Similar <0.08 < 5%

PVA 0.55-1.50 Lower Shorter <0.05 10 to 30 Soy 0.24-0.27 Similar Similar <0.05 < 5% PVA/Soy 0.72-0.81 Similar Similar <0.05 10 to 15

(1) “Cure Temp.” = cure temperature; “ppm” = parts per million; “NA” = not available; “UF” = ureaformaldehyde; “MUF” = melamine-UF; “PVA” = polyvinyl acetate. Cure rate and temperature are relative to production conditions for manufacturing hardwood plywood with a UF resin. Values for “Price Increase” are relative to the cost of hardwood plywood made with a UF resin; effects of cure temperature and rate were not considered. Resin costs are based on price information supplied at public workshops or in stakeholder meetings.

Westcott and Frihart (2004) developed a soy-PF resi n that could be a candidate system for producing HWPW that complies with the pr oposed Phase 1 and

Phase 2 standards. In trials on oriented strandboa rd, these workers found that adding soy flour, at roughly 25% the cost of phenol , could reduce unit resin cost by 40 to 60%, at soy:phenol weight ratios of 1 and 3.4, respectively. While this is data on resin use in oriented strandboard, they pos tulate that results for plywood

could be similar.Chapter VIII Page 205 b. Plant Upgrade: New Equipment

For HWPW, the candidate resins that would likely be used to manufacture panels compliant with the Proposed Phase 1 and Phase 2 sta ndards would not require new equipment for use. For example, several existi ng facilities that currently use urea formaldehyde resins also make HWPW with PVA re sin in response to requests for “green building” compliant materials. In addition to the higher cost of PVA vs. UF resin, there are costs associated with c leaning the presses after using PVA that must be performed before returning t o UF resin production. As such, if manufacturers produced only PVA-bonded HWP W, these cleaning costs would not be a consideration. In our view, manufac turers can produce CARBcompliant HWPW with “drop-in” technology, it is mor e a matter of whether they will choose to produce HWPW for California or not.

c. Small producers

While industry representatives have stated that the re are 19-mills in the U.S., based on the CARB 2003 Survey, some of the smaller HWPW producers

manufacture less than 1-million ft 2 , and would be operated by less than 20 employees. For this size of facility, in addition to higher resin costs, consideration must also be given to potential cost increases due to quality control testing if they continue to use UF resin and docume nting chain-of-custody. If the producer is a member of the Hardwood Plywood & Vene er Association, the costs that would be anticipated for quality control testi ng, labeling, and chain-ofcustody related activities may be less.

C. Cost to the Composite Wood Manufacturing Indust ry

1. Calculation of Total Cost to the Industry

There are about 1,500 companies in the American eng ineered wood products industry, employing over 120,000 workers. Their co mbined production value stood at an estimated $29.5 billion in 2004. This compares to a value of $21.3 billion at the beginning of this century. Th e increase of 38.5% is partially due to higher prices. However, if we exclude the i mpact of inflation, the growth between 2000 and 2004 is still 30.2% (Global Wood T rade Network, 2005).

a. Hardwood Plywood (HWPW)

Presently, about 40% of HWPW produced for Californi a complies with the proposed Phase 1 and Phase 2 standards (Columbia Fo rest Products, 2006). For the remaining 60%, we believe manufacturers cou ld produce a panel with a UF resin that complies with the proposed Phase 1 st andard. Manufacturers could do some or all of the following:Chapter VIII Page 206

• Improve manufacturing process controls to increase efficiency, energy use, and reduce waste;

• Use a lower mole ratio UF resin with a F:U mole ra tio of approximately 1.3 or less;

• Use scavengers or catalysts; and/or

• Co-blend their base UF resin with a very low mole ratio UF resin (< 1.0).

Through application of all or some of these actions , it is reasoned that the cost of a Phase 1 compliant HWPW panel would be increased b y about 1%, due entirely to the increase in resin cost (Appendix G). For ex ample, based on the wholesale price of a HWPW panel presently available for sale of approximately $20 (Pittsburgh Forest Products, 2007), the projected w holesale price of a Phase 1 panel would be approximately $20.25. This increase would apply to both veneer core and composite core products.

To meet the proposed Phase 2 standards, it is likel y that manufacturers would have optimized their production controls and determ ined the essential preprocessing treatments needed to reduce manufacturin g losses. To reduce HCHO emissions further, manufacturers could choose to use of one of three resin systems: MUF, PVA, or soy. In the case of Co lumbia Forest Products, the decision to develop and use a soy-based resin for t heir entire HWPW product line was not based solely on cost, and as such, can not be considered in this

context. The Columbia Forest Products PurebondTM is proprietary, however, if the soy resin technology is publicly available in t he future, then another low cost option would be available. Rather, the estimate co ntained herein is based on the use of a MUF resin containing 15% melamine or PVA. For the MUF resin, hexamine addition may be another cost-competitive o ption (Kamoun et al., 2003). In addition to increased resin costs over U F, it was further assumed that processing times would be lengthened by 10% and 20% , respectively. Through the use of either of these resins, it is reasoned t hat the cost of Phase 2 compliant HWPW panel would be increased by approximately 8% t o 19%. As in the previous example, the projected wholesale price of a Phase 2 panel would be between $21.50 to $23.75, for either a veneer core or composite core product.

