# External Peer Review of EPA’s Draft Document

**Peer Reviewers:** Randy L . Maddalena, Ph.D. Bettina Meyer Octavia Zeleniuc, Ph.D.

Contract No. EP
- C
- 12
- 0 45 Task Order 18 

# Final **Peer Review Report Measuring Formaldehyde Emissions from Low Emitting**  **Hardwood Plywood Panels under Different Conditions of**

**Tem perature and Relative Humidity** 

**September 6 , 2013** 

**Prepared for:** U.S. Environmental Protection Agency Office of Pollution Prevention and Toxics 1200 Pennsylvania Ave., NW ( 7404T ) Washington, DC 20460 **Prepared by:** Versar, Inc. 6850 Versar Center Springfield, VA 22151External Peer Review of EPA’s Draft Document : Measuring Formaldehyde Emissions from Low Emitting Hardwood Plywood Panels under Different Conditions of Temperature and Relative Humidity

i 

### Contents **I. INTRODUCTION ................................**  **................................ ................................**  **..................... 1**  **II. CHARGE TO REVIEWERS ................................**  **................................ ................................**  **.. 2**  **III. INDIVIDUAL PEER REVIEWER COMMENTS ................................**  **............................. 3**  Randy L . Maddalena, Ph.D.
................................ ................................ ................................ ........ 4 Bettina Meyer ................................ ................................ ................................ .............................. 8 Octavia Zeleniuc, Ph.D.
................................ ................................ ................................ ............ 15External Peer Review of EPA’s Draft Document : Measuring Formaldehyde Emissions from Low Emitting Hardwood Plywood Panels under Different Conditions of Temperature and Relative Humidity

1 **I. INTRODUCTION**  In July of 2010, the Formaldehyde Standards for Composite Wood Products Act, or Title VI of the Toxic Substances Control Act (TSCA), was signed into law. The statute establishes formaldeh yde emission standards for hardwood plywood (HWPW), medium density fiberboard (MDF), and particleboard (PB) sold, supplied, offered for sale, or manufactured in the United States. These emission standards are identical to the Phase 2 standards established by the California Air Resources Board’s (CARB) Airborne Toxic Control Measure (ATCM). Both TSCA Title VIand the CARB’s ATCM require formaldehyde emission testing to be conducted quarterl y using the ASTM, International (formerly American Society for Testing and Materials (ASTM)) E1333 large chamber method or ASTM D6007 smal l chamber method. Recent testing has suggested that some ultra

- low emitting formaldehyd e ( ULEF ) composite wood products may

have significantl y increased formaldehyde emissions when the temperature (T) and/or relative humidity (RH) are higher than the standard conditions (i.e., 25 degrees Celsius (°C) and 50 %RH) required in the ASTM E1333 and D6007 test methods. Consequently , EPA initiated testing to assess the effect of elevated T and RH conditions on formaldehyde emissions from NAF and ULEF composite wood products. Specificall y, formaldeh yde emissions from HWPW panels made with NAF

- acrylic, ULEF

- PF (phenol

- formaldehyde), and ULEF

- UF (urea

- formaldehyde) resins were determined using standard methods by a CARB
- approved TPC laboratory

at several T and RH conditions. In addition to testing at the standard T/RH conditions, each HWPW ty

pe (i.e., HWPW made with the three different resins) was tested at 25 °C with 70 and 85 %RH, and at 30 °C with 50, 70, and 85 %RH. At each T/RH condition , three emission tests were conducted on each HWPW ty pe simultaneously

using the ASTM small chamber (D6007) method. The tes t results were evaluated to determine the effect of T and RH on the formaldeh yde emissions of HWPW panels made with each of the three resins. The purpose of the requested letter review is for EPA to receive written comments from individual experts , who w ere selected b y Versar having expertise in testing formaldeh yde emissions from composite wood products
. Final written comments received from reviewers will be made publicall y available on EPA’s electronic public docket and online comment system (Regulation s.gov). **Peer Reviewers :**  **Randy L. Maddalena, Ph.D.** Lawrence Berkeley

National Laboratory **Bettina Meyer** Fraunhofer Institute for Wood Research Wilhelm

