# Final

Assessment of Occupational Exposure to

Formaldehyde From Composite Wood Products

**U.S. Env ironmental Protection A**  **gency**

Office of Pollution Prevention and Toxics

Chemical Engineering Branch 1200 Pennsylvania Avenue N W Wa shington, DC 20460

6 October 20 1 1i **Executive Summary** Introduction This assessment of the occupational exposure to formaldehyde from composite wood products was developed to support EPA rulemaking under the Formaldeh yde Standards for Composite Wood Products Act (FSCWPA). In July 2010, President Obama signed into law the FSCWPA. This law is an amendment to TSCA and di rects EPA to regulate the formaldehyde emissions from hardwood ply wood (HWPW), medium - density fiberboard (MDF), and particleboard (PB). FSCWPA sets formaldeh yde limits equal to the California Air Resources Board (CARB) Airborne Toxic Control Measure (ATCM ) promulgated in 2007. As part of the development of the rule under FSCWPA, EPA is conducting a cost - benefit anal ysis of implementing the formaldeh yde limits cited by FSCWPA. In support of this cost - benefit anal ys is, EPA assessed occupational exposure to formaldeh yde during the life cycle of HWPW, PB, and MDF. Purpose and Scope The purpose of the assessment is , first, the prediction of baseline formaldehyde inhalation and dermal occupational exposure s that are due to all sources of exposure (aggregate exposure) during the life cycle of composite wood products (CWPs), and, second, the determination of the effect s on baseline exposure s of the anal yt ical options for limits on emission levels for offgassing from H WPW, PB, and MDF. The baseline occurs in the year in which EPA will promulgate limits under FSCWPA, which will be 2013. The analy

tical options consist of the following limits on off - gassing emissions for HWPW, PB, and MDF:
 Option 1: emission limits equal to the CARB ATCM Phase 1 limits;  Option 2: emission limits equal to the CARB ATCM Phase 2 limits (which are equal to the limits specified in FSCWPA); and  Option 3: emission limits equal to the no - added formaldehyde (NAF) limits specified in FSCWPA. The ass essed life cycle stages include the following: 1. Manufacture of HWPW, PB and MDF within the United States (domestic manufacturing) ; 2. Manufacture of products co nstructed with domestically - manufactured and imported HWPW, PB and MDF (secondary products) such as the manufacture of furniture (also referred to as composite wood product fabrication); 3. Wholesale and retail of domestically - manufactured and imported HWPW, PB, and MDF and downstream products ; and 4. Office building occupancy and associated use of office furn iture fabricated with domestically - manufactured and imported HWPW, PB, and MDF .ii

The following life cycle stages were not assessed due to data gaps in information needed for their assessment: the commercial use of HWPW, PB, and MDF and their secondary prod ucts in construction work , and the recycling and disposal of HWPW, PB, and MDF and their secondary products. Approach Inhalation exposure monitoring data were compiled for all of the assessed life cycle stages but were not deemed to be adequate for assessment purposes. Time - weighted average (TWA) inhalation exposure monitoring data for sites in which the manufacture, fabrication, wholesale and retail of the three composite wood products likely occurs were compiled from the OSHA Integrated Management Information Sy stem (IM IS) database. Inhalation exposure monitoring data for office buildings were compiled from EPA’s Building Assessment Survey and Evaluation (BASE) study, which was conducted from 1994 through 1998. As explained i n Section 3.2 , these monitoring data were deemed not adequate for the assessment of baseline exposures and the effects of the anal yt ical options on baseline exposures , which were assess ed using mathematical modeling where possible. The compiled monitoring data are presented for perspective onl y. Baseline average inhalation exposures in composite wood fabrication sites and in office buildings and the effects of anal yt ical options on thes e inhalation exposures were assessed using mathematical models for the estimation of indoor air concentrations in combination with estimates of exposure duration (the hours of exposure per day) and frequency (the day s of exposure per year) . For composite wood fabrication, exposure duration and frequency were estimated using census data on pre - baseline aggregate production hours. Inhalation exposures in the manufacturing, wholesale, and retail life cycle stages were ass essed qualitatively

due to gaps in dat a needed for mathematically modeling indoor air concentration. Dermal exposures to formaldehyde in liquid mixtures were quantitativel y assessed using EPA dermal exposure models for CWP manufacturing for pre - baseline conditions only due to data gaps. Derma l exposures to CWPs are not quantifiable using the EPA dermal exposure mod els for liquids and solids and, therefore , dermal exposure was not assessed for the CWP fabrication, whole sale, retail and office occupancy life cycle stages. For all life cycle stag es with the exception of occupancy of office buildings, the number of exposed workers was estimated based on aggregate census data ( Census 2007a). The number of exposed office workers was not determined due to data gaps. The extent of use of personal pro tective equipment (PPE) was noted for manufacture and fabrication based on a review of OSHA inspection reports. However, a limited number of inspection reports were available fo r review and a conclusion as to the prevalence of the use of respiratory prote ction in these life cycle stages could not be made . Average formaldeh yde indoor air concentrations in a CWP fabrication site and an office building were estimated using mathematical models that are based on the principle of mass conservation and the assump tion that the work space is a well mixed box. In these steady - state models the generation rate of formaldehyde due to off - gassing from CWPs is equated to the rate at which airborne formaldeh yd e is exhausted from the work space through ventilation with out door air to satisfy a formaldeh yd e mass balance on the work space. The generation rate was expressed asiii

the product of a formaldehyde off - gassing emission rate and an amount of emitting surface area. The formaldeh yd e off

- gassing emission rate was determi ned from average emission levels for the three composite wood products that would be dom estically produced or imported at the baseline (provided in the EPA report Market Profile for Industries Potentially Affected by the Proposed Formaldehyde Standards for Composite W ood Products Rule (USEPA 2010a) ) and under the analy

tical options (provided in the EPA report Formaldehyde from Pressed Wood Products: Exposure Assessment (USEPA 2009b ) ) . Method for Estimating Average Indoor Air C oncentration in CW

P Fabrication Sites As discussed in Section 4.2.1 , there are indications that sources of formaldehyde other than the off - gassing of formaldehyde from CWPs may ex ist in a CWP fabrication site. Aggregate indoor air concentration s are the sum of the concentration contributed by off - gassing of the three CWPs, the concentration contributed by other formaldehyde sources in the workplace, and the concentration of formal dehyde in ambient outdoor air. However, the extent to which sources in a CWP fabrication site other than off - gassing of CWP contribute to indoor air concentration in CWP fabrication sites is unknown. Attempts to develop methods to estimate concentration contributions from other sources during CWP fabrication were not successful due to data gaps. Therefore, onl y the contributions from off - gassing of the three CWPs and ventilation with outdoor ambient air were acc ounted for in the estimation of aggregate i ndoor air concentration in CWP fabrication sites. Average indoor air concentration in a CWP fabrication site was calculated from the following mathematical model parameters:
 F ormaldeh yd e emission rate (off - gassing emissive flux) of the composite wood products ;  T otal emitting surface area of the composite wood products located in a CWP fabrication site ;  E ffective ventilation rate for an entire CWP fabrication site; and  T he concentration of formaldehyde in the outdoor air for industrial land use areas. The mathematical model is described in detail in Appendix E . The literature search did not yi eld a CWP fabrication site population distribution for these mathematical model parameters , nor did it yield representative values fo r these parameters for CWP fabrication sites in general (with the exception of concentration of formaldeh yd e in the outdoor air) . Due to these data gaps with respect to the model parameters, what - if values for indoor air concentration were estimated. Thi s what - if analy sis was accomplished by estimating the range of possible values for each model parameter (with the exception of outside air concentration) and calculating a range of what - if indoor air concentration values from the estimated ranges of the mo del parameters as discussed in detail in Section 3.3.1.1 . A range of what - if indoor air concentration values was calculated assuming a CWP fabrication site contains only a single CWP ty

pe. Each model parameter (except for outside air concentratio n) was varied between the two bounding values of its range (the low - and high - end values) while keeping the other model parameters constant at an average, a ty pical, or an intermediate value . Section 3.3.1.1 describes in detail how an average, a ty pical, or an intermediate value was determined for each model parameter. In this assessment report, an intermediate value is defined as a value in - between a low - end and h igh - end value. Thisiv

computational procedure resulted in three different low - end indoor air concentration values and three different high - end indoor air concentration values. The broadest range of these calculated low - and high - end values constitutes a range of values for calculated indoor air concentration for a single CWP that is intended to be a broad range that accounts for uncertainty in coinciding values for the model parameters. An indoor air concentration value was also calculated from the average , t ypic al, or intermediate value of each model parameter. These calculations were repeated for each CWP ty pe: HWPW, PB, and MDF. The low - end values of calculated indoor air concentrations for all three CWP ty pes (a total of nine low - end values) were combi ned into a single range of low - end indoor air concentration values. The same procedure was followed for the high - end values for all three CWP ty pes, thereb y yi elding a single range of high - end values. Finally , the intermediate values of indoor air concentration for each CWP ty pe were also combined into a single range of intermediate values. Therefore, three ranges of indoo r air concentration values (one for low - end values , one for intermediate values, and one for high - end values ) were obtained that account for an y mixture of the different CWP ty

pes in a CWP fabrication site. A final range of results for indoor air concentration was obtained b y combining these three ranges into a single encompassing range and a best estimate for indoor air concentration wa s chosen as the midpoint of this overall range as discussed in Section 4.2.5.3 . The resulting values in the estimated range for average indoor air concentration at a CWP fabrication site are characterized as what - if results because each concentration value in this range corresponds to combination of choices, or what - if values, for the model parameters. Although the prevalence of the what - if values for each model parameter at actual CWP fabrication sites is unknown, the ranges of the model parameter values should be realistic such that any given choice, or what - if value, for an y model parameter represents a possible value at actual CWP fabrication sites. Method for Estimating Average Indoor Air C oncentration in Office Buildings Indoor air concentration in office buildings was estimated using a mathematical model for estimation of indoor air concentration resulting from off - gassing emissions from office workstations fab ricated with the three CWPs. This mathematical model was applied to two different office workstation ty pes: open plan workstations and private office workstations. Averag e indoor air concentration in an office building was calculated for each workstation ty pe from the following mathematical model parameters:
 E mitting surface area of panels in the workstation;  E mitting surface area of work surfaces in the workstation;  T he o utdoor air ventilation rate that affects the volume of the office buil ding containing the workstation ;  E mission rate (emissive flux) of the composite wood products used to construct the workstation panels and work surfaces;  T he fraction of the panels’ surf ace area that is finished, or overlayed, and the effectiveness of this finish or overlay as a barrier to off

- gassing emissions from the CWP substrate;  F raction of the work surfaces’ surface area that is finished, or overlayed, and the effectiveness of this finish or overlay as a barrier to off

- gassing emissions from the CWP substrate; andv

 C oncentration of formaldehyde in the outdoor air for commercial land use areas. The mathematical model is described in detail in Appendix E. Representative values for th e emitting surface area of each workstation component (panel and work surface) and the work space ventilation rate were obtained from the Business and Institutional Furniture Manufacturer’s Association (BIFMA) / American National Standards Institute (ANSI ) M7.1 - 2007 standard test method. The work station component emission rates were estimated using CWP emission rates in combination with the extent of finishing or overlay on a workstation component and the reduction in the emission rate of the CWP due to th e finish or overlay acting as a barrier to off

- gassing emission s. In formation was not identified on the relative amounts of the three CWPs used in the fabrication of office workstations, representative values for the extent to which the workstation compone nts are finished or overlayed, and the barrier effectiveness of the finish or overlay . Due to these data gaps in information on representative values for these model parameters, what - if values for indoor air concentration were estimated. What - if values f or indoor air concentration were estimated by

first estimating the range of possible values for the following parameters: extent of finishing or overlay

of each workstation component and the barrier effectiveness of the finishing or overlay . Next , these e stimated ranges of parameter values were used in combination with the range of CWP emission rates obtained from the EPA reports mentioned above and the representative values for the remaining model parameters to estimate a range of what - if values for indoor air concentration in an office building due to each workstation type . A range of what if indoor air concentration values was calculated assuming a workstation consists of only a single CWP ty pe. Low and high ends of the range of what - if average formaldeh yde indoor air concentrations in the building volume containing a workstation were estimated using the mathematical model and (1) the boundin g values of the range of values for the model parameters for which ranges were estimated and (2) the representative values of the remaining model parameters so as to obtain a wide range of indoor air concentration . Additionally , an intermediate what - if va lue of indoor air concentration was calculated using average or intermediate values for the model parameters for which ranges were estimated and the representative values of the remaining model parameters. Section 3.3.1.2 describes in d etail how an average or intermediate value was determined for each model parameter. In this assessment report, an intermediate value is defined as a value in - between a low - end and hi gh - end value. These calculations were repeated for each CWP type: HWPW, PB, and MD F, thus resulting in nine values of what - if indoor air concentrations for each workstation ty pe (a low - end, high - end, and intermediate value of what - if indoor air concentrati on for each of the three CWP ty pe s ). These values were then aggregated into low - end ranges, intermediate ranges, and high - end ranges to account for various mixtures of the different CWP ty pes in each o ffice workstation ty pe . The best estimate concentrati on was calculated as the average of the following two values: the midpoint of the intermediate range for open plan workstations and the midpoint of the intermediate range for private office workstations as discussed in Section 4.5.4.1 . These calculated indoor air concentrations are initial steady - state concentrations resulting from off - gassing of office work stations fabricated from new CWPs . T emporal decay in emissi on rates from the CWPs was not accounted for due to data gaps in information necessary for the modeling of the temporal decay of CWP emission rates in office buildings.vi

Results The results for each assessed life cycle stage are summarized below. Results for Manufacturing At baseline, approximately all domestic production of HWPW, MDF, and PB will be in compliance with the CARB ATCM Phase 2 standard . Onl y small fractions of HWPW and PB domestic production will not be in compliance with the CARB ATCM Phas e 2 standard at baseline. Hence, the CARB Phase 1 and FSCWPA/CARB Phase 2 anal yt ical options will result in a negligible effect on baseline exposure levels for manufacturing. Since approximately all domestic production of CWPs are expected to meet the CA RB ATCM Phase 2 standard at baseline, only

the NAF analy

tical option will affect baseline exposures. NAF resins do not contain any formaldehyde. Therefore, mills that use NAF resins in compliance with NAF standards should achieve a reduction in formaldehy de exposures due to the elimination of the formaldehyde content of resins. However, wood naturally emits formaldeh yde, and it is possible that workers in mills that use only NAF resins may

still experience some formaldehyde exposures due to the natural em ission of formaldehyde from wood. Other sources of formaldeh yde can exist for mills that apply value - added surfaces. However, it is uncertain how many mills appl y value - added surfaces. Dermal exposures to workers during manufacturing can occur during unl oading of liquid UF resin. For the purpose of this assessment, EPA assumes a formaldeh yd e concentration of 0.59% in the UF resin. The EPA/OPPT 2 - Hand Dermal Contact with L iquid Model estimates a dermal exposure of 590 to 1,800 mg/day for exposure to a ch emical at 100% concentration. For the assumed formaldeh yd e concentration of 0.59%, the model estimates worker exposure of 3.5 to 10.6 mg/day . This results in an estimated dose of 0.05 to 0.15 mg/kg/day for an average 70 kg worker. It is uncertain how th e free formaldeh yd e content of CWP resins will change as manufacturers a dopt the CARB ATCM limits. Therefore, both baseline dermal exposures and the effect of anal yt ical options on baseline dermal exposures are uncertain and cannot be estimated. Results f or CW P Fabrication The results of the assessment of indoor air concentration s in CWP fabrication sites at the baseline and the effect of the anal yt ical options on baseline indoor air concentration s are presented in Table ES - 1 through Table ES - 4 . Table ES - 2 provides a summary of the estimates of average indoor air concentration in a CWP fabrication site due to off - gassing from the three CWP ty pes as a range of values and as a single best estimated value for the baseline and the anal yt ical options. Tables ES - 3 and ES - 4 provide average dail y concentration (ADC) and lifetime average dail y concentration (LADC) values, respectively, that correspond to the values given in Table ES - 2. The r esults show that the maximum formaldehyde indoor air concentration decrea ses as lower (more stringent) emission standards are implemented. However, the CARB ATCM Phase 1 anal yt ical option would result in little or no reduction in exposure from the baseline year because most composite wood products are expected to be already meeting more stringent standards b y the baseline ye ar ( 2013 ) . T he minimum indoor air concentration i s identical for all of the different anal yt ical option s because a small portion of the market is expect ed to be already m eeting the NAF standards at the baseline. The emission levels of NAF -vii

compliant composite wood products were assumed to remain unchanged and not be affected b y the anal yt ical options. Results for W

holesale and Retail The formaldeh yd e con centration resulting from off - gassing is expected to decrease with the implementation of more stringent regulations. However, as discussed previously , CARB ATCM Phase 1 anal yt ical option would result in little or no reduction in exposure from the baseline ye ar. This effect is because most composite wood products in the market would already be meeting more stringent limits by 2013. Results for Office Buildings The results of the assessment of indoor air concentration s in office buildings at the baseline and the effect of the anal yt ical options on baseline indoor air concentration s are presented in Table ES - 5 through Table ES - 8 . Table ES - 5 provides for the baseline and each of the anal yt ical options the three ranges of estimated indoor air concentration in an office building f or each of the two ty pes of office furniture workstations. Tables ES - 6 and ES - 7 provide average daily concentration (ADC) and lifetime average dail y concentration (LADC) values, respectively, that correspond to the values given in Table ES - 5. Table ES - 8 presents the best estimated indoor air concentration values from among the results presented in Table ES - 5. Similarly as with the CWP fabrication results, the office building r esults show that the maximum formaldeh yde indoor air concentration decreases as lower (more stringent) emission standards are implemented. Again, the minimum indoor air concentration s remain constant throughout the different anal yt ical options due to the presence of NAF - compliant products at the baseline. The office building result s in Table ES - 8 show the most significant reduction in indoor air concentration from the NAF emission limits.vi ii **Table ES -**  **1 . Estimated**  **Low -**  **End, Intermediate, and High -**  **End Ranges of Values for the**  **Site -**  **Average Indoor Air Concentration**  **for CWP Fabrication**  **at the Baseline and**  **for the Analytical**  **Options Case**  **Intermediate (ppm** **) Low End (ppm)**  **High End (ppm)** Baseline 0.0095

– 0.0181 0.0055

– 0.0092 0.0218

– 0.3934 Phase 1 0.0077 ( - 18.8%)

– 0.0176 ( - 2.7%) 0.0054 ( - 3.2%)

– 0.0092 (0%) 0.0111 ( - 49.3%)

– 0.3787 ( - 3.7%) FSCWPA / P hase 2 0.0072 ( - 23.5%)

– 0.0175 ( - 3.2%) 0.0053 ( - 4.0%)

– 0.0092 (0%) 0.0084 ( - 61.5%)

– 0.3763 ( - 4.3%) NAF 0.0064 ( - 32.0%)

– 0.0110 ( - 39.3%) 0.0052 ( - 5.5%)

– 0.0092 (0%) 0.0064 ( - 70.5%)

– 0.1807 ( - 54.1%) **Table ES -**  **2 . Estimated**  **Overall Range and Best Estimate for the**  **Sit e**  **- Average**  **Indoor Air Concentration for CWP Fabrication**  **at the Baseline and for the**  **Analytical Options**  **Case Overall Range (ppm** **) Best Estimate**  **Concentration 1**  **(ppm )**  **Reduction from Baseline (%)**  Baseline 0.0055

– 0.3934 0.1995 -- Phase 1 0.0054

– 0.3787 0.1920 - 3.7 FSCWPA / Phase 2 0.0053

– 0.3763 0.1908 - 4.3 NAF 0.0052

– 0.1807 0.0930 - 53.4 1 The best estimate concentration is the midpoint of the overall range. The overall range is defined as the low - end value from the low - end range and the high - end value from the high - end range. The reduction from baseline, ADC, and LADC values are calculated from the best est imate concentration value. **Table ES -**  **3 . Overall Range and Best Estimate ADC for**  **CWP Fabrication at the Baseline and**  **for the Analytical**  **Options Case**  **Overall Range (μg/m** **3 )**  **Best Estimate ADC (μg/m** **3 )**  Baseline 1.556

– 110.4 56.0 Phase 1 1.506

– 106.3 53.9 FSCWPA / Phase 2 1.494

– 105.6 53.5 NAF 1.471

– 50.71 26.1ix

**Table ES -**  **4 . Overall Range and Best Estimate LADC for**  **CWP Fabrication at the Baseline and**  **for the Analytical**  **Options Case**  **Overall Range (μg/m** **3 )**  **Best Estimate LADC (μg/m** **3 )**  Baseline 0.8894

– 63.08 32.0 Phase 1 0.8607

– 60.72 30.8 FSCWPA / Phase 2 0.8536

– 60.34 30.6 NAF 0.8407

– 28.98 14.9 **Table ES -**  **5 . Summary of Formaldehyde**  **Indoor Air Concentration s**  **for Office Buildings at**  **the Baseline and for the**  **Analytical Options**  **Open Plan Workstations Case**  **Intermediate (ppm** **) Low End**  **(ppm) High End**  **(ppm)** Baseline 0.0265 - 0.0732 0.0035 - 0.0053 0.2002 - 1.0089 P hase 1 0.0167 ( - 37 .0 %) -

0.0705 ( - 3.7%) 0.0035 (0%) - 0.0053 (0%) 0.0729 ( - 63.6%) - 0.2833 ( - 71.9%) FSCWPA / P hase 2 0.0143 ( - 46 .0 %) -

0.0701 ( - 4.2%) 0.0035 (0%) - 0.0053 (0%) 0.0414 ( - 79.3%) - 0.167 ( - 83.4%) NAF 0.0099 ( - 62.6%) -

0.0346 ( - 52.7%) 0.0035 (0%) - 0.0053 (0%) 0.0184 ( - 90.8%) - 0.0728 ( - 92.8%)

**Private Office Workstations Case**  **Intermediate (ppm** **) Low End**  **(ppm) High End**  **(ppm)** Baseline 0.013 - 0.0332 0.003 - 0.0036 0.0719 - 0.3555 P hase 1 0.0087 ( - 33.1%) - 0.032 ( - 3.6%) 0.003 (0%) - 0.0036 (0%) 0.0273 ( - 62 .0 %) - 0.1011 ( - 71.6%) FSCWPA / P hase 2 0.0077 ( - 40.8%) -

0.0318 ( - 4.2%) 0.003 (0%) - 0.0036 (0%) 0.0163 ( - 77.3%) - 0.0603 ( - 83 .0 %) NAF 0.0058 ( - 55.4%) -

0.0165 ( - 50.3%) 0.003 (0%) - 0.0036 (0%) 0.0082 ( - 88.6%) - 0.0273 ( - 92.3%) Note: Values in parentheses are the percent reductions in the indoor air concentration from the baseline value.x

**Table ES -**  **6 .**  **Summary of Formaldehyde Exposure Concentrations**  **for Office Buildings as**  **Average Daily Concentrations at**  **the Baseline and**  **for the Analytical**  **Options**

**Open Plan Workstations Case**  **Intermediate**

**( μ**  **g /m** **3 )**  **Low End**

**( μ**  **g /m** **3 )**  **High End**

**( μ**  **g /m** **3 )**  Baseline 7.44 - 20.54 0.98 - 1.49 56.17 - 283.1 P hase 1 4.69 - 19.78 0.98 - 1.49 20.46 - 79.49 FSCWPA / P hase 2 4.01 - 19.67 0.98 - 1.49 11.62 - 46.86 NAF 2.78 - 9.71 0.98 - 1.49 5.16 - 20.43

**Private Office Workstations Case**  **Intermediate**

**( μ**  **g /m** **3 )**  **Low End**

**( μ**  **g /m** **3 )**  **High End**

**( μ**  **g /m** **3 )**  Baseline 3.65 - 9.32 0.84 - 1.01 20.17 - 99.75 P hase 1 2.44 - 8.98 0.84 - 1.01 7.66 - 28.37 FSCWPA / P hase 2 2.16 - 8.92 0.84 - 1.01 4.57 - 16.92 NAF 1.63 - 4.63 0.84 - 1.01 2.3 0 - 7.66xi **Table ES -**  **7 .**  **Summary of Formaldehyde Exposure Concentrations**  **for Office Buildings as**  **Lifetime Average Daily Concentrations at**  **the Baseline and for the**  **Analytical Options** 

**Open Plan Workstations Case**  **Intermediate**

**( μ**  **g /m** **3 )**  **Low End**

**( μ**  **g /m** **3 )**  **High End**

**( μ**  **g /m** **3 )**  Baseline 4.25 - 11.74 0.56 - 0.85 32.1 - 161.8 P hase 1 2.68 - 11.3 0.56 - 0.85 11.69 - 45.42 FSCWPA / P hase 2 2.29 - 11.24 0.56 - 0.85 6.64 - 26.78 NAF 1.59 - 5.55 0.56 - 0.85 2.95 - 11.67

**Private Office Workstations Case**  **Intermediate**

**( μ**  **g /m** **3 )**  **Low End**

**( μ**  **g /m** **3 )**  **High End**

**( μ**  **g /m** **3 )**  Baseline 2.08 - 5.32 0.48 - 0.58 11.53

– 57 .00 P hase 1 1.39 - 5.13 0.48 - 0.58 4.38 - 16.21 FSCWPA / P hase 2 1.23 - 5.1 0 0.48 - 0.58 2.61 - 9.67 NAF 0.93 - 2.65 0.48 - 0.58 1.31 - 4.38 **Table ES -**  **8 .**  **Summary of Best Estimate Results**  **for Office Buildings**  **at the**  **Baseline and for the**  **Analytical Options** 

**Case Best**  **Estimate**

**Concentration 1**  **(ppm) Reduction** 

**from Baseline**  **(%) ADC** 

**(μg/m 3**  **) LADC** 

**(μg/m 3**  **)** Baseline 0.0365 -- 10.23 5.85 P hase 1 0.0320 - 12.3 8.97 5.13 FSCWPA / P hase 2 0.0310 - 15.1 8.69 4.97 NAF 0.0167 - 54.2 4.69 2.68 1 The best estimate concentration is the average of the following two values: the midpoint of the intermediate range for open plan workstations and the midpoint of the intermediate range for private office workstations. The reduction from baseline, ADC, and LADC values are calculated from the best estimate concentration value.xii

Uncertainties There is uncertainty in the values of the parameters of the mathematical model for the estimation of average indoor air concentration in a CWP fabrication site. In particular, a s di scussed in Section 3.3.1.1 , there is considerable uncertainty i n the range of values for emitting surface area, and some uncertainty

in the range of values for effective ventilation rate. Therefore, there is uncertainty

in the calculated range of baseline indoor air concentration. It is not possible to determine the direction of uncertainty ( i.e. , whether the estimated values for indoor air concentration are an underestimate or an overestimate). Furthermore, as discu ssed above, if sources other than off

- gassing from CWPs are present in a CWP fabrication site , then the calculated indoor air concentration s would not be representative of aggregate indoor air concentration s . The composition of composite wood product s used in office furniture was not determined and, therefore, panels and work surfaces of office workstations were assumed to be entirel y composed of CWPs. Furthermore, the ty pe and extent of coverage b y finishing or overlay materials on the CWPs used to fabric ate office workstations were also not determined, and a range of values was assumed for these parameters. This assumption introduces uncertaint y into the calculated indoor air concentration s . Furthermore, the mathematical model for the estimation of indo or air concentrations in an office building simplifies the complex nature of office building ventilation sy stems. Ty

picall y in these s ys tems, outdoor air is mixed with a recirculation stream of indoor air prior to being supplied to the various ventilation zones. The return air from these ventilation zones is mixed and then a stream is split for recirculation and mixing with the outdoor air while the balance is exhausted. Therefore, the office environment model neglects the effect of one exposure zone on another resulting from the recirculation of indoor air or the movement of air directly between exposure zones without passing through the ventilation system. The uncertainty in the results due to neglecting the effect of one exposure zone on another is un certain and cannot be quantified without a detailed, rigorous mathematical model with detailed supporting monitoring data. Itis not possible to determine the direction of uncertaint y in the estimated results for indoor air concentration in office buildin gs.xiii **Table of Contents** 1. INTRODUCTION ................................ ................................ ................................ .................... 1 2. P URPOSE AND S COPE OF E XPOSURE A SSESSMENT ................................ ............................... 1 2.1 Manufacturing ................................ ................................ ................................ ......... 9 2.2 Composite Wood Product Fabrication ................................ ................................ .... 9 2.3 Wholesale ................................ ................................ ................................ .............. 10 2.4 Retail ................................ ................................ ................................ ..................... 10 2.5 Commercial Use ................................ ................................ ................................ .... 10 2.6 Disposal and Recycle ................................ ................................ ............................ 10 3. E XPOSURE A SSESSMENT M ETHOD ................................ ................................ ..................... 11 3.1 Literature Search ................................ ................................ ................................ ... 12 3.2 Compilation of Pre - Baseline Exposure Monitoring Data ................................ ..... 13 3.3 Exposure Assessment Methods and Assumptions ................................ ................ 17 3.3.1 Estimation of Indoor Air Concentrations Related to Baseline and Analy tical Options for CWP Fabrication and Office Buildings ............... 18 3.3.1.1 Method for Estimation of Indoor Ai r Concentration for CWP

Fabrication ................................ ................................ ............... 19 3.3.1.2 Method for Estimation of Indoor Air Concentration for Office

Buildings ................................ ................................ .................. 27 3.3.2 Estimation of Dermal Exposures to Formaldehyde in L iquid Resin ........ 37 4. E XPOSURE A SSESSMENT B Y L IFE C YCLE S TAGE ................................ ............................... 37 4.1 Exposure Assessment for Manufacturing ................................ ............................. 37 4.1.1 Description of Life C ycl e Stage ................................ ................................ 37 4.1.2 Production Volumes and Number of Establishments, Workers, Production Hours, and Work Day s ................................ ........................... 41 4.1.3 Pre - Baseline E xposure Monitoring Data ................................ .................. 43 4.1.4 Respiratory

Protection Usage During Manufacturing .............................. 47 4.1.5 Baseline Exposure and the Effect of Analy tical Options on Baseline Exposure for Manufacturing ................................ ...................... 48 4.1.6 Dermal Exposures during Manufacturing ................................ ................. 49 4.2 Exposure Assessment for Composite Wood Product Fabrication ........................ 50 4.2.1 Description of Life C ycl e Stage ................................ ................................ 5 0 4.2.2 Number of Establishments, Workers, Production Hours, and Work Day s ................................ ................................ ................................ . 53 4.2.3 Pre - Baseline Exposure Monitoring Data ................................ .................. 57 4.2. 4 Respiratory

Protection Usage During Composite Wood Product Fabrication ................................ ................................ ................................ 57 4.2.5 Baseline Exposure and the Effect of Analy tical O ptions on Baseline Exposure for Composite Wood Product Fabrication ................. 59 4.2.5.1 Results for Indoor Air Concentration Calculation Trials and

Sensitivity

Anal ys is ................................ ................................ . 59 4.2.5.2 Estimation of a Range of Values for the What - If Low - End and

the What - If High - End Indoor Air Concentrations that Account for All CWP Ty

pes ................................ ................................ .. 60xiv 4.2.5.3 Final Results for the Estimation of What - If Indoor Air

Concentrations ................................ ................................ ......... 61 4.2.5.4 The Assessment of Exposure Level for the Baseline and the

Analy tical Options ................................ ................................ ... 63 4.2.6 Derm al Exposures during Composite Wood Product Fabrication ............ 69 4.3 Exposure Assessment for Wholesale ................................ ................................ .... 69 4.3.1 Description of Life C ycl e Stage ................................ ................................ 69 4.3.2 Use Volumes and Number of Establishments, Employees, Employed Hours, and Work Day s ................................ ............................ 69 4.3.3 Pre - Baseline Exposure Monitoring Data ................................ .................. 70 4.3.4 Baseline Exposure and the Effect of Analy tical Options on Baseline Exposure for Wholesale ................................ ............................. 71 4.3.5 Dermal Exposures during Wholesale ................................ ........................ 71 4.4 Exposure Assessment for Retail ................................ ................................ ........... 71 4.4.1 Description of Life C ycl e Stage ................................ ................................ 71 4.4.2 Use Volumes and Number of Establishments, Employees, Employed Hours, and Work Day s ................................ ............................ 72 4.4.3 Pre - Baseline Exposure Monitoring Data ................................ .................. 73 4.4.4 Baseline Exposure and the Effect of Analy tical Options on Baseline Exposure for Retail ................................ ................................ .... 75 4.4.5 Dermal Exposures during Retail ................................ ............................... 75 4.5 Exposure Assessment for Office Workers during Commercial Use .................... 75 4.5.1 Description of Life C ycl e Stage ................................ ................................ 75 4.5.2 Use Volumes and Number of Establishments, Employees, Employed Hours, and Work Day s ................................ ............................ 75 4.5.3 Pre - Baseline Exposure Monitoring Data ................................ .................. 76 4.5.4 Baseline Exposure and the Effect of Analy tical Options on Baseline Exposure for Office Buildings ................................ ................... 77 4.5.4.1 Determination of a Best Estimate for Indoor Air Concentration 77 4.5.5 Dermal Exposures during Commercial Use ................................ ............. 81 5. U

NCERTAINTIES IN A SSESSMENT RESULTS ................................ ................................ ........ 82 5.1 Uncertainties in Assessment Results for Composite Wo od Product Manufacturing, Fabrication, Wholesale, Retail, and Office Buildings ................. 82 5.1.1 Uncertaint y in the Estimates of Indoor Air Concentration for Composite Wood Product Fabrication ................................ ...................... 82 5.1.2 Uncertaint y in the Estimates of Indoor Air Concentration for Offic e Buildings ................................ ................................ ........................ 83 5.2 Uncertainties in Pre - Baseline Monitoring Data ................................ .................... 84 5.2.1 OSHA IMI S Data ................................ ................................ ...................... 84 5.2.2 BASE Study

Monitoring Data ................................ ................................ .. 92 5.3 Uncertaint y in Number of Production Workers and Employees .......................... 93 6. REF ERENCES ................................ ................................ ................................ ...................... 94 Appendix A: Definition of Terms Appendix B: Data Quality Acceptance Criteria Specificationsxv

Appendix C: Ex isting Formaldeh yde Occupational Exposure Li mits and Formaldeh yde OffGassing Emi ssion Standards for Composite Wood Products Appendix D: Formaldehyde CWP Off - Gassing Emission Level Data for the Pre - Baseline Period, Baseline, and the Analy

tical Options Appendix E : Modeling Methodology for Estimating Indoor Air Concentration s Related to Baseline and Anal yt ical Options Appendix F: Pre - Baseline Formaldeh yde Exposures from OSHA IM IS by Worker Activity and Industry Sector for Composite Wood Product Fabricators Appendix G : Summary

of OSHA Inspection Reports Appendix H: Summary

of Additional Exposure Monitoring Data from Manufacturing Appendix I : Model Results for Indoor Air Concentrations at CWP Fabrications Sites using Pre Baseline Emission Ratesxvi **List of Tables** T ABLE ES - 1. E S TIMATED L OW - E ND , INTERMEDIATE , AND H IGH - END RANGES OF VALUES FOR THE S ITE - AVERAGE INDOOR A IR C ONCENTRATION FOR CWP F ABRICATION AT THE B ASELINE AND FOR THE A NALYTICAL O PTIONS ................................ ......................... VIII T ABLE ES - 2. E STIMATED O VERALL RANGE AND B EST E STIMATE FOR THE S ITE - AVERAGE INDOOR A IR C ONCENTRATION FOR CWP F ABRICATION AT THE B ASELINE AND F OR THE A NALYTICAL O PTIONS ................................ ................................ ............................... VIII T ABLE ES - 3. O VERALL RANGE AND B EST E STIMATE ADC FOR CWP F ABRICATION AT THE B ASELINE AND FOR THE A NALYTICAL O PTIONS ................................ ................................ VIII T ABLE ES - 4. O VERALL RANGE AND B EST E STIMATE LA DC FOR CWP F ABRICATION AT THE B ASELINE AND FOR THE A NALYTICAL O PTIONS ................................ ........................... IX T ABLE ES - 5. S UMMARY OF F ORMALDEHYDE INDOOR A IR C ONCENTRATIONS F OR O FFICE B UILDINGS AT THE B ASELINE AND FOR THE A NALYTICAL O PTIONS ................................ ... IX T ABLE ES - 6. S UMMARY OF F ORMALDEHYDE E XPOSURE C ONCENTRATIONS F OR O FFICE B UILDINGS AS AVERAGE D AILY C ONCENTRATIONS AT THE B ASELINE AND FOR THE A NALYTICAL O P TIONS ................................ ................................ ................................ ......... X T ABLE ES - 7. S UMMARY OF F ORMALDEHYDE E XPOSURE C ONCENTRATIONS F OR O FFICE B UILDINGS AS L IFETIME AVERAGE D AILY C ONCENTRATIONS ATT HE B ASELINE AND FOR THE A

NALYTICAL O PTIONS ................................ ................................ .................. XI T ABLE ES - 8. S UMMARY OF B EST E STIMATE RESULTS FOR O FFICE B UILDINGS AT THE B ASELIN E AND FOR THE A NALYTICAL O PTIONS ................................ ................................ .. XI T ABLE 2 - 1. NAICS INDUSTRY S ECTORS I DENTIFIED F OR THE L IFE C YCLE S TAGES OF HWPW, MDF, AND PB ................................ ................................ ................................ ....... 6 T ABLE 3 - 1. P RE - B ASELINE F ORMALDEHYDE E MI SSION L EVELS FOR D OMESTICALLY P RODUCED C OMPOSITE W OOD P RODUCTS ................................ ................................ ........ 15 T ABLE 3 - 2. S UMMARY OF W HAT - I F M ETHOD FOR THE E STIMATION OF THE W HAT - I F RANGE OF AVERAGE INDOOR A IR C ONCENTRATIONS OF F ORMALDEHYDE AT CWP F ABRICATION S ITES ................................ ................................ ................................ ........... 21 T ABLE 3 - 3. M AT RIX OF V ENTILATION RAT ES AND M IX ING F ACTORS ................................ ........... 22 T ABLE 3 - 4. E STIMATED V ALUES FOR P ARAMETERS IN THE M ATHEMATICAL M ODEL FOR AVERAGE INDOOR A IR C ONCENTRATION AT A CWP F ABRICATION S ITE FOR THE B ASELINE AND THE A NALYTICAL O PTIONS ................................ ................................ ........ 26 T ABLE 3 - 5. D ATA S OURCES F OR THE E STIMATION OF P ARAMETERS OF THE M ATHEMATICAL M ODEL FOR AVERAGE INDOOR A IR C ONCENTRATION AT A CWP F ABRICATION S ITE ................................ ................................ ................................ ............. 27xvii

T ABLE 3 - 6. S UMMARY OF W HAT - IF M ETHOD FOR THE E STIMATION OF THE W HAT - IF RANGE OF AVERAGE INDOOR A IR C ONCENTRATIONS OF F ORMALDEHYDE IN W ORKSTATION V OLUMES ................................ ................................ ................................ .. 30 T ABLE 3 - 7. C OMPARISON OF ASTM E1333 P ARAMETER VALUES WITH T YPICAL O FFICE ENVIRONMENT P ROPE RTIES ................................ ................................ ............................... 33 T ABLE 3 - 8. E STIMATED V ALUES FOR P ARAMETERS IN THE M ATHEMATICAL M ODEL FOR AVERAGE INDOOR A IR C ONCENTRATION RESULTING F ROM E MI SSIONS FROM P RIVATE O FFICE AND O PEN P LAN W ORKSTATIONS F OR THE B ASELINE AND A NALYTICAL O PTIONS ................................ ................................ ................................ ....... 34 T ABLE 4 - 1. U.S. H ARDWOOD P LYWOOD P RODUCTION D ATA AND NUMBER OF M ILLS ................ 42 T ABLE 4 - 2. U.S. RECONSTITUTED W OOD P RODUCT P RODUCTION D ATA AND NUMBER OF M ILLS ................................ ................................ ................................ ................................ 43 T ABLE 4 - 3. S UMMARY OF 2007 E CONOMIC C ENSUS D ATA AND E XPOSURE F REQUENCY AND D URATION C AL CULATED FROM T HESE D ATA FOR U.S. M ANUFACTURING M ILLS ................................ ................................ ................................ ................................ 43 T ABLE 4 - 4. S UMMARY OF F ORMALDEHYDE INHALATION M ONITORING D ATA F OR H ARDWOOD P LYWOOD M ANUFACTURING M ILLS FROM THE OSHA IM IS D ATABASE ................................ ................................ ................................ ......................... 44 T ABLE 4 - 5. S UMMARY OF F ORMALDEHYDE INHALATION M ONITORING D ATA F OR RECONSTITUTED W OOD P RODUCT M ANUFACTURING M ILLS FROM THE OSHA IM IS D ATABASE ................................ ................................ ................................ ......................... 45 T ABLE 4 - 6. S UMMARY OF 2007 E CONOMIC C ENSUS D ATA AND E XPOSURE F REQUENCY AND D URATION C AL CULA TED FROM T HESE D ATA FOR C OMPOSITE W OOD P RODUCT F ABRICATING S ITES ................................ ................................ ........................... 54 T ABLE 4 - 7. S UMMARY OF A LL IM IS TWA P ERSONAL M ONITORING D ATA F OR INDUSTRIES W ITHIN THE CWP F ABRICATOR L IFE C YCLE S TA GE ................................ ...... 57 T ABLE 4 - 8. RESULTS FOR THE C AL CULATION T RIALS F OR THE W HAT - I F L OW - AND H IGH END B ASELINE INDOOR A IR C ONCENTRATIONS ................................ ................................ . 64 T ABLE 4 - 9. RESULTS FOR THE C AL CULATION T RIALS F OR THE W HAT - I F L OW - AND H IGH END CA RB P HASE 1 INDOOR A IR C ONCENTRATIONS ................................ ....................... 65 T ABLE 4 - 10. RESULTS FOR THE C AL CULATION T RIALS FOR THE W HAT - I F L OW - AND H IGH END FSCWPA / CARB P HASE 2 INDOOR A IR C ONCENTRATIONS ................................ ..... 66 T ABLE 4 - 11. RESULTS FOR THE C AL CULATION T RIALS FOR THE W HAT - I F L OW - AND H IGH END NAF INDOOR A IR C ONCENTRATIONS ................................ ................................ ........ 67xviii

T ABLE 4 - 12. E STIMATED L OW - E ND , INTERMEDIATE , AND H IGH - END RANGES OF VALUES FOR THE S ITE - AVERAGE INDOOR A IR C ONCENTRATION AT THE B ASELINE AND F OR THE A NALYTICAL O PTIONS ................................ ................................ ................................ 67 T ABLE 4 - 13. E STIMATED O VERALL RANGE AND B EST E STIMATE S ITE - A VERAGE INDOOR A IR C ONCENTRATION AT THE B ASELINE AND FOR THE A NALYTICAL O PTIONS ................. 68 T ABLE 4 - 14. O VERALL RANGE AND B EST E STIMATE ADC ATT HE B ASELINE AND FOR THE A NALYTICAL O PTIONS ................................ ................................ ................................ ....... 68 T ABLE 4 - 15. O VERALL RANGE AND B EST E STIMATE LA DC ATT HE B ASELINE AND FOR THE A NALYTICAL O PTIONS ................................ ................................ ................................ ....... 68 T ABLE 4 - 16. S UMMARY OF 2007 E CONOMIC C ENSUS D ATA FOR W HOLESALE F ACILITIES ........... 70 T ABLE 4 - 17. S UMMARY OF F ORMALDEHYDE INHALATION M ONITORING D ATA F OR W HOLESALERS FROM THE OSHA IM IS D ATABASE ................................ ........................... 71 T ABLE 4 - 18. S UMMARY OF 2007 E CONOMIC C ENSUS D ATA FOR RETAIL F ACILITIES ................... 73 T ABLE 4 - 19. S UMMARY OF F ORMALDEHYDE INHALATION M ONITORING D ATA FOR RETAILERS F ROM THE OSHA IM IS D ATABASE ................................ ................................ . 74 T ABLE 4 - 20. O VERVIEW OF G ENERAL C HARACTERISTICS OF TH E 100 BASE B UILDINGS ............ 76 T ABLE 4 - 21. S UMMARY OF F ORMALDEHYDE INHALATION M ONITORING D ATA FOR O FFICE O CCUPATIONAL S ETTINGS AND O UT DOOR M EASURED C ONCENTRATIONS FROM T HE BASE S TUDY ................................ ................................ ................................ .................... 76 T ABLE 4 - 22. RESULTS FOR C ALCULATION OF W HAT - I F INDOOR A IR F ORMALDEHYDE C ONCENTRATIONS FOR E ACH A NALYTICAL O PTION ................................ .......................... 79 T ABLE 4 - 23 . C OMBINED ( FOR A LL CWP) RESULTS : C ALCULATED W HAT - I F INDOOR A IR C ONCENTRATIONS AT THE B ASELINE AND FOR THE A NALYTICAL O PTIONS ....................... 80 T ABLE 4 - 24. C OMBINED ( FOR A LL CWP) RESULTS : C ALCULATED W HAT - I F INDOOR A IR ADC S AT THE B ASELINE AND FOR THE A NALYTICAL O PTIONS ................................ .......... 80 T ABLE 4 - 25. C OMBINED ( FOR A LL CWP) RESULTS : C ALCULATED W HAT - I F INDOOR A IR LADC S AT THE B ASELINE AND FOR THE A NALYTICAL O PTIONS ................................ ....... 81 T ABLE 4 - 26. B EST E STIMATE OF W HAT - I F F ORMALDEHYDE E XPOSURE C ONCENTRATION ATT HE B ASELINE AND FOR THE A NALYTICAL O PTIONS ................................ ..................... 81 T ABLE 5 - 1. NUMBER OF OSHA INSPECTIONS AT CWP F ABRICATION F ACILITIES C OMPARED TO THE M AXIMUM NUMBER OF F ACILITIES FROM THE U.S. E CONOMIC C ENSUS ................................ ................................ ................................ .............................. 85xix **List of Figures** F IGURE 2 - 1. L IFE C YCLE AND M ARKET D ISTRIBUTION OF HWPW ................................ ................. 3 F IGURE 2 - 2. L IFE C YCLE AND M ARKET D ISTRIBUTION OF MDF ................................ ..................... 4 F IGURE 2 - 3. L IFE C YCLE AND M ARKET D ISTRIBUTION OF PB ................................ ........................ 5 F IGURE 4 - 1. C OMPARISON OF M ODEL RESULTS FO R RANGES OF W HAT - I F INDOOR A IR C ONCENTRATIONS USING P RE - B ASELINE E MI SSION RATES WITH OSHA IM IS D ATA ....... 62 F IGURE 5 - 1. TWA E XPOSURES FR OM OSHA IM IS FOR A S INGLE INSPECTION F OR A RMSTRONG C ABINETS (NAI CS 337110) ................................ ................................ ......... 88 F IGURE 5 - 2. TWA E XPOSURES F ROM OSHA IM IS FOR A S INGLE INSPECTION F OR M ID C ONTINENT C ABINETRY (NAI CS 337110) ................................ ................................ ........ 88 F IGURE 5 - 3. TWA E XPOSURES F ROM OSHA IM IS FOR A S INGLE INSPECTION FOR B ENVENUTI AND S TEIN (NAI CS 337122) ................................ ................................ .......... 89 F IGURE 5 - 4. TWA E XPOSURES F ROM OSHA IM IS FOR A S INGLE INSPECTION F OR A MERIWOOD INDUSTRIES (NAICS 337122) ................................ ................................ ...... 89 F IGURE 5 - 5. TWA E XPOSURES F ROM OSHA IM IS FOR T WO INSPECTIONS FOR T HE GUNLOCKE C OMPANY (NAI CS 337211 ) ................................ ................................ ........... 90 F IGURE 5 - 6. TWA E XPOSURES F ROM OSHA IM IS FOR T WO INSPECTIONS FOR S ILVER S TREET (NA IC S 337211) ................................ ................................ ................................ .. 90 F IGURE 5 - 7. TWA E XPOSURES F ROM OSHA IM IS FOR A S INGLE INSPECTION F OR T HE C OMMERCIAL F URNITURE G ROUP (NAICS 337127) ................................ ......................... 91xx **List of Abbreviations ADC**  Average dail y concentration **C&D** Construction and demolition **CARB P1** California Air Resources Board Formaldeh yde Regulation Phase 1 **CARB P2** California Air Resources Board Formaldeh yde Regulation Phase 2 **CFM** Cubic feet per minute **CWP** Composite wood product **FSCWPA** Formaldeh yd e Standards for Composite Wood Products Act **HWPW** Hardwood pl ywood **HWPW -**  **CC** Hardwood pl ywood

– composite core **HW PW**  **- VC**  Hardwood pl ywood

– veneer core **LADC** Lifetime average daily concentration **MDF** Medium - density fiberboard **MF** Melamine formaldeh yd e **MSW** Municipal solid waste **NAF** No - added formaldeh yd e **OSHA** Occupational Safety and Health Administration **PB** Particleboard **PF** Phenol formaldeh yde **pMDI** Poly (meth yl ene diphen yl diisocyanate) **PPE** Personal protective equipment **PV A**  Poly (vin ylacetate) **tMDF** T hin medium - density fiberboard **TWA** Time - weighted average **UF** Urea formaldeh yd e **ULEF** Ultra low emitting formaldehydeFormaldeh yd e Occupational Exposure Assessment Report

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October 6, 2011 Page 1 **1. I**  **NTRODUCTION** In March 2008, the Environmental Protection Agency (EPA) was petitioned by the Sierra Club and other signatories under Section 21 of the Toxic Substances Control Act (TSCA) to adopt nationally an Airborne Toxic Control Measure (ATCM) promulgated b y the California Air Resources Board (CARB) in 200 8 that establishes maximum formaldehyde emissions from the three t ypes of composite wood products: hardwood ply wood (HWPW), medium - density fiberboard (MDF) , and particleboard (PB). As described in EPA’s Advance Notice of Proposed Rulemaking (ANPR) published in December 2008 ( 73 FR 73620 ) and in response to this petition , EPA investi gate d whether regulatory action, including possible action under TSCA Section 6, or non - regulatory action might be appropriate to control the levels of formaldehyde emitted from composite wood products. In July 2010, President Obama signed into law the Formaldeh yd e Standards for Composite Wood Products Act ( FSCWPA ). 1 This law is an amendment to TSCA and directs EPA to regulate the formaldeh yd e emissions from HWPW, MDF, and PB. FSCWPA sets formaldehyde limits equal to the CARB ATCM standards . It also requires EPA to promulgate implementing regulations by