The above estimated “per panel” increases were used to calculate the total cost to the HWPW industry. Using production data for 20 02, where California consumption was estimated to be approximately 299-m illion ft 2 or 9.3-million panels (Note: a panel is 4’ x 8’ board or 32ft 2 ), and considering that 40% of the HWPW for California already complies with both the Phase 1 and Phase 2 standards, the total cost to the HWPW industry is e stimated to be approximately $6 million per year for Phase 1 and about $17 milli on per year for Phase 2.

b. Particleboard (PB)

Based on the CARB 2003 Survey, approximately 55% of PB produced in the U.S. complies with the proposed Phase 1 standard, a nd only a small amount ofChapter VIII Page 207

specialty products (< 1%) comply with the proposed Phase 2 standard. For the approximately 45% of U.S. production that does not produce a panel that would comply with the proposed Phase 1 standard, it is pr ojected that to produce a panel with a UF resin that complies with the standa rd, manufacturers could do some or all of the following:

• Improve manufacturing process controls to increase efficiency, energy use, and reduce waste;

• Use a lower mole ratio UF resin with a F:U mole ra tio of approximately 1.1 or less;

• Use scavengers or catalysts; and/or

• Co-blend their base UF resin with a very low mole ratio UF resin (< 1.0).

Through application of all or some of these actions , it is reasoned that the cost of a Phase 1 compliant PB panel would be increased by approximately 4% to 7%, due almost entirely to the increase in resin cost ( Appendix G). For example, based on the wholesale price of a PB panel presentl y available for sale of approximately $10.50 (Random Lengths, 2007), the pr ojected wholesale price of a Phase 1 panel would be between $11 and $11.80.

For the proposed Phase 2 standards, it is likely th at manufacturers would have optimized their production controls and determined the essential pre-processing

treatments that need to be done to reduce manufactu ring losses. To reduce HCHO emissions further, manufacturers could choose to use of one of two resin systems: MUF or PF. As manufacturers will likely c ontinue using UF resins, the

estimate contained herein is based on the use of a MUF resin containing 8%

melamine in combination with the use of lower mole ratio urea-formaldehyde resins (i.e. F:U <1). In addition to increased res in costs over UF, it was further assumed that processing times would be lengthened b y approximately 10%. Through the use of MUF resin, it is reasoned that t he cost of Phase 2 compliant PB panel would be increased by approximately 17% to 30%. As in the previous example, the projected wholesale price of a Phase 2 panel would be between $12.30 and $13.80.

The above estimated “per panel” increases were used to calculate the total cost to the PB industry. Using production data for 2002 , where California consumption was estimated to be approximately 600-m illion ft 2 or 19.5-million panels (Note: a panel is 4’ x 8’ board or 32 ft 2 ), and considering that 55% of current U.S. production already complies with the P hase 1 standard, the total cost to the PB industry is estimated to be approxim ately $4-million per year for Phase 1 and approximately $61-million per year for Phase 2.

c. Medium Density Fiberboard (MDF)

Based on the CARB 2003 Survey, approximately 25% of MDF produced in the U.S. complies with the proposed Phase 1 standard, a nd only a small amount ofChapter VIII Page 208

specialty products (< 1%) comply with the proposed Phase 2 standard. For the approximately 75% of U.S. production that does not produce a panel that would comply with the proposed Phase 1 standard, it is pr ojected that to produce a panel with a UF resin that complies with the standa rd, manufacturers could do some or all of the following:

• Improve manufacturing process controls to increase efficiency, energy use, and reduce waste;

• Use a lower mole ratio UF resin with a F:U mole ra tio of approximately 1.1 or less;

• Use scavengers or catalysts; and/or

• Co-blend their base UF resin with a very low mole ratio UF resin (< 1.0).

Through application of all or some of these actions , it is reasoned that the cost of a Phase 1 compliant PB panel would be increased by approximately 4% to 6%, due almost entirely to the increase in resin cost ( Appendix G). For example, based on the wholesale price of a PB panel presentl y available for sale of approximately $14.00 (Random Lengths, 2007), the pr ojected wholesale price of a Phase 1 panel would be between $14.50 and $15.

For the proposed Phase 2 standards, it was postulat ed that manufacturers would have optimized their production controls and determ ined the essential preprocessing treatments that needed to be done to red uce manufacturing losses. While pMDI hybrid resins have been found to be effe ctive, the high cost of pMDI precludes its consideration in this analysis. As m anufacturers will likely continue using UF resins, the estimate contained herein is b ased on the use of a MUF resin containing 12% melamine in combination with t he use of lower mole ratio urea formaldehyde resin (F:U<1). In addition to in creased resin costs over UF, it was further assumed that processing times would be lengthened by approximately 10%. Through the use of this MUF res in, it is reasoned that the production cost of a Phase 2 compliant MDF panel wo uld be increased about 26%. As in the previous example, the projected who lesale price of a Phase 2 panel would be approximately $17.60. A few manufac turers produce MDF with pMDI, however, pMDI is much more costly than urea- formaldehyde resins (see Table VIII-14). The cost of an MDF panel made from pMDI would be increased by about 135%, due to the increase in resin cost. This increase in resin cost would increase the production cost of a $14.00 MDF panel to about $30. So, staff believes that manufacturers would opt for les s expensive melamine fortified lower ratio urea formaldehyde resins to meet the Ph ase 2 emission standard.

The above estimated “per panel” increases were used to calculate the total cost to the PB industry. Using production data for 2002 , where California consumption was estimated to be approximately 280-m illion ft 2 or 8.7-million panels (Note: a panel is 4’ x 8’ board or 32 ft 2 ), and considering that approximately 25% of current U.S. production alread y complies with the Phase 1 standard, the total cost to the PB industry is esti mated to be approximatelyChapter VIII Page 209

$9-million per year for Phase 1 and approximately $ 49-million per year for

Phase 2.

d. Total Combined Cost to the Industry

For Phase 1, the total combined cost to HWPW, PB, a nd MDF manufacturers in the U.S. is estimated to be $19-million per year, a nd for Phase 2, $127-million per year (Appendix G).