- Klauditz

- In stitut (WKI) **Octavia Zeleniuc, Ph.D.** Transilvania University of BrasovExternal Peer Review of EPA’s Draft Document : Measuring Formaldehyde Emissions from Low Emitting Hardwood Plywood Panels under Different Conditions of Temperature and Relative Humidity

2 **II. CHARGE**  **TO REVIEWERS**  **Charge Questions :**  1) Is the study

scientifically

sound? Was it designed and conducted properly? 2) Are the results presented clearly and appropriately?External Peer Review of EPA’s Draft Document : Measuring Formaldehyde Emissions from Low Emitting Hardwood Plywood Panels under Different Conditions of Temperature and Relative Humidity

3 **III. I NDIVIDUAL PEER REVIEWER COMMENTS** External Peer Review of EPA’s Draft Document : Measuring Formaldehyde Emissions from Low Emitting Hardwood Plywood Panels under Different Conditions of Temperature and Relative Humidity

4 **Review by :**  **Randy L. Maddalena, Ph.D.**External Peer Review of EPA’s Draft Document : Measuring Formaldehyde Emissions from Low Emitting Hardwood Plywood Panels under Different Conditions of Temperature and Relative Humidity

5 **Peer Review Comments on EPA’s Draft Report**  **Measuring Formaldehyde Emissions from Low Emitting Hardwood Plywood Panels under Different Conditions of Temperature and**  **Relative Humidity** Randy L . Maddalena, Ph.D. Lawrence Berkeley

National Laboratory August 5 , 2013 **I. GENERAL IMPRESSIONS** New federal and state laws have moved the building industry toward the use of materials that emit less pollutant indoors with particular emphasis on lowering formaldehyde exposures. As a result, the use of ultra

- low emitting formaldehyde (ULEF) resin and no added formaldehyd e (NAF) resin in composite wood products is increasing. The EPA is required to develop new regulation s to implement the new standards for lower formaldehyde em issions and to consider provisions for materials made with ULEF and NAF resin s . Test methods are available for measuring the amount of formaldehyde emitted from composite wood products under standardized test conditions but the methods do not consider the effect of environmental factors such as temperature (T) and/or (RH) relative humidity . Several published studies of composite wood products have shown a significant and positive correlation between formaldehyde emission and both temperature and relative humidity
. The subject of this review is an investigation of the effect of temperature and humidity on formaldeh yde emissions from composite wood products made with ULEF and NAF resins. The work was done to support EPA’s efforts in developing new regulations and provisions implementing new formaldehyde emission standards. Icommend the EPA for recognizing the potential importance of T/RH and initiating this study . The stated goals of the project are to determine whe ther formaldehyde emissions are affected by elevated T/RH conditions relative to the standard conditions; to determine whether different resin ty pes respond to T/RH differentl y; and to characterize the variability of results from emission tests using small chambers. Overall, the project was well conceived and work appears to be careful and complete producing high quality data. The report is very well written and the conclusions are reasonable and generall y supported b y the work. **II. RESPONSE TO CHARGE Q UESTIONS**  **1. Is the study scientifically sound? Was it designed and conducted properly?**  The objectives and methods of the study were clearly

articulated and the experimental design was appropriate to address the stated objectives. The quality of the work is excellent , including sufficient quality

assurance measures and data interpretation. I particularl y l ike the detail given to measuring and reporting the variability in the small chamber test method results and the careful comparison between the small an d large chamber methods.External Peer Review of EPA’s Draft Document : Measuring Formaldehyde Emissions from Low Emitting Hardwood Plywood Panels under Different Conditions of Temperature and Relative Humidity