January 1, 2013. As part of the development of a rule under FSCWPA, EPA is conducting a cost - benefit anal ys is of implementing the formaldehyde limits cited by FSCWPA. In support of this cost - benefit anal ys is , EPA assessed occupational inhalation and dermal exp osure to formaldeh yd e during the life cycle of HWPW, PB, and MDF. **2. P**  **URPOSE AND S**  **COPE OF E**  **XPOSURE A**  **SSESSMENT** The purpose of the assessment is, first, the prediction of baseline formaldehyde inhalation and dermal occupational exposure that is due to all sources of exposure (aggregate exposure) during the life cycle of composite wood products (CWPs) , and, second, the determination of the effect on baseline exposure of the anal yt ical options for limits on emission levels for off - gassing from HWPW, PB, and MDF. The baseline occurs i n the year in which EPA will promulgate limits under FSCWPA, which will be 2013. T his document discusses various anal yt ical options for limits on emission levels for off - gassing from HWPW, PB, and MDF (i.e., various emission standards) simply for informational purposes. The br eadth of the discussion here should not imply that EPA necessarily

has corresponding flexibility in implementing the statute . The following specific anal yt ical options were assessed in support of the cost - benefit anal ys is for the formaldeh yd e rulemaking a ctivity :
 Analy

tical Option 1: a scenario in which EPA would implement maximum formaldeh yde emission limits equal to the CARB ATCM Phase 1 limits;  Analy

tical Option 2: a scenario in which EPA would implement maximum formaldeh yde emission limits equal to the CARB ATCM Phase 2 limits (which are equal to the limits specified in FSCWPA); and

1 TSCA §§ 601 et seq. (15 U.S.C. §§ 2697 et seq. ), http://www.gpo.gov/fdsys/pkg/PLAW - 111publ199/pdf/PLAW 111publ199.pdfFormaldeh yd e Occupational Exposure Assessment Report

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October 6, 2011 Page 2

 Analy

tical Option 3: a scenario in which EPA would implement maximum formaldeh yde emission limits equal to the no - added formaldeh yde (NAF) limits specified in FSCWPA. Figure 2 - 1 , Figure 2 - 2 , and Figure 2 - 3 depict the life cycle and market distribution for HWPW, MDF, and PB, respectively . Manufacture, import, and export v olumes are expressed in cubic meters of composite wood products and are annual volumes for the year 2005 (Table 2 - 5 of USEPA 2010a). Market distributions are expressed as percentages that represent the amount s of North American produced CWP that are sold to the various CWP fabrication industry sectors and directly to retail (section 2.3.2 of USEPA 2010a). The market distributions of imports are unknown. Percentages may not sum to 100 percent due to rounding. The description of the life cycles, i.e. , the markets and market channels, were obtained from the Hardwood Ply wood and Veneer Association (HPVA) (for HWPW) and the Composite Panel Association (CPA) (for PB and MDF) ( HPVA 2009a ; CPA 2008a). T h is assessment assesses potential worker exposure to formald eh yd e from the following life cycle stages of HWP W , PB and MDF:
 Manufacture of HWP W , PB and MDF within the United States (domestic manufacturing) ;  Downstream manufactur e of products constructed from domestically manufactured and imported HWP W , PB and MDF (e.g. manufacture of furniture using HWP W , PB and MDF) , referred to in this report as composite wood product fabrication ;  Wholesale and retail of domestically manufactured and imported HWPW, PB, MDF, and downstream products fabricated from these CWPs ; and  Occupancy

by office workers of office buildings containing domesticall y manufactured and imported HWPW, PB, MDF, and downstream products fabricated from these CWPs . The life cycle stages not assessed due to major data gaps include the following:
 Commercial construction using HWPW, PB, MDF, and products fabricated from these CWPs ; and  Recycling and disposal of HWPW, PB, MDF, and products fabricated from these CWPs . The life cycle stages that are assessed as well as those that were not assessed are further di scussed below in Sections 2.1 through 2.6 . Table 2 - 1 summarizes the applicable NAICS codes for the assessed life cycle stages .Formaldeh yd e Occupational Exposure Assessment Report

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October 6, 2011 Page 3

**Figure 2**  **- 1**  **. Life**  **C ycle**  **and Market Dist ribution**  **of HWPW**  HWPW Manufacturing 1,844,000 Distributors (Wholesale)

Direct Sale Cabinets Furniture Fixtures Retail Engineered Wood Flooring Wholesale
Commercial and Consumer Use Municipal

Solid Waste (MSW)

Recycle HWPW Im port 4, 0 2 0 ,311 Manufacture and Import (1) Market Channel (2) CWP Fabrication (3) Wholesale and Retail (5) Commercial and

Consumer Use ( 4 ) Disposal and Recycle (5)

HWPW Export 243,763

Figure notes:

1. Market volumes are in cubic meters. 2. According to information from HPVA , HWPW is distributed from the manufacturer or impo rter to CWP fabricators through multiple m arket channels . In some cases, HWPW panels can be sold to retail for direct consum ption. The EPA market profile reports that about 70% of total sales by U.S. HWPW manufacturers ar e to w holesale distributors. 3. The EPA market profile reports that approximately two - thirds of North American HWPW production is for panels. Panels are sold to cabinet manufacturers, retail building materials dealers, furniture manufacturers, and fixture manufacturers. 4. Consumer use is not within the scope o f this assessmen t. 5. Market volumes are not available for wholesale, retail, disposal, and recycle. Construction and Demolition (C&D) Debris LandfillsFormaldeh yd e Occupational Exposure Assessment Report

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**Figure 2**  **- 2**  **. Life C**  **ycle and Market Distribution of MDF**

MDF Manufacturing 3,256,912 Distributors (Wholesale)

Retail

Direct Sale

Over la y Material Ap plicators Ki tchen and Bath , including Counter Tops

Other
Household Furniture
Office Furniture Door Components

Retail Shelving

Laminate Flooring
Electronic Cabinets Moulding and Millwork Wh olesale

Commercial and Consumer Use Mu nicipal Solid Waste (MSW)

Recycle 12 %
17 %
2 %

3 % 6 %

1 %

13 %
1 % 23 %

Store Fi xtures 4 % MDF Import 966,967 MDF Export 163,889 Manufacture and Import Market Channel CWP Fabrication Wholesale and Retail Co mmercial and

Consumer Use (4) Disposal and Recycle 15 %

Figure notes: 1. Market volumes are in cu bic meters. 2. Ac cording to information from CPA, MDF is distributed from the primary manufacturer or importer to CWP fabricators through multiple market channels. In some cases, com

posite wood can be sold directly to retail for direct consumption. 3. Market volumes are not available for wholesale, retail, disposal, and recycle. 4. Consumer use is not within the scope of this assessment. Prefinished Paneling Mobile Home Decking and Underlayment <0.4 %

4 % Construction and Demolition (C&D) Debris LandfillsFormaldeh yd e Occupational Exposure Assessment Report

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**Figure 2**  **- 3**  **. Life C**  **ycle and Market Distribution**  **of PB**

PB Manufacturing 7,275,399 Distributors (Wholesale)

Retail

Direct Sale

Overlay Material Ap plicators Retail Shelving

Flooring , including mobile home decking

Electronic Cabinets Moulding and Millwork Wh olesale
Commercial and Consumer Use M unicipal S olid Waste (MSW)

Recycle 1 % 4 %

< 2.4 %

0. 2 % <2.2 %

Store Fixtures 4 % PB I mport 1,346,903 Ki tchen and Bath, including counter tops 36 %
6 % Door Components
12 % Other

10 % Office Furniture 21 % Household Furniture PB Export 258,827 Manufacture and Import Market Channel CWP Fabrication Wholesale and Retail Commercial and

Consumer Use (4) Disposal and Recycle

Figure notes: 1. Market volumes are in cubic meters. 2. According to information from CPA, PB is distributed from the primary manufacturer or importer to CWP fabricators through multiple market channels. In some cases, composite wood can be sold directly to retail for direct consumption. 3. Market volumes are not avai lable for wholesale, retail, disposal , and recycle. 4. Consumer use is not withi n the scope of this assessment. Underlayment 3 % Prefinished Paneling 2 % Construction and Demolition (C&D) Debris LandfillsFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 6 **Table 2**  **- 1**  **. NAICS Industry Sectors Identified**  **for the Life C**  **ycle St ages**  **of HWPW, MDF, and PB**  **Life Cycle Stage Included**  **NAICS Code s**  **Corresponding NAICS Industry Description**  **s** HWPW Manufacturing 321211 Hardwood veneer & plywood manufacturing MDF Manufacturing 321219 Reconstituted wood product manufacturing PB Manufacturing

C om posite W ood P roduct Fabrication 321911 Wood window & door manufacturing 321918 Other millwork (including flooring) 321991 Manufactured home (mobile home)

manufacturing 321999 All Other Miscellaneous Wood Product

Manufacturing 336213 Motor Home Manufacturing 336214 Travel Trailer & Camper Manufacturing 337110 Wood kitchen cabinet & counter top

manufacturing 337121 Upholstered household furniture manufacturing 337122 Non - upholstered wood household furniture

m anufacturing 337124 Metal Household Furniture Manufacturing 337127 Institutional furniture m anufacturing 337129 Wood television, radio, & sewing machine

cabinet manufacturing 337211 Wood office furniture m anufacturing 337212 Custom architectural woodwork & millwork

m anufacturing 337214 Office Furniture (except Wood) Manufacturing 337215 Showcase, partition, shelving, & locker

m anufacturing 339950 Sign Manufacturing

Wholesale 423210 Furniture merchant wholesaler 423220 Home furnishing merchant wholesaler 423310 Lumber, plywood, & wood panel merchant

wholesaler 423320 Brick, stone, & construction material merchant

wholesaler 423330 Roofing, siding, & insulation material merchant

wholesaler 423390 Other construction material merchant

wholesaler 423440 Other commercial equipment merchant

wholesalers 423450 Medical, dental, & hospital equipment &

supplies merchant wholesalers 423490 Other professional equipment & supplies

merchant wholesaler 423510 Metal service centers and other metal merchant

wholesalers 423610 Elec. equip. and wiring merchant wholesalers 423620 Electric appliance, TV & radio merchant

wholesalers 423710 Hardware merchant wholesalersFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 7 **Table 2**  **- 1**  **Continued**

**Life Cycle Stage Included**  **NAICS Code s**  **Corresponding NAICS Industry Description**  **s** 423720 Plumbing equip. merchant wholesalers 423730 HVAC equip. merchant wholesalers 423740 Refrigeration equipment and supplies merchant

wholesalers 423830 Industrial machinery & equipment merchant

wholesalers 423850 Service establishment equipment & supp

merchant wholesalers 423910 Sporting & recreational goods & supplies

merchant wholesalers 424610 Plastics materials and basic forms and shapes

merchant wholesaler 424950 Paint, varnish, and supplies merchant

wholesalers

Retail 441210 Recreational vehicle dealers 442110 Furniture stores 442210 Floor covering stores 442291 Window

treatment stores 442299 All other home furnishings stores 443111 Household appliance stores 443112 Radio, television, & other electronics stores 443120 Com

puter & software stores 444110 Home centers 444120 Paint and wallpaper stores 444130 Hardware stores 444190 Other building material dealers 444210 Outdoor power equipment stores 444220 Nursery, garden center, & farm supply stores 445110 Supermarkets and other grocery (except

convenience) stores 448110 Men's clothing stores 448120 Women's clothing stores 448130 Children's and infants' clothing stores 448140 Family clothing stores 448150 Clothing accessories stores 448190 Other clothing stores 451120 Hobby, toy, and game stores 451130 Sewing, needlework, and piece goods stores 452111 Department stores (except discount department

stores) 452112 Discount department stores 452910 Warehouse clubs and supercenters 452990 All other general merchandise stores 453110 Florists 453210 Office supplies and stationery stores 453220 Gift, novelty, and souvenir stores 453920 Art dealers 453930 Manufactured (mobile) home dealersFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 8 **Table 2**  **- 1**  **Continued**

**Life Cycle Stage Included**  **NAICS Code s**  **Corresponding NAICS Industry Description**  **s** 453998 All other miscellaneous store retailers (except

tobacco stores) 454113 Mail - order houses 454390 Other direct selling establishments Source: EPA market profile ( USEPA 2010a )Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 9 **2.1 Manufacturing**  The term “manufacturing” in this report refers specificall y to the manufacture of HWPW, MDF, and PB (and is also referred to as “primary manufacturing”) . The scope of this assessment includes the domestic manufacture of these products themselves but excludes an y part of the upstream supply

chain for the manufacture of these products such as resin or veneer manufacturing. Occupational exposures of formald ehyde in UF resin manufacture is covered under the “Draft Final Occupational Exposure and Environmental Release Assessment of Formaldeh yd e in Urea - Formaldeh yde Resin Manufacture and of Substitute Technologies to Reduce Emissions from Composite Wood Product s” (USEPA 2011a). The manufacture of imports, i.e. , the manufacture of HWPW, MDF, and PB in countries outside of the U.S., is not included in the scope of this assessment . The NAICS code 321219 - Reconstituted Wood Product Manufacturing includes both the manufacture of PB and MDF. It also includes the manufacture of composite wood products not included in the scope of this assessment, such as hardboard, oriented strandboard, and waferboard ( Census 2007a) . The NAICS code 321211 - Hardwood Veneer and Ply woo d Manufacturing includes the manufacture of hardwood ply wood . It also includes the manufacture of hardwood veneer ( Census 2007a). These veneers are typically not manufactured at the same facilities that manufacture hardwood ply wood. Therefore, hardwood veneer manufacturing facilities would not be subject to an y requirements under the proposed FSCWPA rule (USEPA 2010a). Therefore, hardwood veneer manufacturing facilities are not included in the scope of this assessment. **2.2 Composite Wood Product Fabrication**  HWPW, MDF, and PB may be converted into articles or other products. For example, HWPW may be pressed into panels and ply wood components (e.g. , curved HWPW, seat backs, chair arms, etc . ) or used for furniture, cabinets, architectural millwork, paneling for commercial buildings, flooring, store fixtures and doors ( OAQPS 2000b ). Similarly , MDF and PB are used in the manufacture of many products including virtually every application where interior panels or strips are required , especiall y in furniture and cabinetry . However, MDF is not used as floor underlay ment or decking except on special request ( Kirk - Othmer 20 11 a). In addition to furniture and cabinetry , PB is used as floor decking in manufactured homes, underlayment in conventional homes, shelving, c ountertops, door cores, stair stepping, door frames, and many other products that require small flat parts as a starting point. A small portion of PB is also extruded or molded into furniture parts, paper roll plugs, brush bases and toilet seats ( Kirk - Othmer 20 11 a). Composite wood products also may have “value - added surfaces” added to the panel product. “Value - added surfaces” include decorative finishes or overlay s and coatings , which may be applied at a “sister” facility of the manufacturer or at unaffil iated finishing sites ( CPA 2007a ; CPA 2009a). A technical bulletin published by the Composite Panel Association (CPA) further discusses the ty

pes of value - added surfaces ( CPA 2007a).Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 10 **2.3 Wholesale**  Wholesalers buy

products from manufacturers in bulk for the purpose of resale to various industries and individuals. Wholesale products may include CWP fabrication products as well as composite wood products ( i.e. , panels) . A single wholesaler may sell many

different t ypes of composite wood products ( Census 2007a) . **2.4 Retail**  Retailers operate from fixed locations and sell products for direct consumption by the purchaser (individuals or businesses). These retailers may receive HWPW, MDF, or PB directl y or as components in CWP fabrication products. L ike the wholesale s ector, the retail sector is not distinguished by composite wood product t ype ( Census 2007a) . **2.5 Commercial Use**  The commercial use of composite wood products includes (1) the use of composite wood products in on - site construction , and (2) the occupancy by offi ce workers of workplace buildings (commercial buildings) containing composite wood products . CWP fabrication products such as furniture and cabinets , in addition to composite wood products, are present in commercial building s . Data g aps for o n - s ite c onstr uction using HWPW, PB, and MDF include the following:
 The volumes of HWPW, PB, and MDF used during on - site construction could not be determined .  T he number of sites and workers engaged in on - site construction could not be determined . Therefore, the size of this life cycle stage and the number of workers exposed during this life cycle stage are unknown .  F ormaldeh yd e monitoring data for on - site construction could not be determined . Therefore, the range of potential exposures that occur during this life cyc le stage is unknown . Due to these data gaps , this assessment does not include an occupational exposure assessment of formaldeh yde during on - site construction. **2.6 Disposal and Recycl**  **e** At end of life, composite wood is either disposed of as municipal solid wastes (MSW) or construction and demolition (C&D) debris materials , or recycled into new products . A total of 15.84 million tons of wood MSW was generated (before recycling) in 2009 in the U.S. Of these 15.84 million tons, 10.08 million t ons were from wood pallets and wood crates (USEPA 2010b ) . Wood pallets and wood crates are likel y not constru cted of CWPs and are outside the scope of this assessment. Of these 15.84 million tons of wood MSW, the remaining 5.76 million tons of wood were from furniture and furnishings ( USEPA 2010b ) . As discussed in this report, CWPs are used in the fabrication of furniture ; therefore, an unknown fraction of the 5.76 million tons of wood likely consist s of CWPs. EPA reports that the only identified recovery of materialsFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 11 from MSW composed of furniture and furnishings was mattress recovery (USEPA 2010b ) . Of all MSW discarded in 2009 (after recovery for recycling and composting), 82% was landfilled or otherwise disposed and 18% was incinerated for energy recovery (USEPA 2010b ). Therefore, it is likely that CWPs in furniture that enters the MSW stream are not recovered and are discarded via landfilling or incineration . C&D materials consist of the debris generated during the construction, renovation, and demolition of buildings, roads, and bridges , which can include wood materials (USEPA 2011c ) . The majority

of building - related C&D materials come from building demolition and renovation with the remainder from new constru ction ( USEPA 2011c ) . A report from 2003 estimated that 20% to 30% of building related C&D debris generated was wood (USEPA 2011c ) . However, it is unknown what fraction of wood C&D debris consists of CWPs. In 1995, the Department of Agriculture estimated that 3.96 million tons 2 of wood products were recovered for recycling into miscellaneous uses ( USDA 1996a). The sources and t ypes of the recovered wood products referred to here were not given, and it is unknown whether the recovered wood material include s CWPs. The term “ m iscellaneous uses ” was not explicitly defined in the text but referred to examples such as insulation, molded pulp products, hardboard, insulating paperboard, and composite wood panels. More recentl y, o f the 10.08 million tons of wood MSW from wood pallets and wood crates, 22% were recovered for recycling as mulch and bedding material (USEPA 2011b ); however, as stated above, wood pallets and wood crates are likely not constructed of CWPs . Several existing and developing technologies ex ist for producing composites using recycled wood - based fiber. These composites include dry - formed wood composites, wet - formed structural fiber products, wood - plastic composites, and wood inorganic composites (Hamilton 1996 a). Data gaps for the disposal an d recycling of HWPW, PB, and MDF include the following:
 The volumes of HWPW, PB, and MDF disposed of as waste and recycled could not be determined .  F ormaldeh yd e monitoring data for the disposal and recycling of composite wood products could not be determin ed . Due to these uncertainties, this assessment does not include an occupational exposure assessment of formaldeh yd e during disposal and recycling. It is noted that d ue to the decay

of formaldeh yd e emission rates from CWPs with time (see Section 3.3.1.1 ), CWPs c an have reduced emission rates and, therefore, a diminished contribution to exposure concentrations when disposed or recycled at their end of life. **3. E**  **XPOSURE A**  **SSESSMENT M**  **ETHOD** This section describes the data collection efforts and the methods used for assessing occupational exposures, and their underlying assumptions.

2 3.96 million U.S. tons or 3.6 million metric tonnes.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 12 **3.1 Literature Search**  This exposure assessment relied on the use of readily available dat a , including exposure monitoring data and mathematical modeling data . A comprehensive literature search of readil y available government, industry , and academic sources was conducted, which included sources from EPA, OSHA, NIOSH, the California Air Resourc es Board (CARB) , SRIInternational, and the Organization for Economic Co - operation and Development (OECD), as well as industry websites, academic journals, and other publications. Additionally , submissions in response to EPA’s ANPR ( 73 FR 73620 ) were reviewed. The ANPR review included 123 public submissions to Docket Number EPA - HQ - OPPT - 2008 - 0627 and 30 public submissions to Docket Number EPA - HQ - OPPT - 2008 - 0267 . Also reviewed were regulations, such as the National Emissions Standards for Hazardous Air Pollutants (NESHAP) for pl ywood and composite wood products and the Housing and Urban Development (HUD) Rule on formaldehyde emissions from certain wood products in manufactured homes (24 CFR § 3280.308). T he following specific databases and studies were searched for formaldehyde air monitoring data:
 OSHA’s Integrated Management Information Sy stem (IMI S);  EPA’s Building Assessment Survey and Evaluation (BASE) study;  The Relationship of Indoor, Outdoor, and Personal Air (RIOPA) project;  The International Agency for Research into Cancer (IARC) Formaldehyde Monograph (Volume 88); and  The Detroit Exposure and Aerosol Research Study (DEARS) . The literature search did not yield an y formaldeh y de air monitoring data that are directl y relevant to this exposure assessment. Data from OSHA IMI S and EPA’s BASE study were the most relevant data obtained and were used in this assessment to provide perspective as discussed in Section 3.2 . Additional ly , other exposure monitoring studies of CWP manufacturers from the literature are cited in this assessment, but data from OSHA IMI S are more comprehensive and more relevant to this exposure assessment than these additional studies as OSHA IMI S contains only U.S. data. A summary

of the abstracts of these additional CWP manufacturer studies are provided in Appendix H . Some of the se additional studies are from monitoring studies of CWP manufacturing mills outside the U.S. The IARC study

cited exposure monitoring studies for various t ypes of settings ( inc luding offices , homes, and institutional and public buildings ) in various countries (including countries in North America, Europe, South America, Asia, and Australia) . Monitoring data for U.S. office buildings from the IARC study were not used because the y were not recent data (they were dated prior to 1990). The RIOPA data were not used as the RI OPA project focused on individuals’ exposures through - out their day . Although limited information was collected to estimate an individual’s exposures during the ir occupations, occupational exposures were not the focus of the project. The DEARS also focused on personal, residential, and outdoor monitoring. Occupational exposures were not the focus of DEARS. Incontrast, OSHA IMI S and EPA’s BASE study

are both f

ocused on occupational exposures. Recent data on formaldehyde concentrations in Hong Kong office buildings were reported in Wong et al. (Wong 2006a) . The minimum of the range of these concentrations is similar to the lowest value reported in the BASEFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 13 study (BASE 1998a) , while the maximum of the range is over twenty times greater than the maximum reported in the BASE study . However, these Hong Kong data were not used because they may not be relevant to exposure in U.S. office buildings. Specifically , it is unknown how determinants of formaldehyde inhalation exposure in Hong Kong office buildings compare to those in U.S. office buildings, such as sources of airborne formaldehyde including the amount of CWP present in office buildings and their formaldehyd e emission rates and ventilation rates. As compared to the above mentioned studies, the BASE stu dy results are the most relevant to this assessment of formaldehyde inhalation exposure in office buildings and are adequate and sufficient for the purpose o f providing perspective on the results of this exposure assessment. Therefore, the BASE study results are presented in this assessment while information from the other studies is not included. Dermal exposure was not included in data searches. Instead, this assessment has relied solel y upon mathematical modeling for dermal exposure assessments. Appendix B of this report presents the quality criteria used during the literature search and data compilation. These quality criteria represent the preference for selecting data. The collected data used in this assessment meet these quality criteria. **3.2 Compilation of Pre**  **- Baseline Exposure Monitoring Data**  Baseline forma ldeh yd e occupational exposure monitoring data are not availabl e because the baseline occurs in the future in the year 2013. As described in Section 3.1 , a literature search for pre - baseline exposure monitoring data was conducted as part of the data gathering for this assessment. Pre - basel ine exposure monitoring data from OSHA IM IS and the EPA BASE study were compiled and evaluated for adequacy for use i n the assessment of baseline exposure and the effect of analy

tical options on baseline exposure. The compiled inhalation exposure monitoring data , which are described below, were not used in the assessment of exposure at the baseline or for the anal yt ical options . The reasons that these data were not used to assess exposure are discussed below. However, these data are still considered useful for reasons also discussed below. **Manufacturing , Composite Wood Product Fabrication,**  **Wholesale and Retail** Pre - basel ine formaldeh yde exposure monitoring d ata for manufacturing, fabrication, wholesale and retail facilities were obtained from the OSHA IMI S database ( OSHA 2009a). At the time the OSHA IMIS data were obtained (June 2010), the most current data were from 200 9. Of the collected IMIS data, only data from the period of 2002 to 2009 were considered for use in the assessment because som e information on the production - weighted average emission levels and the range of emission level s of domestically - produced CWP during the pre - baseline period of 2002 to 2009 is available. This info rmation is presented in Table 3 - 1 ; as seen in this table, the production - weighted average emissio n levels for CWP domestically - produced durin g the period of 2002 to 2009 were close to the CARB Phase 1 limit s , especially after 2008. The pre - baseline OSHA IM IS inhalation exposure monitoring data were determined to not be adequate for the assessment of baseline exposure concentrations and the effect of the anal yt ical options on baseline exposure concentrations due to the following three reasons:Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 14 1. The extent to which exposure levels reported in OSHA IMI S will be affected by the limits o n CWP formaldehyde e mission rates set by FSCWPA is uncertain; 2. The OSHA IMIS data may not be representative of exposure levels that are associated with formaldeh yde off

- gassing emissions from the three CWPs with emission rates equal to baseline or analy

tical option emission rates; and 3. It is unknown whether the OSHA IMIS exposure monitoring data are representative of the exposure of the entire population of exposed workers during the pre - baseline period of time associated with these data. The above three reasons are further disc ussed below. First, the extent to which the sources of exposure associated with the compiled OSHA IMIS monitoring data will be affected b y the FSCWPA is uncertain. OSHA’s occupational exposure limits apply

to aggregate exposure and not to exposure due to an y specific source. Accordingl y, the OSHA IMIS , which is described in Appendix F, does not contain information on the sources of formaldeh yd e that contributed to the observed exposure concentrations , which are a measure of aggregate exposure where more than one source of exposure exist ed . As discussed in Section 4 , sources other than the off - gassing of formaldehyde from the three CWPs may contribute to formaldeh yd e occupational exposure during the life cycle of CWPs . Therefore, the compiled OSHA IMI S monitoring data may be associated with sources of exposure other than off - gassing from the three CWPs. The contributions of an y s uch sources to the observed inhalati on exposure concentrations are not expected to be affected b y the limits on CWP formaldehyde emission rates set by the FSCWPA . Hence, EPA is not able to use the OSHA IMIS data to accuratel y assess the effect of anal yt ical options on baseline exposure because the extent to which the exposure levels reported in OSHA IM IS will be affected by the CWP emission rate limits set by FSCWPA is uncertain . Second, the pre - baseline OSHA IMI S data may not represent baseline or analy tica l option exposure levels. L evels of formaldeh yd e in U.S. workplaces across multiple industries have dec reased from 1979 to 2001 according to a 2008 study of IM IS data (Lavoue 2008a). This decrease in formaldeh yd e levels could be due to OSHA’s implementat ion of a formaldeh yde PELof 1 ppm in 1987 and implementation of the current PE L of 0.75 ppm 3 in 1992 (Lavoue 2008a) . Manufacturers reduced formaldeh yd e emissions from composite wood products b y 80 to 90 percent from the levels of the early 1980s ( CPSC 19 97 a). A decline in emission levels also occurred during the last decade as illustrated in Table 3 - 1 . As discussed above, this table contains emission level data for domestically - manufactured CWPs during the pre - baseline period of 2002 to 2009. The emission level data in Table 3 - 1 indicate that domestic manufacturers produced nat ional production - weighted average emission levels close to the CARB ATCM Phase 1 limits in 2002; however, the manufacturers also produced CWPs with a wide range of emission levels. Furthermore, the emission levels of domestically - manufactured CWPs were
3 For formaldehyde, OSHA has established a PEL of 0.75 ppm as an 8 - hour time - we ighted average exposure and 2 ppm as short - term

exposure limit (maximum allowed exposure for 15 minutes) for all workplaces (OSHA 2008b). The action level is set at 0.5 ppm and requires, among other things, implementation of supervision and follow - up procedures w

hen worker exposure exceeds this value. OSHA considers formaldehyde a potential human carcinogen (OSHA 2008b).Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 15 tr ending towards a greater adoption of the CARB ATCM Phase 1 limi t between 2002 to 2009, but a high percentage of CARB ATCM Phase 1 adoption was not expected until 2009. Therefore, to the extent that the compiled OSHA IMI S pre - baseline inhalation exposure monitoring data are associated with off - gassing of formaldeh yd e from the three CWPs of interest, these data are associated with pre - baseline emission rates for these CWPs . T herefore , the OSHA IMIS exposure levels may not be representative of exposure leve ls resulting from offgassing of formaldeh yd e from CWPs with baseline or anal yt ical option emission rates. Third, it is uncertain whether the OSHA IM IS data are representative of the exposure concentrations for the entire population of exposed workers duri ng the pre - baseline period of time in which exposure monitoring to obtain these data occurred . For some life cycle stages, very few monitoring data were compiled . However, even if an adequate amount of data were available , it is uncertain whether the ins pected facilities in which the exposure concentrations were observed were selected randoml y. Therefore, it is unknown whether such exposure monitoring data are representative of the exposure of the entire population of exposed workers during the pre - basel ine period of time associated with these data . Due to the three considerations discussed above, the OSHA IMIS monitoring data were not used to assess baseline exposure concentrations and exposure concentrations for the anal yt ical options. Due to lack of a dequate exposure monitoring data, baseline exposure and the effect of anal yt ical options on baseline exposure are assessed using mathematical modeling as described in Section 3.3 . However, the monitoring data are still useful. The monitoring data can provide a perspective as to observed formaldeh yde exposures in industries. Additionally, monitoring data obtained from OSHA IMIS provide exposure measurements b y worker activity and thereb y provide perspective as to the different worker activities in each industry that can result in formaldeh yde exposure. **Table 3**  **- 1**  **. Pre**  **- Baseline Formaldehyde Emission**  **Level s for Domest**  **ically -**  **Produced Composite Wood Products**  **Timeline Inform**  **ation**

**Source HWPW**  **a PB**  **b MDF**  **b**

2002 CARB survey **Production -**  **Weighted Average** 0.09 ppm 0.18 ppm 0.25 ppm **% of Production Represented in Survey** 73% 53% 83% **Range in Survey Responses** 0.07 to 0.75 ppm 0.13 to 0.24 ppm 0.03 to 0.31

ppm End of 2008 / Beginning of 2009 ANPR

Submissions 75% of domestically - produced CWP

were CARB Phase 1 compliant 96% of domestically produced CWP were CARB P1 com pliant 96% of

domestically produced CWP were CARB P1 com pliant Later in 2009 ANPR

Submissions 90% of domestics expected to be

CARB P1 compliant -- -- a – A submission from HPVA in May 2008 estimated that domestically - produced HWPW will be in compliance with CARB Phase 1. Phase 2 limits require new technologies, which have not been in commercial use and some only recently invented and patented. Additiona lly, a submission from HPVA in February 2009 estimated that 75%Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 16 of North American HWPW was CARB certified and soon 90% or more will be CARB certified. “CARB certified” is assumed to mean CARB Phase 1 per the statements made in the May 2008 submission. The term “soon” is uncertain; therefore, the point in time in which 90% of domestics were expected to meet CARB Phase 1 is uncertain. b

– A submission from CPA in May 2008 stated that “almost all” domestic production is expected to be compliant with CARB Phase 1 and 2. The volume related to “almost all” is uncertain. This submission also states that “eventually” this rate of compliance would be reached; the time frame associated with “eventually” is uncertain. CPA did estimate that 96% of domestics were Phase 1 com pliant by the end of 2008. **Commercial Use (Office Buildings)**  For office buildings, formaldehyde inhalation exposure monitoring data were obtained from the EPA Building Assessment Survey Evaluation (BASE) study . The BASE study was a five - ye ar study to characterize determinants of indoor air quality (IAQ) . The BASE study c ollect ed indoor air quality

data from 100 randomly

selected public and commercial office buildings in 37 cities in 25 s tates from 1994 to 1998 . The buildings were all occupied buildi ngs randomly selected from cities with populations greater than 100,000 within ten climatic regions. The studied buildings were primaril y (73%) located in urban surroundings. Ninet y - eight percent of the buildings had mechanical ventilation and 44 percent had operable windows. Within each building, a test space with a target population greater than 50 occupants, residing on no more than three floors, and served by no more than two air - handling units was randomly selected. Buildings with highly

publicized indoor environmental quality problems were excluded. The data compiled through the BASE study include general information regarding the building itself, area monitoring of indoor pollutant concentrations, basic occupant statistics, occupant health sy mpto ms and perceptions of indoor air qualit y, and information about the design, maintenance and operation of building heating, ventilating, and air conditioning (HVAC) sy stems. A summary of the results of the BASE study is given in Section 4.5.3 . The BASE study does not contain an y information on the sources of the monitored formaldehyd e indoor air concentrations. Even while assuming that CWPs were the main source of monitored formaldeh yde, the BASE study inhalation exposure monitoring data are not adequate for assessing exposure concentration in this assessment because the emission levels of such CWPs in the studied buildings are unknown. As indicated in Table 3 - 1 and discussed in the subsection above, the formaldeh yde emission levels of new CWP s have been decreasing with time and, therefore, the emission levels of new CWPs depend on their date of manufacture . Furthermore, formaldeh yde emission levels of CWPs decay with time and, therefore, the emission level of aged CWPs depend on the emission level when manufactured and the duration of time they have been in use. Although the B ASE study was conducted in 1994 to 1998, the vintage of the office furniture ( i.e. , the year in which the office furniture were built) , which may contain CWPs and are a likel y source of formaldehyde emissions as further discussed in this document, is unkno wn for each studied building. Therefore, the emission levels of an y CWPs that are components of office furniture in the monitored office buildings at the time the monitoring occurred are unknown.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 17 **3.3 Exposure Assessment Methods and Assumptions**  This section de scribes the methods used for assessing baseline exposures , which are due solel y to off - gassing from CWPs and ventilation with ambient air , the effect of the analy tical options on these baseline exposures, and the assumptions underlying the assessment metho ds. Baseline indoor air concentration and the effect of the anal yt ical options on baseline indoor air concentration were assessed for CWP fabrication and office buildings; the methods for these assessments are discussed below. Baseline indoor air concentration and the effect s of the anal yt ical options on baseline indoor air concentration were not assessed quantitatively for the CWP manufacturing , wholesale and retail life cycle stages due to data gaps, and only qualitative assessments were made. Th e goal of this assessment was to assess aggregate formaldeh yd e indoor air concentration in each assessed life cycle stage . Aggregate indoor air concentration is the sum of the concentration contributed by off - gassing of the three CWPs, the concentration c ontributed by other formaldeh yd e sources in the workplace, and the concentration of formaldehyde in ambient outdoor air. However, due to data gaps, this assessment only assesses formaldehyde indoor air concentration that is due to off - gassing of the three CWPs and the concentration of formal deh yd e in ambient outdoor air. For CWP fabrication sites, as discussed in Section 4.2.1 , there is indication that sources of fo rmaldeh yde other than the off - gassing of formaldehyde from CWPs may exist. However, the extent to which other sources of formaldeh yd e contribute to worker exposure in CWP fabrication sites is unknown. Attempts to develop methods to estimate concentration contributions from other sources during CWP fabrication were not successful due to data gaps. On the other hand, in homes the most significant sources of formaldehyd e are likel y to be CWPs made from UF resins (USEPA 2011b ). The literature search did not identify information to indicate that sources of formaldeh yde in office buildings are significantly different than in homes. Therefore, it is assumed that CWPs are the most significant source of formaldeh yd e in office buildings. It is noted in this regard that the concentration of airborne formaldehyde tends to be lower in office buildings as compared to residential structures. EPA compiled residential indoor air formaldeh yd e monitoring data ( USEPA 2009b ). A comparison of these data with the monito ring data of the BASE study ( BASE 1998a ) shows that the central value of the indoor air concentration s in office buildings are for the most part lower than the central values of residences. This observation is also indicated by a Health Effects Institute report ( HEI 2007 a). However, this comparison neither supports nor detracts from the assumption made here about the predominant ty

pe of emission source in office buildings because airborne concentration is a function of not only

the ty pe of emission source, but also its quantity as well as the ventilation rate. These last two factors are not expected to be similar for office buildings and residential structures. Dermal exposures to formaldehyde in liquid mixtures were quantitativel y assessed for manufacturing. Dermal exposures were assessed only qualitativel y for the CWP fabrication, wholesale, retail, and commercial use life cycle stages. Due to data gaps, quantitative dermal exposure estimates for manufacturing were only made for pre - baseline conditions; bas eline andFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 18 anal yt ical option dermal exposures could not be estimated. The qualitative dermal exposure assessments for CWP fabrication, wholesale, retail, and commercial use were made for baseline and anal yt ical options. The use of respirators as personal protective equipment (PPE) for CWP manufacture and fabrication was considered based on the review of OSHA inspection reports . However, a limited number of inspection reports were available for review and a conclusion as to the prevalence of the use of res piratory

protection in these life cycle stages could not be determined. OSHA guidance on safe practices in the woodworking industry was also considered and is summarized in this assessment report . Exposure duration (the hours of exposure per day) and frequency (the day s of exposure per year) for all assessed life cycle stage s with the exception of office buildings were assessed based on census data on pre - baseline aggregate production hours. The number of exposed workers in each life cycle stage with the e xception of office buildings was estimated to be equal to the pre - baseline number of production workers according to census data. Inhalation e xposure results for baseline and each analy tical option are presented as average daily concentration (ADC) and lif etime average dail y concentration (LADC). The equations for ADC and LADC are presented in Appendix E . ADC and LADC are used as measures of exposure when considering non - cancer and cancer risks, respectivel y (USEPA 2009a ). Formaldeh yde may result in both non - cancer and cancer health effe cts ( ATSDR 1999a ; ATSDR 2010a). The assessment results are presented in Section 4 . **3.3.1 Estimation of**  **In door Air**  **Concentrations Related to Baseline and Analytical**  **Opti ons**  **for CWP Fabrication and Office Buildings**  This section discusses the m athematical models used for estimating baseline indoor air formaldeh yde concentrations due to off - gassing of CWP in CWP fabrication sites and office building s, and the effect on baseline indoor air concentrations of the FSCWPA analy tical options. As discussed in Section 3.2 , the OSHA IMI S and BASE data are likely not representative of exp osure concentrations at baseline or for the anal yt ical options. Therefore, mathematical model ing was used to estimate indoor air concentration for the baseline and the anal yt ical option s . The mathematical model s for the estimation of formaldehyde indoor a ir concentration in CWP fabrication sites and office buildings are presented in this section, while a detailed description of these models and their underlying assumptions is included in Appendix E . These models are based on the principle of mass conservation. As further discussed below, the generation rate of formaldeh yde in these models is expressed as the product of a formaldeh yd e off - gas sing emission rate and an amount of emitting surface area. This generation rate is used in combination with the rate of ventilation of the work space area containing the CWP emitting surface area. This section also contains a discussion of the determination of the values of the se and the other model parameters of these models and the use of the models for estimating what - if values of indoor air concentration at CWP fabrication sites and office buildings. MathematicalFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 19 modeling was not applied to other life cycle stages because data were not available to estimate the model parameters for the other life cycle stages. **3.3.1.1 Method for Estimation of Indoor Air Concentration for CWP** 

**Fabrication** At steady - state, a mass balance equates the formaldehyde generation rate due to off - gassing from HWPW, PB, and MDF present at a CWP fabrication site to the rate at which airborne formaldeh yde is exhausted from the CWP fabrication site through ventilation with outdoor air . As further discussed in detail in Appendix E , the mathematical model for indoor air concentration, which is derived from the mass balance , is as follows:



### = × 

### + Eqn ( 1 )
where: C = Average airborne f ormaldehyde concentration in a CWP fabrication site ( μg/m 3 ) ; F = Emission rate (off - gassing emissive flux) of formaldehyde from the composite wood product ( μg/m 2

- h) ; A = Total e mitting surface area of the composite wood product s located

in a CWP fabrication site (m 2 ) ; Q effective = Effective volumetric ventilation rate for an entire CWP fabrication

site (m 3 /h) ; and C o ind = Concentration of formaldehyde in the outdoor air for industrial

land use areas (μg/m 3 ). The literature search did not yield an exposure site population distribution for the input parameters of Equation 1 , nor did it yield representative values for these input parameters for CWP fabrication sites . Due to these data gaps with respect to the model parameters, what - if values for indoor air concentration were estimated . This what - if anal ys is was accomplished by estimating the range of possible values for each model parameter (with the exception of o utside air concentration as further explained below) and calculating a range of what - if indoor air concentration values from the estimated ranges of the model parameters as further discussed below. The resulting values in the estimated range for average i ndoor air concentration at a CWP fabrication site are characterized as what - if results because each concentration value in this range corresponds to combinations of choices, or what - if values, for the model parameters. Although the prevalence of the model parameter what - if values at actual CWP fabrication site s is unknown, the ranges of the model parameter values should be realistic such that any given choice, or what - if value, for any model parameter represents a possible value at actual CWP fabrication s ites . However, as further discussed below, the ranges of the model parameters were estimated with varying levels of accuracy .Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 20 **What -**  **If Method for Calculating**  **Indoor Air C**  **oncentration** The ranges of possible values for the model parameters were estimated as further discussed below. These ranges consist of low - and high - end values and average, typical, or intermediate values, which are presented in Table 3 - 4 . For the pur pose of this assessment, “intermediate” is defined as a value in - between the low - end and the high - end estimates. Low and high ends of the range of what - if average formaldeh yde indoor air concentrations in CWP fabrication sites were estimated using Equation 1 from what - if values of the model parameters that are within the estimated ranges for these parameters and that result in a wide but realistic range of indoor air concentration. Due to data gaps with respect to the relative amounts of the three CWPs used at fabrication sites, this what - if approach for estimating indoor air concentration was applied to three limiting cases for the ty pe of CWP that is present at CWP fabrication sites: only HWPW, only PB, or onl y MDF. The resu lts of these three limiting cases are combined into ranges to account for mixtures of different CWP ty pes as discussed in Section 4.2.5 . To estimate the what - if low - end indoor air concentration, three estimates of indoor air concentration are calculated, and the minimum value is used as the estimate for the what - if low end in door air concentration. The three estimates are calculated b y using the low - end value for one parameter and the average, typical, or intermediate value for the two other varying parameters and repeating this twice with a different parameter having a low - e nd value each time. The estimate of the what - if high - end indoor air concentration was similarl y calculated. The what - if estimation method is summarized in Table 3 - 2 . An intermediate indoor air concentration was also calculated for each of the three limiting cases for CWP ty pe from the ty

pical, average, or intermediate values of the model parameters. Due to varying uncertaint y of the representativeness of the estimated ty pical, average, or intermediate values of the model parameters, the extent to which these calculated intermediate indoor air concentration s are representative of all exposure levels is unknown. The model results for the range of average formaldehyde indoor air concentration at CWP fabrication sites for the three limiting cases are presented in Section 4.2 .5 .Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 21 **Table 3**  **- 2**  **. Summary of What**  **- If**  **Method for**  **the Estimation of**  **the What**  **- If**  **Range of Average Indoor Air Concentrations**  **of Formaldehyde at**  **CWP Fabrication Sites** 

**Limiting Cases for CWP Type**  **Me thod for Calculating**  **What -**  **if Low**  **- and High**  **- End Indoor Air Concentration** 

Determination of What - if Values of the Indoor Air Concentration Model Parameters that Result in a What - if Lo w End Indoor Air Concentration Determination of What - if Values of the Indoor Air Concentration Model Parameters that Result in a What - if High - End In door Air Concentration

A total of three cases : HWPW only, PB only, or MDF only is used at a fabrication site What - if l ow - end i ndoor a ir c oncentration is

estimated as the minimum value from amongst three low - end estimates of indoor air concentration that are calculated from the following three com

binations of parameter s: 1. High - end ventilation rate, intermediate emitting surface area, we ighted - average emission rate , and average value for the am bient air concentration of formaldehyde ; 2. Lo w - end emitting surface area, ty pical ventilation rate, weighted average emission rate , and average value for the ambient air concentration of formaldehyd e ; 3. Lo w - end emission rate , ty pical ventilation rate, intermediate emitting surface area , and average value for the ambient air concentration of formaldehyde . What - if h igh - end i ndoor a ir c oncentration is estimated as the maximum value from amongst three hig h - end estimates of indoor - air concentration that are calculated from the following three com

binations of parameter s: 1. Lo w - end ventilation rate, intermediate emitting surface area, weighted average emission rate , and average value for the ambient air concentration of formaldehyde ; 2. High - end emitting surface area, typical ventilation rate, weighted - average emission rate , and average value for the ambient air concentration of formaldehyde ; 3. High - end emission rate , ty pical ventilation rate, intermediate emitting surface area , and average value for the am bient air concentration of formaldehyde . The basis for the ranges of values of the indoor air concentration model parameter s is discussed below and summarized in Table 3 - 5 . Range of Values for Effective Ventilation Rate Industrial ventilation rates for all industries, including those unrelated to CWP, vary from 500 to over 10,000 cubic feet per minute (cfm) with a ty pical value of 3 , 000 cfm ( USEPA 1991a) . The adopted range for this analy sis is 500 cfm to 10 ,000 cfm. A mixing factor is applied to account for non - ideal mixing of air; the mixing factor is multiplied by the ventilation rate to estimate an effective vent ilation rate. T he value of the mixing factor ranges from 0.1 (worst - case) to 1 (ideal mixing) with a t ypical value of 0.5 . The various combinations of ventilation rate and mixing factor are given in Table 3 - 3 and the resulting range of effective ventilation rate is 50 to 10 ,000 cfm. The final value s of effective ventilation rate selected for use in the mass balance equation are the following thre e values from Table 3 - 3 : 50 cfm (low - end value) , 1,500 cfm (t ypical value) , and 10 ,000 cfm (high - end value) .Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 22 **Table 3**  **- 3**  **. Matrix of Ventilation Rates and Mixing Factors**  **Ventilation Rates (cfm** **) Effective Ventilation Rates for each Mixing Factor (cfm** **)**

**Worst -**  **Case Mixing Factor Typical Mixing Factor**  **Ideal (no mixing factor)**

**0.1 0.5**  **1** 10,000 (high end) 1,000 5,000 10,000 3,000 (typical) 300 1,500 3,000 500 (worst case) 50 250 500 Source: USEPA 1991a cfm = cubic feet per minute Range of Values for Emitting Surface Area The emitting surface area of composite wood products in CWP fabrication sites is the most uncertain of the three parameter s of the mathematical model . In CWP f abrication sites, CWP panels can be stacked, in which case the emitting surface area of the stac k would be the top surface of the top panel plus the summation of the surface area of the edges of each panel in the stack. It is uncertain how many hours per day

any given panel is expected to remain within a stack and how a stack of panels may grow or s hrink throughout the day . Additionally , panels are handled b y workers as they process the panels, which can include sawing, sanding , routing, and assembling ( OSHA 2009a ; see Appendix F for a categorization of the worker activities identified in the obtained OSHA IMI S data). During processing activities, all sides of the panel can be exposed to the air as workers handle, transfer, and proc ess the panels. Therefore, the emitting surface area of a panel can be equal to all surfaces and edges of the panel for some part of a single day

of operation . Finally , when the panels are assembled into a finished fabricated product, some panel surfaces can be covered due to stacking or overlapping the panels with other materials. There is uncertainty as to the emitting surface area of panels incorporated into a final fabricated product. Additionally , panels can be covered with decorative finishes or o verlay s. However, the effect of barriers due to decorative finishes or overlay s is to reduce the emission rate of the panel but not the emitting surface area ( CPA 2003a) . The principle is that a finished or overlayed surface is still available for emission, but the actual emission rate is reduced due to the overlay . Due to data gaps in information on the range of possible values for emitting surface area and due to the expected high variation in the value for this mod el parameter based on the above discussion, a range for this model parameter is estimated as follows . The estimate of the emitting surface area is based on the aggregate average throughput of CWP panels per site. Throughput is estimated from the estimate d domestic consumption of CWP at baseline, the total number of CWP fabrication sites at baseline, and an estimate of the sites’ operating day s per ye ar. The baseline U.S. consumed volume of CWP for the three CWP ty pes combined, which accounts for domestic produc tion less exports and plus imports, is 18 , 045 , 282 m 3 (USEPA 2010a) with a total surface area of 1, 895 million m 2 (assuming each CWP has a thickness of 3⁄4 inch4 and that both sides of the panel are exposed to air). This quantity of material was divid ed