D. Distributor and Importer Costs

Distributors and importers play an important role i n the distribution of composite wood products to the California marketplace. While they do not typically “add value” to panels or finished goods that contain HWP W, PB, and/or MDF, they are the principal entities that resell products to fabr icators and retailers. As a significant portion of the HWPW, PB, and MDF that i s offered sale or supply in California is handled by distributors or importers, their adherence to the chain-ofcustody requirements of the proposed ATCM are funda mental to ensuring the availability and use of CARB-compliant HWPW, PB, MD F, and finished goods containing those materials in California.

1. Distributors

Distributors are individuals or business entities t o whom HWPW, PB, MDF, or finished goods containing those materials are sold or supplied to, from domestic sources, for the purposes of resale or distribution into commerce. In large part, the major portion of distributors are familiar with the wide range of composite wood products that are presently available for sale or supply in California, and understand that there is a growing demand for “gree n” products, that are environment-friendly. A growing segment of the gre en-products industry is building materials made with no added HCHO resins ( Tables V-22, V-24, and V26), which are typically requested by individuals w ith chemical sensitivities and/or builders pursuing Leadership in Energy and Environm ental Design (LEED) credits (U.S. Green Building Council, 2005). The i ncreased availability of low HCHO emission PB, MDF, and HWPW, may require distri butors to track some additional stock keeping unit (SKU) numbers for Pha se 1 and Phase 2 compliant

materials.

Presently, with a growing interest in green buildin g efforts focused on documenting the use of energy-efficient and/or prod ucts with specified sustainably harvested wood contents, distributors a lready participate in one or more chain-of-custody and labeling programs to assu re that green-products are supplied to customers that request them. With resp ect to the use of sustainably harvested wood, the Forest Stewardship Council over sees one of the most widely recognized programs to verify the use of sus tainable forest management practices and chain-of-custody programs (Forest Ste wardship Council, 1996).Chapter VIII Page 210

Through programs of this kind, a major portion of d istributors are familiar with the level of resources (manpower and cost) that need to be expended to participate in a program of this kind and recognize the benefic ial aspects of their participation. It is projected that requiring dist ributors to track their purchases and sales of CARB-compliant HWPW, PB, and MDF, woul d not constitute a significant increase in the efforts currently being done to comply with on-going chain-of-custody efforts, such as for the Forest St ewardship Council or the

USEPA’s National Emission Standards for Hazardous A ir Pollutants regulation for composite wood products facilities (USEPA, 2002 ).

As distributors may secure goods for customers outs ide of California, they may incur costs for keeping separate records for non-co mpliant HWPW, PB, and MDF

destined for their non-California customers. These costs may be due to maintaining separate data management systems, stora ge facilities, and labels for California and non-California goods.

2. Importers

Importers are individuals or business entities to w hom HWPW, PB, MDF, or finished goods containing those materials are sold or supplied to from overseas sources, for the purposes of resale or distribution into commerce. In large part, importers (e.g., members of the International Wood Products Association) are familiar with the wide range of composite wood prod ucts that are presently available for sale or supply in California, and ini tiate agreements throughout the world for products of lower cost and/or made from r are tree species. As manufacturers, such as Masisa in Chile, supply E1-c ompliant products to Europe, and Chinese manufacturers supply F  and F  products to Japan, importers are well aware of the different em ission and strength standards that exist across the world. Imported products are also being supplied to fulfill demand for green-products, as the availability of g reen-products is limited from

U.S. manufacturers. As for distributors of domesti c composite wood products, an increase in the availability of low HCHO emission P B, MDF, and HWPW, may require importers to track some additional stock ke eping unit (SKU) numbers for Phase 1 and Phase 2 compliant materials.

As for distributors of domestic goods, importers ar e familiar with the level of resources (manpower and cost) that need to be expen ded to participate in chainof-custody and labeling programs and recognize the beneficial aspects of their participation. It is projected that requiring impo rters to track their purchases and sales of CARB-compliant HWPW, PB, and MDF, would no t constitute a significant increase in the efforts currently being done to comply with on-going chain-of-custody efforts, such as for the Forest St ewardship Council (Forest Stewardship Council, 1996).

As importers may secure goods for customers outside of California, they may incur costs for keeping separate records for non-co mpliant HWPW, PB, and MDFChapter VIII Page 211

destined for their non-California customers. These costs may be due to maintaining separate data management systems, stora ge facilities, and labels for California and non-California goods.

E. Fabricator Costs

Fabricators are individuals or business entities th at use HWPW, PB, or MDF to make other goods that are sold or supplied in Calif ornia. Assuming that a major portion of fabricators purchase HWPW, PB, or MDF on an as-needed basis to fill their orders to customers, they would not maintain large surpluses of panels or components in their places of business. To comply with the proposed ATCM, it is estimated that fabricators may incur additional costs due to higher material costs, and depending on their participation in exis ting chain-of-custody and labeling programs, may incur additional costs to im plement a rigorous recordkeeping system to track their purchases and sales o f compliant and noncompliant goods.

1. Case Studies

In the following subsections, three case studies we re examined as a means to gauge the potential increase in cost to fabricators that elect to build products with HWPW, PB, and/or MDF that complies with the propose d Phase 2 standards (Table VI-1). As environment-friendly products are currently being sold as a separate product line (e.g., Neil Kelly Cabinets, P ortland, OR), for sales to medium- or high-price point customers, increases in the cost of HWPW, PB, and/or MDF used to fabricate products in 2009-2012 will likely be passed on to

the customer.

a. Furniture

For furniture to be sold or supplied to California, any furniture maker that elects to build furniture with CARB-compliant HWPW, PB, and/o r MDF, would only be in competition with other furniture makers that must i ncur the same composite wood costs as they do. Presently, aside from upgrading their record-keeping programs to be able to demonstrate the use of CARB-compliant composite wood products, it is not anticipated that the use of these materia ls would require any specialized equipment or tools for furniture makers than would be required for the use of non-compliant wood products. Should a furniture ma ker elect to make furniture for customers in California and out-of-state, and d eciding to use both CARB- and non-compliant composite wood products, added costs associated with keeping separate records and work/storage areas for those p roducts may be incurred.