6 I have two issues with the experimental design described below. First, the study used onl y two temperature levels. Using onl y two temperature levels limits the ability to characterize the linearity of the emission/temperature pro file. This limitation is not expected to weaken the results of the study

because the work was focused specifically on the issue of increasing temperature and humidity

above the standard conditions and only tested a relativel y small temperature range (25 C 
- 30 C  ). Given how the hy potheses were formulated and the limited temperature range being tested, the assumption of linearity in the emission/temperature profile is probably valid. However, the authors should clarify that previous studies found that the relationship was not linear and discuss how those findings might impact their conclusions. For example, both Myers (1985, cited in the report) and Parthasarath y et al. (2011 citation provided at end of the review) found an exponential relationship between formaldehyde emissions and temperature , so it is probably not advisable to extrapolate the relationship found in this study beyond the range tested. The second issue may

be more significant. This reviewer is not familiar with the chromotropic acid method used in the study but NIOSH 3500 method states that there may be negative interference in the formaldehyde measurement if phenols are present at levels greater than 8:1 relative to formaldehyde. This interference may have already been resolved in the metho d used by the third party certifier. However, the report stated that the PF product tested in Riedlinger et al. (2012) seemed to show an increase in emission with T/RH (page 4, paragraph 1 in the report), which is inconsistent with the findings of the curr ent report. The authors need to discuss why their results differ from Riedlinger et al (2012) and discuss the possibility that the lower apparent emissions from th e ULEF
- PF HWPW samples may be due to interference in the anal ytical method. If the reason for the lower formaldeh yde concentrations is an artifact of the anal ytical method , where experimental conditions result ed in higher concentration of phenols in the test chamber , then the comparisons with ULEF
- PF may not be valid. **2. Are the results presen**  **ted clearly and appropriately?** The results of this report are very clearl y presented in sufficient detail to support conclusions with a few exceptions mentioned above and in the specific observation. **III. SPECIFIC OBSERVATIONS Page**  **Line Comment or**  **Question** 1
- 2 The Executive Summary is very well written and complete. 4 2 The Myers (1985) citation in the background found that

formaldeh yde “ emissions increased exponentially” with increasing temperature. This point should be reconciled with the authors’ assumption of a linear relationship between emission and temperature later in the report. Again, I don’t expect this to change the results of the statistical anal ys is but should be discussed in the report. 6 1 I agree with the authors’ use of an extended conditioning time at the

higher T/RH conditions. Others have found that for some composite wood materials , it may

take from one to ten days for the material to come to equilibrium with the humidity (Parthasarathy

et al. 2011). ItExternal Peer Review of EPA’s Draft Document : Measuring Formaldehyde Emissions from Low Emitting Hardwood Plywood Panels under Different Conditions of Temperature and Relative Humidity

7 **Page Line**  **Comment or Question** 

is unclear what e ffect the continued uptake of moisture into the material will have on emission rates but future work may want to confirm that moisture uptake into composite wood does not increase formaldeh yde emissions. 6 2 The exposed surface area of the HWPW is repo rted here but it is not

clear whether the edges/backs are covered. When I tried to estimate the area and other test conditions from the information provided in the report (page 6 , paragraph 2 and page 8, section 3.3.1 and 3.3.2) I was not able to reconcile the factors in the small and large chamber s . I suggest providing a table with the following factors listed for both the large and small chamber s: Lo ading (L, m2/m3); Air change rate (ACH, 1/h); Chamber volume (V, m3); Ventilation rate (Q, m3/h); Area of e mitting surface including edges (A, m2). One of the most important factors that influence results from different size chambers when the emissions are reported at concentration (ppm) is the Q/A (m/h). I was not able to confirm that Q/A was the same for bo th chambers. I was also not able to confirm the emitting sample area for the small and large chamber s . 11 2 P aragraph 2 and Section 4.3 report the method blanks (~0.006) and

chamber blanks (range from 0.009 to more than 0.03, average 0.017 ppm after excluding outlier). Were the blanks/background concentrations subtracted from the measurements when the data were p rocessed? 11 4 Was a formal statistical test used to identify and exclude the two outliers that “exceeded 0.03 ppm”?External Peer Review of EPA’s Draft Document : Measuring Formaldehyde Emissions from Low Emitting Hardwood Plywood Panels under Different Conditions of Temperature and Relative Humidity

8 **Review by :**  **Bettina Me yer** External Peer Review of EPA’s Draft Document : Measuring Formaldehyde Emissions from Low Emitting Hardwood Plywood Panels under Different Conditions of Temperature and Relative Humidity