4 The 2007 North American Downstream Market Report (CPA 2008a), published by the Composite Panel Association, provides PB and MDF panel volumes in terms of square footage at a 3⁄4 inch thickness basis. Therefore, a 3⁄4 inch thickness basis was assumed for these surface area calculations. The 3⁄4 inch thickness basis was assumed for HWPW as well, as HWPW thickness basis data were not identified.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 23 by the total number of assessed CWP fabrication sites , 33,737 sites (USEPA 2010a), and the number of operating days (which was not determined but was assumed to be equal to the assessed frequency

of exposure of 250 day s per year) to obtain 224.6 m 2 per site per day , which is an estimate of the daily throughput, or amount processed daily , of all three CWP ty pes combined (the number of sites and the frequency of exposure are given in Section 4.2.2 ). This intermediate estimate of emitting surface area is predicated on the aggregate average site specific throughput of CWP panels (assuming a 3⁄4 inch thickness) and that both sides of the panel throughput are availab le for emission. As discussed above, i t is recognized that panels processed in a single day can have less than their full two sides available for emission for part of the day . It is additionally recognized that inventoried panels that are not processed i n a given day can also contribute to formaldehyde emissions (such as from a stack of panels) . The effect of these uncertainties on the intermediate estimate cannot be quantified. Since the estimation method of emitting surface area is highl y uncertain, a range of values for emitting surface area was adopted b y assuming that the low - end and high - end values are equal to 10% and 1,000%, respectivel y, of the intermediate estimate of emitting surface area based on throughput. The 10% and 1,000% values of this intermediate estimate are hereinafter referred to as the low - end and high - end estimates, respectively . The adopted range for emitting surface area including the intermediate value is given in Table 3 - 4 . Range of Values for Emission Rate The emission rate is the only parameter of the mass balance equation that will be affected by the FSCWPA; therefore, values for this parameter were obtained for the baseline and for each of the anal yt ical options. Emission level s for the baseline and for the anal yt ical options were obtained from the EPA market profile (USEPA 2010a) and the EPA draft exposure assessment (USEPA 2009b ), respective ly , and are presented in Appendix D . Uncertainty in the values of these emission levels and their applicability to the estimation of averag e indoor air concentration in a CWP fabrication site is discussed below. Representativeness of Emission Levels Reported in the EPA Market Profile The emission level estimates for domestic and Canadian CWPs at baseline were obtained from an EPA survey

of do mestic CWP manufacturers. The survey received the following response rates from the manufacturing facilities (mills) that received the survey: 85% of the 39 HWPW mills surveyed; 100% of the 20 MDF mills surveyed; and 97% of the 31 PB mills surveyed. The mills surveyed onl y included mills subject to FSCWPA and did not include mills that only produce products exempted or not otherwise covered by FSCWPA. Therefore, the survey results for domestic CWPs are likely representative of all U.S. CWP manufacturing mills subject to FSCWPA. However, the EPA market profile notes that some survey responders only

provided information about the compliance standards being achieved but not specific emission level s (USEPA 2010a). Therefore, the surveyed popu lation of mills is likely representative of U.S. mills subject to FSCWPA. The emission level estimates for non - Canadian imported CWPs at baseline were estimated from data from a 2009 presentation by Professional Service Industries (PSI), a CARB third - party certifier (TPC) that mainly certifies mills located in Asia. The mills certified b y PSI are major sources of CWPs imported into the U.S. (USEPA 2010a). The EPA market profile discusses the method in which data were obtained from the presentation and us edFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 24 to estimate imported CWP emission level s at baseline (USEPA 2010a). The representativeness of the emission level values for non - Canadian imported CWP is uncertain. Accuracy of Emission Level Values Reported in the EPA Market Profile As discussed above, some survey responders onl y stated the compliance standard they would achieve and not the specific emission levels of their products; in such case, the actual emission level may be lower than the compliance standard. A ll survey data were assumed to repre sent actual emission levels of products , and therefore these data may be an overestimate of emission level . CARB ATCM emission standards are based on the ASTM E1333 chamber test method ( ASTM 2002a). Therefore, it is assumed that emission level s reported in the survey and provided from PSI are based on the ASTM E1333 chamber test method ( see Appendix E for a description of ASTM E1333). The emission levels from the survey and the PSIpresentation are converted to emission rates in units of flux for use in the indoor air concentration mathematical model according to the equations described in ASTM E1333 ( see Appendix E ) . Another consideration with respect to the accuracy of the emission levels reported in the EPA market profile is the accuracy

associated with the measureme nts made to obtain these values. ASTM E1333 discusses the precision and bias of the large chamber test method in general. However, ASTM E1333 does not discuss the accuracy and precision of the anal yt ical test method recommended in ASTM E1333 for measurin g formaldehyde levels in the chamber air samples: NI OSH 3500 chromotropic acid test procedure. The accuracy and precision of this procedure is discussed in NIOSH 3500 (NI OSH 1994a ). ASTM E1333 does not discuss the overall accuracy of the test chamber method for determining accurate formaldehyde off - gassing emission rates. Additionally , it is uncertain if chamber test results from ASTM E1333 accuratel y represent actual off - gassing rates in real world industrial settings, including CWP fabrication mills. For ASTM E1333 chamber test results to accuratel y represent off - gassing rates in actual CWP fabrication mills, the ASTM E1333 parameters should be consi stent with the actual conditions in the fabrication sites . However, adequate data to perform this comparison were not available. This assessment did not consider how ASTM E1333 uncertainties would impact the overall uncertainty of the assessment results. However, it is likely that ASTM E1333 uncertainties are of small impact to the assessment results comp ared to the uncertainties of other mathematical model parameters. It is also uncertain as to what extent manufacturers will actuall y obtain their predicted emission level s in 2013. Applicability

of Emission L evel Values Reported in the EPA Market Profile to the Estimation of Average Indoor Air Concentration in a CWP Fabrication Site An additional consideration is the decay with time of CWP formaldehyde emission levels. Various literature sources have discussed the decay of formaldeh yd e emission levels with time, such as Groah 2005a, Zinn 1990a, and Gammage 1988a. A wide range of values for the formaldeh yde emission level half li f e for PB, MDF, and HWPW were reported in these articles . The studies, which span a period of approximately 20 years, cite CWP emission level half lives ranging from less than three month s to less than two years. Not all tests used the same test method for determining emission level half life. Additionally , the test method conditions may not be similar to the conditi ons of storage and transport between CWP manufacture and fabrication. Therefore, the test results may not be applicable for the emission level decay experienced during storage and transport. T he initial emission level ha s a moderatel y strongFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 25 influence on half life (Groah 2005a). A higher initial emission level will result in a more rapid decay (Groah 2005a). Therefore, half lives from older studies may not be applicable for newer or future CWPs with lower initial emissi on levels, which would have less rapid decay s. The available literature on formaldeh yde emission level decay indicate that CWPs at CWP fabrication sites could have emission levels less than their emission levels at the time of their manufacture if the time for distribution from manufacturer to fabricator is considerable and depending on the conditions of storage and transport prior to delivery to the fabricator . However, the residence time of CWPs at CWP fabrication sites is small and would likely not resu lt in significant further emission level decay while the CWPs are at the fabrication site. Formaldeh yd e emission level decay is not accounted for in this assessment due to data gaps in decay rates for CWPs manufactured at the baseline or under any of the analy

tical options. In this assessment, formaldeh yd e concentration modeling at CWP fabrication sites assumes the emission levels from the EPA market profile ( USEPA 2010a) are for newly - manufactured CWPs, which may

overestimate the actual emission levels at CWP fabrication sites. The range of emission levels and corresponding emission rates , including weighted - average values for the baseline and anal yt ical options , is given in Table 3 - 4 . These values account for both domestically

manufactured and imported CWP s . See Appendix D for a complete list of the emission level s for baseline and each anal yt ical option. It is important to note that CWPs will continue to emit formaldehyde as they are overlayed and after they are overlayed . However, emissions from overlayed panels at CWP fabrication sites were not accounted for in the estimation of indoor air concentration . Man y overlay materials serve as a barrier and reduce formaldeh yde emissions from 50% to as much as 95% or higher ( CPA 2003a). Therefore, emissions from overlayed products have a diminished effect on indoor air concentrations compared to non - overlayed products at CWP fabrication sites . Value for Ambient Air Formaldehyde Concentration Limited statistics of ambient air formaldeh yde concentrations are available in the EPA draft report Formaldehyde from Pressed Wood Products: Exposure Assessment ( USEPA 2009b ). Table 3 - 1 of the draft exposure assessment provides ambient air formaldehyde concentrations for various land use categories. The CWP fabrication indoor air concentration mathematical model uses the average value of the ambient formaldeh yde concentration for industrial land use areas. The average value is chosen for use in this mathematical model since the low standard deviation indicates limited variation in this parameter and the average value is representative. This average value of 6.28 μg/m 3 is kept constant throughout the what - if calculatio ns.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 26 **Table 3**  **- 4**  **. Estimate**  **d Values for**  **Parameter s in**  **the Mathematical Model for Average Indoor Air Concentration at a CWP Fabrication Site**  **for the Baseline and the**  **Analytical Options** 

**Param eter**  **Nam e**  **Scenario (** **Anal ytical**  **Option) Value of**  **Param eter** 

**U nits**  **Intermediate /** 

**Typical / Average Value**  **Low -**  **End**

**Value High**  **- End** 

**Value** Emitting Surface area All m2 224.6 22.5 2,246 Ventilation Rate All cfm (m3 /h) 1,500

(2,549) 50

(85) 10 ,000

( 16,990 ) HWPW Emission Level Baseline ppm 0.04 0.013 0.163

CARB Phase 1 0.025 0.013 0.058 FSCWPA / CARB Phase 2 0.021 0.013 0.032 NAF 0.013 0.013 0.013 PB Emission Level Baseline ppm 0.06 0.013 0.384

CARB Phase 1 0.05 0.013 0.090 FSCWPA / CARB Phase 2 0.053 0.013 0.057 NAF 0.013 0.013 0.013 MDF Emission Level Baseline ppm 0.08 0.024 0.502

CARB Phase 1 0.07 0.024 0.140 FSCWPA / CARB Phase 2 0.073 0.024 0.082 NAF 0.035 0.024 0.035 Ambient (outdoor) Air Concentration of Formaldehyde All μg/m 3 6.28

**Param eter**  **Nam e**  **Scenario (** **Analytical Option)**  **Value of Param**  **eter**

**U nits**  **Intermediate /**

**Typical / Average Value**  **Low -**  **End**

**Value High**  **- End** 

**Value** HWPW Emission Rate Baseline μg/m2

- h 60.9 18.6 232.9

CARB Phase 1 36.0 18.6 82.9 CARB Phase 2 29.8 18.6 45.7 NAF 18.6 18.6 18.6 PB Emission Rate Baseline μg/m2

- h 81.7 18.6 548.8

CARB Phase 1 77.1 18.6 128.6 CARB Phase 2 75.8 18.6 81.5 NAF 18.6 18.6 18.6 MDF Emission Rate Baseline μg/m2

- h 180.5 56.7 1186.5

CARB Phase 1 173.6 56.7 330.9 CARB Phase 2 172.5 56.7 193.8 NAF 81.6 56.7 82.7 Note s : Table 3 - 5 indicates the sources of these data . Emission rates are shown as both emission levels in units of ppm and as emission rates in units of flux in μg/m2

- h for convenience of the reader. Emissi on levels are assumed to represent the measured concentration from ASTM E1333, while emission rate s in units of flux represent the emission rate value calculated from the measured concentration and the ASTM E1333 test parameters. Appendix E describes ASTM E1333 and the conversion between emission levels in units of concentration and emission rates in units of flux.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 27 **Table 3**  **- 5**  **. Data Sources for the Estimation of**  **Parameter s**  **of the Mathematical Model for**

**Average Indoor Air Concentration at a CWP Fabrication Site Param**  **eter Nam**  **e Intermediate**  **Value Low**  **- End**  **Value High**  **- End**  **Value**

Emitting Surface Area (see “Range of Values for Emitting Surface Area” in Section 3.3.1.1 ) A ggregate average daily throughput estimated as the baseline U . S . consumed volume of CWP divided by the assessed number of fabrication sites and the assessed exposure frequency 10% of aggreg ate

average daily throughput 1,000% of aggregate

average daily throughput

Effective Ventilation Rate (see “Range of Values for Effective Ventilation Rate” and Table 3 - 3 in Section 3.3.1.1 ) Ty pical ventilation rate multiplied by ty pical mixing factor. Worst - case

ventilation rate multiplied by worst case mixing factor High - end ventilation

rate assuming ideal mixing (no mixing factor applied)

HWPW, PB, or MDF Emission Rate s Baseline

Values Production weighted average calculated from data in Table D - 3 in Appendix D Minimum emission

rate f or data in Table D - 3 in Appendix D Maximum emission

rate for data in Table D - 3 in Appendix D Analytical Option 1: CARB Phase 1 Production weighted average calculated from data in Table D - 4 in Appendix D Minimum emission

rate for data in Table D - 4 in Appendix D Maximum emission

rate for data in Table D - 4 in Appendix D Analytical Option 2: FSCWPA/ CARB Phase 2 Production weighted average calculated from data in Table D - 5 in Appendix D Minimum emission

rate for data in Table D - 5 in Appendix D Maximum emission

rate for data in Table D - 5 in Appendix D Analytical Option 3: NAF Production weighted average calculated from dat a in Table D - 6 in Appendix D Minimum emission

rate for data in Table D - 6 in Appendix D Maximum emission

rate for data in Table D - 6 in Appendix D Ambient (outdoor) Air Concentration of Formaldehyde Average value for the industrial land use category from Table 3 - 1 in USEPA 2009b . **3.3.1.2 Method for**  **Estimation of Indoor Air Concentration for**  **Office Buildings** At steady - state, a mass balance equates the formaldehyde generation rate due to off - gassing from HWPW, PB, and MDF that are components of an office workstation 5 to the rate at which airborne formaldeh yd e is exhausted from the volume of th e office building containing the workstation through ventilation with outdoor air. Based on the work b y Carter and Zhang ( Carter 2007a), formaldehyde indoor air concentration is estimated for two ty pes of
5 BIFMA M7.1 - 2007 defines a works tation, or workstation system, as a collection of office furniture (excluding seating) that forms a complete office work space for an individual occupant.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 28 workstations : open plan workstations and private office workstations. Furthermore, both workstation ty

pes contain the following components that may emit formaldehyde : panels, work surfaces, and storage external areas, but storage external areas are assumed to not have any formaldeh yde emissions. The off ice building mathematical model is described in greater detail in Appendix E and is displayed in Equation 2 .

= × ( ) × × ×

× ( ) × × × + Eqn ( 2 ) where : C = Average airborne formaldehyde concentration in the volume of the office building containing the workstation (μ g/m 3 ) ; Apanels = Emitting surface area of panels in the office workstation ( m 2 ) ; Awork surfaces = Emitting surface area of work surfaces in the o ffice workstation

( m 2 ); Q = The rate of ventilation with o utdoor air that affects the volume of

the office building containing the workstation (m 3 /h) ; E CWP = Emissive flux (emission rate ) of the composite wood product used

to construct the workstation component ty pe (μg/m 2

- h) (CWP = HWPW, PB, or MDF); BE = Barrier effectiveness of the finishing, or overlay , of the

workstation component type, expressed as a unitless fraction; Finpanels = Fr action of the panels ’ surface area that is finished, or overlayed ,

with a barrier effectiveness of BE, expressed as a unitless fraction; Fin work surfaces = Fraction of the work surfaces ’ surface area that is finished, or

overlayed , with a barrier effectiveness of BE, expressed as a unitless fraction ; and C o com = C oncentration of formaldehyde in the outdoor air for commercial

land use areas (μg/m 3 ). Representative values for some of the model parameters of this mathematical model , including workstation component emitting surface area, ventilation rate, formaldehyd e emission rates for each of HWPW, PB, and MDF, and outdoor air formaldeh yde concentration, were obtained through a literature search. On the other hand, information was l acking on the relative amounts of the three CWPs used in the fabrication of office workstations, representative values for the extent to which the workstation components are finished or overlayed, and the barrier effectiveness of the finish or overlay . Du e to these data gaps on representative values for these model parameters, what - if values for indoor air concentration were estimated . What - if values for indoor air concentration were estimated b y first estimating the range of possible v alues for the follo wing parameters: formaldehyde emission rates for all three CWP ty pes; extent of finishing or overlay

of each workstation component; and the barrier effectiveness of the finishing or overlay . Then, these ranges of parameter values and the representative va lues for the remaining model parameters were used in Equation 2 to estimate what - if values for indoor air concentration .Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 29 **What -**  **If Method for Calculating**  **Indoor A**  **ir C**  **oncentration** The ranges of possible values f or three model parameters (CWP emission rate, extent of finishing or overlay , and barrier effectiveness ) were estimated as further discussed below. These ranges consist of low - and high - end values and average or intermediate values, which are presented in Table 3 - 8 , which also contains the representative values for the remaining model parameters . For the purpose of this assessment, “intermediate” is defined as a value in - between the low - end and the high - end estimates. Low and high ends of the range of what - if average formaldeh yde indoor air concentrations in the workstation volumes were estimated using Equation 2 from the bounding values of the range of values for the above mentioned three model parameters and from the representative values of the remaining model parameters so as to obtain a wide range of indoor air concentration. Due to data gaps with respect to the relative amounts of the three CWP ty

pes used in the construction of office furniture, this approach for estimating what - if indoor air concentration was applied to three limiting cases for the ty pe of CWP of which the office furniture is constructed: only HWPW, only

PB, or onl y M DF. The results of the three limiting cases are combined into ranges to account for mixtures of different CWP ty pes as discussed in Section 4.5.4 . What - if values for low - end and high - end indoor air concentration were estimated as summarized in Table 3 - 6 . An intermediate indoor air concentration was also calculated for each of the three limiting cases for the CWP ty pe from the intermediate values of the model parameters. The representativeness of the range of values for intermediate indoor air concentration (calculated from the three limiting cases for CWP ty pe) is limited by

the representativeness of the intermediate values for the extent of finishing and barrier effectiveness, which are unknown. The intermediate values for the remaining model parameters are expected to be representative of real world values .Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 30 **Table 3**  **- 6**  **. S ummary of**  **What -**  **if Method for**  **the Estimation of the**  **What -**  **if Range of**  **Average Indoor Air Concentrations of Formaldehyde in**  **Workstation Volumes**

**Limiting Cases for CWP Type**  **Me thod for Calculating**  **What -**  **if Low**  **- and High**  **- End Indoor Air Concentration** 

**What -**  **if Values for Emission**  **Rate, Extent of Finish or Overlay,**  **and Barrier Effectiveness**  **that are used to Calculate**  **a What**  **- if**  **Low -**  **End Indoor Air Concentration**  **1 What**  **- if Values for**  **Emission Rate,**  **Extent of Finish or Overlay,**  **and Barrier Effectiveness**  **that are used to**  **Calculate a**  **What -**  **if High -**  **End Indoor Air Concentration**  **1** Workstation panels and work surfaces are constructed of:  Only HWPW;  Only PB; or  Only MDF  The emission rate of the (unfinished) CWP is equal to the low - end value in a range of values for the emission rate s for the unfinished CWP.  Both sides of workstation panels and workstation work surface are finished or overlayed , and the barrier effectiveness of the finishi ng or overlay is equal to a highest value in a range of values for barrier effectiveness .  The emission rate of the (unfinished) CWP is equal to the high - end value in a range of emission rate s for the unfinished CWP.  Both sides of workstation panels and th e lower side of the workstation work surface are unfinished (their barrier effectiveness is 0%), and the upper side of the workstation wo rk surface is finished or overlayed and has a barrier effectiveness equal to the lowest value in a range of values for the barrier effectiveness . 1 The representative values for the remaining model p arameters (ventilation rate, wo rkstation component emitting surface area , and outdoor air formaldehyde concentration) were used in the calculation. The values of all of the model parameters and their bases are given in Table 3 - 8 below. Values for Emitting Surface Area and Ventilation Rate The emitting surface area of each workstation comp onent and the ventilation rate of the work space volume containing the workstation with outdoor air were obtained from the BIFMA / ANSIM7.1 - 2007 standard test method ( BIFMA 2007a) , which is based on the work by Carter and Zhang ( Carter 2007a ) and their an al ys is of actual office building floor plans and actual office workstations . The BIFMA / ANSIM7.1 - 2007 standard test method uses representative values of workstation component emitting surf ace areas and ventilation rates for the purpose of modeling the i mpact on office indoor air volatile organic compound (VOC) concentrations due to office furniture emissions. Therefore, the values for these parameters obtained from BIFMA M7.1 - 2007 are treated as representative values for the purpose of this assessment. These values are kept constant and are not varied. Range of Values for W

orkstation Component Emission Rate T he BIFMA standard M7.1 - 2007 and the work by Carter and Zhang do not contain any information on observed formaldeh yde emission rate s of actual offic e workstations. Carter and Zhang provide example workstation emission rate s of formaldeh yde but do not discuss the statistical significance of these values such as being representative, worst case, etc. Therefore, workstation component emission rate s (emission rate s for finished CWPs used to construct theFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 31 workstation) were estimated using information on CWP emission rate s, extent of finishing , and barrier effectiveness. These three model parameters are discussed in this subsection. The CWP emission rate is the only parameter of the mass balance equation that will be affected by the FSCWPA; therefore, values for this parameter were obtained for the baseline and for each of the anal yt ical options. Emission levels for the baseline and for the analy tica l options were obtained from the EPA market profile (USEPA 2010a) and the EPA draft exposure assessment (USEPA 2009b ), respectively , and are presented in Appendix D . T he low - end and high - end emissio n rate s for each CWP ty pe are chosen from the low - end and high - end values from Appendix D . An average emission rate for each CWP ty pe is calculated as a volume - weighted average of the domestic and imported CWPs that are consumed domestically as was done in the CWP fabrication calculation method. Table 3 - 8 summarizes the emission rate s used for each calculation step of the what - if method . As summarized in Table 3 - 8 , the what - if values of the extent of finishing or overlaying of panels used for calculating what - if low - end and high - end indoor air concentrations are zero percent and 100 percent of their emitting surface area . These values are logical bounding values, as panels may have both surfaces finished for aesthetic reasons or no finishing at all as a conservative estimate. Similarly , the what - if values of the extent of finishing or overlaying of work surfaces are 50 percent and 100 percent of their emitting surface area . These values are again logical bounding values, as work surfaces are expected to at least be finished on their upper surface for functional purposes . In both cases, the surface area of edges was not accounted for because its effect is negligible. The what - if values for barrier effectiveness used for calculating what - if low - and high - end indoor air concentrations are given in Table 3 - 8 . The low - end and high - end values for barrier effectiveness were the low - end and high - end values identified in the source CPA 2003a . Although this source listed example barrier effectiveness values, it did not describe the extent to which an y given value represented actual office workstations. T he intermediate barrier effectiveness was calculated using BIFMA standard M7.1 - 2007 and BIFMA standard X7.1 - 2007 ( BIFMA 2007b ) . BIFMA standard X7.1 - 2007, which was also adopted as an ANSI standard, is a voluntary

standard for meeting VOC emission limits from office furniture. This standard specifies a formaldeh yd e limit of 50 ppb as measured using the BIFMA M7.1 - 2007 chamber test for all workstation configuration ty pes. Fabricators of office furniture who choose to fabricate workstations that meet the requirement of this standard must construct workstations such that they result in a measured chamber concentration using BIFMA M7.1 - 2007 that does not exceed 50 ppb. The intermediate value for barrier effectiveness was calculated using Equation 2 subject to the following conditions :
 The workstation is tested according to M7.1 - 2007 and results in a test chamber formaldeh yde c oncentration of 50 ppb according to X7.1 - 2007;  The panels have 100 percent of their surfaces finished and the work surfaces have 50 percent of their surfaces finished ; and  The workstation panel and work surface components are constructed of CWPs such that the CWP emission rate is equal to an average pre - baseline emission rate .Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 32 Pre - baseline emission rates were used because these would be the prevalent emission rates at the time the standard was established. Therefore, the calculated intermediate barrier effectiveness is for the pre - baseline period and is assumed to be relevant t o the baseline. Appendix E describes the method for calculating an intermediate barrier effectiveness in greater detail. T he emission rate s used in this analy sis are for new composite wood products ; therefore, the estimated indoor air concentrations are for new office furniture. The applicability of the utilized emission level values to the estimation of emissions from new office furnit ure is uncertain because decay

in formaldehyde emissions from new ly - manufactured CWPs, which is discussed in Section 3.3.1.1 , can occur in the intervening time betw een manufacture of the CWPs and their use as components of office furniture in an office building. Hence, the actual emission levels from the unfinished CWPs would be lower than the values used here resulting in an overestimate of the initial steady - state indoor air concentration associated with new office furniture. Emission level decay

can continue after the initial introduction of office furniture into an office. Such continued decay

of emissions with time and consequent decline of indoor air concentr ation from the initial steady - state level associated with new furniture was not accounted for because the literature search did not yield the necessary information for the estimation of this effect . In addition to the uncertainty of the temporal decay

of e mission rate s, the uncertainties of emission rate s discussed for the CWP fabrication method also apply for the office buildings method. S ome survey

responders only

stated the compliance standard they would achieve and not the specific emission levels of their products; therefore, all survey data are assumed to represent actual emission levels of products. CARB ATCM emission standards are based on the ASTM E1333 chamber test method ( ASTM 2002a). Therefore, the emission level s reported in the EPA survey an d provided from PSI described in Section 3.3.1.1 are assumed to be based on the ASTM E1333 chamber test method ( see Appendix E for a description of ASTM E1333). The emission levels from the survey and the PSI presentation are converted to emission rates in units of flux for use in the indoor air concentration mathematical model according to the equations described in ASTM E1333 ( see Appendix E ). ASTM E1333 discuss es the precision and bias of the large chamber test method in general. However, ASTM E1333 does not discuss the accuracy

and precision of the anal yt ical test method recommended in ASTM E1333 for measuring formaldeh yde levels in the chamber air samples: NI OSH 3500 chromotropic acid test procedure. The accuracy and precision of this procedure is discussed in NIOSH 3500 (NI OSH 1994a). ASTM E1333 does not discuss the overall accuracy of the test chamber method for determining accurate formaldehyde off - gassin g emission rates. To determine if chamber test results from ASTM E1333 accuratel y represent actual off - gassing rate s in office buildings, the ASTM E1333 test parameters should be compared with t ypical office building environment properties . Using the ty pi cal values for ventilation rate and component emitting surface area from Table 3 - 8 and the ty pical open plan and private office volumes determined b y Carter and Zhang ( Carter 2007a) and BIFMA M7.1 - 2007 , the CWP loading ratio and air change rate can be calculated and compared to those values specified in AST M E1333. See Appendix E for the associated equations , a description of the ASTM E1333 test parameters , and the ty pical office environment dimensions . For this comparison, only the workstation panels and work surfac es were used in the calculation of loading ratio, since this assessment assumes storage surfaces are not constructed of CWPs. Table 3 - 7 provides a comparison of the ASTM E1333 parameter values for CWP loading ratio and air change rateFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 33 with those in ty

pical office environments . The ASTM E1333 parameter values for the private office environment result in an air change rate consistent with that in a ty pical private office . The ASTM E1333 loading ratio for MDF is similar to the total CWP loading ratio in ty pical private offices, but the loading ratios for HWPW and PB are approximately twice the value for ty pical private offices . The ASTM E1333 parameter values for a ir change rate and all three loading ratio s are significantly different from those specified in typical open plan environments . This assessment did not consider how ASTM E1333 uncertainties would impact the overall uncertainty of the assessment results. However, it is likely that ASTM E1333 uncertainties are of small impact to the assessment results compared to the uncertainties of other mathematical model parameters. It is also uncertain as to what extent manufacturers will actuall y obtain their predict ed emission levels in 2013. **Table 3**  **- 7**  **. Comparison of ASTM E1333 Parameter Values with Typical Office**  **Environment Properties**

**Param eter**  **ASTM E1333 Values**  **Typical Office Environment**

**Property Values**  **Open Plan Environment**  **Private Office**

**Environment** Air Change Rate (h - 1 ) 0.5 ±0.05 0.92 0.53 CWP Loading Ratio (m 2 /m 3 ) : HWPW 0.43 1.1 0.22 PB 0.43 MDF 0.26 Sources: ASTM 2002a ; BIFMA 2007a , and Carter 2007a This office environment model treats a workstation (either private office or open plan) as a single exposure zone. It also only models the mitigation of airborne concentrations due to the ventilation rate of outdoor air. The ventilation rate of recirculated indoor air, which can vary from building to building, is not included in the model. The premise behind this assumption is that recirculated indoor air would contain the same concentration of formaldehyde as is in the exposure zone. This model assumes that each exposure zone is of the same ty pe (open plan or private office), results in the same formaldeh yde concentration, and, therefore, the exposure zones do not affect one another . Additionally , this model does not account for materials present in office buildings that may act as sinks of formaldehyde , such as carpets and wallboards ( Koontz 1996a) . Ambient (Outdoor) Air Formaldehyde Concentration An average value for the ambient air concentration of formaldehyd e is available from the EPA draft report Formaldehyde from Pressed Wood Products: Exposure Assessment (USEPA 2009b ). Table 3 - 1 of the EPA draft exposure assessment provides ambient air formaldehyde concentrations for various land use categories. The average value for the commercial land use category , 3.26 μg/m 3 , is used as an estimate of the formaldeh yd e concentration in the outdoor air used in office building ventilation. This value is kept constant throughout the what - if anal ys is.Formaldeh yd e Occupational Exposure Assessment Report

– Draft Final Report October 6, 2011 Page 34 **Table 3**  **- 8**  **. Estimated Values for**  **Parameter s**  **in the Mathematical Model for Average Indoor Air Concentration**  **Resulting from**

**Emissions from Private Office and Open Plan Work**  **s tations**  **for the Baseline and Analytical**  **Options**

**Param eter**  **Nam e**  **Work s**  **tation T**  **ype Scenario**  **Value of Param**  **eter Used to De**  **term ine:**  **Source of Data Units**  **Intermediate**

**Concentration Low**  **- End** 

**Concentration High**  **- End** 

**Concentration**

Com ponent Emitting Surface Area Private office workstation All scenarios

m2 Panels: 7.63 Work surfaces: 6.73 External storage surfaces: 10.55 Indoor air concentration was not

assessed for a range of values of emitting surface area because representative values for this parameter w ere obtained from the BIFMA / ANSI M7.1 - 2007 test method and used for all calculations . Storage surfaces are assumed not to be constructed from CWPs and do not factor into the final equation. BIFMA /ANSI M7.1 - 2007 test method Open Plan workstation All scenarios Panels: 11.08 Work surfaces: 6.10 External storage surfaces: 4.57

Ventilation Rate Private office work station All Scenarios m 3 /h 34.7 Indoor air concentration was not assessed for a range of values of ventilation rate because representative values for this parameter w ere obtained from the BIFMA / ANSI M7.1 - 2007 test method and used for all calculations . BIFMA /ANSI M7.1 - 2007 test method Open Plan workstation 15.0

HWPW Emission Rate Applicable to both private office and open plan workstations. Baseline ppm ( μ g/m2

- h) 0.0 43 ( 60.9 ) 0.013 (18.6) 0.163 (232.9) USEPA 2010a Analytical Option 1: CARB Phase 1 0.0 25 ( 36.0 ) 0.013 (18.6) 0.058 (82.9) Appendix D : Table D - 4 through Table D - 6 Analytical Option 2: CARB Phase 2 0.02 1 ( 29.8 ) 0.013 (18.6) 0.032 (45.7) Analytical Option 3: NAF 0.013 (18.6) 0.013 (18.6) 0.013 (18.6)
PB Emission Rate Applicable to both private office and open plan workstations Baseline ppm ( μ g/m2

- h) 0. 057 ( 81.7 ) 0.013 (18.6) 0.384 (548.8) USEPA 2010a Analytical Option 1: CARB Phase 1 0.05 4 (7 7.1 ) 0.013 (18.6) 0.09 (128.6) Appendix D : Table D - 4 through Table D - 6 Analytical Option 2: CARB Phase 2 0.0 53 ( 75.8 ) 0.013 (18.6) 0.057 (81.5)Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report October 6, 2011 Page 35 **Table 3**  **- 8**  **. Continued**

**Param eter**  **Nam e**  **Work s**  **tation T**  **ype Scenario**  **Value of Param**  **eter Used to De**  **term ine:**  **Source of Data Units**  **Intermediate**

**Concentration Low**  **- End** 

**Concentration High**  **- End** 

**Concentration** Analytical Option 3: NAF 0.0 13 ( 18.6 ) 0.0 13 ( 18.6 ) 0.0 13 ( 18.6 )

MDF Emission Rate Applicable to both private office and open plan workstations Baseline ppm ( μ g/m2

- h) 0. 076 ( 180.5 ) 0.024 (56.7) 0.502 (1,186.5) USEPA 2010a Analytical Option 1: CARB Phase 1 0.0 73 (1 73.6 ) 0.024 (56.7) 0.140 (330.9) Appendix D : Table D - 4 through Table D - 6 Analytical Option 2: CARB Phase 2 0.0 73 (1 72.5 ) 0.024 (56.7) 0.082 (193.8) Analytical Option 3: NAF 0.03 5 ( 81.6 ) 0.024 (56.7) 0.035 (82.7) Extent to Which CWP is Finished Applicable to both private office and open plan workstations All Scenarios Percent of surface area that is finished 100% of panel;

50% of wo rk surface 100% of panel;

100% of work surface 0% of panel;

50% of work surface Assumed by EPA

Barrier Eff

ectiveness of CWP F inish Private office workstation All Scenarios Percent reduction in emission factor of unfinished CWP 65 a 95 b 50 c CPA 2007a Open Plan workstation 71 a

Ambient (outdoor) Air Concentration of Formaldehyde Applicable to both private office and open plan workstations All Scenarios μ g/m 3 3.26 Indoor air concentration was not assessed for a range of values of am bient air concentration of formaldehyde because an average value for this parameter was obtained from the EPA draft exposure assessment and used for all calculations. USEPA 2009b

a - The barrier effectiveness used to estimate the intermediate concentration was esti mated by using the average pre - baseline emission rate of all CWPs (3 06.7 μ g/m2

- h) and calculating the barrier effectiveness needed to match the BIFMA/ANSI X7.1 - 2007 emission standard of 50 ppb assuming that 100% of panels and 50% of work surfaces are finished. The calculated barrier eff ectiveness for private office and open plan workstations were 65 % and 7 1 %, respectively.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report October 6, 2011 Page 36 **Table 3**  **- 8**  **. Continued** b - The highest barrier effectiveness for various barrier types provided in CPA 2003a was 95%. The highest barrier effectiveness y ields the lowest concentration for all else being equal. c - The lowest barrier effectiveness for various barrier types provided in CPA 2003a was 50%. The lowest barrier effectiveness yields the highest concentration for all else being equal.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 37 **3.3.2 Estimation of Dermal Exposures to**  **Formaldehyde in Liquid Resin** EPA has developed a series of standard models for quantitatively estimating worker dermal exposures to liquid and solid chemicals duri ng various ty pes of activities. To estimate dermal exposure, all of these dermal exposure models assume a specific surface area of the skin that is contacted b y a material containing the chemical of interest, as well as a specific surface densi ty of the material on the skin. These exposures can be further normalized by accounting for the body weight of the worker. The specific methods used to estimate dermal exposures are discussed in detail in Appendix E . Dermal exposures to formaldehyde contained in liquid urea - formaldehyde (UF) resins are assessed quantit ativel y during manufacturing according to EPA’s standard default model for estimating dermal exposures due to two - hand dermal contact with liquids. Dermal exposures to formaldeh yde due to pressed CWPs are not quantifiable using the EPA dermal exposure mod els for liquids and solids. Due to data gaps, quantitative dermal exposure estimates for manufacturing were onl y made for pre - baseline conditions; baseline and analy tical option dermal exposures could not be estimated. The qualitative dermal exposure ass essments for CWP fabrication, wholesale, retail, and commercial use were made for baseline and anal yt ical options. **4. E**  **XPOSURE A**  **SSESSMENT B**  **Y L**  **IFE C**  **YCLE S**  **T AGE**  Occupational e xposure s resulting from the manufacture and use of baselin e CWPs and effects of the anal yt ical options on the baseline exposures were estimated for CWP fabrication and office building occupancy using the methods described in Section 3 . Exposure s w ere not assessed quantitatively

for CWP manufacture, wholesale, and retail due to data gaps. Instead, qualitative assessments were made for these life cycle stages. Exposures were not assessed for on - site construction using CWP s and for recycling and dis posal of CWPs due to data gaps as discussed in Section 2 . **4.1 Exposure Assessment for Manufacturing**  The assessment of formaldehyde exposures resulting from manufacturin g of composite wood products is presented in this section. **4.1.1 Descriptio**  **n of Life Cycle Stage** The HWPW, PB, and MDF manufacturing processes include the following general steps: the wood components are prepared, assembled, and bonded together using resin, heat , and pressure. Urea - formaldehyde (UF) has historically been used in the manufacture of these CWP (USEPA 2010a), and has recently

been used in the production of most of the volumes of these CWP s ( OAQPS 1999a ; OAQPS 2000a). Hot pressing cures this thermosetting resin which bonds the wood components into panel products ( OAQPS 2000b ). UF resin is sy nthesized from the reaction of urea with formaldehyde; it contains un - reacted formaldeh yde and formaldeh yde that is generated during its s ynthesis reacti on. Also, formaldehyde may be formed as the resin cures during hot pressing in the CWP manufacturing process. Emissions from the CWP result from hydrol yt ic degradation of the cured resin (which is the reverse of the s ynthesis reaction), or from the un - re acted (free ) formaldehyde ( Tohmura 2000a) ; these emissions are a function o f humidity and temperature (USEPA 1996a). Currentl y other resins in addition to UF resin are used in theFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 38 manufacture of the three CWP s . Poly( vinyl acetate ) (PVA) and phenol - formal dehyde (PF) resins are used in the manufacture of HWPW (USEPA 2010a). Melamine - urea - formaldeh yde (MUF) and pol y(meth yl ene diphenyl diisocyanate ) (pMDI) resins are used in the manufacture of PB and MDF and PF is used in the manufacture of PB as well ( OAQPS 2000a). The HWPW, PB, and MDF manufacturing processes are further described below with emphasis on aspects related to resin processing and potential sources of formaldehyd e exp osure. The market profile (USEPA 2010a) provides broad descriptions of the manufacturing processes that complement the descriptions given here. Most of the references used to obtain the process descriptions below are dated prior to 2006. In 2006, EPA implemented the National Emission Standards for Hazardous Air Pollutants (NESHAP) for pl ywood and composite wood products manufacturing industries. Itis unkno wn whether any process change s were implemented in response to this NESHAP. Description of HWPW Manufacturing Process HWPW is generally

made by assembling a hardwood veneer to the face and back of a core of veneer, lumber, particleboard, MDF, a combination of these materials, or other special cores (USEPA 2010a). The overall HWPW manufacturi ng process consists of the following steps that are presented here as two groups of processing steps ( OAQPS 2002b ): 1. L og selection, debarking, bucking (cutting) , heating and then further cutting into veneers and drying of veneers; and 2. Adhesive mixing, v eneer assembly and adhesive application, hot pressing, cutting, and finishing. The two groups combined constitute the manufacturing process in log
- based mills ; in these mills, the process start s with the conversion of logs into veneer and ends w ith the productio n of hardwood pl ywood. The processing steps in the first group constitute the manufacturing process in a hardwood veneer plant, which are outside the scope of work because they will not be impacted b y the FSCWPA. The processing steps in the second group constitute the manufacturing process in purchased veneer
- based mills and 3
- p ly mills for which the raw materials are wood veneers or other p latforms (USEPA 2010a). Resin constitutes between 4.5 and eight percent of HWPW by weight ( HPVA 2009a). It is mixed with fillers and extenders prior to application. The resin is used during the veneer assembly step of HWPW manufacture. In general, veneer assembl y involves coating resin onto various plies of hardwood veneer or other materials and stacking the plies into a glue - bonded assembly . Most hardwood ply wood mills manually

lay - up their assemblies . Inthe majority of hardwood pl ywood mills (regardless of size), roll coaters are used to spread resin (USEPA 2010a), and the panels are fed manually into these coate rs. Generally , resin is applied to one side of a back or face pl y and then a core ply is laid onto the resin - coated surface of the back or face ply . This process continues with a subsequent resin application to the core ply followed b y the lay - up of another ply . This process is repeated until the last ply (a back or face pl y) is in place ( OAQPS 2000b ). An alternative to roll coaters is curtain coaters (pressure head or gravity feed),Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 39 spray coaters (the glue is either mixed with atomized air or directl y atomized using high pressure), and extrusion (glue is turned into foam at 5 times its original volume and the foam is laid on the veneer surface in beads that are spread during pressing) (USEPA 2010a). Spray coating occurs in spray

booths. The alternativ e glue application s ys tems may be used in automated lay - up and may allow for reduction in waste glue resulting from the operation of roll coaters. Other means of reduced adhesive consumption include improved process control (for example, avoidance of over - dried or unevenly dried veneer) and production line cleanliness (to allow quick identification of resin spill sources). Panel design is also a factor in reduce d adhesive consumption ( Baldwin 1995a). After application of the resin, the bundle then moves to a prepress or hot press pre - loader. Once pressed, the hardwood pl ywood then is taken to a finishing process where edges are trimmed and the face and back may or may not be sanded smooth. The primary

source of formaldehyde emissions in the HWPW manufacturing p rocess is the veneer dryer ( OAQPS 2002b ) . Emissions from dryer exhausts are may be controlled with an air pollution control device ( OAQPS 2002b ). Even when that is not so, it is likely that a dryer exhaust is vented through a stack. Hence, it is unknown whether this emission source results in worker exposure. The press is another source of formaldeh yde emissions; emissions from press vents are t ypically not controlled ( OAQPS 2002b ). In addition to vent emissions, formaldehyde may be emitted from the hot press as it opens during the pres sing operation ( Tohmura 2000a ). Exposure to formaldehyde may also occur while handling the HWPW or performing activities in proximity to the press ( OAQPS 1997a ; OAQPS 1998a , and OAQPS 1999b ). Description of PB Man ufacturing Process The raw materials for PB manufacturing, or furnish, are wood particles (wood chips, sawdust, planer shavings and other recycled materials). The manufacturing process consists of wood particle generation or procurement , milling, drying, and blending of the furnish with resin and other additives, forming the resinated material into a mat, hot pressing, and finishing (USEPA 2010a). In order to ensure that the resin bonds correctly with the particles, which affects both the board’s structura l characteristics and final HCHO emissions, it is important that the furnish attain a specific moisture content (USEPA 2010a). The moisture content of the particles entering the dryer may

be as high as 50 percent on a wet basis ( OAQPS 2000b ). The furnish is dried to a very low moisture content to allow for moisture gained by adding resins and other additives (USEPA 1996a). Dryer temperature is routinel y adjusted based on furnish moisture measurements ( OAQPS 2000b ). After drying, face material, or the furnish that will be present on the face of a panel, may be screened for a second time to remove fines, which often absorb too much resin ( OAQPS 2002b ). The dried furnish is sent to holding bins, which provide surge capacity ( USEPA 2010a). From the holding bins the furnish is conveyed to blenders and mixed with resin and other additives. Resin is usually received on - site as a solution of 65% solids in water, stored in tanks, and pumped to the blenders. Additives may include wax (to impart water resistance to the manufactured product and reduce the tendency for equipment plugging), cataly st (to accelerate resin cure and reduce press time), and scavengers for reduction of emissions from the processFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 40 and the manufactured product (USEPA 1996a ; OAQPS 2000b ; USEPA 2010a , and Maloney 1993a). Furnishes are generall y no warmer than 100  F when blended to avoid pre - curing and drying out of the resin (USEPA 1996a). The furnish may be sampled before and after blending to ensure proper mo isture control ( OAQPS 1998c ). Th e dominant ty

pe of blender consists of a small horizontal drum with high - speed, high shear impellers (USEPA 1996a ; Maloney 1993a). Resin and its additives are sprayed through air or airless atomizing nozzles or applied b y centrifugal atomization. In the air spray s ys tem, the supplied air must be exhausted from the blender but in the airless sy stems the elimination of atomizing air eliminates the associated air pollution problem. Additionally , because of the high speed and number of its impellers, the ble nder, especiall y when not full y l oaded with furnish, can act as an axial - ty

pe fan and discharge air causing dusting problems; this may be limited by restricting its air intake ( Maloney 1993a). M ost blenders vent through baghouses ( OAQPS 2000b ). Blenders generally are designed to discharge the resinated particles into a plenum over a belt conveyor that feeds the blended material to a forming machine ( OAQPS 2000b ). In some installations, this plenum is vented back to the blender for recirculation of fines while in other installations it is vented to the suction side of the forming machine ( Maloney 1993a ). Some evaporation of moisture (and hence formaldehyde as well) from the furnish may occur from air exposure when conveyed from the blenders to the forming station (USEPA 1996a). After the blending process, the resinated material is fed to the forming machine that deposits the blended material into a continuous mat. To produce multilayer particleboard, several forming heads can be used in series, or air curr ents can produce a gradation of particle sizes from face to core ( OAQPS 2002b ). Most formers vent to a baghouse ( OAQPS 2000b ). The formed mat is pre - pressed (optional), cut into desired lengths, and conveyed to the hot press. Few presses are vented to an air pollution control device and some of these presses are full y enclosed ( OAQPS 2000b ). After pressing, the particleboard panels are cooled, sanded, trimmed to desired final dimensions, and may

undergo other finishing operations. Emissions from most c oolers are not controlled and some coolers whose emissions are controlled are fully enclosed. The primary

sources of formaldehyde emissions are the dryers, hot presses, board coolers and blenders ( OAQPS 2002b ). Description of MDF Manufacturing Process The raw materials for MDF manufacturing consist of wood chips, sawdust, planer shavings and other recycled materials which are typically delivered from off - site locations. The manufacturing process consists of pulping the raw material to fibers in a refiner , drying, blending the fibers with resin and additives, forming the resinated material in a mat, pressing, and finishing ( OAQPS 2002b ; USEPA 2010a). Raw material is processed through a steam pressurized refiner which discharges through a blow valve into a blowpipe that is connected to a tube dryer ( USEPA 1996a ; OAQPS 2000b , and USEPA 2010a). The pressurized refiner may also vent into the tube dryer. The tube dryers are directly fired or indirectly

heated. Dryer inlet temperature are on average as high as 270°F. The wood fiber is pneumatically drawn through the tube dryers and is separated from the dryer exhaust gas in a cyclonic collector. The dried wood fibers are discharged from the cyclonicFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 41 collectors through air locks into dry storage bins which pro vide surge capacity . The dryer gas exhaust may

be vented to an air pollution control device, including incineration based controls or scrubbers ( OAQPS 2000b ; USEPA 2010a). Most mills blend resin, wax and other additives by injection into the blowline whe re they readil y mix with the fibers under the turbulent flow conditions present in the bowline. This occurs prior to the drying of the fiber in the tube dryer but some mills use mechanical blending that applies the additives to the dried fiber ( USEPA 2010 a). The blowline s ystem is more frequentl y used because it is fully enclosed, thereb y reducing worker exposure and has superior blending performance . However, the resin may lose some reactivity

as a result of the hot, wet environment in the blowlin e tube and therefore a higher resin - to - fiber ratio is required as compared to the conventional blender s ys tem. Based on a 1998 site visit report to the Medite Division of Sierra Pine MDF plant, the plant personnel stated that methylene diphen yl diisocyanate (MD I) resins are alway s added using the blowline sy stem due to pote ntial worker exposure concerns ( OAQPS 1998b ). The resinated fibers are conveyed from the dry storage bin, where they

are deposited as a mat on a continuously

moving screen s ys tem ( OAQPS 2002b ) . Most formers vent to a baghouse (USEPA 1996a). The deposited mat is pre - pressed and sometimes pre - trimmed prior to transferring to the hot press. Hot pressing activates the thermosetting resin and bonds the resinated material into a solid panel. The press may be vented to an air pollution control device, including incineration based controls, scrubbers or a baghouse ( OAQPS 2000b ). Additionally , the press area may

be partially

or full y enclosed and may be vented with fans (OAQPS 2002 a). Based on non - CBI responses from the 1998 information collection request, seven of the 21 presses were full y enclosed at MDF manufacturing facilities ( OAQPS 2000a). After hot pressing, the panels are cooled and finished. The board cooler may be vented to incineration b ased controls and additionally the cooler may

be fully enclosed in a vented enclosure ( OAQPS 2000b ). Finishing operations include sanding, trimming, and sawing. The primary

sources of hazardous air pollutant ( HAP ) emissions (including formaldeh yde emissions) at MDF plants include emissions from pressurized refiners, wood dryers, blenders, formers, presses, and board coolers; the finishing operations may also be a source of HAP emissions ( OAQPS 2000b ). The largest emission sources are wood dryers and press vents. Formaldeh yd e emissions are significantl y higher after resin application. For example, dryer emissions from a blowline sy stem are much higher than the dryer emissions from a conventional blender s ys tem due to the presence of formaldehyde - based resin in the wood material in the former dryer sy stem . While fugitive emissions from the blender, former, and cooler may occur, these emissions are much lower and ar e t ypically not controlled ( OAQPS 2002b ). **4.1.2 Productio**  **n Volumes and Number of Establishments, Workers, Production Hours, and Work Days**  The domestic production volumes and number of sites, or mills, for the manufacture of the three composite wood products are given in Table 4 - 1 and Table 4 - 2 . These data are provided for reference purposes onl y and are not used in the assessment. Thes e tables present data on the number of mills from the Composite Panel Association (CPA) (AWFS 2009a) and the U.S. International Trade Commission (USI TC) (USITC 2008a). The number of mills reported b y the 2007 Economic Census ( Census 2007a) is presented in Table 4 - 3 . The U.S. Census reported a greater number of mills for both NAICS codes than the CPA and USI TC sources. Note that theFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 42 U.S. Census classifies PB and MDF manufacture under a single NAI CS code: 321219

– Reconstituted Wood Product Manufacturing. This NAI CS code also includes fiberboard, hardboard (HB), oriented - strand board (OSB), waferboard, flakeboard, and chipboard, which are outside of the scope of the assessment. Similarly , NAI CS code 321211 - Hardwood Veneer and Ply wood Manufacturing includes the manufacture of hardwood veneers, which are outside the scope of the assessment ( see Section 2 ) . Therefore, the number of mills data for both manufacturing NAICS codes represent mills that manufacture products outside the scope of this assessment. Estimates for the total number of worke rs and aggregate production hours worked for the manufacturing of the three composite wood products were obtained from the EPA market profile ( EPA 2010a) and the 2007 Economic Census ( Census 2007a) and are presented in Table 4 - 3 . The 2007 Economic Census data are likel y an overestimate of the number of workers for the following reasons:
 Trade associations reported that mills have closed down; and  NAI CS codes 321219

– Reconstituted Wood Product Manufacturing and 321211

- Hardwood Veneer and Ply wood Manufacturing both include products outside the scope of this assessment. However, it is assumed that the census data on number of workers and aggregate production hours work ed are proportionally overestimated such that their ratio, used to calculate production hours per day

and day s per year, is representative of mills within the scope of the assessment. Using these data, the average production day s per year per worker (assum ing eight hours per day), and average production hours per day per worker (assuming 250 days per year) were calculated, and the results are given in Table 4 - 3 . These calculated values are compared to the OPPT default values. As default, OPPT assumes people work five day s per week and 50 weeks per year (with two weeks of vacation), which results in 250 work days per year. OPPT also assumes a t ypical work day is eight hours per day . As seen in Table 4 - 3 , the calculated production day s per ye ar (assuming 8 hours per day) do not deviate from the OPPT default value for frequency

of e xposure of 250 day s per year b y more than 10 percent. Based on this comparison, the frequency of exposure for manufacturing is assessed as 250 day s per year. Similarly , all of the calculated values for production hours per day (assuming 250 day s per year) do not deviate from the OPPT default value for duration of exposure of 8 hours per day by more than 10 percent. Based on this comparison, the duration of exposure for manufacturing is assessed as 8 hours per day . **Table 4**  **- 1**  **. U.S. Hardwood Plywood Production Data and Number of Mills Hardwood Veneer and**  **Plywood Mill Composite Wood**  **Product Type 2008 U.S. Production Volume of**  **Composite Wood Product (thousands of ft**  **2 )**  **1 Number of U.S.**  **Mills 2**  Hardwood Plywood Mills Hardwood Plywood 748,400 24 1 U.S. production vo lume data obtained from personal communication with HPVA ( HPVA 2009a). The plywood thickness basis was not provided. 2 Number of U.S. mills obtained from the U.S. International Trade Commission report on wood flooring and hardwood plywood ( USITC 2008a ).Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 43 **Table 4**  **- 2**  **. U.S. Reconstituted Wood Product Production Data and Number of Mills Reconstituted Wood**  **Product Mill Type Composite Wood**  **Produ ct Type**  **2007 U.S. Production Volume of Composite**