In discussions with the American Home Furnishings A lliance, familiarity with the USEPA’s chain-of-custody requirements for plywood a nd composite wood products facilities provides a template for complyi ng with the chain-of-custody requirements for the proposed ATCM.Chapter VIII Page 212 b. Cabinets

For cabinets to be sold or supplied to California, any cabinet maker that elects to build cabinets with CARB-compliant HWPW, PB, and/or MDF, would only be in competition with other cabinet makers that must inc ur the same composite woodrelated costs as they do. Presently, aside from up grading their record-keeping programs to be able to demonstrate the use of CARB- compliant composite wood products, it is not anticipated that the use of the se materials would require any specialized equipment or tools for cabinet makers t han would be required for the use of non-compliant wood products. Should a cabin et maker elect to make

cabinets for customers in California and out-of-sta te, requiring the use both CARB- and non-compliant composite wood products, th ey may incur added costs for keeping separate records and work/storage areas for those products.

In discussions with the Kitchen Cabinet Manufacture rs Association, for large cabinet makers that have captive HWPW, PB, or MDF m anufacturing facilities, substantial investments may be needed to upgrade th ose facilities given that all the composite wood that is produced is used to buil d cabinets. This industry is not as familiar with chain-of-custody programs as t he furniture industry, and as such, is likely to incur some costs in initiating a program and in its day-to-day operation.

c. Windows and Doors

For windows and interior doors to be sold or suppli ed to California, window/door

manufacturers that elects to build windows and inte rior doors with CARBcompliant HWPW, PB, and/or MDF, would only be in co mpetition with other manufacturers that must incur the same composite wo od-related costs as they do. Presently, aside from upgrading their record-k eeping programs to be able to demonstrate the use of CARB-compliant composite woo d products, it is not anticipated that the use of these materials would r equire any specialized equipment or tools for window and door manufacturer s than would be required for the use of non-compliant wood products. Should a window/door manufacturer elect to make products for customers i n California and out-of-state, requiring the use both CARB-compliant and non-compl iant composite wood products, they may incur added costs associated wit h keeping separate records and work/storage areas for those products.

In discussions with the Window and Door Manufacture rs and the Door and Access System Manufacturers Associations, concern w as expressed relative to potential costs associated with having to recertify the fire- and storm-ratings of their products with organizations such as Underwrit ers Laboratory. As certifications of this kind cost in excess of $1,00 0 a piece, manufacturers were not certain if the use of CARB-compliant HWPW, PB, or MDF would substantially alter their products such as to require recertifica tion testing. In conversations with Underwriters Laboratory, staff learned that ne arly all changes of this kindChapter VIII Page 213

may be subject to an engineering evaluation, and wo uld not require product

recertification.

F. Retailer Costs

Retailers are individuals or business entities that sell, supply or offer for sale HWPW, PB, or MDF, in either finished goods or in pa nel form to the public-atlarge (i.e., consumers). To comply with the propos ed ATCM, beginning in 2009,

retailers need to clear their inventories of non-co mpliant products consistent with the sell-through provisions in Table VI-6. A major effort may be needed to inform their suppliers, foreign and domestic, that they mu st verify that their products are compliant with the proposed ATCM. As such, retaile rs need to develop a recordkeeping system to track where they purchase the mer chandise they sell to consumers, and maintain documentation that verifies that the products they sell comply with applicable Phase 1 or Phase 2 standards (i.e. chain-of-custody).

Through contacts made at public workshops, efforts have already been made by a major retailer to secure composite wood products that comply with the European E1 standard. Presently, products meeting the E1 standard are subject to more stringent HCHO emission requirements than a re required in the U.S., which may be more costly to sell than products meet ing less stringent standards, such as the 1985 HUD standard for products used in mobile homes. With action of this kind already taking place, there may be a g reater level of familiarity within the retail sector concerning low HCHO emitting comp osite wood products, and the efforts needed to assure their quality by the t ime the ATCM goes into effect.

G. Consumer Costs

In the following subsections, projected increases i n the price of HWPW, PB, and MDF panels, and resultant increases in the cost of a small home, large home, and a typical home remodeling project, and a low-pr ice point article of furniture

are estimated.

1. Incremental Increase in the Cost of a Standard Panel

Previously, in Tables VIII-12, VIII-14, and VIII-16 , estimates of the price increases for PB, MDF, and HWPW manufactured to com ply with proposed Phase 2 standards were calculated, respectively. I n the following analysis, it is assumed that the approximate increase in the produc tion cost of PB, MDF, and HWPW compliant with the applicable Phase 2 Standard in 2010-2012 would be 30%, 40%, and 15% higher than the wholesale cost of non-compliant products sold in markets outside of California (Table VIII-1 7). Based on the prices of standard-size panels sold today, in the post Phase 2 timeframe, the production cost of a standard PB, MDF, and HWPW panel is estim ated to be approximately $3 to $4, $4 to $6, and $5 to $7 higher than a comp arable panel made with UF resin, depending on the thickness of the panel.Chapter VIII Page 214

Table VIII-17. Estimated Cost of Particleboard, Me dium Density Fiberboard, and Hardwood Plywood Panels Following the Effective Dat e of the Phase 2 Standard 1

---------- Board Thickness ----------

Particleboard 3⁄8 ” 1⁄2” 5⁄8 ” 3⁄4” Pre-Phase 2 Effective Date $9.15 $9.57 $10.66 $11.9 0 Post Phase 2 Effective Date $11.90 $12.44 $13.86 $1 5.47