9 **Peer Review Comments on EPA’s Draft Report**  **Measuring Formaldehyde Emissions from Low Emitting Hardwood**  **Plywood Panels under Different Conditions of Temperature and Relative Humidity**  Bettina Meyer Fraunhofer Institute for Wood Research Wilhelm

- Klauditz

- In stitut (WKI) July 30, 2013 **I. GENERAL IMPRESSIONS** This technical report presents an interesting piece of work. The formaldeh yde emission from wood based panels has been investigated and published by several authors. In 1974, a very important study

on the impact of temperature and relative humidity , resulting in a mathematical model , was published by I. Andersen, Gunnar R. Lundquist und L ars Molhave, “ Liberation of formaldeh yde from particleboard. A mathematical model” (Ugeskr. Læg. 1974: 136: 2145

- 2150). The topic became more and more important due to the discussion of decreasing/reduction of formaldeh yde limit values for wood based panel products worldwide considering the classification of formaldehyde as a toxicological ly relevant compound. In addition , the impact of temperature and re lative humidity became relevant because of different reference chamber test standards worldwide. From m y point of view, this technical report can only be regarded as an indication showing the impact of temperature and relative humidity on low emitting ply

wood boards and not as a scientific report showing important n ew aspects / assessment parameter s or a general ly valid calculation formula due to the several remarks mentioned in this rev iew. **II. RESPONSE TO CHARGE QUESTIONS 1.**  **Is the study scientifically sound? Was it designed and conducted properly?** The technical report is well written and the topic is very important. A detailed description and interpretation of test results was given on bas is of the obtained test results. But due to the following items below, the experimental approach and the resu lts and their interpretation/statistical evaluation need a major revision.

 Special production process of test material cause d by the multi

- layer structure. Note: onl y 5
- layer glued boards with a thickness of 9 mm (and 0.5 inch

– mistake?) have been tested , other thicknesses having more or few er layer s m ay cause different results and need to be verified ;  H igh chamber blank values (in relation to very low emitting test materials) ; and  Analy tical procedure used (chromotropic acid method)External Peer Review of EPA’s Draft Document : Measuring Formaldehyde Emissions from Low Emitting Hardwood Plywood Panels under Different Conditions of Temperature and Relative Humidity

10 From m y point of view, this technical report in the present form can onl y be regarded as an indication showing the impact of temperature and relative humidity on low emitting ply

wood boards. The statistical evaluation of the results is complex, but cannot be assessed on the basis of the available data with respect to these test results due to reasons mentioned above. Details are discussed in following pages of this review. **2. Are the results presented clearly and appropriately?**  The background, expe rimental work , and statistical evaluation of test results are described accur atel y and understandable

– w ith some small exception s as stated below. The technical report was written in a very structured and understandable way
. The literature is adequatel y c ited, but has to be extended. There are some important publication s missing. **My recommendation** : In the present form, the article cannot be published and need s a major revision. **III. SPECIFIC OBSERVATIONS** In the following, I will mainly comment on the main parts or chapter s and refer to corresponding pages. **Page Line**  **Comment or Question** 1
- 2 Chapter 1: Executive Summary The summary gives a good overview of the topic and the main results of this work. 3
- 4 Chapter 2: Backgrou nd Excellent description of the current situation , beginning in 2007 with the

CARB regulation and some first test results concerning the variation of temperature and relative humidity as the base to continue studies on this topic. 5
- 9 Chapter 3: Test design and Procedure s This cha

pter gives a good overview of the experimental design of the investigation. The samples, test methods , and analy tical procedure are described in detail, but raise some questions: **Page 8** 3.2 Test material Test material “All three test materials were 5

- pl y veneer core HWPW: NAF
- acryl ic and ULEF

- PF panels were 9 millimeters thick, the ULEF

UF panels were **0.5 inch** thick
. ” Is this a mistake: 5

- layer pl ywood with thickness of 0.5 inch? 3.3.2 Small chamber tests “A conditioning of 48 hours was used to ensure that test materials were equilibrated to the elevated T and RH conditions used in testing.” “The HWPW specimens remained in the small chambers until steady state HCHO concentration was reached, i.e., approxim ately 2.5 hours after the start of the small chamber test.” Does it mean that the testExternal Peer Review of EPA’s Draft Document : Measuring Formaldehyde Emissions from Low Emitting Hardwood Plywood Panels under Different Conditions of Temperature and Relative Humidity