**Wood Product (thousands of ft 2**  **at 3/4"**

**thickness basis)**  **1 Number of**  **U.S. Mills 2**  Particleboard Mills Particleboard 3,542,666 34 Medium - Density Fiberboard Mills Medium - Density Fiberboard 1,884,264 27 1 U.S. production volume data obtained from the 2007 North American Downstream Market Report ( CPA 2008a ). 2 Number of U.S. mills obtained from “Update on California’s Composite Wood Products Regulation” presented at AWFS Show in Las Vegas, NV on July 18, 20 09 provided by CARB to EPA ( AWFS 2009a ) . The presentation wa s co - presented by CARB and CPA. The number of MDF mills is a high - end estimate that may include some hardboard mills: the presentation did not differentiate between non - CPA - member MDF and HB mills . **Table 4**  **- 3**  **. Summary of 200 7**  **Economic Census Data and Exposure Frequency and Duration Calculated from Th**  **ese Data for U.S. Manufacturing Mills** 

**2007 Econom ic Census Data**  **Param eters Calculated**  **from the Corresp**  **onding 2007 Econom** **ic Census Data** 

**NAICS Code**  **NAICS**

**Industry Description**  **Number of**

**Establishments Maximum** 

**Number of Production**  **Workers Aggregate** 

**Production Hours**  **Worked (hours)**  **Average**

**Production Days per**  **Year (assuming 8**  **h ou**  **r s**  **/day) Average** 

**Production Hours**  **per Day**  **(assuming 250**  **days/yr)** 321219 Reconstituted

wood product manufacturing 262 16,076 34,615,000 269 8.61 321211 Hardwood

veneer & plywood manufacturing 304 15,504 32,256,000 260 8.32 Source: EPA market profile ( USEPA 2010a ) and 2007 Economic Census ( Census 2007a ). **4.1.3 Pre** **-**

**Baseline Exposure Monitoring Data** This section presents a summary of the inhalation exposure monitoring data collected from OSHA IM IS for the period 2002 to 2009 on the manufacture of HWPW, MDF, and PB as well as a summary

of the other compiled inhalation exposure monitoring data on CWP manufacturing . Table 4 - 4 provides the maximum, median, and minimum 8 - hour TWA pe rsonal inhalation monitoring formaldeh yd e concentrations by worker activit y category for the manufacture of HWPW from OSHA IMIS . Table 4 - 5 provides the maximum, median, and minimum 8 - hour TWA personal inhalation monitoring formaldeh yd e concentrations by worker activit y category for the manufacture of reconstituted wood products, including PB and MDF from OSHA IMI S.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report October 6, 2011 Page 44 **Table 4**  **- 4**  **. Summary of Formaldehyde Inhalation Monitoring Data for Hardwood Plywood Manufacturing Mills from the OSHA IMIS Database** 

**Worker Activity**  **Description Total** 

**Number of Sites where**  **Monitoring Occurred**  **Total**

**Number of Data**  **Points Monitored Form**  **aldehyde Concentration 1**  **Year Monitoring Occurred for the Summary Data Points**  **Maximum Median**  **Minim um**  **Maximum Concentration**  **Median**

**Concentration 2**  **Minim um** 

**Concentration (ppm)**  **( μ**  **g /m** **3 )**  **(ppm) (**  **μ g** **/m 3**  **) (ppm)**  **( μ**  **g /m** **3 )**  Press Operation 2 4 1.56 1,917.2 0.695 854.2 0.213 261.8 2003 2003 / 2003 2006 Glue Spreading 2 2 0.32 393.3 0.28 344.1 0.24 295.0 2003 2003 / 2006 2006 Mixing Adhesive 1 1 0.119 146.3 0.119 146.3 0.119 146.3 2006 2006 2006 Lathe Operation 1 1 0.022 27.0 0.022 27.0 0.022 27.0 2004 2004 2004 Production Laborer or Other Operator 2 4 0.142 174.5 0.0695 85.4 0.021 25.8 2007 2004 / 2007 2004 Overall Statistics for All Data Points 4 12 1.56 1,917.2 0.1775 218.1 0.021 25.8 2003 2006 / 2007 2004
1 The formaldehyde concentration in μ g/m 3 was calculated from the provided concentration in ppm by multiplying the concentration in ppm by 1,229 μ g/m 3 /ppm ( see Appendix E ). 2 For worker activities with an even number of data points, the median was calculated as the average of the two middle values. The years are provided for the two middle values.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report October 6, 2011 Page 45 **Table 4**  **- 5**  **. Summary of Formaldehyde Inhalation Monitoring Data for Reconstituted Wood Product Manufacturing Mills from the**  **OSHA IMIS Database**

**Worker Activity**  **Description Total** 

**Number of Sites where**  **Monitoring Occurred**  **Total**

**Number of Data**  **Points Monitored Form**  **aldehy de Concentration**  **1 Year Monitoring Occurred for the Summary Data**  **Points Maximum**  **Median Minim**  **um Maximum**  **Concentration Median** 

**Concentration 2**  **Minim um** 

**Concentration (ppm)**  **( μ**  **g /m** **3 )**  **(ppm) (**  **μ g** **/m 3**  **) (ppm)**  **( μ**  **g /m** **3 )**  Press Operation 1 3 0.12 147 0.089 109 0.009 11 2005 2005 2005 Production Laborer or Other Operator and CSHO 4 6 0.243 299 0.043 53 0.02 25 2005 200 6 / 2005 2006 Overall Statistics for All Data Points 4 9 0.243 299 0.051 62.7 0.009 11 2005 2005 2005
1 The formaldehyde concentration in μ g/m 3 was calculated from the provided concentration in ppm by multiplying the concentration in ppm by 1 , 229 μ g/m 3 /ppm ( see Appendix E ) . 2 For worker activities with an even number of data points, the median was calculated as the av erage of the two middle values. The years are provided for the two middle values.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 46 Appendix H presents additional hist orical exposure monitoring data from a variety of studies and reports. These data are briefl y summarized here for reference purposes . Note that these data include studies from countries other than the United States and their relevance to U.S. mills has n ot been established. Plywood Manufacturing Mills Monitoring Data Sampling data 6 collected in British Columbia from 199 2 to 200 3 indicate that formaldeh yde levels in the ply

wood manufacturing industry are predominantly

below 0.3 ppm ( WorksafeBC 2009a). Other data indicate an exposure range of 0.08 ppm to 0.60 ppm (Fransman 2003 a ) in the ply wood manufacturing sector. Short - term exposure levels and instantaneous ceiling limit values for pl ywo od manufacturing available from one discussion paper ( WorksafeBC 2009a) ranged from 0.14 to 0.29 ppm and 0.33 to 0.44 ppm, respectively , in a 2002 survey . MDF Manufacturing Mills Monitoring Data For MDF manufacturing, the highest estimated geometric mean for ambient formaldeh yde levels was reported as 0.43 ppm in the m ain production area of manufacturing facilities in Quebec ( Lavoue 2005a). In one study ( Chung et al. 2000a), free formaldeh yde levels were determined to be less than 0.14 ppm during machining of the Class B (higher formaldehyde potential) MDF. According to one Swedish report, formaldehyde levels were at 0.2 ppm (arithmetic mean) between 1980 and 1989 in facilities manufacturing MDF ( IARC 1995a ). Particleboard and Fiberboard Manufacturing Mills Monitoring Data Time - weighted average (8 - hour) levels of for maldehyde have been noted to be generally higher than 0.3 ppm in sampling data collected over a period of 15 years (1990 to 2005) for particleboard and fiberboard manufacturing in British Columbia, Ontario, Quebec, and the Netherlands ( WorksafeBC 2009a). Exposures in fiberboard manufacturing ranged from 0.07 to 5.0 ppm for samples taken between 1996 and 2000 ( WorksafeBC 2009a). Exposure levels from between 0.1 and 0.4 ppm (Quebec) (Lavoue 2005 a) to 1.15 ppm (Scandinavia) (Niemel ä and Vainio 1981a) have bee n noted in other studies of the particleboard and MDF manufacturing industry . Eight - hour TWA levels of formaldeh yd e ranging from 0.07 to 0.20 ppm and instantaneous ceiling values that were as high as 7.47 ppm were reported in particleboard manufacturing pl ants in 2002 ( WorksafeBC 2009a). A median of 0.62 ppm was observed for particleboard workers in measurements taken in 1987/1988 ( Horvath et al. 1988a) and a value of 0.3 ppm was reported for particleboard manufacture between 1980 and 1989 ( IARC 1995a).

6 Includes 500 samples collected from identifiable sources of formaldehyde in a number of industries, including the plywood industry where workers are exposed to formaldehyde as a by - product (e.g., off - gassing of the substance during the curing process of urea - formaldehyde glue in a plywood plant)”. WorkSafeBC does not specify whether the exposure in plywo od plants was strictly caused by using UF resins. These samples may be taken at both hardwood and softwood plywood plants.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 47 Fo r particleboard manufacturing, formaldeh yd e exposure levels in the range of 0.08 to 0.9 ppm, with peaks reaching 4.1 ppm, were observed from measurements taken between 1975 to 1983 ( Edling 1988a ). Mean l evels between 0.4 and 2.3 ppm have been reported for particleboard manufacture b y other researchers between 1975 and 1984 ( Kauppinen and Niemelä 1985a). A mean level less than 1 ppm and a maximum level of 1.4 ppm during particleboard manufacture were also reported in 1982 ( Preuss et al. 1985a ). Occupational h ygienists from WorkSafeBC sampled different locations in a fiberboard plant in British Columbia from January to June 2006 and found formaldehyde levels ranging from 0.03 to 1.19 ppm. The highest exposure was in the press outfeed area, rangin g from 0.32 to 1.19 ppm. **4.1.4 Respiratory Protection Usage During Manufacturing**  Since OSHA IMIS data do not provide information on personal protective equipment use, OSHA inspection reports associated with the IMIS data were examined to get an idea of the use of respiratory

protection by

workers when engaged in manufacturing activities. Appendix G presents a summary

of each reviewed inspection report. The nine TWA, person al monitoring IMIS data points for PB and MDF manufacturing in Table 4 - 5 discussed in Section 4.1.3 are associated with four inspections. Of these four inspections , a total of two inspection reports for PB and MDF manufacturing facilities were requested from OSHA. O ne of the two inspection reports (inspection number 307061689 ; see Append ix G), which accounts for four of the nine TWA, personal monitoring IMIS data points, has been received and reviewed , but the other inspection report was no longer available due to its age. Additionally , two other inspection reports were requested from inspections prior to 2002 and hence are not associated with the nine data points discussed above. One of the se two inspection reports (inspection number 303864029 ; see Appendix G) has been received and reviewed , but the other inspection report was no longer available due to its age. Finally , an additional inspection report ( inspection number 312479835; see Appendix G) associated with the CWP fabrication IMI S data (see Section 4.2.3 ) was requested, received, and reviewed. Although the facility was identified in IM IS by a fabricator NAICS code, the inspection report states that the facility manufactures MDF and then fabricates flooring from the MDF. As the monitored workers were associated with the manufacture of MDF, this inspection report is discussed in this section and Appendix G with the manufacturer inspection reports. Of the three reviewed inspection reports, o nl y one r eport for a facility that manufactures MDF primarily for flooring indicated the use of respirators by production workers (press assistants) (inspection number 312479835; see Section 4.2.4 and Appendix G) . The workers were observed wearing 3M 6300 half masks with formaldeh yde cartridges and had the option to use full facepiece respirators. The two TWA measurements taken for press assistants were both below the PEL of 0.75 ppm , although one exceeded OSHA’s TWA a ction l evel (AL) of 0.5 ppm for formaldeh yde. The two facilities associated with the remaining two inspection reports had TWA measurements below the action level. The 12 TWA, personal monitoring IMIS data poi nts for HWPW manufacturing in Table 4 - 4 discussed in Section 4.1.3 are associated with four inspections. None o f these four inspection reports for HWPW manufacturing facilities were requested from OSHA. However, twoFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 48 inspection reports for HWPW manufacturing facilities were requested from inspections prior to 2002 and h ence are not associated with the 12 data points discussed above. Both of these inspection reports have been received and reviewed. Neither report indicated the use of respiratory

protection. The first facility had four TWA measurements and three STEL me asurements (inspection number 303713325; see Appendix G) . All four TWA measurements were below the action level and all three STEL measurements were below the OSHA STELof 2 ppm. The second facility had ten TWA measurements and six STELmeasurements (ins pection number 123445595) ; see Appendix G) . All STELmeasurements were below the OSHA STEL of 2 ppm. Two of the TWA measurements were above the OSHA AL but below the PEL ; the remainder were below the action level. This facility was cited by OSHA for for

maldeh yd e overexposure. The inspection report note d that workers were not observed wearing respiratory protection during the inspection. Although one inspection report (inspection number 123445595; see Appendix G) for HWPW manufacturing noted that workers were not wearing respirators in spite of exposure levels that exceeded the AL (but were below the PEL), respirator use has been noted in another case in MDF manufacturing (inspection number 312479835; see Appendix G) when exposure levels exceeded the AL (but were below the PEL). The need to protect against chemicals and particulates other than formaldeh yde might also dictate respirator use. Therefore, the reported use of respirators in the inspection report for the MDF manufacturing facility could have b een for protection against chemicals other than formaldehyde or it could be a precautionary practice. Overall, the limited number of inspection reports that were available and examined does not provide conclusive evidence that respirators are necessarily worn by workers when their exposure meets or exceeds the formaldeh yde AL or PEL . **4.1.5 Baseline Exposure and**  **the Effect of** **Analytical Options**  **on Baseline Exposure for Manufacturing**  Baseline e xposures and exposures for the anal yt ical options were not assessed quantitatively due to data gaps. The emission rate data for CWPs presented in Appendix D apply to the CWPs after their manufacture. Hence, these emission rates are only relevant to the manufacturing process after the pressing operation and are not applicable to the remainder of the process, which includes unit operations in which uncured res ins are present and the press. These sources of formaldeh yde cannot be assumed negligible in manufacturing mills. As indicated in the pre baseline OSHA IMIS monitoring data presented in Section 4.1.3 , formaldehyde exposures have been observed associated with mixing and appl yi ng adhesives and pressing operations. The literature search did not yield information on modeling indoor air concentration s from these sourc es. Therefore, exposures during baseline and anal yt ical options are assessed qualitatively . At baseline, approximately all domestic production of HWPW, MDF, and PB will be in compliance with the CARB ATCM Phase 2 standard, as shown in Table D - 3 in Appendix D . Only small fractions of HWPW and PB domestic production will not be in compliance with the CARB ATCM Phase 2 standard at baseline. Approximately

0.28% of domestic HWPW production will not be in compliance with an y CARB ATCM standard. However, the emission level of this fraction of HWPW production is estimatedFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 49 to be 0.058 ppm, which is close to the CARB ATCM Phase 2 standard of 0.05 ppm and less than the CARB ATCM Phase 1 standard of 0.08 ppm for HWPW . 7 Approximately

2% of domestic PB production will not be in compliance with the CARB ATCM Phase 2 standard. 7 Of this 2% of domestic PB production, approximately 0.2% of domestic PB production will not meet any CARB ATCM emission standard. However, the emission level of this 0.2% of domestic PB production is estimated to be 0.058 ppm, which is less than the CARB ATCM Phase 2 standard of 0.09 ppm for PB. Additionally , approximately 1.8% of domestic PB production will be in compliance with the CARB ATCM Phase 1 standard with an estimated emission level of 0.09 ppm . Hence, the CARB Phase 1 and FSCWP A/CARB Phase 2 analy tical options will result in a negligible effect on baseline exposure levels for manufacturing. Since approximately

all domestic production of CWPs are expected to meet the CARB ATCM Phase 2 standard at baseline, only the NAF anal yt ical option will affect baseline exposures. NAF resins do not contain any formaldehyde. Therefore, mills that use NAF resins in compliance with NAF standards should achieve a reduction in formaldehyde exposures due to the elimination of the formaldehyde content of resins. However, wood naturally emits formaldeh yde, and it is possible that workers in mills that use only NAF resins may

still experience some formaldehyde exposures due to the natural emission of formaldehyde from wood. Other sources of formaldeh yde can exist for mills that apply value - added surfaces. However, it is uncertain how many mills appl y value - added surfaces. **4.1.6 Dermal Exposures during Manufacturing**  Dermal exposures to workers during manufacturing can occur durin g unloading of liquid UF resin. The free formaldehyde content immediately after manufacture is approximately 0.59% but reduces to 0.1 5% after 24 hours ( Fink 2005a ). For the purpose of this assessment, EPA assumes a formaldeh yd e concentr ation of 0.59% in the UF resin. The EPA/OPPT 2 - Hand Dermal Contact with Liquid Model estimates a dermal exposure of 590 to 1,800 mg/day

for exposure to a chemical at 100% concentration. For the assumed formaldeh yde concentration of 0.59%, the model estimates worker exposure of 3.5 to 10.6 mg/day . This results in an estimated dose of 0.05 to 0.15 mg/kg/day for an average 70 kg worker. The source ( Fink 2005 ) does not specify whether the provided free formaldehyde contents in UF resins are specific to UF resins for CWPs or other applications. Additionally , Fink (20 05) does

7 The EPA market profile ( USEPA 2010a ) indicates that at baseline 0.1% of the volume of U.S. consumed HWPW will be domestically - pr oduced and will have an emission level not meeting the emission standards. The remainder of the U.S. consumed domestically - produced HWPW will have shares of 19.7% of U.S. HWPW consumption (meeting CARB Phase 2) and 16.2% of U.S. HWPW consumption (meeting N AF). Therefore, the volume fraction of domestically - produced HWPW not meeting any emission standard and relative to the total volume of U.S. consumed domestically - produced HWPW is 0.1% / (0.1% + 19.7% + 16.2%) x 100% = 0.28%. Similarly, at baseline 0.2% of the volume of U.S. consumed PB will be domestically - produced and will not meet any emission standard. The remainder of the U.S. consumed domestically - produced PB will have shares of 1.7%, 85.0%, 3.0%, and 7.1% (meeting CARB Phase 1, CARB Phase 2, ULEF, an d NAF, respectively). Therefore, the volume fraction of domestically - produced PB exceeding CARB Phase 2 relative to the total volume of U.S. consumed domestically produced PB is (0.2% + 1.7%) / (0.2% + 1.7% + 85.0% + 3.0% + 7.1%) x 100% = 2.0%.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 50 not specify

the statistical significance of the formaldehyde contents, such as being typical, maximum, minimum, etc. This assessment assumes these form aldeh yde contents are t ypical for UF resins specific for CWPs and representative of pre - baseline conditions . Additionally , it is uncertain how the free formaldeh yde content of CWP resins will change as manufacturers adopt the CARB ATCM limits. The source ( Fink 2005 ) is from 2005 and may not represent resins at bas eline or anal yt ical options. Therefore, both baseline dermal exposures and the effect of anal yt ical options on baseline dermal exposures are uncertain and cannot be estimated . **4.2 Exposure Assessment for Composite Wood Product Fabrication**  The assessment of formaldehyde exposures resulting from the use of the three composite wood products (CWPs) in composite wood product fabrication is presented in this section. **4.2.1 Description**  **of Life Cycle Stage** A general description of the manufacturing process is presented be low. The literature search did not yield d etailed information on the manufacture of specific composite wood fabrication products (downstream products) . The Office of Enforcement and Compliance Assurance (OECA) sector notebook Profile of the W ood Furniture and Fixtures Industry ( OECA 1995a) provides a general process description for wood furniture and fixtures constructed from raw lumber , which does not include composite wood products . A ctivities involved in fabrication of wood furniture from raw lumber i nclude drying raw wood; sawing into appropriate sizes, planing and bending ( i.e. , machining); assembling the wood material into parts; sanding; prefinishing ( e.g., watering, sanding, derosination, bleaching); coating b y spraying, brushing, or dipping; and finishing ( OECA 1995a). As described below, similar activities are used to produce furniture and fixtures from the composite wood products that are the focus of this assessment. The following activities (unit operations) are ty pically used to manufacture wood product s, based on a survey

of Georgia wood products manufacturers ( GDNR 1996a) . Although the reference does not describe if the surveyed manufacturers used composite wood products or raw lumber, it explains that wood product manufacturers may use si milar processes to produce different products using different raw materials. Therefore, the cited activities are likely used to manufacture downstream products using composite wood products as raw materials. The cited activities include the following:
 Application of overlay s or decorative surfaces (other than wood or woody - grass veneers) 8 ;  Assemb ling ;  Gluing ;  Spray

application;  Painting and coating;  Water - based coating;  Solvent - based coating;

8 The appli cation of wood or woody - grass veneers on CWPs is described as HWPW manufacturing in FSCWPA and therefore is not included here as a part of CWP fabrication even though this activity may occur in CWP fabrication sites.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 51

 Staining;  Sealing;  Water - based cleaning; and  Solvent - based co ating. These process activities apply to the following CWP fabrication sectors: millwork, cabinet makers, veneer pl ywood, trusses, prefabricated construction, particleboard and reconstituted wood, wood furniture, miscellaneous furniture, exhibits and showrooms ( GDNR 1996a). Workers are potentially

exposed to formaldehyde during the above - listed activities from unfinished and finished (e.g., overlayed , coated, or painted) composite wood products. However, emission rates from the finished products are generall y lower than those from the unfinished products ( Battelle 1996a). Additionally , the following materials, which are used in CWP fabrication, may also be a potential source of formaldehyde exposure during CWP fabrication :
 Adhesives used in gluing and overlaying barrier surfaces;  Overlay

materials; and  Coatings and varnishes used in finishing operations. Formaldeh yd e - based adhesives may be used in upholstered furniture manufacturing based on the contents of an OSHA inspection report associated with the comp iled IMI S data ( OSHA 2003a). At the inspected site, formaldehyde - based adhesive is mixed and applied by hand to glue wood sections together. The inspection report noted that proper PPE was not used during this activity and formaldeh yd e sampling results w ere below the action level ( OSHA 2003a ; see Appendix G ). Workers also use a formaldehyde - based adhesive with a pneumatic gun to assemble wooden chairs. Workers wear a half - face respirator while assembling the wooden chairs, a lthough the inspection report stated past air sampling indicated formaldeh yde levels were below the PEL ( OSHA 2003a ; see Appendix G ). During the application of overlay materials , adhesive is applied to the decorative overlay , and the overlay and the substrate ( composite wood product) are subsequentl y bonded through a pressing operation. Based on information associated with similar activities that occur during manufacturing of composite wood products , it is inferred that formaldehyde vapor would be emitted during glue application and hot pressing, resulting in potential for inhalation exposure. Some overlay

materials do not require additional adhesive to be bonded with the wood substrate as they are saturated with reactive resins and partially cured as supplied ( CPA 2007a). The overlay s may

be saturated with formaldehyde - based resins and thereby serve as another source of formaldeh yd e. A CPA technical bulletin indicates that several ty pes of adhesiv es may

be used f or the application of overlay s to PB and MDF , such as hot melt adhesives, PVA, acrylic - based formulations, UF, PF, and MF resins ( CPA 2007a ). The finishing operation for wood furniture and cabinets includes the application of several clear and/or color coatings. The coating process may be manual or automatic. The most common manual techniques are wiping, dipping and spraying via spray guns. Automatic application techniques include robotic spraying, roll coating and curtain coating. While spraying and coating processes ty

pically occur in ventilated booths equipped with dry filters to controlFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 52 particulates (USEPA 2000a), workers inside the booth can be significantl y exposed if they are located in the direction of flow of the coating mist ( IR SST undated ). An OSHA inspection report indicates the use of formaldeh yd e - based coating in the finishing of wood cabinets. The employer provided respirators to reduce worker exposure to formaldeh yd e from the coating ( OSHA 2008a ; see Appendix G ). OSHA offers guidance on safe practices in the woodworking industry through its Woodworking eTool (OSHA 2002a). OSHA recommends using ventilated, automated sy stems for applying coatings and adhesives when feasible. OSHA also recommen ds that manual spray

operations be performed in a spray booth or separate, ventilated area. Dip coating should be ventilated with an enclosure or capture hood. T he prevalence of the engineering controls described in the OSHA Woodworking eTool is unknown . In addition to the Woodworking eTool, OSHA has a standard for spray finishing operations (29 CFR 1910.107), which provides detailed requirements for the design and construction of spray booths and rooms (OSHA 2002a). Some information is available on the amount of natural wood products and composite wood products outside the scope of this assessment in fabricator sites. According to the EPA market profile (USEPA 2010a), natural wood products and composite wood products outside the scope of this assessment (e.g. , hardboard) may be used in the composite wood fabrication sectors. While the three composite wood products within the scope of work have the highest formaldeh yde emission rate s, the relative contribution to overall exposure of these other wood prod ucts may be considerable if they

are present at a site in large quantities relative to the three composite wood products. Tables 6 - 4 through 6 - 20 in the EPA market profile (USEPA 2010a) provide the value of raw materials in each of the sectors. For the following sectors, the other composite wood products (such as softwood pl yw ood and hardboard) comprise 10% or greater of the total composite wood product material costs, and therefore, could be present in significant quantities relative to HWPW, PB and MDF :
 Wood window and door manufacturing (NAICS code 321911);  Other millwork (including flooring) (NAI CS code 321918);  Manufactured home (mobile home) manufacturing (NAICS code 321991);  Upholstered household furniture manufacturing (NAI CS code 337121);  Wood television, radio, and sewing machine cabinet manufacturing (NAICS code 337129); and  Showcase, partition, shelving, and locker manufacturing (NAICS code 337215). Therefore, for these sectors, other composite wood products may contribute to overall exposure . However, this anal ys is is based onl y on the costs of the materials and not on the actual volumes of the materials . Data on actual volumes consumed per sector and data to convert material costs to material volumes were not available. The information abo ve indicates the possibility of the existence of potential formaldeh yde exposure sources other than the composite wood products of interest . The relative significance of these other sources is not known. For example, the extent to which formaldehyde - cont aining coatings are used in CWP fabrication is not known and where such materials are used, the extent to which engineering controls such as ventilated spray booths are used to control exposure is also not known.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 53 **4.2.2 Number of Establishments, Workers, Producti** **on Hours, and Work Days** Estimates for the number of establishments, total number of workers, and aggregate production hours worked for each of the industry sectors that comprise the composite wood product fabrication life cycle stage were obtained from the 2007 U.S. Economic Census ( Census 2007a), and are presented in Table 4 - 6 . It is uncertain whether all sites within each identified NAICS sector use the composite woo d products of interest. Therefore, the number of sites and workers identified in Table 4 - 6 m ay represent facilities that do not use composite wood products and are co nsidered maximum values. Using these data, the average number of workers per site, average production day s per ye ar per worker (assuming eight hours per day), and average production hours per day

per worker (assuming 250 days per year) were calculated, an d the results are given in Table 4 - 6 . As seen in Table 4 - 6 , all of the calculated values for production day s per year (assuming 8 hours per day) do not deviate from the OPPT default value for frequency of exposure of 250 day s per year b y more than 10 percent. Based on this observation , the frequency of exposure for composite wood fabrication in general is assessed to be 250 day s per ye ar. Similarly , all of the calculated values for production hours per day (assuming 250 day s per ye ar) do not deviate from the OPPT default value for duration of exposure of 8 hours day s by more than 10 percent. Based on this observation , the average duration of exposure for composite wood fabrication in general is assessed to be 8 hours per day . The result for duration of exposure of 8 hours per day derived from aggregate census data is support ed by

duration data given in IM IS . For all composite wood product fabrication industries identified in Table 4 - 6 and all exposure ty pes (e.g., TWA, STEL) , 182 exposur e data points (sampled in the year 2002 through 2009) were collected. These 182 data points have the following exposure duration data 9 :
 Exposure durations of blank, “dail y”, or other frequency estimate without a duration estimate: 88 data points (48%);  Exposure durations of eight hours per day: 80 data points (44%);  Exposure durations of less than eight hours per day: 10 data points (5%); and  Exposure durations of greater than eight hours per day : four data points (2%).

9 Note: percentages should add to 100 percent but may not due to rounding.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report October 6, 2011 Page 54 **Table 4**  **- 6**  **. Summary of 200 7**  **Economic Census Data and Exposure Frequency and Duration**  **Calculated from Th ese**  **Data for Composite Wood Product Fabricating**  **Sites 2007 Econom** **ic Census Data Param**  **eters Calculated from the Corresponding 2007**  **Econom ic Census Data** 

**NAICS Code NAICS** 

**Industry Description**  **Maximum**

**Number of Establishments**  **Maximum**

**Number of Production**  **Workers Maximum Aggregate** 

**Production Hours Worked**  **(thousands of h ou**  **r s**  **) Average**  **Production Workers per**  **Site Average** 

**Production Days**  **per Year Per Worker**  **(assuming 8 h**  **ou r**  **s /day)**  **Average**

**Production Hours per**  **Day Per Worker**  **(assuming 250 days/yr)**  321911 Wood Window

and Door Manufacturing 1,494 62,089 116,209 42 234 7.49 321918 Other Millwork

(including flooring) Manufacturing 2,101 34,394 68,475 16 249 7.96
321991 Manufactured

Home (mobile home) Manufacturing 376 32,010 60,725 85 237 7.59
321999 All Other

Miscellaneous Wood Product Manufacturing 1,964 27,952 54,290 14 243 7.77
337110 Wood Kitchen

Cabinets and Countertop Manufacturing 9,683 107,206 213,487 11 249 7.97
337121 Upholstered

Household Furniture Manufacturing 1,633 60,721 118,966 37 245 7.84Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report October 6, 2011 Page 55 **Table 4**  **- 6**  **Continued 2007 Econom** **ic Census Data Param**  **eters Calculated from the Corresponding 2007**  **Econom ic Census Data** 

**NAICS Code NAICS** 

**Industry Description**  **Maximum**

**Number of Establishments**  **Maximum**

**Number of Production**  **Workers Maximum Aggregate** 

**Production Hours Worked**  **(thousands of h ou**  **r s**  **) Average**  **Production Workers per**  **Site Average** 

**Production Days**  **per Year Per Worker**  **(assuming 8 h**  **ou r**  **s /day)**  **Average**

**Production Hours per**  **Day Per Worker**  **(assuming 250 days/yr)**  337122 Nonupholstered

Household Furniture Manufacturing 3,428 49,764 95,685 15 240 7.69 337124 Metal Household

Furniture Manufacturing 330 8,827 18,527 27 262 8.40 337127 Institutional

Furniture Manufacturing 782 25,848 52,006 33 251 8.05

337129 Wood

Television, Radio, Phonograph, and Sewing Machine Cabinet Manufacturing 270 1,541 3,094 6 251 8.03

337211 Wood Office

Furniture Manufacturing 457 15,167 31,614 33 261 8.34
337212 Custom

Architectural Woodwork and Millwork Manufacturing 2,228 32,184 64,362 14 250 8.00
337214 Office Furniture

(except wood) Manufacturing 289 19,307 40,614 67 263 8.41Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report October 6, 2011 Page 56 **Table 4**  **- 6**  **Continued 2007 Econom** **ic Census Data Param**  **eters Calculated from the Corresponding 2007**  **Econom ic Census Data** 

**NAICS Code NAICS** 

**Industry Description**  **Maximum**

**Number of Establishments**  **Maximum**

**Number of Production**  **Workers Maximum Aggregate** 

**Production Hours Worked**  **(thousands of h ou**  **r s**  **) Average**  **Production Workers per**  **Site Average** 

**Production Days**  **per Year Per Worker**  **(assuming 8 h**  **ou r**  **s /day)**  **Average**

**Production Hours per**  **Day Per Worker**  **(assuming 250 days/yr)**  337215 Showcase,

Partition, Shelving, and Locker Manufacturing 1,377 34,481 67,716 25 245 7.86 339950 Sign

Manufacturing 6,383 52,755 103,305 8 245 7.83 336213 Motor Home

Manufacturing 80 14,152 27,550 177 243 7.79 336214 Travel Trailer &

Camper Manufacturing 862 39,282 75,327 46 240 7.67 **Totals 33,737**  **617,680 1,211,952**  **18 245**  **7.85** Source s : 2007 U.S. Economic Census ( Census 2007a ) and EPA market profile ( USEPA 2010a )Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 57 **4.2.3 Pre** **-**

**Baseline Exposure Monitoring Data** The exposure monitoring data collected from IMIS for the period 2002 to 2009 on composite wood product fabrication are presented in this section. Table 4 - 7 provides a summary of all IMIS 8 - hour TWA, personal inhalation monitoring data for industry sectors within the composite wood product fabrication life cycle stage. Summary data for the individual sectors is provided in Appendix F . Appendix F also provides the maximum, median, and minimum values of the compiled formaldehyde monitoring data for worker a ctivity categories in each sector. As discussed in Section 4.2.1 , sources of potential exposure in CWP fabrication sites include off - gassing of composite wood pro ducts and possibly other sources such as paints, adhesives and coatings, etc. However, the specific sources of exposure associated with the compiled IMI S data are unknown. **Table 4**  **- 7**  **. Summary of All IMIS TWA Personal**  **Monitoring Data for Industries Within the CWP Fabricator Life Cycle Stage**  **Statistic Concentration**  **1 ppm**  **mg/ m**  **3** Maximum 1 1.229 Median 0.091 0.112 Minimum 0.00001 0.000012 Average 0.170 0.209 Number of Data Points 120 Source: OSHA 2009a 1 The formaldehyde concentration in m g/m 3 was calculated from the provided concentration in ppm by multiplyin g the concentration in ppm by 1.229 m g/m 3 /ppm ( see Appendix E ). **4.2.4 Respiratory Protection Usage During**  **Composite Wood Product Fabrication** Since OSHA IMIS data do not provide information on personal protective equipment use, OSHA guidance on safe practices in the woodworking industry was reviewed to get an idea of OSHA’s recommendations for respiratory prot ection use during composite wood product fabrication. Inspection reports associated with the IMIS data were also examined to get an idea of the observed use of respiratory protection by

workers when engaged in composite wood product fabrication activities . Appendix G contains a summary of each reviewed inspection report. The OSHA Woodworking eTool (OSHA 2002a) offer s guidance on safe practices in the woodworking industry . The eTool requires provision of respirators and gloves to workers performing manual spray activities. Workers downstream of the spraying operation within the spray booth must be provided with an ai r - suppl yi ng respirator (OSHA 2002a) . T he prevalence of the practices required or recommended in the OSHA Woodworking eTool is unknown for the composite wood product fabrication industry . The 120 TWA, personal monitoring data points discussed in Section 4.2.3 are associated with 61 inspections. Of these 61 inspections, a total of 1 3 inspection reports for composite wood product fabrication facilities were obtained from OSHA and reviewed . These 13 in spection reports account for 39 of the 120 TWA, personal monitoring data points. Six other inspection reportsFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 58 were requested but not reviewed either because they are no longer available due to their age or because they were not obtained in time to be considered for this assessment. As previously discussed in Section 4.1.4 , on e of the 13 reviewed inspection reports (inspection number 312479835; see Appendix G) was for a facility identified by

NAICS code as a fabricator. However, the inspection report stated that the facility manufactures MDF and then fabricates flooring from the MDF. As the monitored workers were associated with the manufacture of MDF, this inspection report is discussed in Section 4.1.4 and Appendix G with the manufacturer inspection reports. Although this inspection report is associated with the 120 data points discussed in Section 4.2.3 , it is not included in the discussion of this section below . In addition to the 1 3 reviewed i nspection reports, two inspection reports (inspection number s 303424014 and 304064835 ) were obtained and reviewed for inspections that occurred prior to 2002 and hence are not associated with the 120 data points discussed above. Four other inspection reports for inspections dating prior to 2002 were requested but not reviewed either because they

are no longer available due to their age or because they were not obtained in time to be considered for this assessment. Additionally , a single wholesale facility inspection report was requested, received, and reviewed (inspection number 306629171; see Appendix G). This inspection report is associated with the single wholesale facility I MI S data discussed in Section 4.3.3 . Although IMIS identifies the facility with a wholesaler NAICS code, worker activities described in the IM IS data and inspection report indicate the presence of fabrication activities. Therefore, this inspection report is discussed in this section and Appendix G with the CWP fabrication inspection reports. Inconclusion, a total of 1 6 inspection reports were reviewed , and 15 of the reviewed inspection reports are discussed in this section . In the 1 5 reviewed reports discussed in this section , all measured formaldehyde concentrations were below the OSHA PELof 0.75 ppm for formaldehyde, with levels exceeding the action level (AL) of 0.5 ppm in onl y one facility (inspection numbe r 306021239 ; see Appendix G) . This single facility

is a manufacturer of bath and kitchen wood ca binets and had three TWA measurements exceed the action level. Workers were not observed to be wearing respirators during the inspection at this site . Five of the fifteen reports (33%) reviewed indicated the use of a respirator by workers as follows:
 One of the five reports identified the use of a half - face air purifying respirator in the mixing area where a formaldeh yde - based glue is mixed and applied to wooden frame chairs via pneumatic guns.  Two other reports identified the use of cartridge respirators during spray application of formaldehyde - based coatings.  Another report identified a facility that did not require respirator use in the spray booths, although some workers were observed to be wearing organic vapor cartridge respirators during spraying activities.  The fifth report was for the inspection of a facility in which the only identified inhalation PPE in use was the N95 disposal particulate respirator.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 59 An additional report indicated voluntary use of respirators but respirators were not worn during the inspection. The remaining nine inspection reports did not note the use or availability of respirators. As in MDF manufacturing, respirator use by workers in composite wood product fabrication facilities has been noted when formaldehyde levels are below its AL . This may be a precautionary

practice because spraying activities can increase the potential for exposure to formaldeh yde or it might result from the need to protect against chemicals and particulates other than formaldeh yd e. Only a single instance of the lack of respirator use has been noted (inspection number 306021239; see Appendix G) when exposure levels ex ceeded the AL (but were below the PEL). The limited number of inspection reports that were available and examined show worker exposures to be below the formaldeh yd e PEL but do not provide enough information to conclude that respirators would necessaril y be worn by workers when their exposure meets or exceeds the formaldeh yde action level or PEL . **4.2.5 Baseline Exposure and**  **the Effect of Analytical**  **Options on Baseline Exposure for**  **Composite Wood Product Fabrication** Monitoring data are a preferred approach for asse ssing exposure. However, as previousl y discussed in Section 3.2 , the monitoring data are not adequate for assessing exposure at the baseline and for the analy tical options. Therefore, this exposure assessment uses mathematical modeling to estimate indoor air concentration for the baseline and the analy tical options. The mathematical modeling for indoor air concentration is presented in Section 3.3.1.1 and described in detail in Appendix E . The model parameters include total emitting surface areas for the three CWPs in a CWP fabrication site , CWP formaldehyde off - gassing emission rate s, total effective ventilation rate for a CWP fabrication site , and concentration of formaldehyde in the outside air . As discussed in Section 3.3.1.1 , due to data gaps in information on the values of the se four parameter s at representative CWP fabrication sites, a range of what - if values for indoor air concentration was calculated from bounding values for the ranges of three of the above four parameters. The what if method for estimating indoor air conce ntration was applied to three limiting cases for the CWP ty pe present in the CWP fabrication sites : only HWPW, or only

PB, or only

MDF. The calculation of concentration followed the algorithm outlined in Table 3 - 2 . For each iteration of the algorithm, one paramet er is varied between its minimum and maximum values while the other two varying parameters remain at their intermediate values. The fourth p arameter, ambient air concentration of formaldeh yde, is kept at a constant value. These steps were repeated for each CWP ty

pe. The what - if method used values for each parameter according to Table 3 - 4 . **4.2.5.1 Results for Indoor Air Concentration Calculation Trials and Sensitivity** 

**Analysis** Results for the calculation trials for indoor air concentration that summarized in Table 3 - 2 are presented below. A sensitivity anal ys is based on these results was conducted and is discussed below. Results are presented in Table 4 - 8 for each of the three calculation trials for the baselineFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 60 low - end air concentration for each of the three limiting cases for CWP ty pe and similarly

for the high - end indoor air concentration. This table also contains the results of the c alculation of a baseline intermediate indoor air concentration for each of the three CWP ty pes. Similar results are presented in Table 4 - 9 through Table 4 - 11 for the CARB ATCM Phase 1, the FSCWPA / CARB ATCM Phase 2, and the NAF anal yt ical o ptions . The results in Table 4 - 8 through Table 4 - 11 demonstrate the sensitivi ty of the calculated indoor air concentration to variation in the value of each model parameter. The purpose of observing the sensitivity

of the mass balance equation is to understand the impact of the estimated range of values for each parameter of the e quation on the calculated concentration. As the value of one parameter is varied while the other parameters are kept constant, the changes in the calculated concentration resulting from the variation of a single parameter can be compared to the changes in concentration resulting from the variation of other parameters. For example, the row labeled “Vary Emitting Surface Area” shows the changes in indoor air concentration from varying the emitting surface area from its minimum to its maximum values while ke eping effective ventilation rate and emission rate constant at their intermediate values. This trend is shown for each CWP ty

pe. The results indicate that, for each CWP ty pe, the indoor air concentration is least sensitive to emission rate. The row “Vary Emission Rate” shows the smallest relative changes in indoor air concentration from low - end to high - end value (relative change is defined as the difference between the high - end and low - end values divided by the low - end value). Note that for each “vary

s cenario” the MDF scenario estimates higher exposures than the HWPW and PB scenarios due to the higher emission rates of MDF. The rows “Vary

Emitting Surface Area” and “Vary Effective Ventilation Rate” show relative changes in indoor air concentration of a similar order of magnitude. At baseline, the relative changes in indoor air concentration due to varying emitting surface area and effective ventilation rate are approximately

two to nine times higher than the relative changes due to varying emission rate . The relative changes in indoor air concentration due to varying emitting surface area are higher than the relative changes due to varying effective ventilation rate. This effect is due to the wide range of values of emitting surface area chosen (10% and 1,000% of the intermediate value). This is espec ially notable given that mathematically the mass balance equation would show greater sensitivity

to the effective ventilation rate in general since indoor air concentration is inversely

proportional to the effective ventilation rate. Therefore, particularly at lower values of effective ventilation rate, the indoor air concentration will change more rapidly as effective ventilation rate is changed. On the other hand, indoor air concentration is directly proportional to emitting surface area and emission rate. Therefore, indoor air concentration changes linearly with both emitting surface area and emission rate. **4.2.5.2 Estimation of a Range of Values for the What**  **- If Low**  **- End and the What**  ****

**If High -**  **End Indoor Air Concentrations that Account for All CWP Types** As summarized in Table 3 - 2 , the what - if low - end and high - end indoor air concentrations for each CWP ty

pe were estimated by

choosing the minimum and maximum, respectivel y, of th e results of the three calculation trials made for each of these two concentration values. As discussed in Section 3.3.1.1 , the concentration values that were cho sen as the estimate of the what - if low - end indoor air concentration for each CWP ty pe were combined into a single range of what - if low - end indoor air concentrations that encompasses all three estimates to account forFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 61 the possibility

that a mixture of the three CWP ty pes is used in a CWP fabrication site. This was also done for the chosen high - end indoor air concentration for each CWP ty pe. These ranges for the value s of the what - if low - end indoor air concentration and what - if high - end indoor air conce ntration are given Table 4 - 12 in f or the baseline and the anal yt ical options. **4.2.5.3 Final Results for the Estimation of What**  **- If Indoor Air Concentrations**  The estimated ranges fo r low - and high - end what - if indoor air c oncentration given in Table 4 - 12 were combined into an overall range for the b aseline and each of the anal yt ical options. The overall range is defined as the range bound b y the low - end concentration from the low - end range and the high - end concentration from the high - end range. These overall ranges are presented in Table 4 - 13 . The best estimate concentration values summarized in Table 4 - 13 are calculated as the midpoint of the overall range of estimated concentration values for the baseline and each anal yt ical option. The midpoint of the overall r ange of estimated concentrations is chosen to represent the best estimate due to the varying uncertainties of the model parameter values, which are discussed in Section 3.3.1.1 . Table 4 - 13 also provides the percentage reductions in indoor air concentration from the baseline value for the analy tical options. The rationale for this best estimate comes from considering pre - baseline IMI S data for fabrication and uncertainties in model parameters. Modeling results obtained using pre - baseline emission levels were compared to the pre - baseline IMIS data for fabrication. Thi s compari son is presented in Figure 4 - 1 and shows that the midpoint of the lowest an d highest model results (the midpoint of the overall range of model results) compares well to the median value of the IM IS data. The pre - bas e line emission levels used in the calculations are given in Appendix D and the correspon ding modeling results are give n in Appendix I . However, comparing IM IS data, which are aggregate exposures that may have one or more sources of formaldeh yd e of which CWPs may or may not be included, to model results for off - gassing alone, is highly

uncertain. Likewise, the r epresentativeness of the model parameter values are of varying uncertaint y, as discussed in Section 3.3.1.1 . Therefore, it is most logical to select the midpoint of the lowest and highest model results as the best estimate of formaldehyde concentration .Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 62

**Figure 4**  **- 1**  **. Comparison of Model Results for Ranges of What -**  **If Indoor Air Concentrations**

**using Pre -**  **Baseline Emission Rates with OSHA IMIS Data** The range of what - if indoor air co ncentrations given in Table 4 - 13 i s the estimate of the range of values for the average concentration of airborne formaldehyde in a CWP fabrication site that is due to off - gassing from HWPW, PB, and MDF. As presented in Section 3.3.1.1 and described in detail in Appendix E , these concentration values were estimated based on a steady - state mass balance that equates the formaldeh yde generation rate due to off - gassing from HWPW, PB, and MDF present at a CWP fabric ation site to the rate at which airborne formaldehyde is exhausted from the CWP fabrication site through ventilation with outdoor air. In this model, which is discus sed in detail in Section 3.3.1.1 , the off - gassing emissions from all of the exposed CWP surfaces are diluted with outside air, which contains the ambient concentration of formaldehyde, and the fabrication site is assumed to be a well - mixed box resulting in a uniform indoor air concentration throughout the site. The assumption of a well - mixed box model is based on the assumption that the CWP as well as the ventilation sources are for the most part uniformly distributed in a CWP fabrication site. As discus sed in Section 3.3.1.1 , due to data gaps in inf ormation on the values of the four model parameters at representative CWP fabrication sites, a range of what - if value s for indoor air concentration was calculated from bounding values for the ranges of three of the four parameters. The estimated range for average indoor air concentrati on at a CWP fabrication site is characterized as a range of what - if results because ea ch concentration value in this range corresponds to combinations of choices, or what - if values, for the model parameters. Although the prevalence of the model parameter what - if values at actual CWP fabrication sites is unknown, the ranges of the model parameter values should be realistic such that any given choice, or what - if value, for any model parameter represents a possible value at actual CWP 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40**P r** **e -** **B a** **s e** **l i** **n e** **I M** **I S** **D a** **t a** **a n** **d P** **r e** **- B** **a s** **e l** **i n** **e M** **o d** **e l** **i n** **g R** **e s** **u l** **t s** 

**Conc en**  **tra tio**  **n (p**  **pm)** IM IS D at a Overall R ange of

M od el Result s Hi gh - End R ange of

M od el R esult s Intermed iat e Range of Mod el Resul ts Low - End R ange of

M od el Re sult sFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 63 fabrication sites. However, as discussed in Section 3.3.1.1 , the ranges of the model parameters were estimated w ith varying levels of accuracy . Itwas not possible to validate the modeling results for indoor air concentration as further discussed in Section 5.1.1 . **4.2.5.4 The Assessment of Exposure Level for the Base**  **line and the Analytical** 

**Options** The duration of e xposure was assessed to be eight hours pe r day as presented in Section 4.2.2 ; therefore , the estimated what - if steady - state average indoor air concentrations in a CWP fabricat ion site presented in Table 4 - 13 are assessed as the 8 - hour TWA exposure concentration . As discussed in Section 4.2.4 , there is insufficient information to determine whether respiratory PPE is utilized by

workers and therefore the estimated what - if indoor air concentration was assessed as the exposure concentration. T his exposure concentration is due only to off - gassing from the CWP pro ducts. As discussed in Section 4.2.1 , there is some indication of potential sources of formaldehyd e inhalation exposure in a CWP fabrication site other than off - gassing of formaldeh yde from the three CWPs (such as adhesives and the application of overlay s). The relative significance of the contribution of these other potential sources to aggregate exposure is unknown. Different approaches were considered for their assessment but they were not assessed due to data gaps. Average dail y concentration (ADC) and lifetime average daily concentration (LADC) were calculated for each indoor air concentration value reported in Table 4 - 13 . As describe d in Appendix E , ADC and LADC were calculated assuming exposure duration of 8 hour s per day and exposure frequency

of 250 day s per ye ar over 40 working ye ars per lifetime for ADC and over a lifetime of 70 ye ars for LADC. The ADC and LADC results are presented in Table 4 - 14 and Table 4 - 15 . Results in Table 4 - 13 show that the maximum formaldehyde exposure concentration decreases as lower (m ore stringent) emission standards are implemented. However, the CARB ATCM Phase 1 limits result in little or no reduction in exposure from the baseline ye ar. This effect is because many composite wood products are expected to be already meeting more stri ngent standards b y 2013. Note the minimum exposure concentrations remain constant throughout the different anal yt ical option periods. This effect is because a small portion of the market is expected to be already meeting the NAF standards b y the baseline period. The emission level s of NAF compliant composite wood products are assumed to remain unchanged and no effect of anal yt ical options is expected for these products.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report October 6, 2011 Page 64 **Table 4**  **- 8**  **. Results for the Cal**  **culati on**  **Trials for the What -**  **If Low -**  **and High -**  **End Baseline**  **Indoor Air Concentration s** 

**Varied Param eter**  **Calculated Concentration for Baseline, ppm**  **Intermediate 4**  **Low End 5**  **High End 6**  **HWPW PB**  **MDF HWPW**  **PB MDF**  **HWPW PB**  **MDF** Vary Emitting Surface Area 1 0.0095 0.0110 0.0181 0.0055 0.0057 0.0064 0.0488 0.0637 0.1345 Vary Effective Ventilation Rate 2 0.0058 0.0060 0.0071 0.1362 0.1809 0.3934 Vary Emission Rate 3 0.0064 0.0064 0.0092 0.0218 0.0445 0.0902 1 For area, the intermediate value is based on the aggregate average per - site throughput calculated using domestic composite wood product consumption data from the EPA market profile . The high - end and low - end values are calculated assuming 1,000% and 10% of the aggregate average throughput, respectively. 2 Effective v entilation is varied based on values shown in Table 3 - 3 . The low - end , ty pical , and high - end values are 50, 1,500 and 10 ,000 cfm, respectively. 3 Emission rate is varied based on values shown in Table 3 - 4 . 4 Intermediate concentration is calculated using intermediate value for surface area, ty pical value for effective ventilation rate , and we ighted - average baseline emission rate for each CWP type. 5 Lo w - end values calculated according to Table 3 - 2 . 6 High - end values calculated according to Table 3 - 2 .Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report October 6, 2011 Page 65 **Table 4**  **- 9**  **. Results for the Calculation**  **Trials for the What -**  **If Low -**  **and High -**  **End CARB Phase 1**  **Indoor Air Concentration**  **s**