Estimated Increase $2.75 $2.87 $3.20 $3.57

Medium Density Fiberboard 3⁄8 ” 1⁄2” 5⁄8 ” 3⁄4” Pre-Phase 2 Effective Date $9.89 $11.01 $12.86 $14. 53 Post Phase 2 Effective Date $13.85 $15.41 $18.00 $2 0.34

Estimated Increase $3.96 $4.40 $5.14 $5.81

Hardwood Plywood 1⁄2” Birch 3⁄4” Birch 3⁄4” Oak 3⁄4” Maple Pre-Phase 2 Effective Date $33.95 $39.99 $42.99 $38 .00 Post Phase 2 Effective Date $39.04 $45.99 $49.43 $4 3.70

Estimated Increase $5.09 $6.00 $6.44 $5.70

(1) Random Lengths (2006b). Pre-Phase 2 and Post Phase 2 dollar values are for a standard 4’ x 8’ panel.

2. Increase in Material Cost for New Home Construc tion

In this analysis of incremental new house construct ion, staff found that the

increase in construction cost would be less than 0. 1%. These costs are relative

to statistics from the National Association of Real tors, which show the 2006 average median home price for four southern Califor nia cities to be $574,000 (National Association of Realtors, 2007).

a. Two-bedroom House

Staff estimated the incremental cost of a one story , one bath, 800 ft 2 house (Appendix F). To develop the estimate, a building plan house was obtained (Dream House Source, Not Dated (a)), and commercial ly available software was used to calculate the amount of composite wood mate rials that would be used to build the kitchen and bathroom cabinets, where the major portion of the HWPW, PB, and MDF is used in a home (Planit Solutions, In c., 2004). Based on the total amount of HWPW, PB and MDF estimated, the increment al “per panel” production cost was then applied. Based on this in cremental cost analysis, staff

found that the increased cost of construction for a n 800 ft 2 house is about $200. Assuming that the incremental increase in construct ion cost is added to the priceChapter VIII Page 215

of a median priced home of $574,000, the estimated increased cost is about

0.03%.

Alternatively, housing costs can be calculated a di fferent way. If the proposed ATCM industry-wide cost increase for Phase 2 ($127 million) is assumed to be applied to new housing starts, then an overall cost per new house can be determined. According to real estate statistics, t he two year average (2004 to 2005) for California housing starts (single family homes and multi-family units) was about 200,000 per year (California Building Ind ustry Association, 2006; Not Dated). If it is assumed that 50% of the HWPW, PB, and MDF for California is used for new home construction, then the overall in crease would be $300 per new home (i.e., ($127 million x 0.5) ÷ 200,000 = $300 per housing start).

b. Four-bedroom House

To develop this estimate, staff performed the same analysis as the two-bedroom house, but based on the building plan for a four be droom, three bath home (Dream House Source, Not Dated (b)). As Appendix F describes, the incremental construction cost of a 2,000 ft 2 house is about $390. Therefore, assuming this increase in construction cost is adde d to the price of a median priced home of $574,000, the estimated increased co st is about 0.07%.

In the context of existing profit margins for large home builders, which range from 8 to 16%, the increase in material cost of composit e wood products poses an insignificant factor in the cost of new home constr uction.

c. Remodeling Project

The average cost of a kitchen remodel ranges from $ 15,000 to $25,000, where the cost of the cabinets is a major portion of the cost. Depending on the size of the home being remodeled, the cost of the composite wood materials used to build the cabinets and countertops may range from $ 400 to $600 at present-day prices (Tables VIII-18 and VIII-19), while the purc hase price of the cabinets would be ten- to 15-times higher. Assuming the mix of wood products identified previously would still be used, the increase in mat erial cost is estimated to range from 26 to 27%. At this level of increase, the cos t of composite wood materials used to build the cabinets in a kitchen remodeling project would rise by $104 to $160. This represents a 1% increase to the cost of a remodeling project.

3. Increase in Material Costs for Low Price Point Case Goods

Particleboard is used to manufacture a wide variety of low price point case goods, such as pre-assembled or ready-to-assemble b ook cases. Assuming that the cost of Phase 2-compliant PB will be more expensive than currently available panels, an estimate of how much the cost of the PB in a pre-assembled book case would increase, in consideration of the p reviously developed costChapter VIII Page 216

estimate for 2-compliant PB (Table 14). For purpos es of this analysis, it was

assumed that bookcases built with MDF or HWPW would be medium price point commodities and less affected by the projected incr eases in PB cost that could have a significant impact on the viability of low p rice point case goods.

For a typical four-shelf bookcase (79” height x 29” width x 11” depth), the following amounts of PB are used:

• one 4’ x 8’ panel of 3⁄4” PB for the shelves and sid e panels;

• one 4’ x 8’ panel of 3⁄8 ” PB for the back; and

• one 2’ x 8’ panel of 3⁄4” PB for the top and bottom rails, frames, etc.

Assuming a present-day cost of a 3⁄4” panel at $11.90 and a 3⁄8 ” panel at $9.15 (Table 14), the total cost of PB used to build the above bookcase would be $27.00 (i.e., [(11⁄2 x $11.90) + $9.15] = $27.00). T o bracket the range of prospective cost increases, it is assumed that the cost of resin used to make Phase 2-compliant PB could range from 15 to 100% mo re expensive than UF resin. At 15%, the estimated increase in PB cost w ould be $1.22, bringing the total cost of PB to $28.22, a 5% increase over the present-day cost. At 100%, the estimated increase in PB cost would be $8.10, b ringing the total cost of PB to $35.10, a 30% increase over the present-day cost.

H. Impacts to Small Business

As all HWPW, PB, MDF, and finished goods offered fo r sale or supply in California will be required to meet the proposed Ph ase 1 and Phase 2 standards in 2009 to 2012, there should be no specific detrim ental impact on small business, and all entities in the distribution chai n would be required to use or sell compliant products.