11 **Page Line**  **Comment or Question**

samples were conditioned only for 48 hours and testing was done for 2.5 hours? A clarification should be given in the description. Referring to ASTM D 6007 , the test has to be carried out until a steady state concentration is reached and the time has to be calculated b y an equation using the mass transfer coefficient or a second possibility is to run the small chamber with preconditioned samples as the large ASTM E 1333 chamber test (7 day s). If the samples were onl y conditioned for 48 hours, are there some additional test results to verify the proper conditioning of the samples

– meaning was the equilibrium reached? Are the K

- values calculated and/or are there additional test results to verify a steady state concentration? **Page 9:** 3.3.3 Chromotropic acid anal ys is The calibration curve was extended to lower concentrations to “assure accurate determination of HCH O emissions from the panels”... (s ummary

i n Section 4 of the report)

. From m y point of view , the chromotropic acid method can no longer be regarded as the “state of the art” analy tical test method for formaldehyde determination due to several problems

– see below. Another anal ytical method has to be used to determined formaldehyde emission

– especially for these low ranges/levels. As stated in:

- ASTM E 1333 standard , “Detailed procedures based on acetylacetone, pararosanilin, DNPH and MBTH have been found to give results equivalent or greater in accuracy and precision than chromotropic acid” and

- ASTM D 6007 standard , “NIOSH 3500 anal ytical method: phenols as negative interference at an 8:1 excess over formaldehyde, modifications in the anal yt ical procedure shall be made when relatively high ph enol to formaldeh yde concentration (8:1) are anticipated (Lit.: Hakes, D., Johnson, G. and Marhevka, J., April 1984 and Technical Bulletin No. 415, 1983) .” Additionally , the CARB ATCM Standard Operating Procedure (SOP) SAS 20 , “Sampling and Analy sis of F ormaldehyde Emissions from Composite Wood Products ,” June 2012, describes the DNPH method by anal ys is by

high performance liquid chromatography (HPL C) as anal yt ical procedure wi th detection limits of 0.6 ppb and estimated quantification limit (EQL) of 3 pp b. In 2010, difficulties in high detection limit have already been noticed b y CARB in reference to small

- scale test methods in combination withExternal Peer Review of EPA’s Draft Document : Measuring Formaldehyde Emissions from Low Emitting Hardwood Plywood Panels under Different Conditions of Temperature and Relative Humidity

12 **Page Line**  **Comment or Question**

NI OSH 3500 chromotropic acid method and were published in CWP

10
- 002. Therefore , CARB recommend s using MBTH or the acetyl acetone method for small

- scale test methods. 10
- 11 Chapter 4: Quality Assurance / Quality C ontrol **Page 10**

4.1 Chamber Test C onditions The test conditi ons are described well, but back ground test results in the conditioning chamber are an important parameter in addition. Investigations of very

low emitting materials stored in an area of high emitting materials can showed an impact on absorbing formaldehyde. 4.2 Chromotropic Acid Calib ration Only a single calibration curve has been established at the beginning of this study in August 2012 and the slope was compared to the calibration curves done between March and July 2012 in this laboratory . It was indicated based on the slope, that th e laboratory spectrophotometer and the preparation of calibration standards were consistent over time. As mentioned in this chapter, this is a standard practice for the TPC, but from my point of view it is not sufficient. The I SO, JI S , and EN standards request a calibration curve in a c ontinuously

repeating period. For example, the European referen ce chamber test method for wood

- based materials EN 717

- 1, 2005
- 01: “Wood

- based panels

– Determination of formaldehyde release, Part 1: Formaldeh yd e emission b y the chamber method” requires in chapter 9.4.1 “ The calibration curve shall be checked at least once a week
. ” European labs being accredited have to act this way and WKI uses the same procedure for ASTM chamber test evaluation , as well as for European test methods. **Page 11** 4.3 Chamber HCHO Background The large chamber background was detected with 0.010 ppm, small chamber backgrounds were given with an average value of 0.020 ( + 0.009) ppm for 22 measurements, excluding two tests which exceed ed 0.03 ppm , the averaged background level was given with 0.017 ( + 0.005) ppm, with a maximum of 0.026 ppm and a minimum of 0.009 ppm. Indeed, the background levels determined during this investigation correspond to those requested by ASTM standards. From m y point of view , th e back ground level has to be much lower to determine the formaldehyde emission of very low emitting materials. Referring to the European test chamber standard EN 717