**Varied Param eter**  **Calculated Concentration for Phase 1, ppm , and % Change from** **Corresponding Baseline Value Intermediate**  **4 Low End**  **5 High End**  **6 HWPW**  **PB MDF**  **HWPW PB**  **MDF HWPW**  **PB MDF**  Vary Emitting Surface Area 1 0.0077 ( - 18.8%) 0.011

( - 3.0%) 0.0176

( - 2.7%) 0.0054

( - 3.2%) 0.0057

( - 0.6%) 0.0064

( - 0.8%) 0.0309

( - 36.6%) 0.0604

( - 5.2%) 0.1296

( - 3.6%) Vary Effective Ventilation Rate 2 0.0055 ( - 4.6%) 0.0059

( - 0.8%) 0.0070

( - 1.0%) 0.0826

( - 39.3%) 0.1710

( - 5.5%) 0.3787

( - 3.7%) Vary Emission Rate 3 0.0064 (0%) 0.0064

(0%) 0.0092

(0%) 0.0111

( - 49.3%) 0.0143

( - 67.8%) 0.0288

( - 68.0%) 1 For area, the intermediate value is based on the aggregate average per - site throughput calculated using domestic composite wood product consumption data from the EPA market profile . The high - end and low - end values are calculated assuming 1,000% and 10% of the aggregate average throughput, respectively. 2 Effective v entilation is varied based on values shown in Table 3 - 3 . The low - end , ty pical , and high - end values are 50, 1,500 and 10 ,000 cfm, respectively. 3 Emission rate is varied based on values shown in Table 3 - 4 . 4 Intermediate concentration is calculated using intermediate value for surface area, typi cal value for effective ventilation rate, and we ighted - average Phase 1 emission rate for each CWP type. 5 Lo w - end values calculated according to Table 3 - 2 . 6 High - end values calculated according to Table 3 - 2 .Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report October 6, 2011 Page 66 **Table 4**  **- 10**  **. Results for the Calculation Trials for the What**  **- If Low**  **- and High**  **- End**  **FSCWPA / CARB Phase 2 Indoor Air**  **Concentration s** 

**Varied Param eter**  **Calculated Concentration for FSCWPA / Phase 2, ppm, and % Change from Corresponding**  **Baseline Value Intermediate**  **4 Low End**  **5 High End**  **6 HWPW**  **PB MDF**  **HWPW PB**  **MDF HWPW**  **PB MDF**  Vary Emitting Surface Area 1 0.0072 ( - 23.5%) 0.011

( - 3.9%) 0.0175

( - 3.2%) 0.0053

( - 4.0%) 0.0057

( - 0.7%) 0.006 3

( - 0.9%) 0.026 5

( - 45.7%) 0.059 5

( - 6.7%) 0.12 88

( - 4.2%) Vary Effective Ventilation Rate 2 0.0054 ( - 5.8%) 0.0059

( - 1.1%) 0.0070

( - 1.2%) 0.069 3

( - 49.1%) 0.168 1

( - 7.1%) 0.376 3

( - 4.3%) Vary Emission Rate 3 0.006 4 (0%) 0.006 4

(0%) 0.009 2

(0%) 0.0084

( - 61.5%) 0.011 0

( - 75.4%) 0.019 0

( - 78.9%) 1 For area, the intermediate value is based on the aggregate average per - site throughput calculated using domestic composite wood product consumption data from the EPA market profile . The high - end and low - end values are calculated assuming 1,000% and 10% of the aggregate average throughput, respectively. 2 Effective v entilation is varied based on values shown in Table 3 - 3 . The low - end , ty pical , and high - end values are 50, 1,500 and 10 ,000 cfm, respectively. 3 Emission rate is varied based on values shown in Table 3 - 4 . 4 Intermediate concentration is calculated using intermediate value for surface area, typical value for effective ventilation rate, and we ighted - average Phase 2 emission rate for each CWP type. 5 Lo w - end values calculated according to Table 3 - 2 . 6 High - end values calculated according to Table 3 - 2 .Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report October 6, 2011 Page 67 **Table 4**  **- 11**  **. Results for the Calculation**  **Trials for the What**  **- If Low**  **- and High**  **- End**  **NAF Indoor Air**  **Concentration s** 

**Varied Param**  **eter Calculated Concentration for Phase NAF, ppm, and % Change from** **Corresponding Baseline Value Intermediate**  **4 Low End**  **5 High End**  **6 HWPW**  **PB MDF**  **HWPW PB**  **MDF HWPW**  **PB MDF**  Vary Emitting Surface Area 1 0.0064 ( - 32.0%) 0.0064

( - 41.3%) 0.0110

( - 39.3%) 0.0052

( - 5.5%) 0.0052

( - 8.0%) 0.0057

( - 11.1%) 0.0184

( - 62.2%) 0.0184

( - 71.1%) 0.0637

( - 52.7%) Vary Effective Ventilation Rate 2 0.0053 ( - 7.9%) 0.0053

( - 11.3%) 0.0060

( - 15.1%) 0.0451

( - 66.9%) 0.0451

( - 75.1%) 0.1807

( - 54.1%) Vary Emission Rate 3 0.0064 (0%) 0.0064

(0%) 0.0092

(0%) 0.0064

( - 70.5%) 0.0064

( - 85.5%) 0.0110

( - 87.8%) 1 For area, the intermediate value is based on the aggregate average per - site throughput calculated using domestic composite wood product consumption data from the EPA market profile . The high - end and low - end values are calculated assuming 1,000% and 10% of the aggregate average throughput, respectively. 2 Effective v entilation is varied based on values shown in Table 3 - 3 . The low - end , ty pical , and high - end values are 50, 1,500 and 10 ,000 cfm, respectively. 3 Emission rate is varied based on values shown in Table 3 - 4 . 4 Intermediate concentration is calculated using intermediate value for surface area, typical value for effective ventilation rate, and we ighted - average NAF emission rate for each CWP type. 5 Lo w - end values calculated according to Table 3 - 2 . 6 High - end values calculated according to Table 3 - 2 . **Table 4**  **- 12**  **. Estimated**  **Low -**  **End, Intermediate, and High -**  **End Range**  **s of Values for the**  **Site -**  **Average Indoor Air Concentration**  **at the Baseline and**  **for the Analytical**  **Options Case**  **Intermediate (ppm )**  **Low End (ppm) High End (ppm)**  Baseline 0. 0095

– 0.0181 0.0055

– 0.0092 0.0218

– 0.393 4 Phase 1 0.0077 ( - 18.8%)

– 0.0176 ( - 2.7%) 0.0054 ( - 3.2%)

– 0.0092 (0%) 0.0111 ( - 49.3%)

– 0.3787 ( - 3.7%) FSCWPA / P hase 2 0.0072 ( - 23.5%)

– 0.0175 ( - 3.2%) 0.0053 ( - 4.0%)

– 0.0092 (0%) 0.0084 ( - 61.5%)

– 0.3763 ( - 4.3%) NAF 0.0064 ( - 32.0%)

– 0.0110 ( - 39.3%) 0.0052 ( - 5.5%)

– 0.0092 (0%) 0.0064 ( - 70.5%)

– 0.1807 ( - 54.1%)Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report October 6, 2011 Page 68 **Table 4**  **- 13**  **. Estimate**  **d Overall Range and Best Estimate**  **Site -**  **Average In**  **door Air Concentration at the**  **Baseline and for**  **the Analytical**  **Options**

**Case Overall Range** 

**(ppm) Best Estimate** 

**Concentration 1**  **(ppm) Reduction** 

**from Baseline (%)**  Baseline 0.0055

– 0.3934 0.1995 -- Phase 1 0.0054

– 0.3787 0.1920 - 3.7 FSCWPA / Phase 2 0.0053

– 0.3763 0.1908 - 4.3 NAF 0.0052

– 0.1807 0.0930 - 53.4 1 The best estimate concentration is the midpoint of the overall range. The overall range is defined as the low - end value from the low - end range and the high - end value from the high - end range. The reduction from baseline, ADC, and LADC values are calculated from the best estimate concentration value. **Table 4**  **- 14**  **. Overall Range and Best Estimate ADC at the**  **Baseline and for the**  **Analytical Options**  **Case Overall Range**  **(μg/m 3**  **) Best Estimate ADC**  **(μg/m 3**  **)** Baseline 1.556

– 110.4 56.0 Phase 1 1.506

– 106.3 53.9 FSCWPA / Phase 2 1.494

– 105.6 53.5 NAF 1.471

– 50.71 26.1 **Table 4**  **- 15**  **. Overall Range and Bes t**  **Estimate LADC at the Baseline and**  **for the Analytical**  **Options Case**  **Intermediate (μg/m**  **3 )**  **Best Estimate LADC (μg/m** **3 )**  Baseline 0.8894

– 63.08 32.0 Phase 1 0.8607

– 60.72 30.8 FSCWPA / Phase 2 0.8536

– 60.34 30.6 NAF 0.8407

– 28.98 14.9Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 69 **4.2.6 Dermal Exposures during Composite Wood Product Fabrication**  Dermal exposures to CWPs are not quantifiable using the EPA dermal exposure models for liquids and solids (these models are onl y applicable to dermal exposure to uncured resin, which may occur upstream of the press in the CWP manufacturing process) . **4.3 Exposure Assessment for Wholesale**  This section presents and discusses the assessment of formaldeh yd e exposures from the wholesale of composite wood products. **4.3.1 Description**  **of Life Cycle Stage** Wholesalers b uy

products from manufacturers in bulk for the purpose of resale to various industries and individuals. Wholesale products may include composite wood products and CWP fabrication products ( downstream products ) . A single wholesaler may sell many

different ty

pes of composite wood products. The U.S. Census Bureau defines wholesale facilities as those who “sell or arrange the purchase or sale of capital or durable goods to other businesses ” ( Census 2007a). However, IM IS data, which are presented in Section 4.3.3 , indicate that some wholesale facilities may

also process composite wood products on site (the reported worker activities at wholesale facilities include “sawing”). **4.3.2 Use Volumes and Number of Establishments, Employees, Employed Hours, and Work**  **Days** In formation related to the number of sites, number of emplo yees, and facility - specific use rates (including storage and wholesale) of composite wood products and CWP fabrication articles made of composite wood products were researched. Data for the number of sites and employees from the 2007 U.S. Economic Census are provided in the EPA market profile (USEPA 2010a). However, actual loading data of the total emitting surface area of composite wood products at wholesale settings were not found . Table 4 - 16 summarizes the census data identified for wholesale facilities that may s ell composite wood products or articles fabricated from composite wood products as obtained from the EPA market profile . It is uncertain whether all facilities in the identified NAICS codes sell composite wood products or downstream articles made of compo site wood products. Therefore, the number of sites and employees identified in Table 4 - 16 m ay represent wholesalers that do not use composite wood products and are c onsidered maximum values.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 70 **Table 4**  **- 16**  **. Summary of 2007 Economic Census Data for Wholesale Facilities**

**NAICS Code**  **NAICS Industry Description Maximum**  **Number of Establishments**  **Maximum**

**Number of Paid**  **Employees** 423210 Furniture merchant wholesalers 6,640 69,103 423220 Home furnishing merchant wholesalers 7,540 93,060 423310 Lumber, plywood, millwork, and wood panel merchant wholesalers 8,428 138,739 423320 Brick, stone, and related construction material merchant wholesale 3,383 35,005 423330 Roofing, siding, and insulation material merchant wholesalers 2,587 32,662 423390 Other construction material merchant wholesalers 3,383 37,920 423440 Other commercial equipment merchant wholesalers 4,352 48,976 423450 Medical equipment merchant wholesalers 8,282 141,282 423490 Other professional equipment and supplies merchant wholesalers 2,297 D 10 423510 Metal service centers and other metal merchant wholesalers 10,148 144,954 423610 Elec. equip. and wiring merchant wholesalers 13,277 169,355 423620 Electric appliance merchant wholesalers 3,110 44,819 423710 Hardware merchant wholesalers 6,828 83,542 423720 Plumbing equip. merchant wholesalers 6,939 86,092 423730 HVAC equip. merchant wholesalers 5,071 50,495 423740 Refrigeration equipment and supplies merchant wholesalers 1,265 11,024 423830 Industrial machinery and equipment merchant wholesalers 29,838 319,557 423850 Service establishment equipment and supplies merchant wholesalers 4,576 D 10 423910 Sporting and recreational goods and supplies merchant wholesalers 6,192 55,842 424610 Plastics materials and basic forms and shapes merc hant wholesaler 3,248 32,552 424950 Paint, varnish, and supplies merchant wholesalers 1,649 14,631 Source: EPA market profile ( USEPA 2010a ) **4.3.3 Pre** **-**

**Baseline Exposure Monitoring Data** F ormaldeh yd e monitoring data for various worker activities at various wholesale settings were obtained from the OSHA IMI S database ( OSHA 2009a) . Onl y two data points from a single wholesale site classified under one of the NAICS codes identified in Table 2 - 1 were available for the pre - baseline period (2002 to 2009). Table 4 - 17 presents these data by worker a ctivity .

10 "D " is used to indicate that the data have been withheld to avoid disclosure .Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 71 **Table 4**  **- 17**  **. Summary of Formaldehyde Inhalation Monitoring Data for**  **Wholesalers from the OSHA IMIS Database** 

**Industry Worker** 

**Activity Description**  **Number of**

**Sites Monitored**  **Monitored**

**Form aldehyde**  **Concentration (ppm)**  **Monitored**

**Form aldehyde**  **Concentration (**  **μ g** **/m 3**  **) 1**  **Monitoring**

**Type Year** 

Furniture Merchant Wholesalers Band Saw

Operator 1 0.002 2.46 Personal 2003 Not Detected Not Detected Personal 2003 Panel Saw Operator 0.002 2.46 Personal 2003 CNC Operator Not Valid 2 Not Valid Personal 2003 1 The formaldehyde concentration in μ g/m 3 was calculated from the provided concentration in ppm by multiplying the concentration in ppm by 1 , 229 μ g/m3 /ppm ( see Appendix E ). 2 Data point reported as “not valid” in the IMIS database; likely an invalid measurement. **4.3.4 Baseline Exposure and**  **the Effect of** **Analytical Options**  **on Baseline Exposure for Wholesale**  Exposures in wholesale settings are not assessed quantitatively due to data gaps. T here is a lack of information on the ventilation rate at wholesale settings to allow for a what - if anal ys is similar to what was completed for the fabrication life cycle stage. Therefore, it is not possible to accuratel y quantify the exposure conce ntrations during the baseline period and the reduction of exposure concentrations resulting from the anal yt ical options. The formaldeh yd e concentration resulting from off - gassing is expected to decrease with the implementation of more stringent regulations . However, as discussed previously , the implementation of CARB ATCM Phase 1 limits is expected to result in little or no reduction in exposure from the baseline year. This is because most composite wood products in the market would already be meeting mor e stringent limits by 2013. **4.3.5 Dermal Exposures during Wholesale**  Dermal exposures to CWPs are not quantifiable using the EPA dermal exposure models for liquids and solids. **4.4 Exposure Assessment for Retail**  This section presents and discusses the assessment of formaldeh yd e exposures from retail due to composite wood products. **4.4.1 Description**  **of Life Cycle Stage** Retailers operate from fixed locations and sell products for direct consumption by the purchaser (individuals or businesses). These retailers may receive HW PW, MDF, or PB directl y asFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 72 products or included in articles fabricated using composite wood products. L ike wholesale sectors, retail sectors are not distinguished by composite wood product ty pe (Census 2007a). **4.4.2 Use Volumes and Number of Establishments, Emp**  **loyees, Employed Hours, and Work Days**  In formation related to the number of sites, number of emplo yees, and facility - specific use rates (including storage and retail) of composite wood products and CWP fabrication products were researched. The number of si tes and employees data from the 2007 U.S. Economic Census ( Census 2007a) was identified. However, actual loading data of the total emitting surface area of composite wood products at wholesale settings were not found . Table 4 - 18 summarizes the census data identified for retail facilities that may sell composite wood products or articles fabricated from composite wood products. It is uncertain whether all facilities in the identified NAI CS codes sell composite wood products or downstream articles made of composite wood products. Therefore, the number of sites and employees identified in Table 4 - 18 may represent retailers that do not use composite wood products and are considered maximum values. The duration and frequency of exposure were assumed to be 8 hours per day and 250 day s per ye ar, respectivel y. This is supported to some extent by I MI S data on duration. Some exposure data points in IMI S do not include an exposure duration and other data points include an exposure duration of “daily” or other frequency without comment on the number of hours of exposure per day . For retail , 17 exposure data points (sampled in 2002 through 2009) were collected. For these 17 data points, the following exposure duration data were included in IM IS : 11

 Exposure durations of blank or “dail y”: seven data points (41%);  Exposure durations of eight ho urs per day : three data points (18%);  Exposure duration of three hours per week: one data point (6%);  Exposure duration of 40 hours per week: three data points (18%); and  Exposure duration of “monthly”, “routinely”, or “varies”: three data points (18%).

11 Note: percentages should add to 100 percent but may not due to rounding.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 73 **Table 4**  **- 18**  **. Summary of 2007**  **Economic Census Data for Retail Facilities NAICS**  **Code NAICS Industry Description**  **Maximum Number**  **of Establishments Maximum**  **Number of Paid Employees**  441210 Recreational vehicle dealers 3,100 42,669 442110 Furniture stores 28,834 266,374 442210 Floor covering stores 14,534 89,420 442291 Window

treatment stores 2,652 9,626 442299 All other home furnishings stores 19,124 192,057 443111 Household appliance stores 9,336 70,045 443112 Radio, television, and other electronics stores 29,051 309,374 443120 Com

puter and software stores 10,428 92,777 444110 Home centers 6,953 579,442 444120 Paint and wallpaper stores 7,860 35,491 444130 Hardware stores 16,454 143,738 444190 Other building material dealers 39,551 405,755 444210 Outdoor power equipment stores 4,357 25,882 444220 Nursery, garden center, and farm supply stores 15,895 141,014 445110 Supermarkets and other grocery (except convenience)

stores 64,881 2,432,425 448110 Men's clothing stores 8,321 57,340 448120 Women's clothing stores 36,220 339,798 448130 Children's and infants' clothing stores 7,102 98,729 448140 Family clothing stores 28,254 642,117 448150 Clothing accessories stores 7,494 37,575 448190 Other clothing stores 12,034 97,581 451120 Hobby, toy, and game stores 9,357 135,688 451130 Sewing, needlework, and piece goods stores 5,663 49,450 452111 Department stores (except discount department stores) 3,533 534,189 452112 Discount department stores 5,001 690,265 452910 Warehouse clubs and supercenters 4,260 1,244,237 452990 All other general merchandise stores 33,061 294,783 453110 Florists 19,822 93,967 453210 Office supplies and stationery stores 9,558 112,734 453220 Gift, novelty, and souvenir stores 31,391 193,317 453920 Art dealers 6,677 23,126 453930 Manufactured (mobile) home dealers 3,878 21,068 453998 All other miscellaneous store retailers (except tobacco

stores) 17,270 88,296 454113 Mail - order houses 7,324 220,516 454390 Other direct selling establishments 22,077 131,013 Source: EPA market profile ( USEPA 2010a ) **4.4.3 Pre** **-**

**Baseline Exposure Monitoring Data** F ormaldeh yd e exposure monitoring data for various worker activities at various retail settings obtained from the OSHA IMI S d atabase ( OSHA 2009a) for the period of 2002 to 2009 are presented in Table 4 - 19 . Pre - baseline data are available for seven retail sectors only , and for most only a single monitoring data point is available. A total of 17 data points are available for the entire sector during the pre - baseline period.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 74 **Table 4**  **- 19**  **. Summary of Formaldehyde Inhalation Monitoring Data for Retailers from the OSHA IMIS Database**

**Industry Worker Activity**  **Description Number of Sites** 

**Monitored Num**  **ber of Data**

**points Monitored** 

**Form aldehyde**  **Concentration (ppm)**  **Monitored**

**Form aldehyde**  **Concentration (**  **μ g** **/m 3**  **) 1**  **Monitoring**

**Type Year**  Recreational Vehicle Dealers Sawing 1 1 0.002 2.46 Personal 2006
Furniture Stores Cabinet Maker 1 1 0.069 84.8 Personal 2002 Front Right of Store 1 5 Not Detected 2 Not Detected 2 Area 2008 Front Left of Store Not Detected 2 Not Detected 2 Area 2008 Back Left of Store Not Detected 2 Not Detected 2 Area 2008 Back Right of Store Not Detected 2 Not Detected 2 Area 2008 Middle of Store Not Detected 2 Not Detected 2 Area 2008 All Other Home Furnishing Stores Sale 1 1 0.017 20.9 Area 2006 Radio, Television & Other Electronic Stores Warehouse Handler 1 1 0.14 172.1 Personal 2004 Home Centers Cabinet Maker/Painter 1 1 0.00001 2 0.012 2 Personal 2007 Other Building Material Dealers Laminator 1 1 0.055 67.6 Personal 2003 Painting 1 1 0.1 122.9 Personal 2008 Operator 1 0.19 233.5 Personal 2008 Driver 1 1 Not Detected 2 Not Detected 2 Area 2004 Sales Rep 1 1 Not Detected 2 Not Detected 2 Area 2002 Department Stores (except Discount Department Stores) Merchandise Coordinator 1 1 Not Detected 2 Not Detected 2 Area 2003 Unpack Clothing 1 1 Not Detected 2 Not Detected 2 Area 2006 1 The formaldehyde concentration in μ g/m 3 was calculated from the provided concentration in ppm by multiplying the concentration in ppm by 1 , 229 μ g/m 3 /ppm ( see Appendix E ) . 2 The minimum reliable quantitation limit (RQL) identified for OSHA sampl ing and analysis methods is 0.00058 ppm. Non - detected values and values below

this RQL are set equal to the RQL for the exposure calculations.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 75 **4.4.4 Baseline Exposure and**  **the Effect of** **Analytical Options**  **on Baseline Exposure for Retail**  Exposures in retail settings are not assessed quantitatively due to data gaps. There is a lack of information on the ventilation rate at retail settings to allow for a what - if analy sis similar to what was completed for the fabrication life cycle stage. T herefore, it is not possible to accuratel y quantify the exposure concentrations during the baseline period and the reduction of exposure concentrations resulting from the anal yt ical options . The formaldeh yd e concentration resulting from off - gassing is expe cted to decrease with the implementation of more stringent regulations. However, as discussed previously , the implementation of CARB ATCM Phase 1 limits is expected to result in little or no reduction in exposure from the baseline year. This is because m ost composite wood products in the market would already be meeting more stringent limits by 2013. Although the U.S. Census Bureau defines the retail trade sector as “ establishments engaged in retailing merchandise, generall y without transformation, and ren dering services incidental to the sale of merchandise , ” the limited IMI S data indicate that sawing, assembling, building, painting, and other laboring activities are performed at some retail facilities. A further search of one facility reported in the IMI S suggests that some fabrication sites could be involved in direct retail. For example, one company makes custom cabinets and sells these cabinets to builders, dealers, and consumers. This company is classified under NAICS 444190: “Other Building Materia l Dealers . ” The exposures at fabrication sites have been assessed in Section 4.2 . **4.4.5 Dermal Exposures during Retail**  Dermal exposures to CWPs are not quantifiable usi ng the EPA dermal exposure models for liquids and solids. **4.5 Exposure Assessment for**  **Office Workers during Commercial Use**  This section presents and discusses the assessment of formaldeh yd e exposures resulting from the occupancy

of office buildings (commercial buildings) containing composite wood products b y office workers . **4.5.1 Description**  **of Life Cycle Stage** The commercial use of composite wood products includes the occupancy by office workers of office buildings (commercial buildings) containing composite wood products. These office workers may

be exposed to airborne formaldehyde emitted from CWPs or CWP fabrication products that are present in the commercial building. **4.5.2 Use Volumes and Number of Establi**  **shments, Employees, Employed Hours, and Work Days**  Data that provide inventories of each composite wood product within commercial office buildings were not found. Additionally , census data that provide the number of commercial use sites, the total number o f employees, and employee hours worked per day and day s worked perFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 76 ye ar in office settings were not found. These data are difficult to obtain as commercial use settings, such as office buildings, occur across multiple industries. For example, the industries described in the upstream life cycle stages in this report (manufacturing, wholesale, retail) all may involve office settings in addition to the settings described in their respective sections above. **4.5.3 Pre** **-**

**Baseline Exposure Monitoring Data** This section p rovides pre - baseline indoor air concentration monitoring data obtained from the BASE study from 1994 to 1998 . These data are presented to compare to the model results presented in the next subsection. Table 4 - 20 presents some general characteristics of the 100 commercial and public office buildings collected from the BASE study , including the construction date, floor area, number of floors and occupants. **Table 4**  **- 20**  **. Overview of General Characteristics of the 100 BASE Buildings Characteristic (unit)**  **Range Average**  **Median Construction Date (year)**  1850 - 1996 1961 1972 **Gross Floor Area (m 2**  **)** 1,665 - 134,195 24,756 13,964 **Occupied Floor Area (m 2**  **)** 629 - 98,474 16,380 8,477 **Number of Floors Above Grade** 1

– 53 9 5 **Number of Building Occupants (including visitors)**  87

– 6,500 1,020 705 Source: BASE 1998a Formaldeh yd e was detected in a quantifiable amount in all 100 buildings. Table 4 - 21 presents a summary of the monitored formaldehyde concentrations in office buildings that were obtained from the BASE study

( BASE 1998a). The study only presented the overall formaldehyde concentrations within the buildings and did not distinguish exposures according to worker activities. Table 4 - 21 a lso provides the summary statistics of the monitored outdoor formaldeh yde concentrations from the BASE study , which were measurements made outside of the office buildings . **Table 4**  **- 21**  **. Summary of Formaldehyde Inhalation Monitoring Data for Office Occupational Settings**  **and Outdoor Measured Concentrations from the BASE Study Percentile**  **Form aldehyde Concentration (**  **μ g** **/m 3**  **) Form**  **aldehyde Concentration (ppm)**

**Indoors Outdoors**  **Indoors Outdoors**  100 th (Maximum) 51 13 0.041 0.011 95 th 32 10 0.026 0.008 75 th 21 5.7 0.017 0.005 50 th (Median) 15 3.0 0.012 0.002 25 th 9.2 1.4 0.007 0.001 5 th 4.4 0.40 0.004 0.000 Arithmetic Mean 16 3.9 0.013 0.003 Source: BASE 1998aFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 77 **4.5.4 Baseline Exposure and**  **the Effect of** **Analytical Options**  **on Baseline Exposure for Office Buildings**  What - if values for indoor air concentrations in an office building related to baseline and the anal yt ical option s were estimated using mathematical mod eling. The mathematical modeling for indoor air concentration is presented in Section 3.3.1.2 and described in detail in Appendix E . The estimation results are given in Table 4 - 22 . The results in Table 4 - 22 are for the three limiting ca ses of the office workstation being fabricated from 100% HWPW, 100% PB, and 100% MDF. These results were combined into a single range, which is given in Table 4 - 23 . The range of what - if indoor air concentrations given in Table 4 - 23 is the estimate of the range of values for the steady - state indoor air formaldehyde concentration i n a work space resulting from the off - gassing emissions from new HWPW, PB, and MDF components of the workstation occup yi ng the work space and due to the ventilation with outside air containing ambient formaldeh yde. The emitting surface area of each workst ation component and the ventilation rate of the work space containing the workstation are values given in BIFMA M7.1 - 2007

– “ Standard Test Method for Determining VOC Emissions from Office Furniture Systems, Components and Seating”. In homes , the most significant sources of formaldehyde are likel y to be CWPs made from UF resins (USEPA 2011b ). The literature search did not identify information to indicate that sources of formaldeh yd e in office buildings are significantly different than in home s. Therefore, it is assumed that CWPs are the most significant source of formaldehyde in office buildings. Office building ventilation sy stems likely contain a recirculation component, which results in the mixing of air from various sections of the office building with outside air and the subsequent recirculation of the mixed air throughout the office building. Thus, the formaldehyde concentration in any

given work space can be affected by the formaldeh yde concentration in other sections of the office bui lding. The mathematical modeling does not account for this effect. **4.5.4.1 Determination of a Best Estimate for Indoor Air Concentration**  The best estimate exposure concentrations, ADC, and LADC results are presented in Table 4 - 26 . The best estimate exposure concentrations for the baseline and each anal yt ical option were determined b y averaging the following values: the midpoint of the intermediate range of concentrations for open plan workstations and the midpoint of the intermediate range of concentrations for private office workstations. The midpoints of the intermediate ranges of concentration estimates were used for the following reasons. First, all of the high - end conc entration estimates at the baseline are on the order of or greater than 0.1 ppm for both workstation ty

pes. Indoor air in buildings with a formaldeh yde concentration of 0.1 ppm is considered highl y polluted air. It is not likely that ty pical office buildings will have workstations with highly

polluted air at the baseline even if the buildings do use new furniture . Second, the low - end concentration estimates at the baseline and for each analy tical option are on the order of 0.003 to 0.005 ppm for both wor kstation ty

pes. The ambient air formaldehyde concentration for commercial land use areas used for this assessment is 3.26 μg/m 3 or about 0.00265 ppm. T heFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 78 low - end concentration estimates are the same order of magnitude as the ambient air formaldeh yde conc entration. Itis likely that formaldehyde concentrations in office buildings at the baseline would be greater than the ambient air formaldeh yde concentration. Therefore, the intermediate range of concentration estimates is more reasonable in comparison w ith the low and high - end ranges and was used to derive the best estimate concentrations. The midpoints of the intermediate ranges for both workstation ty pes are averaged together to provide the best estimate concentrations. The best estimate reduction f rom baseline, ADC , and LADC values are calculated from the best estimate concentration values. Itis assumed that office workers spend most of their time at workstations. Therefore, this indoor air concentration is the exposure concentration for office w orkers. As described in Appendix E, ADC and LADC were calculated assuming exposure duration of 8 hours per day and exposure frequency

of 250 day s per year over 40 working ye ars per lifetime for ADC and over a lifetime of 70 years for LADC. Similarly as with the CWP fabrication results, the office building r esults show that the maximum formaldeh yde exposure concentration decreases as lower (more stringent) emission standards are implemented. Again, the minimum exposure concentrations in Table 4 - 22 and Table 4 - 23 remain constant throughout the different anal yt ical options due to th e presence of NAF compliant products at the baseline. The office building results in Table 4 - 26 show the most significant reduction in exposure concentration from th e NAF emission limits .Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 79 **Table 4**  **- 22**  **. Results for Calculation of**  **What -**  **If Indoor Air**  **Formaldehyde Concentration**  **s for**  **Each Analytical**  **Option Case**  **CWP**

**Type Low**  **- End of Range**  **Intermediate Value**  **High -**  **End of**

**Range Open Plan Workstations**  **(ppm) 1**  Baseline HWPW 0.0035 0.0265 0.2002 PB 0.0035 0.0346 0.4680 MDF 0.0053 0.0732 1.0089 Analytical Option (1): CARB Phase 1 HWPW 0.0035 (0%) 0.0167 ( - 36.8%) 0.0729 ( - 63.6%) PB 0.0035 (0%) 0.0328 ( - 5.2%) 0.1117 ( - 76.1%) MDF 0.0053 (0%) 0.0705 ( - 3.7%) 0.2833 ( - 71.9%) Analytical Option (2): FSCWPA / CARB Phase 2 HWPW 0.0035 (0%) 0.0143 ( - 45.9%) 0.0414 ( - 79.3%) PB 0.0035 (0%) 0.0323 ( - 6.7%) 0.0717 ( - 84.7%) MDF 0.0053 (0%) 0.0701 ( - 4.2%) 0.1670 ( - 83.4%) Analytical Option (3): NAF HWPW 0.0035 (0%) 0.0099 ( - 62.5%) 0.0184 ( - 90.8%) PB 0.0035 (0%) 0.0099 ( - 71.3%) 0.0184 ( - 96.1%) MDF 0.0053 (0%) 0.0346 ( - 52.8%) 0.0728 ( - 92.8%) **Private Office Workstations (ppm)**  **1** Baseline HWPW 0.0030 0.0130 0.0719 PB 0.0030 0.0165 0.1659 MDF 0.0036 0.0332 0.3555 Analytical Option (1): CARB Phase 1 HWPW 0.0030 (0%) 0.0087 ( - 32.5%) 0.0273 ( - 62.0%) PB 0.0030 (0%) 0.0157 ( - 4.7%) 0.0409 ( - 75.3%) MDF 0.0036 (0%) 0.0320 ( - 3.5%) 0.1011 ( - 71.6%) Analytical Option (2): FSCWPA / CARB Phase 2 HWPW 0.0030 (0%) 0.0077 ( - 40.6%) 0.0163 ( - 77.4%) PB 0.0030 (0%) 0.0155 ( - 6.1%) 0.0269 ( - 83.8%) MDF 0.0036 (0%) 0.0318 ( - 4.0%) 0.0603 ( - 83.0%) Analytical Option (3): NAF HWPW 0.0030 (0%) 0.0058 ( - 55.3%) 0.0082 ( - 88.6%) PB 0.0030 (0%) 0.0058 ( - 64.8%) 0.0082 ( - 95.1%) MDF 0.0036 (0%) 0.0165 ( - 50.4%) 0.0273 ( - 92.3%) Note: For the purpose of this assessment, “intermediate” is defined as a value in - between the low - end and the high end ( see Section 3.3.1.2 ). 1 For the analytical options, the percent decrease from the corresponding baseline value is given in parentheses . For example, for Analytical Option (1) for open plan workstation s , the high - end value for HWPW is 0.07 29 ppm - a 6 3.6 percent decrease from the high - end baseline value.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 80 **Table 4**  **- 23**  **. Combined (for All CWP) Results: Calculated What**  **- If**  **Indoor Air Concentrations**  **at the Baseline and**  **for the Analytical**  **Options Open Plan Workstations**  **1 Case**  **Intermediate (ppm** **) Low End**  **(ppm) High End**  **(ppm)** Baseline 0.0265 - 0.0732 0.0035 - 0.0053 0.2002 - 1.0089 P hase 1 0.0167 ( - 37 .0 %) -

0.0705 ( - 3.7%) 0.0035 (0%) - 0.0053 (0%) 0.0729 ( - 63.6%) - 0.2833 ( - 71.9%) FSCWPA / P hase 2 0.0143 ( - 46 .0 %) -

0.0701 ( - 4.2%) 0.0035 (0%) - 0.0053 (0%) 0.0414 ( - 79.3%) - 0.167 ( - 83.4%) NAF 0.0099 ( - 62.6%) -

0.0346 ( - 52.7%) 0.0035 (0%) - 0.0053 (0%) 0.0184 ( - 90.8%) - 0.0728 ( - 92.8%)

**Private Office Workstations**  **1 Case**  **Intermediate (ppm** **) Low End**  **(ppm) High End**  **(ppm)** Baseline 0.013 - 0.0332 0.003 - 0.0036 0.0719 - 0.3555 P hase 1 0.0087 ( - 33.1%) - 0.032 ( - 3.6%) 0.003 (0%) - 0.0036 (0%) 0.0273 ( - 62 .0 %) - 0.1011 ( - 71.6%) FSCWPA / P hase 2 0.0077 ( - 40.8%) -

0.0318 ( - 4.2%) 0.003 (0%) - 0.0036 (0%) 0.0163 ( - 77.3%) - 0.0603 ( - 83 .0 %) NAF 0.0058 ( - 55.4%) -

0.0165 ( - 50.3%) 0.003 (0%) - 0.0036 (0%) 0.0082 ( - 88.6%) - 0.0273 ( - 92.3%) 1 For the analytical options, the percent decrease from the corresponding baseline value is given in parentheses . For example, for Analytical Option (1) for open plan workstations , the mi nimum of the high - end value s is 0.07 29 ppm - a 6 3.6 percent decrease from the high - end b aseline value. **Table 4**  **- 24**  **. Combined (for All CWP) Results: Calculated**  **What -**  **If Indoor Air ADCs**  **at the Baseline and**  **for the Analytical**  **Options**

**Open Plan Workstations Case**  **Intermediate**

**( μ**  **g /m** **3 )**  **Low End**

**( μ**  **g /m** **3 )**  **High End**

**( μ**  **g /m** **3 )**  Baseline 7.44 - 20.54 0.98 - 1.49 56.17 - 283.1 P hase 1 4.69 - 19.78 0.98 - 1.49 20.46 - 79.49 FSCWPA / P hase 2 4.01 - 19.67 0.98 - 1.49 11.62 - 46.86 NAF 2.78 - 9.71 0.98 - 1.49 5.16 - 20.43

**Private Office Workstations Case**  **Intermediate**

**( μ**  **g /m** **3 )**  **Low End**

**( μ**  **g /m** **3 )**  **High End**

**( μ**  **g /m** **3 )**  Baseline 3.65 - 9.32 0.84 - 1.01 20.17 - 99.75 P hase 1 2.44 - 8.98 0.84 - 1.01 7.66 - 28.37 FSCWPA / P hase 2 2.16 - 8.92 0.84 - 1.01 4.57 - 16.92 NAF 1.63 - 4.63 0.84 - 1.01 2.3 - 7.66Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 81 **Table 4**  **- 25**  **. Combined (for All CWP) Results: Calculated What**  **- If**  **Indoor Air LADCs at** 

**the Baseline and**  **for the Analytical**  **Options**

**Open Plan Workstations Case**  **Intermediate**

**( μ**  **g /m** **3 )**  **Low End**

**( μ**  **g /m** **3 )**  **High End**

**( μ**  **g /m** **3 )**  Baseline 4.25 - 11.74 0.56 - 0.85 32.1 - 161.8 P hase 1 2.68 - 11.3 0.56 - 0.85 11.69 - 45.42 FSCWPA / P hase 2 2.29 - 11.24 0.56 - 0.85 6.64 - 26.78 NAF 1.59 - 5.55 0.56 - 0.85 2.95 - 11.67

**Private Office Workstations Case**  **Intermediate**

**( μ**  **g /m** **3 )**  **Low End**

**( μ**  **g /m** **3 )**  **High End**

**( μ**  **g /m** **3 )**  Baseline 2.08 - 5.32 0.48 - 0.58 11.53 - 57 .00 P hase 1 1.39 - 5.13 0.48 - 0.58 4.38 - 16.21 FSCWPA / P hase 2 1.23 - 5.1 0.48 - 0.58 2.61 - 9.67 NAF 0.93 - 2.65 0.48 - 0.58 1.31 - 4.38 **Table 4**  **- 26**  **. Best Estimate of**  **What -**  **If Formaldehyde**  **Exposure Concentration at the**

**Baseline and for**  **the Analytical**  **Options**

**Case Best Estimate** 

**Concentration 1**  **(ppm) Reduction** 

**from Baseline**  **(%) ADC** 

**(μg/m 3**  **) LADC** 

**(μg/m 3**  **)** Baseline 0.0365 -- 10.23 5.85 P hase 1 0.0320 - 12.3 8.97 5.13 FSCWPA / P hase 2 0.0310 - 15.1 8.69 4.97 NAF 0.0167 - 54.2 4.69 2.68 1 The best estimate concentration is the average of the following two values: the midpoint of the intermediate range for open plan workstations and the midpoint of the intermediate range for private office workstations. The reduction from baseline, ADC, and LADC values are calculated from the best estimate concentration value . **4.5.5 Dermal Exposures during Commercial Use**  Dermal exposures to CWPs are not quantifiable using the EPA dermal exposure models for liquids and solids.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 82 **5. U**  **NCERTAINT IES**  **I N**  **A SSESSMENT**  **R ESULTS**  **5.1 Uncertainties in Assessment Resu**  **lts for Composite Wood Product Manufacturing, Fabrication, Wholesal**  **e, Retail**  **, and Office Buildings** This section discusses the uncertainties in the results of the assessment of occupational formaldeh yde exposure at composite wood product manufacturing, fabrication, wholesale, and retail sites , and office buildings . Baseline indoor air concentration and the effect of the anal yt ical options on it were assessed quantitatively for CWP fabrication and office buildings only , and therefore the discussion of uncert ainty in the assessment of indoor air concentration is limited to th ese life cycle stage s and is presented in Section 5.1.1 and Section 5.1.2 , respectivel y . Uncertaint y in the assessed number of production workers for the manufacturing and fabrication life cycle stages and in the number of employees in the wholesale and retail life cycle stages is discussed in Section 5.3 . Dermal exp osures were assessed quantitatively for manufacturi ng . Due to data gaps in information on the free (un - reacted) formaldeh yd e content in resins that will be used at baseline and for each anal yt ical option, only pre - baseline dermal exposures were estimated for manufacturing. The dermal exposure level at the baseline and for the analy tical options was assumed to be equal to the estimated pre - baseline dermal exposure level. This assumption would overestimate the dermal exposures at baseline and the anal yt ica l options if the free formaldeh yde content of resins is lower at the baseline and for the anal yt ical options . **5.1.1 Uncertainty in the Estimates of Indoor Air Concentration for Composite Wood Product**  **Fabrication** The assessment of site - average formaldeh yd e indoor air concentrations for composite wood product fabrication relies on a mass balance approach that equates the emission rates due to offgassing to the rate at which airborne formaldeh yd e is exhausted from the work space through ventilation. As discussed in Section 3.3.1.1 and Appendix E , indoor air concentration was calculated from the four parameter s in the mass balance equation , which are emitting surface area, emission rate due to off - gassing , effective ventilation rate , and ambient air formaldeh yd e concentration , as well as the assumption of a well - mixed box for the fabrication site . A s discussed in Section 3.3.1.1 , due to data gaps on the values of the se four parameter s at representative CWP fabrication sites, a range of what - if values for indoor air concentration was calculated from bounding values for the ranges of three of the four parameters. CWP fabrication sites were assumed to contain only HWPW, or only

PB, or onl y MDF in this what - if approach . As discussed in Section 3.3.1.1 , there is considerable uncertainty in the range of values for emitting surface area, and some uncertainty in the range s of values for effective ventilation rate and for emission rates . Therefore, there is uncertainty in th e calculated ranges of baseline indoor air concentration due to off - gassing and the effect of the anal yt ical options on the baseline concentrations . It is not possible to determine the direction of uncertaint y ( i.e. , whether the estimated values for indoor air concentration are an underestimate or an overestimate). Although IMIS data and emission rates for the pre - baseline period are available, they cannot be used to perform a general validation of the calculation method nor can this information be us edFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 83 to estimate values for effective ventilation rate and emitting surface area for the following reasons:
 The calculated assessment results are onl y an estimate of airborne concentrations due to off - gassing. IM IS monitoring data are intended to be measure ments of aggregate airborne concentrations and do not contain information on the source or sources of exposure and the contributions to the aggregate concentrations where different sources of exposure existed when the monitoring occurred.  It is uncertain a s to whether the IMIS monitoring data are representative of the exposures experienced by workers in the CWP fabrication industries during the pre - baseline period (see Section 5.2.1 ) . The modeling metho d used to estimate formaldehyde concentrations in this assessment only accounts for the off

- gassing of formaldeh yd e from the three composite wood products of interest and the formaldeh yde concentration in ambient air . As discussed in Section 4.2.1 , there is some indication that sources other than the three CWP s of interest may contribute to formaldeh yd e airborne concentrations. The number of sites in which these other sources may be present, the number of workers that would be potentially exposed to emissions from these other sources, and the magnitude of such potential exposure are not known. The assessment results for the bas eline and anal yt ical options are not an estimate of aggregate indoor air concentration where other sources of formaldeh yd e exist. **5.1.2 Uncertainty in the Estimates of Indoor Air Concentration for**  **Office Buildings** Data on the composition of composite wood products in office furniture was not found. Therefore, the composition of each of the three types of composite wood products in office workstations is unknown . As discussed in Section 3.3.1.2 , panels and work surfaces were assumed to be wholly

made of composite wood products. Information on the ty pe and extent of overlay s on the composite wood products was also not found. The effect of uncertainty about the composition of CWPs in office workstations and the overlay s on these CWPs on the assessment of baseline exposure and the effect of anal yt ical options on baseline exposure are undetermined. The office building method us es emission rate s for new composite wood products and do not account for the decay

of emissions with time. Therefore, this method to estimate formaldehyde concentrations in office buildings only accounts for new office furniture and does not account for the decay of emission rate s with time. Data to describe the decay of emission rate s with time in office buildings were not found through the literature search . Therefore, the estimated airborne concentrations presented in this assessment are only applicab le to offices with new office furniture . The method used simplifies the complex nature of office building ventilation sy stems. Ty picall y in these sy stems, outdoor air is mixed with a recirculation stream of indoor air prior to being supplied to the variou s ventilation zones. The return air from these ventilation zones is mixed and then a stream is split for recirculation and mixing with the outdoor air while the balance is exhausted. Therefore, the office environment model neglects the effect of one expo sure zone on another resulting from the recirculation of indoor air or the movement of air directl y betweenFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 84 exposure zones without passing through the ventilation sy stem. The uncertainty in the results due to neglecting the effect of one exposure zone on another is uncertain and cannot be quantified without a detailed, rigorous mathematical model with detailed supporting monitoring data. Although monitoring data from the BASE study and emission rate s for the 2002 to 2009 pre baseline period are available, they cannot be used to perform a general validation of the calculation method or a validation of the assumed values for the surface area covered by overlay materials and their associated barrier effectiveness. The ages of the office furniture workstations present in the buildings studied in the BASE study are unknown . It is likely that much of the office furniture that contributed to the exposure concentrations observed in the BASE study were of various ages and not representative of new office furniture. The emission rates for CWP that are components of this aged office furniture at the time of monitoring are not known because their initial value when these CWP were new is not known and the extent of their decay with time until the time of monitoring is not known. Furthermore, even where monitoring occurred for new office furniture (a situation that cannot be determined from the BASE study data), the emission rates of CWPs used in this furniture is unknown. Hence, model validation is not possible using the BASE study data because the emission rates of CWPs present in office furniture in the monitored buildings is unknown . **5.2 Uncertainties in Pre**  **- Baseline Monitoring Data**  **5.2.1 OSHA IMIS Data**  This section discusses uncertainties associated with OSHA IMI S monitoring data. The uncertainties discussed below appl y to the IMIS data collected for each life cycle stage (CWP manufacturing, fabrication, wholesale, and retail). The major conclusion of this discussion is that it is uncertain whether the collected IMIS data a re representative of the formaldeh yd e exposure concentrations that occurred during the pre - baseline period of 2002 to 2009 in facilities of the industries within each life cycle stage assessed in this report. Representativeness of IMIS Data The representat iveness of the measured exposure concentrations in IMIS for the entire population of exposed workers is examined below. The discussion below presents statistics of the IMI S data obtained for the CWP fabrication life cycle stage onl y since a larger amount of data were obtained for this life cycle stage. Very few data were obtained for the CWP manufacturing, wholesale, and retail life cycle stages. Table 5 - 1 presents data on the total number of unique OSHA inspections conducted within each NAI CS industry

code of the CWP fabrication life cycle stage. A total of 78 inspections were conducted at 77 facilities between 2002 and 2009, indicating that most inspections occurred at separate facilities. The table compares the number of inspected facilities to the total number of facilities for that particular industry sector based on estimates from the 2007 Economic Census. The sample size (the number of inspected facilities) ra nges from zero to 19 over all of the industries. Sampling theory guarantees an accurate degree of confidence in the estimate of a population mean when the sample size is at least 30 samples. When at least 30 samples areFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 85 obtained, it is not required for the population to have a normal distribution to guarantee an accurate degree of confidence. However, accuracy does require that the samples are random (Walpole 2002a). **Table 5**  **- 1**  **. Number of OSHA Inspections at CWP Fabrication Facilities Compared to the** 

**Maximum Number of Facilities from the U.S. Economic Census**

**NAICS Description**  **2007 U.S. Econom ic**  **Census Data OSHA IMIS Data (2002 to 2009)**  **Maximum Number of Establishments**  **Number of Unique**  **Inspections Number of** 

**Unique Facilities**  321911 Wood window & door Manufacturing 1,494 4 4 321918 Other millwork (including

flooring) 2,101 9 9 321991 Manufactured home (mobile

home) Manufacturing 376 0 0 321999 All other misc. wood product

Manufacturing 1,964 8 8 337110 Wood kitchen cabinet &

countertop Manufacturing 9,683 20 19 337121 Upholstered household

furniture Manufacturing 1,633 4 4 337122 Nonupholstered wood

household furniture Manufacturing 3,428 12 12 337124 Metal household furniture

Manufacturing 330 0 0 337127 Institutional furniture

Manufacturing 782 5 5 337129 Wood television, radio, &

sewing machine cabinet Manufacturing 270 0 0 337211 Wood office furniture

Manufacturing 457 6 6 337212 Custom architectural

woodwork & millwork Manufacturing 2,228 2 2 337214 Office furniture (except

wood) Manufacturing 289 2 2 337215 Showcase, partition, shelving,

& locker Manufacturing 1,377 5 5 339950 Sign manufacturing 6,383 0 0 336213 Motor home Manufacturing 80 1 1 336214 Travel trailer & camper