I. References

Akzo Nobel. 2005. Kenocatch 4315L. Product infor mation, Casco Adhesives, Sundsvall, Sweden. 2 pp.

American Plywood Association (APA). 2003. The Engi neered Wood Association Market Outlook. Structural Panels and Engineered W ood 2003-2008. From : http://www.cintrafor.org/CONFERENCE_TAB/ifpm%202003 /Presentations/Adair Cintra%2003.pdf Accessed : 28 January, 2007.

Answers.com. Not Dated. Hardwood Veneer and Plywo od: Information From

Answers.com. From : http://answers.com/topic/hardwood-veneer-and-plywoo d

Accessed : 25 January 2006.

Bomersheim W. Not Dated. A quick look at the best growth hardwood import

markets based on current trends.Chapter VIII Page 217

CARB. 2003. Analysis of Data Collected in the CAR B 2003 Composite Wood Products Survey of Products Offered for Sale in 200 2. Unpublished data.

Cognard P. 2005. Woodworking and furniture adhesi ves. Part 5: Applications

and end uses. Accessed : 20 September 2006. From : http://www.specialchem4adhesives.com/resources/arti cles/printarticle.aspx?id=1

235

Columbia Forest Products. 2006. PurebondTM. Produ ct Information, Columbia Forest Products, Portland, OR. 2 pp.

Composite Panel Association (CPA). 2006. 2005 Nor th American Shipments Report: Particleboard, Medium Density Fiberboard, H ardboard. CPA, Gaithersburg, MD. 18 pp.

CPA. 2007. Welcome to the Composite Panel Associa tion. From: http://www.pbmdf.com/AboutCPA/index.asp Accessed: 5 January 2007.

CPA. ND. Buyers and Specifiers Guide to North Ame rican Particleboard, Medium Density Fiberboard, and Hardboard Products a nd Manufacturers: 2006.

From: http://www.pbmdf.com/aboutCPA/memberdirectory.asp Accessed: 10 July

2006.

Dream House Source. Not Dated (a). Home Plan 9802 . Accessed: 20 July

2006. From: http://www.dreamhousesource.com/Plan.asp?PlanID=980 2

Dream House Source. Not Dated (b). Home Plan 1840 1. Accessed: 20 July

2006. From: http://www.dreamhousesource.com/Plan.asp?PlanID=184 01

Encyclopedia of American Industries. 2007. SIC 24 35: Hardwood veneer and plywood. Available: www.referenceforbusiness.com/industries/LumberWood/Hardwood-Veneer-Plywood.html Accessed : 30 January, 2007

Forest Stewardship Coucil. 1996. Chain-of-custody . Fact sheet, 2 pp.

Frihart CR. 2005. Chapter 9: Wood adhesion and ad hesives, p. 215-278. In: RM Rowell (ed). Handbook of Wood Chemistry and Woo d Composites. CRC Press, Boca Raton.

Global Trade Atlas. Wood Products Imports. Not Da ted. From : http://www.fas.usda.gov/ffpd/wood_products_presenta tions/world_importers/worl d’s_leading_wood_product_importers.pdf Accessed : 28 January 2007.Chapter VIII Page 218

Global Wood Trade Network. 2005. Veneer, plywood and engineered wood product manufacturing in the U.S. Accessed : 28 January 2007. From : http://www.globalwood.org/market1/news20050501.htm

Global Wood Trade Network. 2007. China wood produ cts prices. Accessed : 28 January 2007. From : http://www.globalwood.org/market1/aaw20070101d.htm

Goldboard Development Corporation. 2000. Overview of Goldboard® Products.

From : http://www.goldboard.com/products/products.html Accessed : 12

December 2001.

Hardwood Plywood and Veneer Association (HPVA). 20 07. List of Email from Bill Altman to Angela Csondes.

Home Depot. 2006. Product information table: Plyw ood. Accessed : 20 September 2006. From : http://homedepot.bighammersoftware.com

Howard, JL. 2001. United States Department of Agric ulture (USDA). U.S. Timber Production, Trade, Consumption, and Price Statistic s 1965-1999.

Howard JL. 2005. U.S. Forest Products Annual Mark et Review and Prospects, 2001-2005. Research Note FPL-RN-0299, USDA, Forest Service, Forest Products Laboratory, Madison, WI. 11 pp.

Industry Canada. 2005a. Wood-based panel products : Technology roadmap. I.

Introduction and overview. From : http://strategis.ic.gc.ca/epic/internet/infiif.nsf/en/oc01504e.html Accessed : 13 April 2006.

Industry Canada. 2005b. Wood-based panel products : Technology roadmap. II. Panels in perspective. From : http://strategis.ic.gc.ca/epic/internet/infiif.nsf/en/oc01505e.html Accessed : 13 April 2006.

Kamoun C, A Pizzi, and M Zanetti. 2003. Upgrading melamine-ureaformaldehyde polycondensation resins with buffering additives. I. The effect of hexamine sulfate and its limits. Journal of Applie d Polymer Science, 90: 203-

214.

Marutzky R. 1989. Chapter 10: Release of formalde hyde by wood products. In : Pizzi A (ed). 1989. Wood Adhesives: Chemistry and Technology, Volume 2:

307-388.

National Association of Home Builders (NAHB). Not Dated. Housing: 2004 Facts, Figures & Trends. NAHB, Public Affairs, Was hington, DC. 50 pp.

NAHB. 2006. Median and average price per square f oot of floor area in new one-family houses sold by location. Accessed : 7 February 2007. From : http://www.nahb.org/fileupload_details.aspx?content ID=560Chapter VIII Page 219

Oakwood Veneer Company. 2006a. Company Price List : 4’ x 8’ A-B. From: http://www.oakwoodveneer.com/prices/prices4_8_ab.ht ml Downloaded: 19 September 2006.