Manufacturing 862 0 0

**Total** 33,737 7 8 7 7Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 86 For each fabrication industry , less than 30 samples were obtained between 2002 and 2009. Therefore, an accurate degree of confidence in the estimate of the population mean cannot be guaranteed without knowledge of whether the population is represented b y a normal distribution. While all of the fabrication industries in Table 5 - 1 can be aggregated together to yield a sample size of 78 (the total number of inspections) , such aggregation would not resolve the second criterion for an accurate degree of confidence: random sampling. Examination of the randomness of the sampling is made using knowledge of how OSHA conducts inspections. Lavoue et al. ( Lavoue 2008a) anal yz ed formaldehyde exposures from U.S. industries from the OSHA IMI S database using data from 1979 to 2001. The authors note that exposures in IMI S have long been suspected to not be representative of exposures in the U.S. population. The authors fo und the IMIS exposures to mainly result from complaints, referrals, or programs targeted at specific industrial sectors. However, the authors also note that, “within industries, available evidence suggests that bias relating to selecting companies with hi gh exposure levels during complaint visits should be of small amplitude”. The pre - baseline exposure monitoring data presented in the assessment were examined to further evaluate any selection bias. OSHA may

initiate an inspection due to a referral by a fe deral or state government agency or a worker complaint regarding workplace hazards. Alternatively , OSHA may inspect establishments that were selected under the agency’s programmed inspection plan. The “inspection ty

pes” for the compiled IM IS data are : (1 ) referral (15%); (2) complaint (58%); (3) program - planning (25%); and (4) follow - up (2%) (see Appendix A , Definition of Terms for exposure and inspection types). These inspection types are further discussed below. The Site - Specific Targeting program is O SHA’s main programmed inspection plan for non construction workplaces that have 40 or more workers. The selection criteria involve several parameter s such as the number of injury and illness cases, the number of day s away from work, and the number of work ers who receive job transfers or work restrictions due to injury or illness. In addition to the Site - Specific Targeting program, OSHA also implements both national and local emphasis inspection programs to target high - risk hazards and industries. Some ar eas that OSHA focuses on are amputations, lead, cry stalline silica, shipbreaking, trenching and excavations, process safety management in petroleum refineries, hexavalent chromium, diacetyl , recordkeeping and combustible dust ( OSHA 2010a). Programmed and planned inspections may or may not be considered random. If a particular industry were chosen for a programmed or planned inspection , the facilities inspected within the selected industry would have been chosen randomly . However, it is possible a facility was specificall y chosen as part of a program or plan if the facility

had a history

of problems or hazards, in which case the choice of facilit y would not have been random. Complaint and referral inspection ty pes would not be considered random, since OSHA inspected the given facility based on evidence that a problem existed from an employee or other agency with knowledge of the facility . It is difficult to determine whether follow - up inspections would be considered random without knowing the inspection ty pe for the original inspection. Although OSHA t ypically inspects establishments with potential workplace hazards, these hazards may

or may not be related to formaldehyde overexposure. For example, OSHA may inspect an establishment that manufactures PB aft er an emplo ye e files a complaint concerningFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 87 dust exposure. Since the establishment processes formaldeh yde - containing materials, personal monitoring for formaldehyde was also conducted during the inspection although there may or may not be a formaldehyde o verexposure. Therefore, it cannot be assumed that a facilit y inspected b y OSHA through one of the programs described above is necessarily an outlying or aty pical facility

with high formaldeh yde exposures. It is uncertain whether the programmed and planned inspections included in the IMI S data presented in this assessment randomly selected the inspected facilities. Therefore, it cannot be concluded whether an y of the OSHA IMIS data are the result of random sampling. In conclusion, it is uncertain whether OSHA IM IS monitoring data are representative of the exposure concentrations of formaldeh yd e in the industries from which the data were obtained. Intra
- Site Variability in M onitored Indoor Air Concentration This subsection discusses the variability in the m easured indoor air concentrations during a single inspection at a single facility . This discussion is limited to CWP fabrication sites since only this life cycle stage had an adequate amount of data to allow this analy sis. The variation in indoor air conc entration of fabricator sites was considered by examination of IM IS monitoring data. Figure 5 - 1 through Figure 5 - 8 display formaldehyde indoor air concentrations from OSHA IMIS for composite wood product fabricators in which multiple worker activities were monitored for a single site. The graphs display formaldehyde concentration as a function of monitored worker activity . CSHO stands for Compliance Safety and H ealth Officer and represents the exposures for the inspector. Worker activities with only a single exposure level are shown with only a median exposure concentration measurement. These figures illustrate that many of these site inspections resulted in sim ilar exposure concentrations for all monitored worker activities (exposure level for the worker activity with the highest exposure level is ty picall y greater than the exposure level of the worker activity with the lowest exposure level by

up to approximate ly

100%). However, for some sites, there are worker activities with greater variation than this, including the frame operator at Armstrong Cabinets, the painter U cell at The Gunlock e Company , and the August 25th auto spray line at Silver Street. Most of these have higher values than the other measurements. Most of the pre - baseline monitoring data presented in the assessment consist of multiple measurements for a single worke r activity

at a given site. There is considerable variability in the monitored worker activities from site to site . In conclusion, intra - site variability in the monitored exposure level ranges from small to as much as 100% or greater based on examination of IMI S data for which multiple worker activities at a single site were monitore d.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 88

**Figure 5**  **- 1**  **. TWA Exposures from OSHA IMIS for a Single Inspection for Armstrong Cabinets (NAICS 337110)** 

**Figure 5**  **- 2**  **. TWA Exposures from OSHA IMIS for a Single Inspection for**  **Mid Continent Cabinetry (NAICS 337110)**  0 0.1 0.2 0.3 0.4 0.5 0.6 0.7

Laminato r Ty ler Operator Frame Operator PainterExposureLevel(ppm) Minimum

Median Maximum

0 0.005 0.01 0.015 0.02 0.025

Assember I Sealer Fini sher I Finisher II Sprayer I Sprayer IITWAExposureLevel(ppm) Minimum

Median MaximumFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 89

**Figure 5**  **- 3**  **. TWA Exposures from OSHA IMIS for a Single Inspection for**  **Benvenuti and Stein (NAICS 337122)** 

**Figure 5**  **- 4**  **. TWA Exposures from OSHA IMIS for a Single Inspection for**  **Ameriwood Industries (NAICS 337122)**  0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4

Spray Painter Cabinet Fin is her CS HOExposureLevel(ppm) Minimum Median Maximum

0 0.02 0.04 0.06 0.08 0.1 0.12

Autodri ll Selco #2 Foi ler CSH OExposureLevel(ppm) Minimum

Median MaximumFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 90

**Figure 5**  **- 5**  **. TWA Exposures from OSHA IMIS for**  **Two In spections for The Gunlocke**  **Company (NAICS 337211)**

**Figure 5**  **- 6**  **. TWA Exposures from OSHA IMIS for Two Inspections for Silver Street (NAICS 337211)**  0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16

Inspector U Cell Lab orer U Cell Sander U Cell Sander W Cell Sprayer Boot h #7 PainterU Cell July 1, 2005 August 9 , 2005ExposureLevel(ppm) Minimum Median Maximum

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7

Panel Saw Operator Auto Spray Line Ro uterO perator Auto Spra y Line August 1 1, 2004 August 2 5, 2004ExposureLevel(ppm) Minimum Median MaximumFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 91

**Figure 5**  **- 7**  **. TWA Exposures from OSHA IMIS for**  **a Single Inspection for The**

**Commercial Furniture Group (NAICS 337127)**

**Figure 5**  **- 8**  **. TWA Exposures from OSHA IMIS for a Single Inspection for Parenti & Raffaelli**  **(NAICS 321918)** 0 0.02 0.04 0.06 0.08 0.1 0.12

Sealer Booth Fabric Store Ro om Fabric Cu tterExposureLevel(ppm) Exposure (single measurement)

0 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08

Cutter Assembler Cabin et MakerExposureLevel(ppm) Minimum

Median MaximumFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 92 **5.2.2 BASE Study Monitoring Data**  A total of 100 commercial and public office buildings were monitored in the BASE study between 1994 and 1998. To determine the representativeness of the BASE sample of office buildings, the BASE study authors compared this sample to larger samples of U.S. office buildings using data collected b y the Energy Information Administration of the U.S. Department of Energy through the 1995 Commercial Building Energy Consumption Survey

(CBECS). The BASE study

authors w ere able to perform two comparisons: 1) a comparison of the BASE buildings to a larger sample of large urban office buildings; and 2) a comparison of the BASE buildings to a larger sample of all U.S. office buildings. The BASE study authors determined that the BASE buildings are most similar to the CBECS sample of large , urban office buildings ; specificall y, buildings with more than 50 occupants in Metropolitan Statistical Areas (MSAs) 12 (BASE 2001a) . The BASE study authors note that the BASE buildings wer e selected from cities with populations greater than 100,000. However, MSAs are urbanized areas with populations greater than 50,000. Therefore, there is a slight discrepancy in the comparison of the surrounding populations of the BASE study buildings an d the large , urban office buildings from CBECS. Furthermore, the BASE buildings were selected from downtown areas. The BASE study authors found the BASE buildings to be three to four times larger than the CBECS sample of large, urban office buildings. C onsistent with this finding, a separate survey conducted by the Building Owners and Managers Association (BOMA) found that downtown office buildings tend to be larger than other metropolitan area office buildings. Although these differences in surrounding population and building size are noted, the BASE study authors found th at BASE study buildings most likely

represent large , urban office buildings (BASE 2001a). Based on the CBECS sample of all U.S. office buildings, the BASE buildings do not represent th e entire population of all U.S. office buildings well. However, the BASE study authors note that, although the large, urban office buildings account for only 11% (or about 80,000) of all U.S. office buildings (about 705,000), this building t ype represents 73% (or about 19,428,229) of all U.S. office workers (about 26,563,566) according to the CBECS data (BASE 2001a). Therefore, the BASE study office buildings are most similar to the office building ty pe (large, urban office buildings) that house approximately 73% of all U.S. office workers. Note that these statistics are based on survey data from 1995. It is unknown how these statistics have changed since 1995. The second criterion, random sample selection, is anal yz ed next. The building selection crite ria described in the BASE study documents indicate that the BASE study did randoml y select office buildings for study . Buildings were selected randoml y in randomly selected cities . The study authors selected buildings in ten climatic regions of the U.S. ( BASE 2001a; NI ST 2008a). Whether the measured formaldeh yde concentrations are representative of year - round concentrations in these buildings is also anal yz ed . T he BASE study focused its building measurements during the winter and summer months. Building ventilation sy stems are more likely to operate at minimum outdoor air ventilation rates during the winter and summer to 12 The U.S. Office of Management and Budget defines a Metropolitan Statistical Area (MSA) as: “a county or group of contiguous counties that contain (1) at least one city of 50,000 inhabitants or more (‘twin cities’ with a combined population of at least 50,000 inhabitants) or (2) an urbanized area of at least 50,000 inhabitants and a total MSA population of at least 100,000 (75,000 in New England)” (BASE 2001a).Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page 93 minimize the amount of air heating or cooling required. NIST conducted an anal ys is of the ambient temperatures recorded during the BAS E study and concluded that approximately 62% of the data could possibly

correspond to buildings operating with minimum outdoor air ventilation rates (NI ST 2008a). However, the building operations during winter and summer were not compared against their op erations during spring or autumn. Therefore, it cannot be concluded for certain whether buildings were operating at lower outdoor air ventilation rates during the BASE study . NIST additionally analyzed the BASE study data on the ventilation system design s and the measured ventilation rates. NIST concluded that the ratio of the minimum outdoor air ventilation rate to total supply air ventilation based on the ventilation sy stem designs had an average value of 0.19 and a median of 0.12. The observed ratio of actual outdoor air ventilation rate to total supply

air ventilation had an average value of 0.38 and a median of 0.22 (NI ST 2008a). This observation illustrates that, in general, many of the studied buildings operated at outdoor air ventilation rates greater than the s ys tem design minimum. In conclusion, it has been established that the studied buildings are representative of large, urban commercial and public office buildings from the time frame of the study . However, it is uncertain whether the measured formaldeh yde concentrations are representative of concentrations that occurred in these buildings during an entire ye ar or if they are onl y representative of winter and summer concentrations. **5.3 Uncertainty in**  **Number of Production**  **Workers and Employees**  U. S. Census data on the number of production workers (for CWP manufacturing and fabrication) and employees (for wholesale and retail) are presented for the NAI CS industry sectors associated with each life cycle stage. While these data were not used for the quantitative assessment, they were presented to indicate the total number of production workers and employees potentially exposed to formaldehyde emission s from composite wood products. These data likely represent an overestimation for the following reaso ns . Census data represent the overall statistics for the entire industry sector. Additionally , Census data do not contain specific information on the type of composite wood products associated with these statistics. Some sites within these industry secto rs may

not manufacture , use, or sell the composite wood products of interest . For an y given site, it is uncertain whether the breathing zone for all production workers or employees would be affected b y the off - gassing of formaldeh yde from the composite woo d products of interest . Therefore, there is some uncertainty in assessing whether the number of production workers and employees presented in this assessment is an overestimate. However, for the reasons listed above, the number of production workers and employees from U.S. Census data is likely

an overestimate of the actual exposed population who would be affected b y the regulation. More specific information on the actual exposed population is not available.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

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Formaldehyde Resin Manufacture and of Certain Chemicals for Substitute Technologies to Reduce Emissions from Composite Wood Products ; U.S. Environmental Protection Agency (USEPA) , Office of Pollution Prevention and Toxics, Chemical Engineering Branch and Exposure Assessment Branch : Washington, DC, October 2011. USEPA 2011b. An Introduction to Indoor Air Quality (IAQ): Formaldehyde [Online]; U.S. Environmental Protection Agency (USEPA), Updated February

15, 2011. http://www.epa.gov/iaq/formalde.html . USEPA 2011c. Construction and Demolition Materials ; U.S. Environmental Protection Agency (USEPA), Updated July

27, 2011. http://www.epa.gov/wastes/nonhaz/industrial/cd/index.htm . USI TC 2008a. Wood Flooring and Hardwood Plywood: Competitive Conditions Affecting the U.S. Industries ; USI TC Publication 4032; U.S.

International Trade Commission (USI TC), Washington, DC, August 2008. Walpole 2002a. Walpole, Ronald E.; Myers, Ray mond H.; Myers, Sharon L.; Ye, Keying. Probability and Statistics for Engineers and Scientists , 7th ed.; Prentice Hall: Upper Saddle River, NJ, 2002; pp 234 - 236. Wong 2006. Wong, L.T.; Mui, K.W.; Hui, P.S. A statistical model for characterizing common air pollutants in air - conditioned offices.

Atmospheric Environment **2006** , 40 , 4246 - 4257. WorksafeBC 200 9 a. Occupational Exposure Limits for Formaldehyde ; Formaldehyde OEL Study , Policy and Research Division, WorksafeBC: Vancouver, BC, July 2009. Zinn 1990a. Zinn, Terry

W.; Cline, Dennis; L ehmann, William F. L ong - term study of formaldeh yde emission decay from particleboard. Forest Prod. J. **1990** , 40 (6), 15 - 18.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011

**Appendix A**  **DEFINITION OF TERMS**Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page A - 1 **Definition of Terms**  **Am erican Conference of**  **Governmental Industrial Hygienists (ACGIH)**  ACGIH is a member - based organization of industrial hygienists whose goal is to advance occupational and environmental health. ACGIH performs individual lab tests and develops with th eir own exposure limits that are sometimes used as suggested standards. **Action Level** Action level means a concentration designated in 29 CFR 1910 for a specific substance, calculated as an 8 - hour time weighted average (TWA), which initiates certain required activities such as exposure monitoring and medical surveillance. **CARB Compliant Products** In 200 8 , the California Air Resources Board (CARB) issued an air borne toxic control measure (ATCM) for three composite wood products. The emission standards were issued in two phases. Products that are manufactured in accordance with emissions standards issued under Phase 1 and Phase 2 of the CARB rule are referred to as CARB Phase 1 compliant and CARB Phase 2 compliant prod ucts, respectivel y. Products that do not meet the standards set by CARB are herein referred to as non - CARB compliant products. Table C - 2 in Appendix C summarizes the CARB emission standards. **Ceilin g Limit (C)**  The air concentration for a substance that should not be exceeded during an y part of the occupational exposure. **Composite Wood Products**  **(CWPs)** The manufacture of most composite wood products involves an operation where the wood material is bon ded with a resin. In this report, composite wood products refer specificall y to h ardwood ply wood, medium - density fiberboard, and particleboard . **Composite Wood Product Fabrication**  The manufacture of commercial or consumer products, such as cabinets and fur

niture, from HWPW, MDF, and PB. **Emission Level** A term used to indicate concentration of formaldehyde in a test chamber for a CWP. Inthis report, emission levels are assumed to be measured using the ASTM E1333 large chamber test method .Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page A - 2 **Emission Rate** A term that is used in this document to describe the emissions of formaldeh yde as a flux, meaning a quantity (such as mass) of formaldehyde emitted per unit emitting area and per unit time. Concentrations measured using ASTM E1333 may

be used to calculate emission rates ( in units of flux ) according to the method described in ASTM E1333 ( see Appendix E ). Emission rates are alternatively referred to as emission factors (see the BIFMA M7.1 - 2007 method). **Exposure** Contact with a s ubstance by inhalation, dermal contact, or ingestion. The magnitude of exposure is a measure of the concentration of a substance contacted over a period of time. **Exposure Assessment** The process of determining how people come into contact with a hazardous substance, how often and for how long they are in contact with the substance, and how much of the substance they

are in contact with. **Exposure Pathway** The route a substance takes from its source (where it began) to its end point (where it ends), and how people can come into contact with (or get exposed to) it. An exposure pathway has five parts: a source of contamination (such as a composite wood product); an environmental media and transport mechanism (such as the off - gassing of formaldeh yde through air); a point of exposure (such as an individual’s breathing zone); a route of exposure (inhalation), and a receptor population (people potentially or actuall y exposed). When all five parts are present, the exposure pathway

is termed a completed expos ure pathway.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page A - 3 **Hardwood Plywood (HWPW)** According to FSCWPA, a hardwood or decorative panel that is: i. intended for interior use; and ii. c omposed of (as determined under the standard numbered ANSI/HPVA HP

– 1

–2009) an assembly of layers or plies of veneer, joined b y an adhesive with : I . lumber core; II . particleboard core; III . medium - densit y fiberboard core; IV . hardboard core; or V . an y other special core or special back material. This does not include : i. military - specified ply

wo od; ii . curved ply

wood; or ii i. any other product specified in

— I . the standard entitled ‘Voluntary Product Standard

— Structural Plywood’ and numbered PS1

– 07; or II . the standard entitled ‘Voluntary Product Standard

—Performance Standard for Wood Based Structural - Use Panels’ and numbered PS 2

– 04. Note that the definition of hardwood pl ywood includes engineered veneer and any laminated product unless EPA exempts them by

rule - making. **Laminated Product** According to FSCWPA, a product: (I) in wh ich a wood veneer is affixed to: (aa) a particleboard platform; (bb) a medium - densit y fiberboard platform; or (cc) a veneer - core platform; and (II) that is : (aa) a component part; (bb) used in the construction or assembly of a finished good; and (cc) produced b y the manufacturer or fabricator of the finished good in which the product is incorporated. EPA has the discretion to change this definition.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page A - 4 **Life C**  **ycle** All stages of a product’s development, from manufacture and processing to distribution, use, and disposal and recycling. **Manufacturing** The manufacture of the composite wood products: HWPW, MDF, and PB. May

also be referred to as “primary manufacturing”. **Medium -**  **Density Fiberboard (MDF)**  According to FSCWPA, a panel composed of cellulosic fib ers made b y dry forming and pressing a resinated fiber mat (as determined under the standard numbered ANSI A208.2

–2009) . **No Added Formaldehyde (NAF) Resins**  According to FSCWPA : (A) IN GENERAL : (i) a resin formulated with no added formaldehyde as part of the resin cross - linking structure in a composite wood product that meets the emission standards in subparagraph (C) as measured b y : one test conducted pursuant to test method ASTM E

– 1333

– 96 (2002) or, subject to clause (ii), ASTM D

– 6007

– 02; and 3 months o f routine quality control tests pursuant to ASTM D

– 6007

– 02 or ASTM D

– 5582 or such other routine quality control test methods as may be established by

the Administrator through rulemaking. (ii) Test results obtained under clause (i)(I) or (II) by an y test m ethod other than ASTM E

– 1333

– 96 (2002) must include a showing of equivalence b y means established by the Administrator through rulemaking. (B) INC LUS IONS : The term ‘no - added formaldehyde based resin’ may

include any

resin made from : (i) soy ; (ii) poly vinyl acetate; or (iii) methylene diisocyanate. (C) EMI SSI ON STANDARDS : The following are the emission standards for composite wood products made with no - added formaldeh yde - based resins under this paragraph: (i) No higher than 0.04 parts per million of formaldehyde for 90 percent of the 3 months of routine quality control testing data required under subparagraph (A)(ii). (ii) No test result higher than 0.05 parts per million of formaldeh yde for hardwood ply wood and 0.06 parts per million for particleb oard, medium - density fiberboard, and thin medium - density

fiberboard.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page A - 5 **National Institute for Occupational Safety and Health**  **(NIOSH)** As part of the Centers for Disease Control, NI OSH is responsible for conducting research and making recommendations for the prevention of work - related illnesses and injuries. **Occupational Exposure** Contact with a substance as a result of one’s work environment. **Occupational Safety and Health Administration (OSHA)**  OSHA is the main federal agency charged with the enforcement of safet y and health legislation. OSHA has the regulatory

authorit y to set exposure limits for specific chemicals or groups of chemicals. **OSHA Integrated Management Information System (IMIS)**  IM IS is an on - line data entry and information retrieval sy stem designed to collect, process, retrieve, and communicate penalty

assessment, arbitration, and collection information regarding OSHA's inspections. **OSHA Inspection Type: FAT**  **- CAT**  **Complaint** OSHA inspections following a fatalit y or catastrophe at a facility . OSHA inspections resulting from worker complaints of unsafe or unhealthful working conditions. **Follow -**  **Up** A follow - up inspection determines if the employer has corrected previously

cited violations. I f the employer fails to abate a former violation, he or she is subject to additional penalties until the violation is corrected. **Planned**

**Programmed**

**Related** The inspection was planned based on a particular reason, which can vary . An example reason may include OSHA determining that a certain industry has a particular hazard more than others, so a random sample of facilities within that industry

is selected for inspection. Planned and/or programmed inspections aimed at specific high - hazard industries, workplaces, occupations, health substances, or other industries identified in OSHA’s current inspection procedures. The inspection was conducted due to concern o ver the facility regarding a different category , and upon investigation, OSHA determined that a related hazard should be monitored.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page A - 6 **Referral Unprogrammed**  OSHA inspections resulting from referrals. Referrals may come from an y source including but not limited to: state EPA, health department, fire department, building code inspectors, newspaper, and related OSHA inspections. The facility

was not inspected ba sed on any planned or programmed list of industries or facilities. These are the most random of OSHA inspections. **Particleboard (PB)** According to FSCWPA, a panel composed of cellulosic material in the form of discrete particles (as distinguished from fibers, flakes, or strands) that are pressed together with resin (as determined under the standard numbered ANSI A208.1

–2009) This d oes not include any product specified in the standard entitled ‘Voluntary Product Standard

—Performance Standard for Wood - Ba sed Structural - Use Panels’ and numbered PS 2

– 04. **Peak Concentration** The maximum air concentration of a chemical that is observed for a given sampling event. **Permissible Exposure Limit (PEL)**  PEL s are regulatory limits issued by

OSHA for the amount or co ncentration of a substance in the air. They may also contain a skin designation. OSHA PEL s are based on an 8 - hour time weighted average (TWA) exposure. **Potential Dose** The amount of a substance that is taken in b y the body through ingestion, inhalation or dermal contact. In this report, the potential dose, also referred to as “dose” applies to the amount of the substance that is inhaled. **Recommended Exposure Limit (REL)**  Unless noted otherwise, REL s are time - weighted average (TWA) concentrations for up to a 10 - hour workday during a 40 - hour workweek. Unlike PEL s, which are regulatory limits, REL s are recommended limits issued by NIOSH.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page A - 7 **Short -**  **Term Exposure Limit (STEL)**  A STELis defined as a 15 - minute TWA exposure that should not be exceeded at any time during the work day even if the 8 - hr TWA is within established limits. An averaging period other than 15 minutes may be used when this is warranted b y observed biological effects. The American Conference of Governmental Industrial Hygienists (ACGIH) recommend s that exposures beyond the time - weighted average limit (whether regulatory or otherwise) up to the STEL should not occur more than 4 times per day

with at least 60 minutes between successive exposures i n this range. **Threshold Limit Value (TLV)** TLVs are recommended exposure limits that are issued by the ACGIH. TLVs are airborne concentrations of substances to which it is believed that nearl y all workers may be repeatedly

exposed day

after day without adv erse effect. There are three categories of TLVs: TLV - TWA; TLV STEL ; and TLV - C. **Time -**  **Weighted Average (TWA) Concentration**  Average air concentration of a substance based on a normal 8 - hour work day

and a 40 - hour work week. OSHA PEL s are based on an 8 - hour t ime - weighted average (TWA) exposure.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page A - 8 **Ultra Low -**  **Emitting Formaldehyde (ULEF) Resin**  According to FSCWPA : (A) IN GENERAL : (i) The term ‘ultra low - emitting formaldeh yde resin’ means a resin in a composite wood product that meets the emission standards in subparagraph (C) as measured by : (I) 2 quarterl y tests conducted pursuant to test method ASTM E

– 1333

– 96 (2002) or, subject to clause (ii), ASTM D

– 6007

– 02; and (II) 6 months of routine quality control tests pursuant to ASTM D

– 6007

– 02 or ASTM D

– 5582 or such other routine quality

control test methods as may be established by

the Administrator through rulemaking. (ii) Test results obtained under clause (i)(I) or (II) by an y test method other than ASTM E

– 1333

– 96 (2002) must include a showing of equivalence b y me ans established by the Administrator through rulemaking. (B) INC LUS IONS : The term ‘ultra low - emitting formaldeh yde resin’ may include : (i) melamine - urea - formaldehyde resin; (ii) phenol formaldeh yd e resin; and (iii) resorcinol formaldehyde resin. (C) EMI S SI ON STANDARDS : (i) The Administrator may, pursuant to regulations issued under subsection (d), reduce the testing requirements for a manufacturer onl y i f its product made with ultra low emitting formaldeh yd e resin meets the following emission standards: (I) For hardwood pl ywood, no higher than 0.05 parts per million of formaldehyde. (II) For medium - density

fiberboard : (aa) no higher than 0.06 parts per million of formaldeh yde for 90 percent of 6 months of routine quality control testing data required under subparagraph (A)(ii); and (bb) no test result higher than 0.09 parts per million of formaldeh yde.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page A - 9 (III) For particleboard : (aa) no higher than 0.05 parts per million of formaldeh yde for 90 percent of 6 months of routine quality control testing data required under subparagraph (A)(ii); and (bb) no test result higher than 0.08 parts per million of formaldeh yde. (IV) For thin medium - density fiberboard : (aa) no higher than 0.08 parts per million of formaldeh yde for 90 percent of 6 months of routine qu ality control testing data required under subparagraph (A)(ii); and (bb) no test result higher than 0.11 parts per million of formaldeh yde. (ii) The Administrator may not, pursuant to regulations issued under subsection (d), exempt a manufacturer from third party

certification requirements unless its product made with ultra low - emitting formaldehyde resin meets the following emission standards: (I) No higher than 0.04 parts per million of formaldeh yde for 90 percent of 6 months of routine quality contro l testing data required unde r subparagraph (A)(ii). ( II) No test result higher than 0.05 parts per million of formaldeh yde for hardwood ply wood and 0.06 parts per million for particleboard, medium - density fiberboard, and thin medium - density fiberboard.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011

**Appendix B** 

**DATA QUALITY ACCEPTANCE CRITERIA SPECIFICATIONS**Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page B - 1 **Data Quality Acceptance Criteria Specifications Specifications f** 

**or Data Elements Acceptance**  **Criterion: Description/Definition**  **Specification** Currency Is the information up to date? Does

it reflect current conditions? Process Description: Year of source is 1990 or after Number of Sites and Production Data: Year of source is 2000 or after and correlates with number of sites Exposure Data: Priority - Year of source is 2004 or after 1 Consider - Year of source is 1999 or after Geographic Scope Does the information reported reflect

an area relevant to the assessment? All Data: Priority

– sources describing U.S. sites When U.S. data are not available, consider sources from countries with geographic proximity that may adopt similar processes or from other developed countries that may have similar regulatio ns and standards. Process Description: Consider

– sources describing Canadian, Mexican, or European processes. Number of Sites and Production Data: Consider

– North American sites (and interpolate to estimate U.S. sites and production) Exposure Data: Consider

– Canadian or European data. Accuracy/Reliability Is the information or data from a

peer - reviewed, government, or industry - specific source? Is the source published? Is the author engaged in a relevant field such that competent knowledge is expected (i.e., the author writes for an industry trade associatio n publication versus a general newspaper)? All Data: U.S. or other government publication For an academic researcher:  Publication in peer - reviewed journal  Presentation at a technical conference  Source has documented qualifications/ credentials to disc uss particular topic For an industry expert or trade group:  Presentation at a technical conference where the information is subject to review by other industry experts  Source has documented qualifications/ credentials to discuss particular topic  Source represents a large portion of the industry of interestFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page B - 2 **Acceptance Criterion:**  **Description/Definition Specification**  Unbiased 2 Is the information objective towards

a particular product or outcome? All Data:  Objective of the information is clear.  Methodology is designed to answer a specific question. Com parability Are the data comparable to other

sources that have been identified or are they significantly different than other sources? Production Data, Exposure Data, and Number of Sites: Values are within the same order of magnitude of each other. Process Description: Matches or is similar to other information for the same industry and will be evaluated on a case - by - case basis. Representativeness Do the data reflect typical industry

practices? All Data: Information is relevant to the industry and from a reputable source with qualifications in the industry of interest. Data are based on a large industry survey or study, as opposed to a case study or sample from a limited number of sites. Applicability For surrogate data, are the data

expected to be similar for the industry of interest? Surrogate data used to fill data gaps must be judged to be similar to the data of interest:  Industry is similar in size  Same types of chemicals are used  Similar processes and activities are performed  Similar levels o f engineering controls and personal protective equipment are used 1 EPA promulgated in 2004 the Plywood and Composite Wood Products MACT Rule for hazardous air pollutants (HAPs), including formaldehyde, for regulated units. 2 Information from advocacy groups should be collected and judged for acceptability. While such information may be biased, it may provide references to other useful sources.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011

**Appendix C**  **EXISTING FORMALDEHYDE OCCUPATIONAL EXPOSURE LIMITS A** **ND FORMALDEHYDE OFF**  **- GASSING EMISSION STANDARDS FOR COMPOSITE**  **WOOD PRODUCT S** Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page C - 1 **Formaldehyde Occupational Exposure Limits** The Occupational Safety and Health Administration (OSHA) set s permissible exposure limits (PEL s) to regulate worker exposure to formaldehyde in occupational settings. OSHA has established two ty

pes of exposure limits for airborne exposures to formaldehyde : a 0.75 p arts p er m illion (ppm) time - weighted average (TWA) PEL over an 8 - hour period and a 2 ppm short - term exposure limit (STEL) over a 15 - minute period. Table C - 1 summarizes these OSHA exposure limits as well as other formaldehyde exposure limits for the U.S. and for other countries.

**Table C -**  **1. Existing Occupational Exposure Limits for Formaldehyde Country**  **Concentration (ppm) Type**  USA - ACGIH 0.3 Ceiling USA -NIOSH 0.016 TWA USA - OSHAb 0.75 TWA USA - OSHA 2.0 STEL Canada - Alberta 2.0 Ceiling Canada - Ontario 0.3 Ceiling Canada - Quebec 2.0 Ceiling Sweden 0.5 TWA New Zealand 1.0 Ceiling Australia a 1.0 TWA Japan 0.5 TWA United Kingdom 2.0 TWA a – Australia proposed a lower occupational exposure limit of 0.3 ppm in 2008 (Chimar Hellas undated) . b

– The OSHA action level for formaldehyde is 0.5 ppm TWA (29 CFR § 1910.1048) . Source s : IARC 2006a, Chimar Hellas undated, and OSHA 2010b **Formaldehyde Emission Standards for Composite Wood**  **Products** Emission standards have been established in the U.S. for HWPW, MDF, and PB. The American National Standards Institute (ANSI) established a voluntary standard for MDF and PB , while the Department of Housing and Urban Development (HUD) established national standard s for ply wood and particleboard (CARB 2007 a). In 200 8 , CARB issued an air toxics control measure (ATCM) for the state of California, which provided stricter formaldeh yde emission standards than the existing national standards ( see Table C - 2 ). The ANSI standards have been revised to reflect the CARB ATCM emission standards. The CARB regulation focuses only on three t ypes of composite wood products: HWPW, PB, and MDF. CARB set emission standards for each of the se products based o n be st achievable control technologies (BACT s ). The BACT s were selected based on CARB survey results, information in the open literature , and expert judgment on low - and no - added formaldehyde resinFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page C - 2 technologies. The selected BACT s are such that the three regulated products have different emission standards ( CARB 2007a). CARB reported the resin ty pes used b y the manufacturers who resp onded to the CARB 2003 survey ( CARB 2007a) .  Of the HWPW manufacturer responses, which accounted for 73% of domestic H WPW production: o A ll companies reported using ammonia - UF resin. The lowest emission rate s were achieved with the use of catal ys ts, such as ammonium chloride or hexamethylenetetramine.  Of the PB manufacturer responses, which accounted for 53% of domestic PB production: o 51% of the reported production volume used a straight poly mer UF resin ; o 48% of the reported production volume used a methanol - UF resin; and o 1% of the reported production volume used a blended PF - UF resin.  Of the MDF manufacturer responses, which represented 83% of domestic MDF production: o 40% of the reported production volume used a straight poly mer UF resin ; o 20% of the reported production v olume used a methanol - UF resin; o 39% of the reported production volume used a melamine - UF resin with s o dium chloride catal ys t; and o 1% of the reported production volume used MDI resin . The majority

of the reported resins used were UF resins with many using additives , such as ammonia or methanol , and catal ys ts.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page C - 3 **Table C -**  **2. California Phase 1 and Phase 2 Form aldehyde Emission Standards**  **ASTM E1333 Standard Concentrations (ppm) a**  **Phase 1 Formaldehyde Emission Standards Effective**  **Date HWPW** **- VC**  **b HWPW** **- CC**  **c PB**  **MDF tMDF**  **d** Jan 2009 0.08

— 0.18 0.21 0.21 July 2009

— 0.08

— — — **Phase 2 Formaldehyde Emission Standards**  **Effective Date**  **HWPW -**  **VC b**  **HWPW -**  **CC c**  **PB MDF**  **tMDF d**  Jan 2011 0.05

— 0.09 0.11

— Jan 2012

— — — — 0.13 July 2012

— 0.05

— — — a – ppm = parts per million. In this case, parts of formaldehyde per million parts of air. b

– HWPW - VC = hardwood plywood

– veneer core. c – HWPW - CC = hardwood plywood

– composite core. d

– tMDF = thin medium - density fiberboard (8 - mm or thinner). Source: CARB 2007aFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report October 6, 2011 Page C - 4 **Table C -**  **3. Formaldehyde Emission Limits and Corresponding Emission Rates as Measured using ASTM E1333 under HUD, CARB, and FSCWPA**  **HUD, CARB, and FSCWPA Limits as Measured from ASTM E1333**  **ASTM E1333 Test**  **Parameters Calculated Values**  **(see Appendix E**  **) Concentration**  **(ppm) Concentration** 

**(mg/m 3**  **) Loading** 

**Ratio (m**  **2 /m**  **3 )**  **Air**

**Change Rate (hr**  **- 1**  **) Formaldehyde** 

**Emission Rate**  **(mg/m 2**  **- hr)**  **Area -**  **Specific**

**Airflow Rate (m**  **3 /m**  **2 -**  **hr) HWPW**  HUD 0.2 0.246 0.43 0.5 0.2858 1.16 CARB Phase 1 0.08 0.098 0.43 0.5 0.1143 1.16 FSCWPA / CARB Phase 2 0.05 0.061 0.43 0.5 0.0715 1.16 ULEF 0.045 0.0553 0.43 0.5 0.0643 1.16 NAF 0.04 0.0492 0.43 0.5 0.0572 1.16 **PB** HUD 0.3 0.369 0.43 0.5 0.4287 1.16 CARB Phase 1 0.18 0.221 0.43 0.5 0.2572 1.16 FSCWPA / CARB Phase 2 0.09 0.111 0.43 0.5 0.1286 1.16 ULEF 0.045 0.055 0.43 0.5 0.0643 1.16 NAF 0.04 0.049 0.43 0.5 0.0572 1.16 **MDF** HUD None -- -- -- -- -- CARB Phase 1 0.21 0.258 0.26 0.5 0.4963 1.92 FSCWPA / CARB Phase 2 0.11 0.135 0.26 0.5 0.2600 1.92 ULEF 0.05 0.061 0.26 0.5 0.1182 1.92 NAF 0.04 0.049 0.26 0.5 0.0945 1.92Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011

**Appendix D**  **FORMALDEHYDE CWP OFF -**  **GASSING EMISSION LEVEL DATA FOR THE PRE**   ** BASELINE PERIOD, BASELINE, AND THE** **ANALYTICAL OPTIONS** Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page D - 1 Use of Emission Levels in the Assessm ent of Formaldehyde Occupational Exposure Emission levels for formaldeh yde off - gassing from CWP, which have units of concentration, are converted to emission rate s , which have units of flux , and are used in the mass balance equations used to calculate ind oor air concentrations due to off - gassing of CWPs in fabrication sites and in office buildings for the baseline and the three analy tical optio ns. Pre - baseline emission levels are used to calculate pre - baseline indoor air concentrations in CWP fabrication sites for the purpose of comparing model results to pre - baseline OSHA IMIS data as described in Section 4.2.5.3 . Pre - baseline emission levels are also used to estimate the barrier effectiveness of the finishing (coating, overlays, etc) of the CWP from which office building workstation components are fabricated. This barrier effectiveness is used in the calculation of formaldehyde indoor air concentration in office buildings for the baseline and the three analy tical options ( see Section 3.3.1.2 and Appendix E ) . Emission Levels of P re - B aseline CWP s This section discusses the available pre - baseline emission level data and the estimation of pre baseline emission levels . The pre - baseline emission levels used in this assessment are summarized in Table D - 1 below. The data used to estimate these emission levels are presented in Table D - 2 . Considerable information is avail able on the emission levels of domestically- produced pre baseline products as shown in Table D - 2 . As seen in this table, at the beginning of the pre baseline period of 2002 to 2009, the production - weighted average emission level s of domestically - produced CWP were close to the CARB ATCM Phase 1 limits while the range of emission levels for these products had a lower bound that was less than the CARB ATCM Phase 1 standard emission level, and an upper bound that was considerabl y greater. InANPR submissions, it is noted that 75% of HWPW and 96% of PB and MDF met the CARB ATCM Phase 1 limit by

2009. Therefore, the CARB ATCM Phase 1 limits were assumed to be representative of average pre - ba seline emission levels for CWP produced domestically during the pre - baseline period of 2002 to 2009, and the average emission levels for domestically produced HWPW, PB, and MDF were equated to the CARB ATCM Phase 1 limits (0.08 ppm, 0.18 ppm, and 0.21 ppm, respectivel y). Emission levels of imported pre - baseline CWPs are not available and were estimated taking into account temporal trends in the emission levels of domestically- produced CWP and the reported emission levels of imported CWP. The emission level s of baseline products (domestically produced and imported) and their share of U.S. consumption is provi ded in the market profile (USEPA 2010a) in Table 12 - 5 . A comparison of Table D - 2 and Table 12 - 5 in the market profile (repro duced as Table D - 3 in this appendix) shows that a considerable decrease in the emission levels of domesticall y - produced CWP will occur in going from the pre - baseline period to the baseline. This temporal trend was assumed to app ly to imported CWP such that there would be a decline in the emission levels of imported CWP from the pre - baseline period to the baseline. The pre - baseline emission levels for Canadian imported CWP and non - Canadian imported CWP were estimated differently as discussed below.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page D - 2 According to Table 12 - 5 in the market profile (USEPA 2010a), baseline CWP imported from Canada have emission levels that are identical to the emission levels of domestically - produced baseline CWP. This similarity was assumed to extend to the pre - baseline period, and therefore CWP imported from Canada during the pre - baseline period were assumed to have emission levels that are identical to the values assumed for domestically produced pre - baseline CWP. Most of the non - Canadian imported CW P will adhere to the CARB Phase 2 , ULEF, or NAF standards at baseline , but will have emission level values that are different from those of U.S. and Canadian CWP . The baseline emission levels of non - Canadian imports are likel y not representative of pre - ba seline emission levels of these imports a ssuming that there will be a decline in emission levels of imported CWP from the pre - baseline to baseline as discussed above . The fraction of imported baseline CWP that will not adhere to an y of the CARB emission s tandards will be approximately 26%, 37 %, and 10% for HWPW, PB, and MDF, respectivel y. The average values of the emission level s for these volumes will be 0.163 ppm, 0.384 ppm, and 0.502 ppm for HWPW, PB, and MDF , respective ly , as shown in Table D - 2 . Itis assumed that these emission levels are representative of the average pre - baseline emission levels for each CWP ty pe for imported CWP. In conclusion, the average emission levels for domestic and Canadian pre - baseli ne HWPW, PB, and MDF are assumed to be equal to the CARB ATCM Phase 1 limits (0.08 ppm, 0.18 ppm, and 0.21 ppm, respectivel y). The average emission level s for imported pre - baseline HWPW, PB, and MDF are assumed to be equal to 0.163 ppm, 0.384 ppm, and 0.5 02 ppm, respectivel y. An average emission level for all three CWP was used in the estimation of barrier effectiveness for use in the calculation of office building indoor air concentration . Therefore, these emission levels are average d together. First, a volume - weighted average of the emission level s of domestically - produced and imported CWP is calculated for each individual CWP ty pe. The EPA market profile provides the 2005 volume - based shares of domestic consumption of domestic/Canadian and imported CWP (Table 12 - 4 in USEPA 2010a). The volume - based shares of domestic consumption of non - Canadian imported CWPs are 64%, 3.5%, and 7.6% for HWPW, PB, and MDF, respectivel y. The shares of domestic/Canadian CWPs are the difference between 100% and the import shares. A volume - weighted average emission level is calculat ed for each CWP ty

pe as follows. The emission rate s (in units of flux) are similarly calculated . For HWPW: ( 0 . 64 ) × ( 0 . 163 ) + ( 0 . 36 ) × ( 0 . 08 ) = 0 . 13 For PB: ( 0 . 035 ) × ( 0 . 384 ) + ( 0 . 965 ) × ( 0 . 18 ) = 0 . 19 For MDF: ( 0 . 076 ) × ( 0 . 502 ) + ( 0 . 924 ) × ( 0 . 21 ) = 0 . 23 Next, a single volume - weighted average emission level for all three CWP typ es is calculated from the three CWP weighted averages calculated above . Table 12 - 4 in the EPA market profile (USEPA 2010a) also provides annual consumption volumes of the three CWP for the year 2005. Based on these data, the consumption volumes of HWPW, PB, and MDF as a fraction of total theFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page D - 3 total consumption volume for these three CWP was 31. 1 %, 46.4%, and 22.5%, respectively . The single volume - weighted average emission level for all three CWPs is calculated as follows. The emission rate s (in units of flux) are similarly calculated. ( 0 . 311 ) × ( 0 . 13 ) + ( 0 . 464 ) × ( 0 . 19 ) + ( 0 . 225 ) × ( 0 . 23 ) = 0 . 18 **Table D -**  **1 . Pre**  **- Baseline Formaldehyde Emission Levels for CWPs used in th**  **is Assessment**  **CWP Type Dom**  **estic or**

**Import Units**  **Average Value**  **Volume**  

** Weighted** **Average Basis**  HWPW Domestics ppm 0.08 0.13 CARB ATCM Phase 1 Limit

Im ports ppm 0.163 Baseline imports that do not meet any emission standard PB Domestics ppm 0.18 0.19 CARB ATCM Phase 1 Limit

Im ports ppm 0.384 Baseline imports that do not meet any emission standard MDF Domestics ppm 0.21 0.23 CARB ATCM Phase 1 Limit

Im ports ppm 0.502 Baseline imports that do not meet any emission standard **Volume -**  **Weighted Average of the**  **Volum e**  **- Weighted**  **Averages for the Three CWP s (ppm)**  0.18 HWPW Domestics μg/m2

- h 114.3 190.3 Calculated from emission level based on ASTM E1333 (see Appendix E) Im ports μg/m2

- h 232.9 PB Domestics μg/m2

- h 257.2 267.3

Im ports μg/m2

- h 548.8 MDF Domestics μg/m2

- h 496.3 548.9

Im ports μg/m2

- h 1 , 186.5 **Volume -**  **Weighted Average of the**  **Volum e**  **- Weighted**  **Averages for the Three CWP s (μg/m** **2 -**  **h)** 3 06.7Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page D - 4 **Table D -**  **2 .**  **Data U**  **sed to Determine Pre -**  **Baseline Emission Levels for Composite Wood**  **Products Timeline**  **Inform ation** 

**Source HWPW**  **a PB**  **b MDF**  **b Dom**  **estic CWPs**

2002 CARB survey **Production -**  **Weighted Average** 0.09 ppm 0.18 ppm 0.25 ppm **% of U.S.**  **Production Represented in Survey** 73% 53% 83% **Range in Survey Responses** 0.07 to 0.75 ppm 0.13 to 0.24 ppm 0.03 to 0.31 ppm End of 2008 / Beginning of 2009 ANPR

Submissions 75% of domestically - produced

CWP we re CARB Phase 1 compliant 96% of domestically produced CWP were CARB P1 compliant 96% of

domestically produced CWP were CARB P1 compliant Later in 2009 ANPR

Submissions 90% of domestics expected to

be CARB P1 compliant -- -- **Average E**  **mi ssion Levels**  **for Imported Baseline CWPs**  **That Do No t Meet Any of the CARB Emission**  **Standards ( USEPA 2010a**  **) c**  Baseline EPA market

profile 0.163 ppm 0.384 ppm 0.502 ppm a – A submission from HPVA in May 2008 estimated that domestically - produced HWPW will be in compliance with CARB Phase 1. Phase 2 limits require new technologies, which have not been in commercial use and some only recently invented and patented. Additionally, a submission from HPVA in February 2009 estimated that 75% of North Am erican HWPW was CARB certified and soon 90% or more will be CARB certified. “CARB certified” is assumed to mean CARB Phase 1 per the statements made in the May 2008 submission. The term “soon” is uncertain; therefore, the point in time in which 90% of dome stics were expected to meet CARB Phase 1 is uncertain. b

– A submission from CPA in May 2008 stated that “almost all” domestic production is expected to be compliant with CARB Phase 1 and 2. The volume related to “almost all” is uncertain. This submission also states that “eventually” this rate of compliance would be reached; the time frame associated with “eventually” is uncertain. CPA did estimate that 96% of domestics were Phase 1 compliant by the end of 2008. c – Average emission levels of imported CWPs at baseline that do not meet any of the CARB emission standards are used as estimates of the average emission levels of all imported CWPs during pre - baseline. Emission Levels of Baseline CWP and CWP that Would be Produced Under the Anal yt ical Option s Th e EPA market profile provides emission levels for CWPs at baseline. These emission levels and their corresponding volume - based share s of U.S. consumption are summarized in Table D - 3 below. Emission levels and their corresponding volume - based shares of U.S. consumption for the anal yt ical option s were determined based on the baseline values and are given in Table D - 4 through Table D - 6 (USEPA 2009b ) .Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page D - 5 **Table D**  **- 3**  **. Baseline Emission**  **Levels and Corresponding U.S. Consumption (**  **C opy of**  **T able**  **12 -**  **5 in Market Profile) Emission**  **Standard Hardwood Plywood**  **MDF Particleboard** 

**U.S./Can. Non**  ****

**U.S./Can. U.S./Can.**  **Non**   ** U.S./Can.** **U.S./Can. Non**  **** **U.S./Can. Average Em** **issions (ppm)** None 0.058 0.163 - 0.502 0.058 0.384 CARB P1 - - - - 0.090 - CARB P2 0.032 0.015 0.082 0.047 0.057 0.036 ULEF - - 0.024 - 0.042 - NAF 0.013 - 0.035 - 0.013 - **Share of U.S. Consumption** None 0.1% 16.6% - 0.8% 0.2% 1.1% CARB P1 - - - - 1.7% - CARB P2 19.7% 47.4% 79.2% 7.2% 85.0% 1.9% ULEF - - 4.2% - 3.0% - NAF 16.2% - 8.6% - 7.1% - **Weighted Average Emission Levels (ppm)** National Average **0.043 0.076**  **0.057**Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page D - 6 **Table D -**  **4 .**  **Emission Levels**  **and Corresponding U.S. Share of Consumption for Analytical**  **Option 1 (CARB Phase 1) Emission**  **Standard Hardwood Plywood**  **MDF Particleboard** 

**U.S./Can. Non**  ****

**U.S./Can. U.S./Can.**  **Non**   ** U.S./Can.** **U.S./Can. Non**  **** **U.S./Can. Average Em** **issions (ppm)** None - - - - - - CARB P1 ( **previously NOT**  CARB P1) 0.058 a 0.058 - 0.14 b 0.058 a 0.090 **Already at** CARB P1 - - - - 0.090 - CARB P2 0.032 0.015 0.082 0.047 0.057 0.036 ULEF - - 0.024 - 0.042 - NAF 0.013 - 0.035 - 0.013 - **Share of U.S. Consumption** None - - - - - - CARB P1 ( **previously NOT**  CARB P1) 0.1% 16.6% - 0.8% 0.2% 1.1% **Already at** CARB P1 - - - - 1.7% - CARB P2 19.7% 47.4% 79.2% 7.2% 85.0% 1.9% ULEF - - 4.2% - 3.0% - NAF 16.2% - 8.6% - 7.1% - **Weighted Average Emission Levels (ppm)** National Average **0.025 0.073**  **0.05 4**  Source: USEPA 2009b a – This share of consumption wa s previously given for products not meeting any standard at baseline , but the baseline emission level com plies with CARB Phase 1 and thus does not change . b

– This emission level is 67% of the CARB Phase 1 limit.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page D - 7 **Table D -**  **5 . E**  **mission Level**  **s and**  **C orres**  **ponding U .**  **S . S**  **hare of C**  **onsumption for Analytical**  **Option 2 (FSCWPA/CARB P hase 2)**  **Emission Standard**  **Hardwood Plywood MDF**  **Particleboard**

**U.S./Can. Non**  ****

**U.S./Can. U.S./Can.**  **Non**   ** U.S./Can.** **U.S./Can. Non**  **** **U.S./Can. Average Em** **issions (ppm)** None - - - - - - CARB P1 - - - - - - CARB P2 ( **previously not** CARB P2) 0.032 0.032 - 0.082 0.057 0.057 **Already at** CARB P2 0.032 0.015 0.082 0.047 0.057 0.036 ULEF - - 0.024 - 0.042 - NAF 0.013 - 0.035 - 0.013 - **Share of U.S. Consumption** None - - - - - - CARB P1 - - - - - - CARB P2 ( **previously not** CARB P2) 0.1% 16.6% - 0.8% 1.9% 1.1% **Already at** CARB P2 19.7% 47.4% 79.2% 7.2% 85.0% 1.9% ULEF - - 4.2% - 3.0% - NAF 16.2% - 8.6% - 7.1% - **Weighted Average Emission Levels (ppm)** National Average **0.021 0.073**  **0.053** Source: USEPA 2009bFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page D - 8 **Table D -**  **6 . Emission**  **Level s**  **and C orresponding U**  **. S**  **. Share of Consumption for Analytical**  **O ption 3 (NAF)**  **Emission Standard**  **Hardwood Plywood MDF**  **Particleboard**

**U.S./Can. Non**  ****

**U.S./Can. U.S./Can.**  **Non**   ** U.S./Can.** **U.S./Can. Non**  **** **U.S./Can. Average**  **Em issions (ppm)**  None - - - - - - CARB P1 - - - - - - CARB P2 - - - - - - NAF ( **previously not NAF with non**  **** **NAF em**  **issions** ) a 0.013 0.013 0.035 0.035 0.013 0.013 NAF ( **previously not NAF with NAF**  **em issions**  ) b 0.024 - - **Already at** NAF 0.013 - 0.035 - 0.013 - **Share of U.S. Consumption** None - - - - - - CARB P1 - - - - - - CARB P2 - - - - - - NAF ( **previously not NAF with non**  **** **NAF em**  **issions** ) a 19.8% 64. 0 % 79.2% 8.0% 89.9% 3% NAF ( **previously not NAF with NAF**  **em issions**  ) b 4.2% - - **Already at** NAF 16.2% - 8.6% - 7.1% - **Weighted Average Emission Levels (ppm)** National Average **0.013 0.035**  **0.013** Source: USEPA 2009b a – These shares of consumption we re previously given for products not meeting the NAF standard at baseline, and the emission level s were changed to match the domestic baseline NAF emission level s . b - These share s of consumption we re previously given for p roducts not meeting the NAF standard at baseline , but the baseline emission level complies with NAF and thus does not change.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011

**Appendix E** 

**MODELING METHODOLOGY FOR**  **ESTIMATING INDOOR AIR**  **CONCENTRATIONS RELATED TO**  **BASELINE AND ANALYTICAL**  **OPTIONS**Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6 , 2011 Page E - 1 **1 .0**  **Indoor Air Concentration**  **Assessment Metho**  **ds** This section of this appendix describes the modeling methodology for estimating indoor air concentration s related to baseline and anal yt ical option periods for the three composite wood products of interest: HWPW, PB, and MDF. Both inhalation and dermal exposures are assessed. **1 .1**  **CWP Fabrication Indoor Air**  **Concentration Assessment Method**  An airborne concentration of a chemical contaminant in a control volume may be determined from a mass balance on the chemical as presented in Equation 1 ( USEPA 1991a) .