Oakwood Veneer Company. 2006b. Company Shopping C art: 3-ply Veneer.

From: https://oakwoodveneer.com/shop/shop_3ply.html Downloaded: 20 September 2006.

Osman Z, A Pizzi, W Kantner, and MC Triboulot. 200 5. PUF panel adhesives doped with additional urea and reinforced by isocya nates. Holz als Roh- und Werkstoff, 63: 53-56.

Pittsburgh Forest Products Company. 2007. Unit co st price for hardwood plywood panels. From: http://www.sticktrade.com/members/5425.htm Accessed: 26 February 2007.

Pizzi A. 1994. Advanced Wood Adhesives Technology . Marcel Dekker, Inc., New York. 289 pp.

Planit Solutions, Inc. 2004. cabnetware case plan ner. Product brochure. From: http://www.planitsolutions.com/us/cabnetware/global .forms.brochure.aspx?brand

=3 Accessed: 29 August 2006.

Random Lengths. 2006a. Forest Product Market Pric es and Statistics: 2005 Yearbook, Volume LXI. Random Lengths Publications, Inc., Eugene, Oregon. 312 pp. [ISBN: 1-884311-23-7]

Random Lengths. 2006b. Panel price guide: Monthly average for June 2006. Yardstick, 16(6): 18.

Random Lengths. 2007. Panel price guide: Monthly average for January 2007. Yardstick, 17(1): 18.

Schuler A. 2006. Construction markets & building material prices: How strong is the relationship? Structural Building Components M agazine, March 2006: 20-23.

Sellers T Jr. 2001. Wood adhesive innovations and applications in North America. Forest Products Journal, 51(6): 12-22.

Spelter H. 1989. Plywood Manufacturing Cost Trend s, Excluding Wood, in

Western U.S. Mills: 1975-1988. General Technical R eport FPL-GTR-64. USDA, Forest Service, Forest Products Laboratory, Madison , WI. 12 pp.

Spelter H. 1992. HCHO emissions debate invites sc rutiny of lab tests, economics. Panel World, March 1992: 22-24.Chapter VIII Page 220

U.S. Census Bureau. 2003. 2002 NAICS Definitions: 321 Wood Product Manufacturing. Accessed : 5 January 2007. From : http://www.census.gov/epcd/naics02/def/NDEF321.HTM# N3212

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U.S. Census Bureau. Not Dated. Timber Products. Production, Foreign Trade and Consumption by Type of Product. Accessed : 7 February 2007. From : http://www.census.gov/compendia/statab/tables/07s08 58.xls

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### IX. Environmental Impacts of the Proposed Airborne Toxic

Control Measure

The primary intent of the proposed ATCM is to prote ct public health by reducing emissions of and human exposure to HCHO released fr om composite wood products. The proposed ATCM also provides air qual ity benefits by reducing ozone formation, as HCHO is a compound that undergo es atmospheric

transformations to form ozone. In consideration of the data analyses performed herein, staff has determined that no significant ad verse environmental impacts should occur as a result of adopting this ATCM. Th is chapter describes the potential impacts that the proposed ATCM may have o n the environment.

A. Legal Requirements

The California Environmental Quality Act (CEQA) and CARB policy require an analysis be performed to determine the potential ad verse environmental impacts of proposed regulations. To meet this requirement, CARB must assess the extent and severity of reasonably foreseeable envir onmental impacts, and respond (in writing) to all significant environment al issues raised in the public review period and at the Board hearing. Presently, CARB’s regulatory program is certified by the Secretary of Resources (cf. Pub lic Resources Code §21080.5), which allows CARB to include an environmental analy sis in the Initial Statement of Reasons (ISOR) instead of preparing an environme ntal impact report or negative declaration. Written responses to signifi cant environmental issues raised by the public will be included in the Final Statement of Reasons (FSOR)

for the ATCM.

Public Resources Code §21159 requires that the envi ronmental analysis prepared by CARB include analyses of the following “reasonably foreseeable”

items:

• Impacts of the methods of compliance;

• Feasible mitigation measures; and

• Alternate means of compliance with the ATCM, (see subsection VII.G.).

With respect to mitigation measures, CEQA requires state agencies to identify and adopt feasible mitigation measures that would m inimize any significant adverse environmental impacts described in the envi ronmental analysis.

B. Analysis of Reasonably Foreseeable Environmenta l Impacts

To manufacture HWPW, PB, and MDF that complies with the proposed Phase 1 and Phase 2 standards, manufacturers may choose to use an alternative resin instead of UF, or modify their existing UF resin th rough the use of additives. A discussion of the potential health effects from the use of isocyanates, melamine,Chapter IX Page 222

phenol and soy flour is provided below and in subse ction VII.G. of this staff report. The principal compounds considered in the following evaluation are:

• Phenol (from PF resins);

• Melamine (as an additive to UF resins);

• Polyvinyl acetate (as a no added HCHO adhesive for HWPW);

• Methanol (as an additive/reagent used with UF resi ns);

• Methylene Diisocyanate (as a no added HCHO adhesiv e for MDF); and

• Soy flour (as a no added HCHO adhesive for HWPW).

1. Air Quality

In setting new HCHO emission standards for PB, HWPW , and MDF, reductions in statewide HCHO emissions would be expected to oc cur at all points along the distribution chain. Because HCHO is a VOC, the pro posed ATCM would also be reducing an ozone precursor. For example, the use of soy flour-based resins would essentially reduce volatile organic compound emissions to near-zero. As some resin systems have lower energy requirements i n their manufacturing process, reductions in carbon dioxide emissions tha t contribute to global warming would be expected.

Of the projected alternative resin systems, reports indicate that exposure from air may occur for phenol, methanol, and methyl diisocya nate (MDI); however, none of these compounds have been classified as carcinog ens by IARC (CARB, 1997a, 1997b; Department of the Environment and Wat er Resources of the Australian Government, Not Dated; National Oceanic and Atmospheric Administration, 2003). Current typical UF resins c an contain methanol, as a coreactant, however, we believe that Phase 2 emission standards will not result in increase in any methanol use. In fact, we anticipa te that the future use of alternative resin systems, may decrease methanol us e. Polyvinyl acetate (PVA)

contains no hazardous materials under the current O SHA standard and is not listed as a carcinogen by IARC (Franklin Internatio nal, 2006; Gamblin, 1997). In the workplace, potential respiratory effects from p henol and MDI have been the subject of controls for many years (Gilbert, 1987).

With regard to greenhouse gas emissions, use of an alternative resin system may provide a minor increase or decrease in energy- related carbon dioxide emissions. Overall, it is assumed that California’ s demand for HWPW, PB, and MDF will continue to be met by manufacturers in the West, resulting in no net change in transport-related carbon dioxide emission s. Although, if the current trend continues, increasing amounts of products cou ld be supplied from overseas manufacturers, whose market share has grown dramati cally in the last ten years (Figures VIII-1 to VIII-3). The increase in overse as imports, and associated transport-related carbon dioxide emissions, may in part be due to the U.S. becoming a growing market for high-emitting product s from overseas. As such, the establishment of more stringent HCHO emission s tandards in California mayChapter IX Page 223

help to forestall the rising trend in transport-rel ated carbon dioxide emissions, as those products would need to be sold elsewhere and may be sold closer to where they are manufactured.

2. Potential Water Quality Impacts

Use of any of the alternative resins is not expecte d to pose a significant threat to water quality. Phenol is reported to have a half-l ife of 2 to 20 days, and does not bioaccumulate in aquatic wildlife (Commonwealth of Australia, 2005). Melamine has a low toxicity to aquatic life, and is effectiv ely degraded by waste-water treatment plants (DSM Melamine, 2002; Organization for Economic Cooperation and Development, Not Dated). Due to its miscibilit y in water, methanol principally dissolves and dilutes to very low conce ntrations in the event of surface water exposures (Malcolm Pirnie, 1999). The potent ial for environmental spills of MDI is low, and releases to water result in the for mation of polyurea compounds, with no toxicological effects (Gilbert, 1987; Yakab e et al., 1999).

3. Potential Hazardous Waste Impacts

Potential hazardous waste impacts on soil quality f rom a spill of the alternative resin systems are not expected to be significant. Phenol can be transported to soil from air or water, and could possibly accumula te in landfills at low levels. Recently, Gusse et al. (2006) demonstrated that bio degradation of phenolic resins could be achieved using white rot fungi, whi ch may provide opportunities for phenolic resin recycling and/or recovery of pro duction constituents. Melamine, if released to soil could pose an accumul ation problem, but due to its low toxicity, does not pose a significant environme ntal risk (Organization for Economic Cooperation and Development, Not Dated). Low concentrations of methanol are unlikely to persist, as it will underg o rapid biodegradation under a wide range of geochemical conditions (Malcolm Pirni e, 1999). Spills of MDI will result in the formation of soild polyurea compounds , whose ecological impacts are likely to be slight and reversible (Gilbert, 19 87).

4. Potential Bioaccumulation Impacts

The toxicities of soy flour, PVA, and melamine are low, and as such, bioaccumulation does not pose a significant environ mental risk to humans or wildlife. Phenol has a relatively short half-life and does not tend to bioaccumulate (Commonwealth of Austrailia, 2005). Bioaccumulation of MDI is unlikely due to its high reactivity with hydroxyl r adicals in air, and low solubility in water (Gilbert, 1987; Yakabe et al., 1999).Chapter IX Page 224

C. Reasonably Foreseeable Feasible Mitigation Meas ures

Staff has concluded that no significant adverse env ironmental impacts would occur from implementing the proposed ATCM. As no a dverse impacts are anticipated, no mitigation measures would be needed

.

D. Reasonably Foreseeable Alternative Means of Com pliance

The use of various types of alternative resin syste ms constitutes the alternative means of compliance with the proposed ATCM. The po tential health effects resulting from the use of the alternative resin sys tems are discussed in Chapter VII of the ISOR. For example, while the use of MDI resin is not expected to be widespread, worker safety protocols have been devel oped in the U.S. for facilities that may choose to utilize those resins. Based on the data analyses performed and input from public meetings, the propo sed HCHO emission limits for PB, HWPW, and MDF are needed to reduce emission s to ambient air and human exposures in homes, schools, and workplaces. The existence of a commercially viable “no added HCHO” technology prov ides justification for an incremental reduction by all manufacturers in the n ear-term and more stringent

limits in 2011 to 2012.

E. Community Health and Environmental Justice

Environmental justice is a core consideration in CA RB’s efforts to provide clean air for all California communities (CARB, 2001). T he proposed ATCM, calling for more stringent HCHO emission limits in selected com posite wood products, would not cause significant adverse impacts in any community. Rather, implementation of the proposed ATCM is aligned with the principle of pollution prevention, and would likely reduce exposures to HC HO in all communities, including low-income areas and ethnically diverse c ommunities.

F. References

CARB. 1997a. Methanol. In : CARB. Toxic Air Contaminant List Summaries, p. 631-634. Stationary Source Division, Sacramento, C A.

CARB. 1997b. Phenol. In : CARB. Toxic Air Contaminant List Summaries, p. 767-770. Stationary Source Division, Sacramento, C A.

CARB. 2001. Policies and Actions for Environmenta l Justice. Planning & Technical Support Division, Sacramento, CA. 13 pp.

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