### = Eqn (1)
where: C = Airborne c oncentration of the chemical in the work sp ace (μg/m 3 ) ; S = G eneration rate of the chemical as a vapor or gas from the source of

interest in the work space (μg/h) ; and Q = Volumetric ventilation rate of the work space (m 3 /h) . The following assumptions apply to this model:
 Extinction of the chemical (adsorption, absorption, or chemical transformation) resulting from deposition on walls and equipment, condensation of hot vapors, and photodegradation of chemicals is negligible;  The incoming air is contaminant - free;  The concentration of contaminant at initial time is negligible (there is no background concentration or other generation sources of the contaminant);  The generation and ventilation rates are c onstant over time (steady - state assumption); and  Room air and ventilation air mix ideally . Equation 1 is modified to account for the presence of contaminant in the incoming (outdoor) air. A new mass balance is derived to arrive at Equation 2.



### = + Eqn (2) where : C o ind = C oncentration of contaminant in the outdoor air (μg/m 3 ). To account for non - ideal mixing of the ventilation air and the contaminated room air, a dimensionless mixing factor, k, is used . One interpretation of the mixing factor i s a representation of the fraction, k, of the ventilation air that completel y mixes with an unknown fraction of the room volume and the contaminant emitted from the source at the generation rate, S . The remaining fraction , 1
- k, of the ve ntilation air only mixes with the remaining (andFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6 , 2011 Page E - 2 unknown) fraction of the room volume, which does not mix with the emitted contaminant at generation rate, S (Reinke 2009a) . The mixing factor is multiplied by the ventilation rate to approximate an effective ventilation rate, which accounts for non - ideal mixing. The effective ventilation rate, × , is then substituted into Equation 2 .
= × Eqn ( 3 )



### = + Eqn ( 4 ) Equation 4 is applied to the calculation of the formaldehyde indoor air concentration at a CWP fabrication site as follows:

 The entire site constitutes the work space.  The ideal ventilation rate, Q , is equal to the total ventilation rate of the entire site .  The mixing factor, k, represents a fraction of the work space volume that effectivel y mixes with a fraction of the ventilation air and the formaldeh yde emitted at generation rate, S, to result in the average indoor air concentration, C .  The contaminant c oncentration in outdoor air is equal to the mean formaldehyde concentration in ambient air for industrial land use areas according to the EPA e xposure a ssessment (USEPA 2009b ), which is equal to 6.28 μg/m 3

.  The source generation rate, S, is the rate of formaldehyde off - gassing from the three CWP that are present at a CWP fabrication site (which is the only source considered in this assessment). This input parameter is expressed as the product of the off - gassing emissive flux of formalde hyde (in terms of mass per time per composite wood product emitting surface area) and the emitting surface area.



### = × 

### + Eqn ( 5 ) where : F = Emission rate ( off - gassing emissive flux) of formaldehyde from the composi te wood product (μg/m 2

- h) ; and A = Emitting surface area of the composite wood product (m 2 ) . Formaldeh yd e off

- gassing emissions from CWP decline with time, but this phenomenon is not relevant to the estimation of indoor air concentration in a CWP fabrication site because the residence time of the CWP at the site is expected to be small (day s to weeks) as compared to the time required for the emission rate, F , to decline to an extent that would significantly affect the resulting indoor air concentration (w eeks to months). The concentration, C, becomes the average steady - state concentration of airborne formaldeh yde due to formaldeh yde off - gassing from CWP in the entire CWP fabrication site. Section 3.3.1.1 discusses the input parameters in Equation 5 and their use in the mass balance equation, and the values of these parameter s used are shown in Table 3 - 4 of that section. The emissive flux values in Table 3 - 4 are derived from data in Appen dix D .Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6 , 2011 Page E - 3 **1.2 Office Buildings**  **In door Air Concentration**  **Assessment Method**  A mass balance approach similar to the one used for estimating formaldehyde indoor air concentration in CWP fabrication sites is used for the estimation of indoor air concentration in office buildings. The rate of formaldeh yde off - gassing from CWP components of office furniture that is expected to be present in a typical office work space is equated to the rate of exhaustion of airborne formaldeh yde from this typical office work space through ventilation. The rate of formaldeh yde off - gassing from CWPs is estimated using a formaldeh yde source model in which the generation rate of formaldeh yd e is equal to an emission rate multiplied by an emitting surface area of the of fice furniture expected to be present in a ty pical office work space. The rate of exhaustion of indoor air formaldeh yde is based on an ASHRAE outdoor air ventilation standard for this ty pical office work space. Several parameters for the model, specifica lly

emitting surface area and ventilation rate, are based on the modeling work presented in Carter and Zhang, 2007 and the BIFMA M7.1 - 2005 standard test method. The remaining parameter, the emission rate , is determined using data from the EPA market profi le (USEPA 2010a), similarly

as was done for the CWP fabrication method, and using other assumptions and calculations described in subsection 1.2.3 and 1.2.4 below. Carter and Zhang attempted to define a standard, representative “worst - case” office environm ent, in support of the BIFMA M7.1 - 2005 standard test method. Carter and Zhang discussed using the BIFMA office environment model to calculate the impact of office furniture on indoor volatile organic compound (VOC) concentrations, such as formaldeh yde. S teady - state indoor airborne formaldeh yde concentrations from office furniture in open work space areas and private offices are calculated from the office environment model with the following basic components:
 Inputs:

— Outdoor, clean air ventilation flow rate ,

— Surface area of composite wood products , and

— Formaldeh yd e emission rates of composite wood products as a constant value ;  Output:

— Steady - state concentration at a specific time (C(t)) . The work b y Carter and Zhang assumes the outdoor, clean air does not contain the VOC of interest (in this case, formaldehyde). This exposure assessment accounts for observed concentrations of formaldehyde in ambient air. This exposure assessment assumes the outdoor air used for office building ventilation contains formaldehyde at a concentration equal to the mean formaldehyde concentration in ambient ai r in commercial areas according to the EPA e xposure a ssessment (USEPA 2009b ). **1 .**  **2 .1**  **Calculation Method** The steady - state c oncentration in a typical o ffice e nvironment due to e missions from an o ffice w orkstation s ys tem or individual components may be calculated using Equation 6 (Carter and Zhang, 2007) , which is based on the same mass balance principles as the mass balance model used for the CWP fabrication me thod :Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6 , 2011 Page E - 4

= × + Eqn ( 6 )



### = × 

### + Eqn ( 7 )
where: C = concentration in the defined office environment at the particular time

( μ g/m 3 ) due to a specific component ; A = source amount in the office environment ( m 2 ) ; E = estimated emissi ve flux at a particular time ( μ g/m 2

- h ) ; Q = outdoor air ventilation rate in the office environment (m 3 /h) ; and C o com = concentration of formaldehyde in the outdoor air for commercial land use

areas (μg/m 3 ) . The total overall concentration is calculated b y summing the contribution from each component. This summation results in the following:



### = ∑ × 

### + Eqn ( 8 ) Here, the summation is performed over all workstation components i, where i represents each component ty

pe of the office workstation. This model is applied to two office workstation types: open plan workstations and private office workstations. The following subsections present the values used for the model parameters for both office works tation ty pes. The model parameters are:
 The source amount of each workstation component, A i , where the components are:

— Panels ,

— Work surfaces ,

— Storage external surfaces ;  The emissive flux of each workstation component, E i ; and  The outdoor air ventilation rate in the office workstation environment, Q. **1 .2**  **.2 B**  **IFMA 2005 Workstation Model**  **Parameters A**  **i and Q**  As used in Carter and Zhang 2007, the BIFMA standard test method M7.1 - 2005 13 specifies two sets of workstation parameters based on typical open plan and private office environments. 14 These t ypical workstation parameters are for the purpose of estimating the impact of office furniture on the VOC concentrations in office spaces. F or a “t ypical open plan office environment of a single workstation sy stem,” BIFMA specifi es : 13 Updated test method M7.1 - 2007 has since been published with identical workstation parameters. BIFMA M7.1 - 2007 has also been adopted by ANSI as an ANSI standard . 14 The state of CA has also adopted the BIFMA standards for open plan workstations: CA, 2007. California Department of Public Health. Open Office Panel Systems Indoor Air Quality Specification.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6 , 2011 Page E - 5

 Total workstation area dimensions: floor area of 5.94 m 2 (64 ft2 ) by 2.74 m high (9 ft high) (576 ft 3 or 16.3 m 3 ) ;  Accounts for standard 1.83 m x 1.83 m (6 ft x 6 ft) open plan workstation system, traffic area and support space (copiers, files, storage, etc.) ; and  Outdoor air ventilation rate (Q) of 4.17 L/s (8.84 cfm) (minimum required ventilation rate per ASHRAE Standard 62.1 - 2004) . For a “ty pical private office environment of a single workstation s ys tem,” BIFMA specifies:
 Total office dimensions: floor area of 23.78 m 2 (256 ft2 ) by 2.74 m high (9 ft high) (2 , 304 ft 3 or 65.2 m 3 ) ;  Accounts for standard 13.38 m 2 (144 ft2 ) private office workstation system, traffic area and support space (copiers, files, storage, etc.) ; and  Outdoor air ventilation rate (Q) of 9.63 L/s (20.4 cfm) (minimum required ventilation rate per ASHRAE Standard 62.1 - 2004) . Individual open plan and private office workstation component surface ar eas and outdoor air ventilation rates are tabulated in Table E - 1 .

**Table E -**  **1 . BIFMA**  **M7.1 -**  **2007 St**  **andard Workstation Model Parameters**
**Workstation System** **Type Workstation Component Type Surface Area (A**  **i )**  **Outdoor Air Ventilation**  **Rate (Q)**  **Panel Area Work Surface** 

**Area Storage Total** 

**External Area** Open Plan 11.08 m 2 (119.3 ft2 ) 6.103 m 2 (65.69 ft2 ) 4.569 m 2 (49.18 ft2 ) 15.0 m3 /h

(8.84 cfm) Private Office 7.633 m 2 (82.16 ft2 ) 6.734 m 2 (72.48 ft2 ) 10.55 m 2 (113.6 ft2 ) 34.7 m3 /h

(20.4 cfm) To determine the workstation surface areas listed above in Table E - 1 , Carter and Zhang first determined the footprint size for all workstations present on the office building floor plans (4,594 open plan workstations and 4 30 private office workstations). The 50 th percentile workstation footprint size was taken as representative of the standard workstation size, resulting in areas of 3.34 m 2 (36 ft2 ) for an open plan workstation and 13.47 m 2 (145 ft2 ) for a private office. Because total workstation surface areas vary within workstations of identical floor area, the 90 th percentile conditions for total furniture surface area within the 50 th percentile workstation footprint size were chosen to provide a representative office environment. This resulted in 1,982 open plan workstations and 142 private offices. Within this data set, the panel, work surface and storage surface areas were determined as a percentage of total workstation surface area and averaged, resulting in the va lues presented in Table E - 1 . The parameter values in Table E - 1 are also presented in Table 3 - 8 in the main body of the report. The ventilation rate values originally presented in Carter and Zhang, 2007 were in units of L/s and cfm. The ventilation rate values were converted to units of m 3 /h for use in the assessment method equation.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6 , 2011 Page E - 6 **1 .**  **2.3 Formaldehyde Emissive Flux for Workstation Component Types**  **(E i** **)** The BIFMA standard and the work b y Carter and Zhang do not contain an y information on observed formaldeh yde emission rate s of actual office workstations. Carter and Zhang provide example workstation emission rate s of formaldeh yde but do not discuss the statistical significance of these values such as being representative, worst case, etc. The formaldeh yd e emission rate of a workstation component is a function of the ty pe of CWP that the component is constructed of and the typ e of finishing, if an y, for the CWP. The finishing of CWP is the overlay of the CWP with other material that retard emissions from the surface on to wh ich they

are applied. This effect is described as barrier effectiveness , or a percent reduction of the emission rate of the CWP substrate ( CPA 2003a). The literature search did not yi eld an y information on how the three CWPs are finished and the extent to which they are used together and in combination with other material to fabricate the various components of the workstations. This information is needed for the estimation of representative values of the emissions rate s. Due to these data gaps, indoor ai r formaldeh yde concentration was estimated for a range of emission rate s that is derived from a what - if anal ys is. For the what - if anal ys is, the panel and work surface components were assumed to be made entirel y of a single CWP ty pe, with the CWP ty

pe chan ging for each iteration of the what - if anal ys is. Storage external surfaces were assumed to be constructed of materials other than CWPs with no emission of formaldeh yde. The what - if anal ys is follows the algorithm described in Section 3.3.1.2 and in Table 3 - 6 of the main body of the report . For each iteration of the what - if analy sis, the emissive flux of the workstation component ty pe is calculated from the emissive flux (emission rate in units of flux) of the CWP ty pe , extent of finishing of the component ty pe, and barrier effectiveness chosen for the given iteration as follows:

= × ( 1 − ) × + × ( 1 − ) Eqn ( 9 ) where: E i = emissive flux of the workstation component ty pe (μg/m 2

- h) ( i = panels, work surfaces, or storage external surfaces); E CWP = emissive flux of the composite wood product used to cons truct the

workstation component type (μg/m 2

- h) ( CWP = HWPW, PB, or MDF); BE = barrier effectiveness of the finishing , or overlay , of the workstation

component ty

pe, expressed as a unitless fraction ; and Fin i = fraction of the workstation component surface area that is finished or

overlayed with a barrier effectiveness of BE, expressed as a unitless fraction ( i = panels, work surfaces, or storage external surfaces). The values of E CWP used in Equation 9 are provided in Table 3 - 8 in the main body of the report , which are derived from the tables in Appendix D . The values of BE are also provided in Table 3 - 8 in the main body

of the report. The barrier effectiveness values used to estimate the low - end and high - end concentrations were obtained from CPA ( CPA 2007a) . The derivation of the intermediate valu e of barrier effectiveness is described in the following subsection (subsection 1.2. 5 ) of this appendix.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6 , 2011 Page E - 7 **1.2.4 Am**  **bient Air Formaldehyde Concentration in Commercial Land Use Areas**  **(C o**  **com )**  This exposure assessment assumes the outdoor air used for office building ventilation contains formaldeh yde at a concentration equal to the mean formaldeh yde concentrat ion in ambient air in commercial land use areas according to the EPA e xposure a ssessment (USEPA 2009b ). Table 3 - 8 in Section 3.3.1.2 of the main body of the rep ort provides the value for the concentration of formaldeh yde in the outdoor air for commercial land use areas, which is 3.26 μg/m 3

. The overall equation used to calculate the formaldehyde concentration is presented in Equation 10 . Equation 10 is calculate d for each iteration of the algorithm described in Section 3.3.1.2 of the main body

of the report using the parameter values given in Table 3 - 8 . Recall that it i s assumed storage external surfaces are not constructed of CWPs and do not emit formaldeh yde. T herefore, storage external surfaces are not included in Equation 10 .

= × ( ) × × ×

× ( ) × × × + Eqn ( 10 ) Note that the emission rate s used in this analy sis are for new composite wood products and do not account for the decay of emissions with time. Therefore, this method to estimate formaldeh yde exposures in office buildings onl y accounts for new office furniture and does not account for the decay

of emission rate s with time. Data to describe the decay of emission rate s with time were not identified. **1 .**  **2. 5**  **Determination of Intermediate Value for Barrier Effectiveness**  The ANSI / BIFMA M7.1 - 2007 standard test method specifies a full - scale chamber test method for determining VOC emissions of complete workstation sy stems, workstation components, and seating. The determined emissions can then be used to estimate the impact of the workstation on the VOC concentration in a ty pical office environment. The standard test method specifies a chamber ventilation rate of 12 to 20 cfm (22 to 36 m 3 /h) per workstation system during emissions testing. BIFMA standard X7.1 - 2007 is a voluntary standard for meeting VOC emission limits from office furniture. This standard specifies a formaldehyde limit of 50 ppb as measured using BIFMA M7.1 - 2007 for all workstation sy stems ty pes. BIFMA test method M7.1 - 2007 states that the background conc entration of the compound of interest (such as formaldeh yde) in the chamber should be measured prior to conducting the chamber test. This background concentration is then subtracted from the measured concentration in the test chamber exhaust or return air . Therefore, the resulting concentration, which is equated to the emission rate from the workstation divided by the chamber ventilation rate, is a net concentration due onl y to the workstation. The 50 ppb formaldeh yde limit is therefore the net concentration determined from the chamber test. To define an intermediate case, EPA assumed a typical office workstation (both open plan and private office) meeting the BIFMA X7.1 - 2007 standard for formaldeh yd e. EPA estimated that 100 percent of the workstation panel and 50 percent of the work surface area were coated with a barrier of unknown effectiveness . These assumed values are logical bounding values. WorkFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6 , 2011 Page E - 8 surfaces are expected to be finished on their upper surface , and panels may be finished on both surfac es for aesthetic purposes. EPA averaged the pre - baseline emission rate s to estimate an average CWP emission rate for the workstation panel and work surface areas ( see Appendix D for derivation of the average pre - baseline emiss ion rate ) . The parameters used are shown in Table E - 2 . Since chamber testing requires that the net formaldehyde concentration be used to determine the emissions from the workstation, the ambient air concentration is s ubtracted f rom Equation 10 presented in the previous subsection 1.2. 4 . The net formaldeh yde concentration , C net , is then used in stead in the left - hand side of Equation 10 . This new equation is presented below and is solved for the intermediate barrier effectiveness using the values for concentration and each parameter given in Table E - 2 .

= × ( ) × × ×

× ( ) × × × Eqn ( 11 ) **Table E -**  **2 . Parameters Used to Determine**  **Intermediate Barrier**  **Effectiveness Param**  **eter Value**  **Source** Net Formaldehyde C oncentration in C hamber 61.5 μg/m3 BIFMA X7.1 - 2007 standard for formaldehyde (unit converted from 50 ppb) Panel Emission Rate 3 06.7 μ g/m 2

- h Weighted average of domestic and import

pre - baseline emission rate s , averaged over all three CWP types ( see Section 3 and Appendix D ) Work Surface Emission Rate 3 06.7 μ g/m 2

- h Storage Panel Emission Rate 0 μ g/m 2

- h Carter 2007a Panel Area 11.08 m 2 (open plan) 7.633 m

2 (private office) Carter 2007a Percent Panel Area with Barrier 100% EPA Assumption Work Surface Area 6.1 m 2 (open plan) 6.734 m

2 (private office) Carter 2007a Percent Work Surface Area with Barrier 50% EPA Assumption Storage Panel Surface Area 4.57 m 2 (open plan) 10.55 m

2 (private office) Carter 2007a Storage Panel Surface Area with Barrier N/A EPA Assumption Ventilation Rate 36 m3 /h The high - end ventilation rate for chamber testing specified in BIFMA M7.1 - 2007 N/A

– Not applicable The intermediate barrier effectiveness calculated from the parameters for the open plan and private office workstations were 71 percent and 65 percent, respectively . These intermediate barrier effectiveness values were used for all intermediate indoor air concentration c alculations for open plan and private office workstations following the algorithm outlined in Section 3.3.1.2 and Table 3 - 6 in the main body of the report.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6 , 2011 Page E - 9 **1.3 Calculation of ADC and LADC from Model Results**  **for CWP Fabrication and Office Buildings**  Mode l results from Equation 5 and Equation 10 above are inputs to estimate ADC and LADC. The average daily

concentration (ADC) and lifetime - average daily concentration (LADC) are calculated from the concentration for each modeled scenario outlined in Section 3 of the main body of the report for each baseline and anal yt ical - option scenario. ADC and LADC are calculated from Equation 12 ( EPA 2009a).



### = × × × Eqn ( 12 )
where: EC = Exposure con centration (μg/m 3 ) ; C = Contaminant concentration in air (μg/m 3 ) ; E D = Exposure duration (hr/day ; default: 8) ; EF = Exposure frequency (days/y r; default: 250) ; WY = Working years per lifetime (years; ADC and LADC: 40 years) ; and AT = Averaging time (lifetime in years x 365 day s/ yr x 24 hours/day; ADC: 40

ye ars, LADC: 70 years) . **1 .**  **4 Dermal Exposure Assessment Method**  **for All Life Cycle Stages** EPA has two general categories of assessing dermal exposure when measurements are not available: ( 1) qu antitative dermal exposure models and ( 2) qualitative dermal exposure assessments. Both categories of dermal exposure assessments are discussed below. EPA has developed a series of standard models for quantitatively estimating worker dermal exposures to liquid and solid chemicals duri ng various ty pes of activities. To estimate dermal exposure, all of these dermal exposure models assume a specific surface area of the skin that is contacted b y a material containing the chemical of interest, as well as a sp ecific surface density of the material on the skin . EPA has developed a series of standard models for quantitatively estimating worker dermal exposures to liquid and solid chemicals duri ng various ty pes of activities. To estimate dermal exposure, all of these dermal exposure models assume a specific surface area of the skin that is contacted b y a material containing the chemical of interest, as well as a specific surface densi ty of the material on the skin. The models also assume no use of controls or glo ves to reduce the exposure. These assumptions and default parameters are defined based on the nature of the exposure (e.g., one hand or two hand, immersion in material, contact with surfaces). The standard EPA dermal model e quation is shown in Equation 1 3 (USEPA 1991a ; USEPA 2000b ).

= ×

_ × × Eqn ( 13 ) where: EXP dermal = Dermal exposure to the liquid or solid chemical per day (mg chemical/worker - day) ;Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6 , 2011 Page E - 10 AREA surface = Surface area of the skin that is in contact with liquid or solid

material containing the chemical (840 cm2 ; EPA/OPPT 2 - Hand Dermal Contact with Liquid Model ); Q remain_skin = Quantity of the liquid or solid material containing the chemical that remains on the skin after contact (0.7 - 2.1 mg/cm 2

- event ; EPA/OPPT 2 - Hand Dermal Contact with L iquid Model ) ; F chem = Weight fraction of the chemical of interest in the material being

handled in the activity ; and N event = Frequency of events for the activity (EPA default = 1 ev ent/worker - day) . Dermal dose s in this report are estimated in units further normalized by worker body weight, as indicated in Equation 14 :

_ = ⁄ Eqn ( 14 ) where : EXP dermal_bw = Dermal exposure to the liquid or solid chemical per day normalized by

worker body

weight (mg chemical/kg - day) ; EXP dermal = Dermal exposure to the liquid or solid chemical per day (mg chemical/worker - day) ; and BW worker = Body weight of an average worker (kg; EPA default value = 70 kg

(USEPA 1997a) . For several categories of exposure, EPA uses qualitative assessments to estimate dermal exposure. Table E - 4 summarizes these categories and the resulting qualitative dermal exposure assessments. Where c hemicals were monomers that had been reacted or additives that would not likely to be released from a resin matrix, dermal exposures are characterized as not quantifiable.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report October 6 , 2011 Page E - 11 **Table E**  **- 3**  **. Standard EPA Default Values for Use in the Worker Dermal Exposure Models**

**Default Model Example Activities**  **AREA su**  **rface a**  **(cm 2**  **) Q**  **remain_skin b** 

**(m g/cm**  **2 -**  **event) Resulting Contact** 

**AREA su**  **rface × Q**  **remain_skin (m**  **g/event) Physical Form**  **: Liquids** EPA/OPPT 1
-Hand Dermal Contact with Liquid Model  Liquid sampling activities  Ladling liquid/bench - scale liquid transfer 420 (1 hand mean) Lo w: 0.7

High: 2.1 Lo w: 290

High: 880 EPA/OPPT 2
-Hand Dermal Contact with Liquid Model  Maintenance  Manual cleaning of equipment and containers  Filling drum with liquid  Connecting transfer line 840 (2 hand mean) Lo w: 0.7

High: 2.1 Lo w: 590

High: 1,800 EPA/OPPT 2
-Hand Dermal Immersion in Liquid Model  Handling wet surfaces  Spray painting 840 (2 hand mean) Lo w: 1.3

High: 10.3 Lo w: 1,100

High: 8,650 **Physical Form : Solids**  EPA/OPPT 2
-Hand Dermal Contact with Container Surfaces Model  Handling bags of solid materials (closed or em pty) No defaults No defaults < 1,100 c EPA/OPPT 2
-Hand Dermal Contact with Solids Model  Solid sampling activities  Filling/dumping containers of powders, flakes, granules  Weighing powder/scooping/mixing (i.e., dye weighing)  Cleaning solid residues from process equipment  Handling wet or dried material in a filtration and drying process No defaults No defaults < 3,100 c

a - These default values were adopted in the 2000 EPA report on screening - level dermal exposure estimates ( USEPA 2000b ) and are the mean values for men taken from the EPA Exposure Factors Handbook, 1997 ( USEPA 1997a ). b - These default values were adopted in the 2000 EPA report on screening - level dermal exposure estimates ( USEPA 2000b ). The report derived the selected ranges of values for liquid handling activities from: U. S. EPA. A Laboratory Method to Determine the Retention of Liquids on the Surface of Hands. U.S. Environmental Protection Agency, Office of Pollution Prevention and Toxics, Exposure Evaluation Division. EPA 747 - R - 92 - 003. September 1992. c - These default va lues were adopted in the 2000 EPA report on screening - level dermal exposure estimates ( USEPA 2000b ). The report derived values for dermal contact for solids handling activities from: Lansink, C.J.M., M.S.C. Breelen, J. Marquart, and J.J. van Hemmen: Skin E xposure to Calcium Carbonate in the Paint Industry. Preliminary Modeling of Skin Exposure Levels to Powders Based on Field Data (TNO Report V 96.064). Rijswi jk, The Netherlands: TNO Nutrition and Food Research Institute, 1996.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6 , 2011 Page E - 12 **Table E -**  **4 .**  **EPA Default Qualitative Assessments for Screening -**  **Level Estimates of Dermal Exposure**  **Category Derm**  **al Assessment** Corrosive substances (pH>12, pH<2) Negligible Materials at temperatures >140  F (60  C) Negligible Cast Solids (e.g., molded plastic parts, extruded pellets ) Non - Quantifiable (Some surface contact may occur if manually transferred) “Dry” surface coatings (e.g., fiber spin finishes, dried paint) Non - Quantifiable (If manual handling is necessary and there is an indication that the material may abrade from the surface, quantify contact with fingers/palms as appropriate) Gases/Vapors Non - Quantifiable (Some contact may occur in the absence of protective clothing) Source: USEPA 1991a **3 .0**  **Converting Units of Concentration** This section presents the methodology for converting between airborne concentrations measured in volume - or mole - based parts - per million (ppm) and airborne concentrations measured in mi cro grams per cubic meter ( μ g/m 3 ). This assessment conducts exposure and dose calculations us ing concentrations in mg/m 3 or μ g/m 3 depending on the magnitude of the values. This section presents concentration units in μ g/m 3

. To convert the units of concentration between a volume - or mole - based ppm to ug/m 3 at ambient room conditions, it is assumed that the ideal gas law applies to a mixture of formaldeh yde and air at ambient conditions. T he mass - based concentration of formaldeh yde in air from the ideal gas law is solved for as follows:



### = = × 1 , 000 , 000 × 1 , 000 Eqn ( 1 5 ) where: C = formaldeh yde concentration ( μ g/m 3 ) ; m = total mass of formaldeh yde ( μ g ) ; V = total volume of gas (m 3 ) ; y = mole fraction of formaldehyde (mol/mol) ; P = total pressure (atm) ; M = molecular weight of formaldehyde (g/mol) ; R = universal gas constant (m 3

- atm/kmol - K) ; and T = temperature (K) . Here, the mole fraction of formaldeh yd e, y , is equal to the formaldeh yd e concentration in parts per million (ppm) divided by one million. At ambient conditions (1 atm and 298 K), with aFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6 , 2011 Page E - 13 formaldeh yde mole cular weight of 30.03 g/mol and a gas constant of 0.082 m 3

- atm/kmol - K, the unit conversion is 1 , 229 μ g/m 3 per ppm of formaldehyde. **4 .0**  **ASTM E1333 Large Chamber Test Method** In this assessment, an e quation is needed to calculate emission rate s from the meth ods use d to measure them. In this assessment, the ASTM E1333 large chamber test method is used to convert between chamber - test measured formaldehyde concentrations (emission levels) and emission rate s. The equation used is Equation 1 5 below. This subsec tion presents some general background information on chamber test methods and then describes the ASTM E1333 large chamber test method. The standard method for measuring emissions from composite wood product s is to use a test chamber ( Kim 2007a). The chamb er method is based on a mass balance approach that measures the mass flow rates of formaldehyde entering and leaving the chamber s ys tem at stea dy - state ( Hodgson 2007a). Standard chamber methods are either referred to as the large or small chamber method based on the specified chamber size. Ingeneral, c ommon large chamber methods for estimating formaldeh yde emissions require minimum chamber sizes between 10 to 22 cubic m eters. In addition to chamber size, large chamber methods specify several test paramete rs, including the loading ratio , air exchange rate, chamber temperature and humidity . This section discusses the ASTM E1333 large chamber test method. The ASTM E1333 h as been used b y the composite wood product industry for establishing compliance of their products with the U.S. Department of Housing and Urban Development (HUD) and ANSI standards for f ormaldehyde emissions ( Hodgson 2007a ). It is also the reference test method specified in CARB’s regulation. The purpose of ASTM E1333 is to measure the formaldeh yd e concentration in air and the emission rate from a number of large test samples (composite wood products) containing formaldeh yde under conditions designed to s imulate product use. ASTM E1333 is primarily used for testing newl y m anufactured panel products (ASTM 200 2a). Prior to testing, this method requires test samples to be conditioned for seven day s. During conditioning, the samples must be placed in a mann er such that there is a minimum of six - inch spacing in - between the panels. The conditioning is followed by a 16 - to 20 - hour exposure period in a large - scale chamber. The chamber is operated at specific product loading ratios and an air exchange rate that are t ypical of the indoor environment. Air samples are taken from the chamber at steady - state conditions and the formaldeh yd e concentration is anal yz ed. Table E - 5 lists the product - specific loading ratios for the composite wo od products of interest. Table E - 6 lists the test parameters for ASTM E1333. **Table E -**  **5 . ASTM E1333 Loading Ratios for Hardwood Plywood, Medium**  **- Density**  **Fiberboard, and Particleboard Composite Wood Product**  **Loading Ratio (L)**  **ft 2**  **/ft 3**  **m 2**  **/m 3**  Hardwood plywood 0.13 0.43 Medium - density fiberboard 0.08 0.26 Particleboard 0.13 0.43Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6 , 2011 Page E - 14 **Table E -**  **6 . Specified Parameters for ASTM E1333**  **Test Param eter**  **ASTM E1333 Value** Loading Ratio (m2 /m 3 ) (L) See Table E - 5 Minimum Chamber Size (m 3 ) 22.7 Tem perature (°C) 25 ±1 Relative Humidity (%) 50 ±4 Air Exchange Rate (h - 1 ) (n) 0.5 ±0.05 Edge Sealing None Conditioning 7 days ±3 hrs Test Duration 16 to 20 hrs The emission rate of formaldehyde is dependent on several parameters. At steady - state conditions, the emission rate ( ER) or area - specific emission rate of formaldehyde in μ g/m 2

- h is calculated as:



### = × × Eqn ( 16 ) where: V = chamber volume (m 3 ) ; n = chamber air exchange rate (h - 1 ) ; C net = net formaldeh yd e chamber concentration ( μ g/m 3 ) ; and A = total surface area of sample (m2 ) . The emission rate represents the flux of formaldehyde or the mass of formaldehyde emitted per unit area of wood material per time ( μ g/m 2

- h). As seen in Equation 16 , the emission rate is a function of the chamber volume, V, and test sample surface area, A. The ratio of these parameter s is often specified in a large chamber meth od in terms of a “loading ratio.” Loading ratios (L) are calculated as the emittin g surface area of the wood sample divided by the chamber volume (m 2 /m 3 ):

= , or = × Eqn ( 17 ) Substituting Equation 17 into Equation 16 yi elds Equation 18 , which is used to calculate emission rate s from the measured net formaldeh yde chamber concentration (emission level) using the parameters given in Table E - 5 and Table E - 6 .



### = × Eqn ( 1 8 ) In chamber methods, air is continuously circulated inside the test environment. The area - specific air flow rate (m 3 /m 2 - h or m/h) is the ratio between the air flow rate Q (m 3 /h) entering the chamber and the total surface area, A, of the test sample. The area - specific air flow rate is als o calculated as the product of the chamber volume, V, and the air exchange rate, n, divided b y the test sample surface area as follows.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6 , 2011 Page E - 15



### = × Eqn ( 19 ) Substituting Equation 17 into 19 , the area - specific air flow rate may be expressed as a quotient of n/L .



### = × × 

### = Eqn ( 20 ) After steady - state conditions are achieved, a minimum of two air samples are taken from the chamber at a rate of 1±0.05 L/min for 60 minutes ±5 seconds. The quantity of formaldehyde in the sample is determined by an adaptation of the National Institute for Occupational Safet y and Health (NIOSH) 3500 chromotropic acid test procedure (ASTM 200 2a), where air is bubbled through a 1 - percent sodium bisulfite solution and anal yz ed us ing a UV - Vis spectrophot ometer.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011

**Appendix F**  **PRE -**  **BASELINE FORMALDEHYDE EXPOSURES FROM OSHA IMIS**  **BY WORKER ACTIVITY**  **AND INDUSTRY SECTOR FOR COMPOSITE WOOD PRODUCT**  **FABRICATORS**Formalde hyde Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page F - 1 Background on IMIS Data IM IS is designed to collect, process, retrieve, and communicate penalty assessment, arbitration, and collection information regarding OSHA inspections. For each data point, the data base contained information on the following data elements:
 Inspection date;  Id entity

of inspected facility ;  Inspection ty

pe (e.g., inspection in response to a complaint, referral, or as part of a program);  Worker job description;  Exposure concentration;  Exposure concentration measurement type (personal or area monitoring);  Exposure ty

pe ( i.e. , time weighted average (TWA) or peak exposure);  Frequency

or duration of exposure;  Number of emplo ye es at the inspected facility ;  Number of emplo ye es exposed; and  Appl icable OSHA PEL. OSHA IMI S data for most of the NAICS codes given in Table 2 - 1 were obtained from OSHA in June 2010. The OSHA occupational exposure limits for formaldeh yde are given in Appendix C . The “exposure t ypes” for the obtained data include TWA, STEL , ceiling, peak exposures or not detected or not found. Only TWA data were used to develop exposure estimates (in terms of average dail y concentrations (ADCs) and lifetime - average dail y concentrations (LADCs)). STEL , ceiling, and peak me asurements are not representative of daily average concentration levels and were therefore excluded (refer to Appendix A for a definition of these terms). Also, measurements that resulted in a non - detected formaldehyde concentration do not include their m easurement t ype in the OSHA IMI S database ( i.e. , TWA or STELmeasurement ty pe). Therefore, it is unknown whether a non - detected value was the result of a measurement over an extended duration of time for the purpose of determining TWA exposure or measurem ent over a fifteen - minute duration. For this reason, non - detected and not - found results were excluded except as discussed below. Additionally , only

personal monitoring data were included in the assessment except in the case of the retail life cycle stage. IM IS contains few personal monitoring data from 2002 and onward for this life cycle stage, and the inclusion of area monitoring data approximately doubled the number of included data points. Most of these area monitoring data have non - detect values. Ar ea monitoring data in a strictly retail setting are considered representative of potential worker exposure and are expected to be TWA data. The non - detected value was set equal to the lowest reliable quantitation limit (RQL) identified among OSHA’s sampli ng and analy sis methods for formaldeh yde. The RQL was identified as 0.00058 ppm ( OSHA 2010b ). Also, any detected values for all life cycle stages less than this RQLwere set equal to the RQL.Formalde hyde Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page F - 2 Grouping Data b y Worker Activity This appendix presents a summary of OSHA IMIS data for CWP fabrication industry sectors grouped b y their worker activity. This grouping was performed as part of this exposure assessment to provide perspective as to the different worker activities monitored by OSHA and to present st atistics of the monitoring data according to worker activity . There is some uncertainty about the worker activities recorded in IMI S. The worker activities were not recorded or identified in a consistent manner in IMI S. For example, for CWP fabrication , gluing activities are identified as “apply wood glue” and “glue machine operator”. Therefore, this appendix presents OSHA IMI S data grouped such that similar worker activities are grouped into a single worker activity

category . Additionally , some worke r activities are similar or can be expected to result in similar exposures, such as “sawing”, “routing”, and “cutting”, and are compiled into a single category . Other worker activities are compiled into a single category due to uncertaint y in the exact jo b description, such as “wood worker”, “laborer”, or “operator” . Table F - 1 presents a summary of the TWA, personal monitoring data from OSHA IMI S for CWP fabrication organized by worker activit y description categories.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report October 6, 2011 Page F - 3 **Table F**  **- 1.**  **Pre -**  **Baseline Fo**  **rmaldehyde Exposures by Organized by Worker Activity Category for Composite Wood Product**  **Fabr icators from OSHA IMIS** 

**Industry Worker** 

**Activity Description**  **Number of**

**Sites Monitored**  **Number of**

**Data Points Monitored** 

**Form aldehyde**  **Concentration (ppm)**  **Monitored**

**Form aldehyde**  **Concentration (m**  **g/m 3**  **) Year**  **Description of Concentration**  **Level**

Wood Kitchen Cabinets and Countertop Manufacturing Painting /

Laminating / Finishing / Spraying 14 22 0.69 0.85 2003 Maximum 0.15 0.18 2004, 2007 Median 0.0006 0.001 2004 Minimum Fabricating / Assembling / Building 1 1 0.2 0.25 2004 1 Data Point
Other Operations / Maintenance 1 2 0.52 0.639 2004 Maximum 0.28 0.343 2004, 2004 Median 0.038 0.047 2004 Minimum Sawing / Cutting / Routing 1 2 0.070 0.086 2005 Maximum 0.054 0.066 2005, 2005 Median 0.037 0.046 2005 Minimum Sanding 1 1 0.035 0.043 2003 1 Data Point Com pliance, Safety, and Health Officer 1 1 0.025 0.031 2006 1 Data Point Upholstered Household Furniture Manufacturing Painting /

Laminating / Finishing / Spraying 1 2 0.092 0.11 2004 Maximum 0.06 0.074 2004, 2004 MedianFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report October 6, 2011 Page F - 4 **Table F -**  **1. Continued**

**Industry Worker** 

**Activity Description**  **Number of**

**Sites Monitored**  **Number of**

**Data Points Monitored** 

**Form aldehyde**  **Concentration (ppm)**  **Monitored**

**Form aldehyde**  **Concentration (m**  **g/m 3**  **) Year**  **Description of Concentration**  **Level** 0.028 0.034 2004 Minimum Other Operations / Maintenance 2 3 0.11 0.137 2003 Maximum 0.04 0.049 2004 Median 0.04 0.049 2004 Minimum Gluing 1 1 0.009 0.011 2003 1 Data Point

Nonupholstered Household Furniture Manufacturing Painting /

Laminating / Finishing / Spraying 8 10 0.59 0.73 2004 Maximum 0.330 0.405 2008, 2007 Median 0.031 0.038 2008 Minimum Fabricating / Assembling / Building 1 1 0.22 0.27 2007 1 Data Point Other Operations / Maintenance 1 5 0.1129 0.139 2009 Maximum 0.0625 0.077 2009 Median 0.0278 0.034 2009 Minimum Com pliance, Safety, and Health Officer 3 3 0.14 0.172 2008 Maximum 0.089 0.109 2009 Median 0.0712 0.088 2008 MinimumFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report October 6, 2011 Page F - 5 **Table F -**  **1. Continued**

**Industry Worker** 

**Activity Description**  **Number of**

**Sites Monitored**  **Number of**

**Data Points Monitored** 

**Form aldehyde**  **Concentration (ppm)**  **Monitored**

**Form aldehyde**  **Concentration (m**  **g/m 3**  **) Year**  **Description of Concentration**  **Level**

Wood Office Furniture Manufacturing Painting /

Laminating / Finishing / Spraying 4 8 0.58 0.713 2004 Maximum 0.055 0.068 2004, 2005 Median 0.009 0.011 2004 Minimum Fabricating / Assembling / Building / Laboring 1 1 0.02 0.025 2004 1 Data Point
Other Operations / Maintenance 1 2 0.04 0.049 2005 Maximum 0.03135 0.039 2005, 2005 Median 0.0227 0.028 2005 Minimum Sawing / Cutting / Routing 2 4 0.067 0.082 2004 Maximum 0.049 0.060 2004, 2004 Median 0.0048 0.006 2004 Minimum Sanding 1 3 0.028 0.034 2005 Maximum 0.027 0.033 2005 Median 0.0219 0.027 2005 Minimum Institutional Furniture Manufacturing Painting /

Laminating / Finishing / Spraying 3 3 0.21 0.258 2005 Maximum 0.06 0.074 2007 Median 0.0189 0.023 2002 MinimumFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report October 6, 2011 Page F - 6 **Table F -**  **1. Continued**

**Industry Worker** 

**Activity Description**  **Number of**

**Sites Monitored**  **Number of**

**Data Points Monitored** 

**Form aldehyde**  **Concentration (ppm)**  **Monitored**

**Form aldehyde**  **Concentration (m**  **g/m 3**  **) Year**  **Description of Concentration**  **Level** Other Operations / Maintenance 2 3 0.10 0.123 2007 Maximum 0.06 0.074 2007 Median 0.01 0.012 2002 Minimum

Showcase, Partition, Shelving, and Locker Manufacturing Painting /

Laminating / Finishing / Spraying 2 3 0.228 0.280 2004 Maximum 0.216 0.265 2004 Median 0.13 0.160 2005 Minimum Press Operating 1 2 0.187 0.230 2004 Maximum 0.138 0.169 2004, 2004 Median 0.088 0.108 2004 Minimum Com pliance, Safety, and Health Officer 1 1 0.184 0.226 2004 1 Data Point Custom Architectural Woodwork and Millwork Manufacturing Other Operations

/ Maintenance 1 3 1 1.229 2008 Maximum 0.44 0.541 2008 Median 0.04 0.049 2008 Minimum Sawing / Cutting / Routing 1 1 0.068 0.084 2004 1 Data Point Other Millwork (including flooring) Manufacturing Painting /

Laminating / Finishing / Spraying 1 1 0.13 0.160 2003 1 Data Point Fabricating / 1 2 0.075 0.092 2002 MaximumFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report October 6, 2011 Page F - 7 **Table F -**  **1. Continued**

**Industry Worker** 

**Activity Description**  **Number of**

**Sites Monitored**  **Number of**

**Data Points Monitored** 

**Form aldehyde**  **Concentration (ppm)**  **Monitored**

**Form aldehyde**  **Concentration (m**  **g/m 3**  **) Year**  **Description of Concentration**  **Level** Assembling / Building / Laboring 0.03805 0.047 2002, 2002 Median 0.0011 0.001 2002 Minimum Other Operations / Maintenance 2 3 0.243 0.299 2006 Maximum 0.184 0.226 2006 Median 0.0992 0.122 2002 Minimum Sawing / Cutting / Routing 1 1 0.05 0.061 2004 1 Data Point Press Operating 2 3 0.55 0.676 2008 Maximum 0.317 0.390 2008 Median 0.06 0.074 2004 Minimum

Wood Window

and Door Manufacturing Painting /

Laminating / Finishing / Spraying 1 1 0.00438 0.005 2007 1 Data Point Fabricating / Assembling / Building / Laboring 2 2 0.24 0.295 2006 Maximum 0.1465 0.180 2006, 2009 Median 0.053 0.065 2009 Minimum Motor Home Manufacturing Trailer Cleaning 1 1 0.0023 0.003 2002 1 Data Point All Other All Activities 8 18 1.00 1.229 2005 MaximumFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report October 6, 2011 Page F - 8 **Table F -**  **1. Continued**

**Industry Worker** 

**Activity Description**  **Number of**

**Sites Monitored**  **Number of**

**Data Points Monitored** 

**Form aldehyde**  **Concentration (ppm)**  **Monitored**

**Form aldehyde**  **Concentration (m**  **g/m 3**  **) Year**  **Description of Concentration**  **Level** Miscellaneous Wood Product Manufacturing 0.144 0.177 2005, 2006 Median 0.003 0.003 2003 Minimum Table F - 2 through Table F - 12 present summary statistics of the TWA, personal monitoring data from OSHA IMI S by NAICS code for the CWP fabrication life cycle stage . Not all NAICS codes within CWP fabrication are included in thi s summary ; onl y NA IC S codes for which data were obtained from OSHA IMI S.

**Table F -**  **2. Summary Statistics for Pre -**  **Baseline Monitoring Data for NAICS Code 321911**

**Monitored Form aldehyde Concentration**  **Number of Monitored Sites**  **Number of Data Points**  **Year (ppm)**  **( μ**  **g /m** **3 )**  Maximum 0.24 295.0 3 3 2006 Median 0.053 65.1 2009 Minimum 0.0044 5.4 2007 Mean 0.099 121.8 N/A Standard deviation 0.124 152.9 N/AFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report October 6, 2011 Page F - 9 **Table F -**  **3. Summary Statistics for Pre -**  **Baseline Monitoring Data for NAICS Code 321918 Monitored Form**  **aldehyde Concentration Number of**  **Monitored Sites Number of Data**  **Points Year**  **(ppm) (**  **μ g** **/m 3**  **)** Maximum 0.55 676.0 6 10 2008 Median 0.1146 140.8 N/A Minimum 0.0011 1.4 2002 Mean 0.17093 210.1 N/A Standard deviation 0.164 201.6 N/A **Table F -**  **4. Summary Statistics for Pre -**  **Baseline Monitoring Data for NAICS Code 337110**

**Monitored Form aldehyde Concentration**  **Number of Monitored Sites**  **Number of Data Points**  **Year (ppm)**  **( μ**  **g /m** **3 )**  Maximum 0.69 848.0 16 29 2003 Median 0.137 168.4 2004 Minimum 0.0006 0.7 2004 Mean 0.197 242.6 N/A Standard deviation 0.204 250.9 N/AFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report October 6, 2011 Page F - 10 **Table F -**  **5. Summary Statistics for Pre -**  **Baseline Monitoring Data for NAICS Code 337121 Monitored Form**  **aldehyde Concentration Number of**  **Monitored Sites Number of Data**  **Points Year**  **(ppm) (**  **μ g** **/m 3**  **)** Maximum 0.111 136.6 3 6 2003 Median 0.040 49.2 N/A Minimum 0.009 11.1 2003 Mean 0.053 65.6 N/A Standard deviation 0.039 48.5 N/A

**Table F -**  **6. Summary Statistics for Pre -**  **Baseline Monitoring Data for NAICS Code 337122**

**Monitored Form aldehyde Concentration**  **Number of Monitored Sites**  **Number of Data Points**  **Year (ppm)**  **( μ**  **g /m** **3 )**  Maximum 0.590 725.1 11 19 2004 Median 0.170 208.9 2008 Minimum 0.028 34.2 2009 Mean 0.222 273.4 N/A Standard deviation 0.182 223.7 N/AFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report October 6, 2011 Page F - 11 **Table F -**  **7. Summary Statistics for Pre**  **- Baseline Monitoring Data for NAICS Code 337127**  **Monitored Form aldehyde Concentration**  **Number of Monitored Sites**  **Number of Data Points Year**  **(ppm) (**  **μ g** **/m 3**  **)** Maximum 0.210 258.1 3 6 2005 Median 0.060 73.7 N/A Minimum 0.010 12.1 2002 Mean 0.076 94.0 N/A Standard deviation 0.073 89.8 N/A

**Table F -**  **8. Summary Statistics for Pre -**  **Baseline Monitoring Data for NAICS Code 337211**

**Monitored Form aldehyde Concentration**  **Number of Monitored Sites**  **Number of Data Points**  **Year (ppm)**  **( μ**  **g /m** **3 )**  Maximum 0.580 712.8 6 18 2004 Median 0.029 35.6 N/A Minimum 0.005 5.9 2004 Mean 0.082 100.9 N/A Standard deviation 0.140 171.5 N/AFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report October 6, 2011 Page F - 12 **Table F -**  **9. Summary Statistics for Pre -**  **Baseline Monitoring Data for NAICS Code 337212 Monitored Form**  **aldehyde Concentration**  **Number of Monitored**  **Sites Number of Data Points**  **Year (ppm)**  **( μ**  **g /m** **3 )**  Maximum 1.00 1229 2 4 2008 Median 0.25 312.2 N/A Minimum 0.04 49.2 2008 Mean 0.39 475.6 N/A Standard deviation 0.45 550.0 N/A

**Table F -**  **10. Summary Statistics for Pre**  **- Baseline Monitoring Data for NAICS Code 337215** 

**Monitored Form aldehyde Concentration**  **Number of Monitored Sites**  **Number of Data Points**  **Year (ppm)**  **( μ**  **g /m** **3 )**  Maximum 0.23 280 3 6 2004 Median 0.19 228.0 N/A Minimum 0.09 108.2 2004 Mean 0.17 211.6 N/A Standard deviation 0.05 65.6 N/AFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report October 6, 2011 Page F - 13 **Table F -**  **11. Summary Statistics for Pre -**  **Baseline Monitoring Data for NAICS Code 336213 Monitored Form**  **aldehyde Concentration**  **Number of**  **Monitored Sites**  **Number**

**of Data Points**  **Year (ppm)**  **( μ**  **g /m** **3 )**  Single Data Point 0.0023 2.8 1 1 2002 **Table F -**  **12. Summary Statistics for Pre -**  **Baseline Monitoring Data for NAICS Code 321999**

**Monitored Form aldehyde Concentration**  **Number of Monitored Sites**  **Number of Data Points**  **Year (ppm)**  **( μ**  **g /m** **3 )**  Maximum 1.00 1229 8 18 2005 Median 0.14 177.0 N/A Minimum 0.003 3.4 2003 Mean 0.20 249.6 N/A Standard deviation 0.26 313.6 N/AFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011

**Appendix G** 

**SUMMARY OF OSHA INSP ECTION REPORTS** Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page G - 1 One data gap of the exposure assessment is the use of personal protective equipment (PPE) in manufacturing facilities. To help resolve this data gap, OSHA inspection reports associated with the obtained OSHA IMIS data were obtained from OSHA. This appendix summarizes the PP E information found in the reports received as of January 201 1 . Table G - 1 and the following sections present the findings of the review of the inspection reports received. **Table G**  **- 1**  **. Su mmary of OSHA Inspection Reports and Findings on PPE Use** 

**Nam e of Inspected Facility**  **Personal Protective Equipment (PPE) Worn by Workers**  **D uring Inspection**  **Respirator Use During**  **Inspection Manufacturing**  Carolina Curves Inspection No. 303713325 Ear plugs, safety glasses/goggles, aprons No McKnight Plywood Inspection No. 123445595 Safety glasses, rubber gloves, back braces No Marshfield Door Systems Inspection No. 303864029 Safety glasses, gloves No Fiberesin Industries Inspection No. 307061689 Safety glasses, gloves, eye protection No Unilin Flooring NC, LLC Inspection No. 312479835 3M 6300 half mask with formaldehyde cartridges Yes **Composite Wood Product Fabrication** Plymart Inc. Inspection No. 308245372 Unknown No Bushline Inc. Inspection No. 306132275 Half face air purifying respirator Yes England Inc . Inspection No. 307674051 Safety glasses, smock, hearing protection No Commercial Furniture Group Inspection No. 311144059 Safety glasses and hearing protection No Harris Tarkett Inspection No. 307206987 Safety glasses, gloves, and hearing protection No Gunlocke Company Inspection No. 307690578 Unknown No Armstrong Cabinets Inspection No. 306021239 Gloves, apron No Wood Goods Industries, Inc. Inspection No. 307041707 Respirator with organic vapor cartridge, nitrile gloves, safety glasses, hard hat, ear plugs, and steel toe shoes Yes (not required) Parenti & Rafaelli, Ltd Inspection No. 305228652 Safety glasses, steel toe shoes, gloves, and half

- face respirators. Dust masks are also available for use. Yes
Benvenuti and Stein Inspection No. 312188972 Half - face cartridge respirator, safety glasses, safety shoes Yes Ameriwood Industries Inc. Inspection No. 311606883 Safety glasses, ear plugs NoFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page G - 2 **Table G**  **- 1**  **. Su mmary of OSHA Inspection Reports and Findings on PPE Use** 

**Nam e of Inspected Facility**  **Personal Protective Equipment (PPE) Worn by Workers**  **D uring Inspection**  **Respirator Use During**  **Inspection** Tru - Wood Cabinets, Inc. Inspection No. 307013250 Safety glasses, earplugs No Jimson Manufacturing Co. Inspection No. 303424014 Safety glasses No Newood Display Fixtures Manufacturing Company Inspection No. 304064835 Respirator Yes Simple Designs Manufacturing Inspection No. 306629171 Safety glasses, gloves, ear protection; dust masks are “available for use” No
**1.0 M** **ANUFACTURING Carolina Curves Inc.**  **, Inspection 303713325**  The inspection occurred as a result of referral. Carolina is primarily engaged in the manufacture of curved pl ywood products for the furniture industry (e.g. , chairs, bed posts, and other furniture items). These operations include receiving pl ywood, laminated veneer using an amino resin containing formaldeh yd e ( 0.1

– 0.5%), mold pressing of veneer (using pressure/Rf to curve ply wood), wood cutting, sanding, shaping operations. Inspection of the curved wood products is the final phase of the curved ply wood operation prior to shipping. According to the air sampling reports, workers may

wear ear plugs, safet y glasses/goggles and aprons as PPE. These reports did not indicate the use of a respirator during an y of the inspected activity . **M cKnight Plywood, Inspection 123**  **445595** This inspection was a planned health inspect ion . McKnight Pl ywood makes laminated hardwood ply wood products such as hardwood flooring using purchased veneers and formaldeh yde - based glues (0.21% formaldehyde in the glue used in the old building and 0.32% in the glue used in the flooring plant). Some of the operations at McKnight Ply wood include pl yw ood sorting, glue application, pressing, cooling, cutting and sanding the finished products. OSHA cited the facility

for formaldeh yd e overexposure. However, based on the inspection summary and the air sampl ing reports, the only PPE worn at the facility

are safet y glasses, rubber gloves, and back braces. These PPE are onl y worn in some areas of the facility . **Marshfield Door S ystems, Inc. Inspection 303864029**  The inspection occurred as a result of a complaint. Workers at the inspected facility are potentially

exposed to formaldehyde in the smoke emitted from the electronic press. Air sampling reports from the inspection indicated the use of PPE such as safety glasses and gloves by some workers. Respirators were not worn.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page G - 3 **Fiber e**  **sin Industries, Inc. ,**  **Inspection 307061689** The inspection occurred as a result of a complaint. Fibersin Industries manufactures particleboard. Air monitoring during the inspection indicated no overexposure to formaldeh yd e at the inspected facility . Because no over exposures were found, it is not mandatory for the employer to provide workers with respiratory protection. Eye protection is provided to workers, but the wearing of eye protection is not enforced. PPE for the press operator include the occasional use of gloves and the use of safety glasses and hearing protection. **Unilin Flooring NC, LLC. ,**  **Inspection No. 312479835** OSHA conducted a partial inspection of the facility as a result of a non - formal complaint. The inspection did not cover a ll operations at the facility and OSHA did not identify an y violation of OSHA standards or regulations. The inspected facility manufactures high density MDF used primarily in flooring material. The company provides respiratory

protection training and fit t esting for workers in the production area. Workers were wearing 3M 6300 half masks with formaldeh yde cartridges; they also had the option of using full face cartridge respirators and had been fit tested of both types of respirators. The company also condu cts periodic formaldeh yd e sampling and has performed a ventilation study on - site. **2.0 C**  **OMPOSITE W**  **OOD P**  **RODUCT F**  **ABRICATION Plymart**  **Inc. Inspection No. 308245372** Ply mart is a high production cabinet shop with a series of large warehouse size buildings. The cabinets are mainl y constructed of particleboard frames with hardwood doors. OSHA conducted a combined safety and health programmed inspection at the facility and cited Ply mart for poor ventilation and housekeeping in the spray finish booth. However, air sampling throughout the facility indicated that concentrations of formaldehyde, as well as dust and solvent were all below the PELand that there was no overexposure. He nce, the company had “decided not to require tight fitting respirators.” **Bushline Inc. Inspection No. 306132275** This inspection was a general schedule comprehensive occupational health inspection. Bushline manufactures upholstered furniture. During the OS HA inspection, the facility was cited for poor ventilation in the spray

booth, the lack of PPE hazard assessment or employee training certification, lack of impervious gloves and clothing for workers handling corrosive liquids, as well as eye and face prot ection for emplo ye es potentially exposed to hazards from acids or caustic chemicals. Formaldeh yd e glue is mixed and applied by hand to glue wood sections together in the rough mill area. The report stated that “proper PPE and an eyewash and shower were not provided in this area” and that formaldehyde sampling results were below the action level. An employee wore the Cabot Safet y half face air purifying respirator while mixing the adhesive in the chair line area, where wooden frame chairs are assembled using pneumatic guns and a formaldeh yde glue. Past air sampling indicated that the formaldeh yd e concentration was below the PELin this area.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page G - 4 **England Inc. Inspection No. 307674051** This inspection was a general schedule comprehensive occupational health inspecti on. England In c. manufactures furniture cushions and mattresses. During the inspection, the facility was cited for not providing the proper PPE where there is potential for exposure. The only worker PPE (worn in select areas of the facility) are safet y gla sses, smock, and hearing protection. It appears that no respirators were worn. The facility uses a water - based non - toxic glue in its processes, and sampling results show formaldeh yde exposure below the OSHA PEL . **Harris -**  **Tarkett Inc. Inspection No. 307206987** This inspection was a general schedule comprehensive occupational health inspection. During the inspection, workers were observed to wear a combination of safety glasses, gloves, and hearing protection in the wood processing area, and in the long strip ar ea, where wood products are being sorted, cut, glued, pressed and finished. It appears that no respirator was worn in the areas with potential formaldehyde exposure. Respirators were also not worn by workers in the chemical room of the finishing department where they were exposed to methyl isobutyl ketone above the PEL and STEL levels. **The Commercial Furniture Group. Inspection No. 311144059** This inspection was a general schedule comprehensive occupational health inspection. The Commercial Furniture Group m anufactures wooden chairs at the inspected facility . The operation here consists of a rough mill, a frame assembly area, a spray

finishing area, a fabric cutting and storage area, and an upholstery area. The inspection report did not indicate the use of fo rmaldeh yde - based adhesives although formaldehyde could be emitted from the wood boards used to manufacture chairs. According to the report, workers wear safety glasses and hearing protection in certain areas of the facility. There was no indication for res piratory use. Air sampling results also indicate the formaldeh yde concentration was below the OSHA PEL , therefore, the facility

would not be required to provide respirators for formaldehyde exposures. **Gunlock e**  **Company, LLC. Inspection No. 307690578** The inspection at Gunlocke Company was conducted as a result of a compliant. During the inspection, the observed workers were not wearing respirator s . **Armstrong Cabinets Prod ucts. Inspection No. 306021239**  This inspection was a planned health inspection. Ar mstrong Cabinets manufactures bath and kitchen wood cabinets. OSHA cited the compan y for not providing protective eye and face equipment to prevent chemical splashes. The facility has a written respiratory

protection program but the use of a respirator is not mandatory . During the inspection, workers were not wearing respirators or dust masks even though the facility has seven spray booths. Occasional PPE worn include apron and gloves. **Wood Goods Industry Inc. Inspection No. 307041707** The inspection was con ducted as a result of a complaint. The inspection summary suggests that this facility

produced various wood products, such as tables, from rough lumber. Lumber was rip - sawed, chopped, and glued with non - hazardous wood glue (does not contain formaldehyde). The facility

also had a spray

operation where three chemical spray s, a water based stain, a vin yl sealer, and a clear top coat were sprayed onto the wood products. Employees rotated betweenFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page G - 5 spraying operations and hand sanding, wiping stains, and setting t ables on the conveyor tracks. Air sampling for formaldehyde was conducted on an employee spraying the top coat. The other two coatings do not appear to contain formaldeh yde. The facility

had an operational spray booth in place but did not require respirator use. During air sampling of spraying activities, only some workers were observed to wear a respirator with organic vapor cartridges. Other PPE worn b y workers during air sampling include nitrile gloves, safet y glasses, hard hat, ear plugs, and steel toe shoes. **Parenti & Rafaelli, Ltd. Inspection No. 305228652** The inspection was conducted under the Site Specific Targeting program. A safety inspection had been initiated previously and the health inspection was initiated to address health issues su ch as spray booths, exposure to wood dust and formaldehyde. The company had no previous history of OSHA inspections. The compan y required the use of half face respirators in the spray booth and dust masks are available to the rest of the employees. The company also required employees to wear safet y glasses, steel toe shoes, gloves, and respirators i n the spray booths. The compan y made custom millwork and woodwork for commercial and residential sites. The ty pes of wood used vary

depending on customer specifi cation but includes fir, pine, oak, maple, mahogan y, cherry and particleboard. Air sampling for formaldehyde was below the PEL . **Benvenuti and Stein, Inc. Inspection No. 312188972** The health inspection was initiated due to a non - formal complaint regarding a chemical spill. The compan y made custom design wooden cabinets and the facility was divided into cabinet making, cabinet finishing, and the dock. The finish coating used during the spray operation contained formaldeh yde. The compan y provided a half - face c artridge respirator to reduce emplo ye e exposure to formaldeh yde but did not implement a written respirator program. Other PPE worn by workers include safet y glasses and safet y shoes. **Am eriwood Industries Inc. Inspection No. 311606883**  OSHA conducted this partial health inspection as follow - up to a previous inspection that was conducted in response to a complaint. OSHA determined that the formaldehyde exposure for workers operating the autodrill was well under the PELbased on personal monitoring. Workers onl y wore safet y glasses and ear plugs during air sampling. **Tru -**  **Wood Cabinets, Inc. Inspection No. 307013250** OSHA conducted this partial health inspection in response to a complaint. Tru - Wood Cabinets, In c. manufactures wood cabinets (kitchen and bathroom) to be installed on new homes. At the time of inspection, the company employed 279 employees in two working shift s . The compan y had two buildings: frame door production and spray painting operations were conducted in building #1, while panel cutting and finis hing occurred in building #2.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011 Page G - 6 Monitoring data show exposure for formaldeh yd e was below the OSHA PEL. The only PPE listed in OSHA’s air sampling worksheets were safety glasses and ear plugs. The inspection report indicates voluntary use of particulate masks by workers in building #2; however, it was uncertain how frequent these respirators were being worn. **Jimson Manufacturing Co. Inspection No. 303424014** OSHA conducted this partial health inspection in response to a complaint. This company manufactures furniture for retail stores. Sheets of MDF are received at the company (facility) and the wood is cut to size using panel saws. Foil is applied to edges and flat pieces of wood via heat and pressure; and furniture is assembled with staple guns. OSHA monit oring indicates that the formaldeh yd e exposure level was well below the OSHA PEL . The PPE listed in OSHA’s air sampling worksheets included prescription glasses and safet y glasses (with or without side shields). Dust masks and respirators were not worn. **Ne wood Display Fixtures Manufacturing Company. Inspection No. 304064835**  Newood Display

Fixtures Manufacturing is a large store fixture manufacturer with a staff of 60 employees. The health inspection was initiated based on an anonym ous complaint alleging exp osure to lacquer, paints, and formaldeh yde in the west end of the mill. Some of the operations that occur at this facility

include spray

painting operation, glue - up, and packing. The spray area consists of three spray

rooms and a spray

painting prep area. The lacquer pump is electricall y interconnected to the ventilation system, so that the spray guns will not operate if the ventilation sy stem is inoperable. Sampling results indicated that formaldehyde TWA reached 0.299 and 0.276 ppm; however, the 8 - hour TWA were quite low due to the shortness of the sampling period. The inspection did not result in a citation. The only PPE listed in the air sampling report is 3M -N95 - 8210. This appears to refer to the N95 disposable particulate respirator model 8210. **Simple Designs Manufacturing Inc. Inspection 306629171**  This inspection was a partial health inspection conducted as a result of a complaint. The inspected facility

makes furniture using ply wood, hardboard, particleboard, and oriented strand board (OSB). The comp any safet y process manual states that safety glasses and ear protection must be worn throughout the mill area. Gloves are also required in some areas of the plant. Dust masks are available for use. Air sampling reports also indicate the occasional use of an apron. However, none of the workers inspected wore a respirator.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011

**Appendix H**  **SUMMARY OF ADDITIONAL EXPOSURE MONITORING DATA FROM**  **MANUFACTURING**Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report October 6, 2011 Page H - 1 **Table H**  **- 1**  **. Formaldehyde Exposure Levels for Plywood, Particleboard, and Medium -**  **Density Fiberboard Manufacture**

**Authors/Articles Publication**  **Air Concentrations of**  **Form aldehyde**  **Study Population**

**(Exposed Workers)**  **Abstract and Salient Points** The Workers’ Com pensation Board BC (WorkSafeBC) Discussion Paper

– Occupational exposure limit for formaldehyde. March 20, 2007 Not Applicable Plywood manufacturing: predominantly below 0.3 ppm as 8 - hour TWA Pressed/panel particle/fiberboard manufacturing: 0.3 ppm as 8 - hour TWA exceeded at times with an exposure range of 0.07 to 5.00 ppm Workers in a

variety of industries in British Columbia including those in the pressed/panel particle/fiberboard manufacturin g facilities. **Abstract:**

None Available **Salient Points:**  Sam pling data collected by WorkSafeBC over a period of 15 years (1990 to 2005) in British Columbia and other locations, including Ontario, Quebec, and the Netherlands indicate that worker exposure to formaldehyde is likely to occur primarily in the forest panel board manufacturing sector ( **plywood** , **particle/fiberboard** , oriented strand board, laminated wood products manufacturing), resin manufacture, acute care hospitals, university and other laborato ries, and funeral homes.

 The exposure data indicate that, overall, exposure levels have decreased over time as control and procedural measures have improved. This is particularly evident when one compares readings taken in the early 1980s with those in th e late 1990s.

 The results indicate that industries in which exposure levels were predominantly below

the current 0.3 ppm 8 - hour TWA exposure limit include:

- Foundries;

- Resin manufacturing; and

- Plywood manufacturing.

 Industries in which the current 0.3 ppm 8 - hour TWA exposure limit (for British Columbia) was exceeded include (range of exposure shown):

- Paperboard & cardboard manufacturing (0.04 to 0.38 ppm);

- Laminated wood products manufacturing (0.24 to 0.38 ppm);

- **Pressed/panel particle/fiberboard m anu**  **facturing (0.07**
**– 5.00**  **ppm)** ;

- Oriented strand board manufacturing (0.03 to 0.32 ppm);

- Funeral homes (none detected to 0.74 ppm);Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report October 6, 2011 Page H - 2 **Table H**  **- 1**  **. Formaldehyde Exposure Levels for Plywood, Particleboard, and Medium -**  **Density Fiberboard Manufacture**

**Authors/Articles Publication**  **Air Concentrations of**  **Form aldehyde**  **Study Population**

**(Exposed Workers)**  **Abstract and Salient Points**

- University laboratories (0.52 to 1.15 ppm);

- Hospitals & medical clinics and laboratories (0.02 to 1.35 ppm); and

- Poultry hatcheries (0.1

– 0.35 ppm).

 Formaldehyde exposure levels in a plywood manufacturing plant in 2002, as reported by the Ontario Ministry of Labour, ranged from 0.16 to 0.17 ppm as 8 - hour TWA, with a 15 - mi nute STEL range of 0.14 to 0.29 ppm and ins tantaneous ceiling limit values ranging from 0.33 to 0.44 ppm.

 Formaldehyde exposure levels in two particleboard manufacturing plants were also reported by the Ontario Ministry of Labour in 2002. The 8 - hour TWA levels ranged from 0.07 to 0.20 ppm in one p lant and from 0.08 to 0.11 ppm in the other. The range of the 15 - mi nute STELs was from 0.15 to 0.54 ppm and 0.14 to 0.29 ppm, respectively, and for instantaneous ceiling limit values, from 0.18 to 7.47 ppm and 0.17 to 0.50 ppm, respectively.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report October 6, 2011 Page H - 3 **Table H**  **- 2**  **. Formaldehyde Exposure Levels for Plywood Manufacture** 

**Authors/Articles Publication**  **Air concentrations of**  **Form aldehyde**  **Study Population**

**(Exposed Workers)**  **Abstract and Salient Points** Fransman W et al. Respiratory symptoms and occupational exposures in New Zealand plywood mill workers . Ann Occup

Hyg. 2003 Jun;47(4):287 - 95. 0.08 ppm to 0.60

ppm (0.01 to 0.74 mg/m 3 ) [Geometric mean of this range = 0.06 ppm (0.08 mg/m 3 )] 112 plywood mill

workers. **Abstract:**

OBJECTIVES: To study work exposure and respirat ory symptoms in Ne w Zealand plywood mill workers. METHODS: Personal inhalable dust (n = 57), bacterial endotoxin (n = 20), abietic acid (n = 20), terpene (n = 20) and formaldehyde (n = 22) measurements were taken and a respiratory health questionnaire was administered to 112 plywood mill workers. RESULTS: Twenty - six percent of the dust exposures exceeded 1 mg/m(3); however, none of the samples exceeded the legal limit of 5 mg/m(3) [geometric mean (GM) = 0.7 mg/m(3), geometric standard deviation (GSD) = 1.9] . Workers in the composer area (where broken sheets are joined together) were significantly (P < 0.01) more highly exposed. Endotoxin levels were low to moderate (GM = 23.0 EU/m(3), GSD = 2.8). Abietic acid levels ranged from 0.3 to 2.4 micro g/m(3) (GM = 0.7 micro g/m(3), GSD = 1.8) and were significantly (P < 0.05) higher for workers in the composer area of the process. Geometric mean levels of alpha - pinene, beta - pinene and Delta(3) - carene were 1.0 (GSD = 2.7), 1.5 (GSD = 2.8) and 0.1 (GSD = 1.4), respect ively, and alpha - pinene and beta pinene levels were significantly (P < 0.001) higher for workers in the 'green end' of the process, up to and including the veneer dryers. Formaldehyde levels ranged from 0.01 to 0.74 mg/m(3) [GM = 0.08 mg/m(3) (= 0.06 ppm.) , GSD = 3.0]. Asthma symptoms were more common in plywood mill workers (20.5%, n = 112) than in the general population [12.8%, n = 415, adjusted OR (95% CI) = 1.5 (0.9 - 2.8)]. Asthma symptoms were associated with duration of em ployment and were reported to lessen or disappear during holidays. No clear association with any of the measured exposures was found, with the exception of formaldehyde, where workers with high exposure reported more asthma symptoms (36.4%) than low exposed workers [7.9%, adjusted OR ( 95% CI) = 4.3 (0.7 - 27.7)]. CONCLUSIONS: Plywood mill workers are exposed to inhalable dust, bacterial endotoxin, abietic acid, terpenes and formaldehyde, and they appear to have an increased risk of developing work - related respiratory symptoms. These sympt om s may be due to formaldehyde exposure, although a potential causal role for other exposures cannot be excluded.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report October 6, 2011 Page H - 4 **Table H**  **- 2**  **. Formaldehyde Exposure Levels for Plywood Manufacture** 

**Authors/Articles Publication**  **Air concentrations of**  **Form aldehyde**  **Study Population**

**(Exposed Workers)**  **Abstract and Salient Points**

**Salient Points:**  Personal measurements for inhalable dust (n = 57), bacterial endotoxin (n = 20), abietic acid (n = 20), terpene (n = 20) and formaldehyde (n = 22) were taken and a respiratory health questionnaire was administered to 112 New Zealand plywood mill workers.

 Formaldehyde levels ranged from 0.08 ppm to 0.60 ppm (0.01 to 0.74 mg/m 3 ), the geometric mean of this range was determined to be 0.06 ppm (0.08 mg/m 3 )

 Asthma symptoms were more common in plywood mill workers (20.5%, n = 112) than in the general population (12.8%, n = 415). No clear association with any of the measured exposures was found, with the exception of formaldehyde, where workers with high exposure reported more asthma symptoms (36.4%) than low exposed workers.

 Plywood mill wo rkers appear to have an increased risk of developing work related respiratory symptoms. These symptoms may be due to formaldehyde exposure, although a potential causal role for other exposures cannot be excluded. Ballarin C et al. Micronucleated cells in nasal mucosa of formaldehyde exposed workers . Mutat Res.

1992 Jul; 280(1):1 - 7. 0.07 - 0.08 ppm

(0.1 mg/m 3 ) in the sawmill and shearing - press departments 0.32 ppm (0.39 mg/m 3 ) in the warehouse area. 15 nonsmoking

workers in a plywood factory **Abstract:**

The frequency of mic ronuclei (MN) and cytology of respiratory nasal mucosa cells were evaluated in 15 nonsmokers exposed to formaldehyde in a plywood factory. Each subject was paired with a control matched for age and sex. Mean levels of exposure to formaldehyde ranged from about 0.1 mg/m 3 in the sawmill and shearing - press departments to 0.39 mg/m 3 in the warehouse area. There was a contemporary exposure to low levels of wood dust (inspirable mass ranged from 0.23 mg/m 3 in the warehouse to 0.73 mg/m 3 during sawing operations). Nasal respiratory cell samples were collected by an otorhinolaryngologist near the inner turbinate using a brush for endocervical cy tology. After staining (Feulgen plus Fast Green and Papanicolaou's method for MN analysis and cytology, respectively), about 6000 cells were screenedFormaldeh yd e Occupational Exposure Assessment Report - Draft Final Report October 6, 2011 Page H - 5 **Table H**  **- 2**  **. Formaldehyde Exposure Levels for Plywood Manufacture** 

**Authors/Articles Publication**  **Air concentrations of**  **Form aldehyde**  **Study Population**

**(Exposed Workers)**  **Abstract and Salient Points**

for micronuclei and scored in parallel for cytology according to a histopathological scale. A higher frequency of micronucleated cells was observed in the exposed group than in the controls (0.90±0.47 vs. 0.25±0.22, Mann - Wh itney U test: p less than 0.01). Cytological examination indicated chronic phlogosis in the nasal respiratory mucosa of plywood factory wo rkers, with a high frequency of squamous metaplasia cells (mean score 2.3±0.5 vs. 1.6±0.5 in the control group, Mann - Wh itney U test: p less than 0.01). **Salient Points:**  The authors examined smears of nasal respiratory mucosa cells sampled from the inner turbinate of 15 nonsmokers who were exposed to formaldehyde released from a urea - formaldehyde glue used in a plywood factory.

 Estimates of formaldehyde air concentrations ranged from: 0.21 to 0.60 mg/m 3 (mean 0.39±0.20 mg/m 3 ) in the warehouse where seven subjects worked, 0.08 to 0.14 mg/m 3 (mean 0.1±0.02 mg/m3 ) in the shearing press where six subjects worked, and 0.09 mg/m 3 (only one sample taken) in the sawmill area where two subjects worked.

 Mean wood dust concentrations for the three areas were 0.23±0.1mg/m 3 , 0.41±0.21 mg/m3, and 0.73 mg/m3, respectively. Exposed subjects worked at the factory for 2 to 19 years (mean 6.8±5.0 years).

 The authors found a statistically significantly higher percentage of micronucleated mucosal cells in the exposed group compared with the control group (0.91%±0.47 versus 0.25%±0.22). Malaka T and K odama AM. Respiratory health of plywood Arch Environ

Health. 1990 Sep - Oct; 45(5):288 - 94 0.28 ppm to 3.48

ppm Average personal exposure was 1.13 186 male plywood

workers **Abstract:**

This study was undertaken to enlarge our understanding of the adverse health effects of formaldehyde exposure in the workplace and community environment. The respiratory health status of 186 male plywood workers was evaluated by spirometric tests, respirat ory questionnaires, and chest x - rays.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report October 6, 2011 Page H - 6 **Table H**  **- 2**  **. Formaldehyde Exposure Levels for Plywood Manufacture** 

**Authors/Articles Publication**  **Air concentrations of**  **Form aldehyde**  **Study Population**

**(Exposed Workers)**  **Abstract and Salient Points** workers occupationally exposed to formaldehyde . ppm Area concentrations of formaldehyde were measured in the work environment and found to range from 0.28 to 3.48 ppm. The average personal exposure was to 1.13 ppm of formaldehyde. Exposure to formaldehyde was associated with decrements in the baseline spirometric values (i.e., forced expiratory volume in 1 sec (FEV1.0), forced expiratory volume/forced vital capacity (FEV/FVC), and FEF25% - 75%) and with several respiratory symptoms and diseases, including cough, phlegm, as thma, chronic bronchitis, and chest colds. The results of the study support the hypothesis that chronic exposure to formaldehyde induces symptoms and signs of chronic obstructive lung disease. **Salient Points:**  In this cross - sectional study of 186 plywood workers, area concentrations of formaldehyde ranged from 0.28 to 3.48 ppm. The average personal exposure wa s 1.13 ppm .
 Reported average respirable and total wood - dust concentrations in workplace air were 0.60 and 1.35 mg/m 3 , respectively.

 Exposure was a ssociated with increased complaints of cough, phlegm production, asthma, chronic bronchitis and colds.

 Decrement in FEV 1 /FVC ratio in exposed subjects compared to controls was small but significant, although the authors noted that the clinical significan ce of the differences was unclear.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report October 6, 2011 Page H - 7 **Table H**  **- 3**  **. Formaldehyde Exposure Levels for Particleboard and Medium -**  **Density Fiberboard Manufacture (Includes Wood Workers and Oriented Strand Board Manufacture)** 
**Authors/Article Publication**  **Air concentrations of Form**  **aldehyde Study Population** 

**(Exposed Workers) Abstract and Salient Points**  The Workers’ Com pensation Board BC (WorkSafeBC) Discussion Paper

– Occupational exposure limit for formaldehyde. March 20, 2007 Not Applicable 0.03 - 0.032 ppm for oriented strand board Workers in a variety

of industries in British Columbia including those in the plywood, particle/fiberboard, and oriented strand board manufacturing facilities. **Abstract:**

None available **Salient Points:**  Sam pling data collecte d by

WorkSafeBC over a period of 15 years (1990 to 2005) in British Columbia and other locations, including Ontario, Quebec, and the Netherlands indicate that worker exposure to formaldehyde is likely to occur primarily in the forest panel board manufactur ing sector (plywood, particle/ fiberboard, **oriented strand board**  , laminated wood products manufacturing), resin manufacture, acute care hospitals, university and other laboratories, and funeral homes.

 Industries in which the current 0.3 ppm 8 - hour TWA exp osure limit (for British Columbia) was exceeded include (range of exposure shown):

- Paperboard & cardboard manufacturing (0.04 to 0.38 ppm);

- Laminated wood products manufacturing (0.24 to 0.38 ppm);

- Pressed/panel particle/fiberboard manufacturing (0.07 to 5.00 ppm);

- **Oriented strand board manufacturing (0.03 to 0.32 ppm);**

- Funeral homes (none detected to 0.74 ppm);

- University laboratories (0.52 to 1.15 ppm);

- Hospitals & medical clinics and laboratories (0.02 to 1.35 ppm); and

- Poultry hatcheries (0.1 to 0 .35 ppm). **For other details of this study, as they relate to exposure levels in plywood and**  **particle/fiberboard manufacturing, see Table H**  **- 1.** Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report October 6, 2011 Page H - 8 **Table H**  **- 3**  **. Formaldehyde Exposure Levels for Particleboard and Medium -**  **Density Fiberboard Manufacture (Includes Wood Workers and Oriented Strand Board Manufacture)** 
**Authors/Article Publication**  **Air concentrations of Form**  **aldehyde Study Population** 

**(Exposed Workers) Abstract and Salient Points**  Lavoue J et al. 2005 Investigation of Determinants of Past and Current Exposures to Formaldehyde in the Reconstituted Wood Panel Industry in Quebec Annals of

Occupational Hygiene. 2005 49(7):587 - 602 Geometric means

(GMs) of personal and area levels between 0.1 and 0.4 ppm for MDF and PB. Highest estimated am bient GM 0.43 ppm in the main production area of MD F manufacturing facilities. Highest personal estimated GM 0.22 ppm for wo rker s in close proximity to the press in the PB manufacture process. Em ployees in the 12 plants (number not specified) **Abstract:**

OBJECTIVES: Past and present formaldehyde measurements made in facilities manufacturing reconstituted wo od panels in Quebec have been collected to assess formaldehyde exposure and its determinants in this industry . METHODS: All 12 plants manufacturing OSB, MDF, and PB in Quebec were visited by a r esearch team which to ok area and personal measurements. Past measurements taken by governmental occupational health teams in these plants were also collected. Log transformed formaldehyde concentrations were analyzed with extended linear mixed - effects mode ls. RESULTS: During 2001

–2002, 275 measurements were taken by the research team, while 590 measurements dating back to 1984 were collected from governmental files. The area measurements had a global GM of 0.28 ppm [geometric standard deviation (GSD): 3.1]. The GM of the personal measurements was 0.17 ppm (GSD: 2.3). The fixed effects of the models for personal and area measurements explained 61 and 57% of the variance, respectively. Job (working area for area concentrations), process (PB, MDF, OSB), season of sampling, origin of the data (research, governmental) and year of sampling were significant determinants of exposure . Proximity to the press, winter conditions, PB and MDF processes and governmental data resulted in the highest exposure s. Significant within - sampling campaign correlation was found for both personal and area models. The final mo dels include different residual variances by process for personal measurements and by working area for area measurements.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report October 6, 2011 Page H - 9 **Table H**  **- 3**  **. Formaldehyde Exposure Levels for Particleboard and Medium -**  **Density Fiberboard Manufacture (Includes Wood Workers and Oriented Strand Board Manufacture)** 
**Authors/Article Publication**  **Air concentrations of Form**  **aldehyde Study Population** 

**(Exposed Workers) Abstract and Salient Points** 

CONCLUSIONS: Several determinants o f exposure to formaldehyde in the reconstituted wo od panel industry were successfully identified. Higher levels found in governmental data as compared to research data may be explained by a ‘worst - case’ strategy bias. The observed intra sampling campaign c orrelation supports existing results suggesting that measurements taken in a small time frame tend to be correlated. Exposure s in this sec to r are low compared to the 8 - hour TWA OELs of mo st Canadian jurisdictions (e.g., 0.75 ppm) but close to the most demanding ones (e.g., 0.3 ppm, as for British Columbia). **Salient Points:**  Twelve plants manufacturing OSB, MDF, and PB in Quebec were visited from June 2001 to March 2002. The visits were conducted by a team of 2

–4 industrial hygienists and technicians and lasted 1 to 2 days.  The research team to ok area and personal measurements. Past measurements taken by governmental occupational health teams in these plants we re also collected. The visits performed by the research team yielded 275 measurements while 590 measurements were available from governmental files.  Exposure s to formaldehyde in the OSB manufacturing industry were mo stly below

0.1 ppm with some work zones/ jobs associated with somewhat higher levels according to the governmental data.  Formaldehyde exposure levels in the MDF and PB manufacturing industries were similar, with observed and estimated GMs of personal and area levels between 0.1 and 0.4 ppm depen ding on the source of data. The highest estimated ambient GM was 0.43 ppm in the main production area of MDF manufacturing facilities (this estimate is increased to 1.28 ppm when governmental data are used). The highest personal estimated GM is 0.22 ppm fo r worker s in close proximity to the press in the PB manufacture process (this estimate is increased to 0.62 ppm if the governmental data are considered).Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report October 6, 2011 Page H - 10 **Table H**  **- 3**  **. Formaldehyde Exposure Levels for Particleboard and Medium -**  **Density Fiberboard Manufacture (Includes Wood Workers and Oriented Strand Board Manufacture)** 
**Authors/Article Publication**  **Air concentrations of Form**  **aldehyde Study Population** 

**(Exposed Workers) Abstract and Salient Points** 

 Governmental measurements were consistently found higher than those measured by the research team, pointing to the probable existence of a ‘worst - case’ bias in governmental data.  Area measurements were consistently higher than personal measurements. This i s consistent with the fact that the most exposed worker s are those who spend the most time in the production area unprotected by ventilated booths. While none of the personal measurements in this study was greater than 2 ppm, 4% and 6% of the research and governmental ambient concentrations, respectively, were greater than this value.  Although the results of this study point to generally low personal full - shift exposure to formaldehyde in the industrial sec to r studied, the potential for short - term high expo sure s associated with specific and occasional tasks cannot be ruled out on the basis of our study.  Levels reported prior to 1985 are consistently higher than those in this study database. According to the authors, this maybe explained by the generalized us e, around 1985, of low formaldehyde emission resins.  The measured and estimated TWA levels of exposure to formaldehyde in this sec to r can be considered low com pared to the 8 hour TWA OELs of most Canadian jurisdictions (e.g. 0.75 ppm) but close to the most demanding ones (e.g., 0.3 ppm, as for British Columbia).Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report October 6, 2011 Page H - 11 **Table H**  **- 3**  **. Formaldehyde Exposure Levels for Particleboard and Medium -**  **Density Fiberboard Manufacture (Includes Wood Workers and Oriented Strand Board Manufacture)** 
**Authors/Article Publication**  **Air concentrations of Form**  **aldehyde Study Population** 

**(Exposed Workers) Abstract and Salient Points**  Chung KY et al. A study on dust emission, particle size distribution and formaldehyde concentration during machining of MDF. Ann Occup Hyg.

2000 Sep; 44(6): 455 - 66. Less than 0.14 ppm

(0.17mg/m 3 ) N/A **Abstract:** A study to characterize the quantity, particle size distribution, and mo rphology of dust created during the machining of MDF was carried out. Four different types of MDF boards were included in this study, including a 'zero - formaldehyde' bo ard that contains isocyanate - based resin, rather than urea - formaldehyde resin. In addition, natural softwood (pine) and natural hardwood (oak) were included in the study, for comparison with MDF. The results show that in general, the dust generated by mach ining MDF is comparable in terms of particle size distribution and morphology with the dust generated by similarly machining hardwood or softwood. The quantity of dust generated during sanding is higher for sanding MDF compared with sanding either hardwood or softwood. However, for sawing, there is no significant difference between MDF and natural woods, in terms of the quantity of dust generated. Free formaldehyde in the air was less than 0.17mg/m 3 during machining of the Class B (higher formaldehyde potential) MDF board. There was no measurable isocyanate in the dust generated from the boards.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report October 6, 2011 Page H - 12 **Table H**  **- 3**  **. Formaldehyde Exposure Levels for Particleboard and Medium -**  **Density Fiberboard Manufacture (Includes Wood Workers and Oriented Strand Board Manufacture)** 
**Authors/Article Publication**  **Air concentrations of Form**  **aldehyde Study Population** 

**(Exposed Workers) Abstract and Salient Points**  Herbert FA et al. Respiratory consequences of exposure to wood dust and formaldehyde of workers manufacturing oriented strand board. Arch Environ

Health. 1994 Nov - Dec; 49(6):465 - 70. Up to 0.27 ppm 99 workers em ployed in the manufacture of oriented strand board. **Abstract:**

A cross - sectional study was performed at a plant in which 99 workers were employed in the manufacture of oriented strand board. This group wa s com pared with 165 unexposed workers from the petroleum industry. Both groups were assessed, using a questionnaire, spirometry, and skin prick tests to common environmental antigens. Environmental studies showed a low

dust level of 0.27 mg/m3 , consisting of particles of a mass median aerodynamic equivalent diameter of 2.5 microns. There were parameter concentrations of formaldehyde, up to 0.27 ppm. A significant difference between the oriented strand board workers and oil field workers was noted for the forced expiratory volume in 1s/forced vital capacity ratio, without significant differences in either the forced expiratory volume in 1 s or the forced vital capacity. Oriented strand board workers who were current smokers were three times as likely to have a for ced expiratory volume in 1s/forced vital capacity ratio of less than 75% of that found in the currently smoking oil field workers. Significant reductions in forced expiratory volume in 1s (p = .044) and forced vital capacity (p = .022) in oriented strand b oard workers were noted across the work shift. The oriented strand board workers complained of self - reported asthma and of lower respiratory tract symptoms significantly more frequently than did oil workers for all of the symptoms examined. The prevalence of atopy wa s not different in the two groups. Lung function was significantly better in oriented strand board workers who had no symptoms, compared with oriented strand board workers who were symptomatic. (ABSTRACT TRUNCATED AT 250 WORDS) **Salient Points:**  In this cross - sectional study**,** 99 workers employed in the manufacture of oriented strand board were compared with 165 unexposed worke rs from the petroleum industry.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report October 6, 2011 Page H - 13 **Table H**  **- 3**  **. Formaldehyde Exposure Levels for Particleboard and Medium -**  **Density Fiberboard Manufacture (Includes Wood Workers and Oriented Strand Board Manufacture)** 
**Authors/Article Publication**  **Air concentrations of Form**  **aldehyde Study Population** 

**(Exposed Workers) Abstract and Salient Points** 

 Parameter concentrations of formaldehyde, up to 0.27 ppm, were noted.  Environmental studies showed a low dust level of 0.27mg/m 3 , consisting of particles of a mass median aerodynamic equivalent diameter of 2.5 microns.  Significant reductions in forced expiratory volume and forced vital capacity were noted across the work shi ft in oriented strand board workers.  Oriented strand board workers complained of self - reported asthma and of lower respiratory tract symptoms significantly more frequently than did oil workers for all of the symptoms examined. Edling C et al. Occupational exposure to formaldehyde and histopathological changes in the nasal mucosa . Br J Ind Med.

1988 Nov; 45(11):761 - 5. 0.08 to 0.9 ppm.

(midpoint of this range is 0.49 ppm). Peaks of up to 4.1 ppm w ere measured during the 8 - year period 75 workers from two

particle board processing plants and a laminate plant **Abstract:**

To study the cytotoxic effect of formaldehyde on the human nasal mucosa, 75 men with occupational exposure to formaldehyde or to formaldehyde and wood dust were examined, looking particularly at early signs of irritative effects and histopathological changes in the nasal mucosa. All men underwent a medical examination, and a nasal biopsy specimen was examined by a pathologist and graded from 0 - 8 according to the morphological chang es. A high frequency of nasal symptoms, mostly a running nose and crusting, was related to exposure to formaldehyde. Only three men had a normal mucosa; the remainder had loss of cilia and goblet cell hyperplasia (11%) and squamous metaplasia (78%); in six cases (8%) there was a mild dysplasia. The histological grading showed a significantly higher score when compared with unexposed contents (2.9 v 1.8). There was no dose response relation, no malignancies, and no difference in the histological score betwee n those exposed to formaldehyde or to formaldehyde and wood dust.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report October 6, 2011 Page H - 14 **Table H**  **- 3**  **. Formaldehyde Exposure Levels for Particleboard and Medium -**  **Density Fiberboard Manufacture (Includes Wood Workers and Oriented Strand Board Manufacture)** 
**Authors/Article Publication**  **Air concentrations of Form**  **aldehyde Study Population** 

**(Exposed Workers) Abstract and Salient Points** 

**Salient Points:**  Measurements taken by in - house hygienists during an 8 - year period before the study (between 1975 and 1983) were in the range 0.08 to 0.9 ppm with peaks reaching 4.07 ppm. A mean TWA concentration wa s not reported, but the midpoint of this range is 0.49 ppm . Air concentrations were qualitatively assessed as being “somewhat higher” during earlier periods.  Wood dust air concentrations in the particle board plants ranged from 0.6 to 1.1 mg/m 3 ; air in the laminate plant was reported to be without wood dust.  Em ployment durations ranged from 1 to 39 years with a mean of 10.5 years.  Runny nose, nasal crusting, and runny eyes when at work were reported by 60 and 75% of the exposed subjects, respectively. Gross clinical examination showed that 25% of exposed worker s had either swollen nasal mucosa or dry nasal mucosa.  The authors reported that the average histological score for the exposed group (2.8) was statistically significantly greater than the control score (1.8) and that there was no difference in average hi stological scores between the exposed workers from the particle board plants, where confounding exposure to wood dust occurred, and those from the laminate plant (without wood dust exposure). This observation supports the hypothesis that the observed nasal epithelial lesions were caused by formaldehyde and not by an interaction between formaldehyde and wood dust.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report October 6, 2011 Page H - 15 **Table H**  **- 3**  **. Formaldehyde Exposure Levels for Particleboard and Medium -**  **Density Fiberboard Manufacture (Includes Wood Workers and Oriented Strand Board Manufacture)** 
**Authors/Article Publication**  **Air concentrations of Form**  **aldehyde Study Population** 

**(Exposed Workers) Abstract and Salient Points**  Horvath EP et al. 1988. Effects of formaldehyde on the mucous membranes and lungs: A study of an industrial population. JAMA. 1988 Feb

5; 259(5):701 - 7. 0.17 to 2.93 ppm

(mean of 0.69 ppm) 109 workers in a

particle board and mo lded plastics plant **Abstract:**

One hundred nine workers and 254 control subjects were studied to evaluate the effects of formaldehyde on the mucous membranes and lungs. A modified, respiratory symptom questionnaire and spirometry were administered to all study participants before and after their work shift, and formaldehyde levels were determined for each test subject. Over the course of the monitored work shift, test sub jects demonstrated a dose - dependent excess of irritant symptoms and a statistically significant decline in certain lung function parameters. Analysis of test and control subject data combined revealed a correlation between formaldehyde exposure and these p ulmonary changes. Baseline spirometry values were not significantly different between test and control groups, and formaldehyde - exposed workers did not report an excess of respiratory symptoms. Formaldehyde is a dose - dependent irritant of the eyes and muco us membranes at low - level exposures. It can exert a small, across - shift effect on airways but after a mean exposure of 10 years does not appear to cause permanent respiratory im pairment. **Salient Points:**  The duration of exposure among exposed workers range d from <1 year to 20 years, with a mean and median of 10.3 and 10 years, respectively.  Estimates of formaldehyde air concentrations ranged from 0.17 to 2.93 ppm with a mean of 0.69 ppm. Nuisance particles (predominantly softwood dust) were also detected in the particle board area.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report October 6, 2011 Page H - 16 **Table H**  **- 3**  **. Formaldehyde Exposure Levels for Particleboard and Medium -**  **Density Fiberboard Manufacture (Includes Wood Workers and Oriented Strand Board Manufacture)** 
**Authors/Article Publication**  **Air concentrations of Form**  **aldehyde Study Population** 

**(Exposed Workers) Abstract and Salient Points** 

 The percentages of particle board workers reporting a number of symptoms of respiratory irritation over a work shift were statistically significantly greater than work shift reporting percentages for a nonexposed group of 264 food - processing workers: cough (34.9 versus 18.9%), chest pains (9.2 versus 2%), phlegm production (26.6 versus 9.8%),burning nose (28.4 versus 2%), stuffy nose (33.9 versus 14.2%), burning or w atering eyes (39.5 versus 9.1%), itchy nose (21. 1 versus 7.9%), and sore/burning throat (22 versus 3.9%).  The authors concluded that the effects noted were possibly not only due to formaldehyde alone but could also be attributed to the presence of respirable particles of wood dust. Kauppinen TP and Nie melä RI Occupational exposure to chemical agents in the particleboard industry . Scand J Work

Environ Health. 1985 Oct; 11(5):357 - 63. Before 1975,

greater than 2 ppm during many wo rk phases. Means b elow 2 ppm during most work phases during 1975 and 1984 . For area measurements, means between 0.4 ppm and 2.3 ppm (depending on individual locations in the plant). Not available **Abstract:** Most of the measurements concerned formaldehyde and wood dust. The other substances measured included terpenes, solvents, and heptachlor. Before 1975, the formaldehyde concentration regularly exceeded 2 ppm during many work phases. Considerable im provements in ventilation and the composition of glues have occurred since then, and today the exposure level is below 2 ppm during mo st work phases. High peak concentrations, 20 to 30 ppm at the highest, were characteristic of exposure in earlier years. The concentrations of wood dust have also decreased (e.g., from over 5 mg/m 3 to 1 mg/m 3 or below during forming). These data have be en used to evaluate past exposures in an epidemiologic study on cancer risks in the particleboard, plywood, and sawmill industries.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report October 6, 2011 Page H - 17 **Table H**  **- 3**  **. Formaldehyde Exposure Levels for Particleboard and Medium -**  **Density Fiberboard Manufacture (Includes Wood Workers and Oriented Strand Board Manufacture)** 
**Authors/Article Publication**  **Air concentrations of Form**  **aldehyde Study Population** 

**(Exposed Workers) Abstract and Salient Points**  Alexandersson R et al. Exposure to formaldehyde: Effects on pulmonary function . Arch Environ

Health. 1982 Sep - Oct; 37(5): 279 - 84. 0.37 ppm (0.45

mg/m 3 ) 47 woodworkers **Abstract:** Forty - seven subjects exposed to formaldehyde (mean air concentration 0.45 mg/m 3 ) and 20 unexposed subjects, all of whom were employed at a carpentry shop, were studied with regard to symptoms and pulmonary function. Symptoms involving eyes and throat irritation as well as chest oppression were significantly more common in the exposed subjects than in the unexposed controls. Spirometry and single breath nitrogen washout were normal Monday morning before exposure to formaldehyde. A reduction in forced expiratory volume in 1 sec by an average of 0.2 L (P = 0.002), percent forced expirato ry volume by 2% (P = 0.04), maximum midexpiratory flow by 0.3 L/sec (P = 0.04), and an increase in closing volume in percentage of vital capacity by 3.4% (P - 0.002) were seen after a day of work and exposure to formaldehyde, suggesting bronchoconstriction . Smokers and nonsmokers displayed similar changes in spirometry and nitrogen wa shout.Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report

October 6, 2011

**Appendix I**  **MODEL RESULTS FOR INDOOR AIR CONCENTRATIONS AT CWP FABRICATION**

**SITES USING PRE -**  **BASELINE EMISSION RATES**Formaldeh yd e Occupational Exposure Assessment Report - Draft Final Report October 6, 2011 Page I - 1 **Table I -**  **1. Results for the Calculatio n Trials for the What**  **- If Low**  **- and High**  **- End**  **Pre -**  **Baseline Indoor Air Concentrations**

**Varied Param eter**  **Calculated Concentration for Pre**  **- Baseline, ppm**  **Intermediate 4**  **Low End 5**  **High End 6**  **HWPW PB**  **MDF HWPW**  **PB MDF**  **HWPW PB**  **MDF** Vary Emitting Surface Area 1 0.019 0.024 0.044 0.006 0.007 0.009 0.142 0.197 0.399 Vary Effective Ventilation Rate 2 0.007 0.008 0.011 0.414 0.580 1.186 Vary Emission Rate 3 0.012 0.018 0.018 0.022 0.044 0.090 1 For area, the intermediate value is based on the aggregate average per - site throughput calculated using domestic composite wood product consumption data from the EPA market profile . The high - end and low - end values are calculated assuming 1,000% and 10% of the aggregate average throughput, respectively. 2 Effective v entilation is varied based on values shown in Table 3 - 3 . The low - end , ty pical , and high - end values are 50, 1,500 and 10 ,000 cfm, respectively. 3 Emission rate is varied based on values shown in Table 3 - 4 . 4 Intermediate concentration is calculated using intermediate value for surface area, typical value for effective ventilation rate, and we ighted - average pre - baseline emission rate for each CWP type. 5 Lo w - end values calculated according to Table 3 - 2 . 6 High - end values calculated according to Table 3 - 2 . **Table I -**  **2. Combined (for All CWP) Results: Estimated Range of Values for the What -**  **If Low -**  **and High -**  **End Indoor Air Concentrations for**  **Pre -**  **Baseline Case**  **Intermediate (ppm )**  **Low End (ppm)**  **High End (ppm)** Pre - Baseline 0.019

– 0.044 0.006

– 0.018 0.022

– 1.186