- 1 , the back ground level has to be lower than 0.005 ppm before starting theExternal Peer Review of EPA’s Draft Document : Measuring Formaldehyde Emissions from Low Emitting Hardwood Plywood Panels under Different Conditions of Temperature and Relative Humidity

13 **Page Line**  **Comment or Question**

t est. 12 and Annex Chapter 5: Statistical Methods (and Appendix) It can be regarde d as complex statistical work, but I assume that the results cannot be assessed accuratel y based on the basis of the obtained/available data
. 13
- 19 Chapter 6: Test Results **Page 14**

6.2 Small Chamber Emission Tests In Table 2 , the test results were mentioned in order of testing (ref. Table 1) but this causes a difficult overview of test results in respect to the impact of T and RH. My proposal is to sort the test results co rresponding to the test material first. The second criteria can be the temperature and third criteria the relative humidity
. Example: **Resin type**  **T RH**  **HCHO mea**  **n Resin**  **type T**  **R**

**H HCHO**  **mean** NAF
acrylic 25 50 ... ... NAF
acrylic 30 50 ... ... 25 70 ... ... 30 70 ... ... 25 85 30 85 ULEF
- PF 25 50 ULEF
PF 30 50 25 70 30 70 25 85 30 85 ULEF
UF 25 50 ULEF
UF 30 50 25 70 30 70 25 85 30 85 As shown in T able 2 , the lowest test result has been detected with 0.012 ppm for NAF

- acrylic boards (average of 0.015 ppm). Most of the test results are within the range of 0.02 up to 0.05 ppm, and only the results for ULEF

- UF boards exceed this range after increasing the temperature and/or relative humidity
. Due to high bac kground level (blank value) of chambers and the anal yt ical method chromotropic acid, the test results have to be regarded critical. Measuring an average blank value of the test chamber of app. 0.02 ppm (see technical report, page 11), a test result of 0.0 12 ppm has to be verified because the blank value was lower than those measured for the test sample. **Page 15** “ A more complex relationship with respect to T and RH is observed forExternal Peer Review of EPA’s Draft Document : Measuring Formaldehyde Emissions from Low Emitting Hardwood Plywood Panels under Different Conditions of Temperature and Relative Humidity

14 **Page Line**  **Comment or Question**

the ULEF

-PF panel type. For this panel Type HCHO emissions are similar for both T levels at 50% RH and at 85%RH, but they differ considerably at 70%RH. It is not clear what is causing this type of relationship .” As stated above, the analy tical method used (chromotropic acid) can probab ly cause minor values and misinterpretati on b ecause phenols are regarded as causing a negative interference at an 8:1 excess over formaldeh yde. For verification , another anal ytical test method (acetyl acetone or DNPH) had to be used. An inhomogeneity of test material may also be considered.External Peer Review of EPA’s Draft Document : Measuring Formaldehyde Emissions from Low Emitting Hardwood Plywood Panels under Different Conditions of Temperature and Relative Humidity

15 **Review by :**  **Octavia Zeleniuc, Ph.D.**External Peer Review of EPA’s Draft Document : Measuring Formaldehyde Emissions from Low Emitting Hardwood Plywood Panels under Different Conditions of Temperature and Relative Humidity

16 **Peer Review Comments on EPA’s Draft Report**  **Measuring Formaldehyde Emissions from Low Emitting Hardwood Plywood Panels under Different Conditions of Temperature and**  **Relative Humidity** Octavia Zeleniuc , Ph.D. Transilvania University of Brasov July 29 2013 **I. GENERAL IMPRESSIONS** Overall it is a comprehensive report, developed on 8 chapters (references included) well defined, presenting relevant data related to the effect of elevated T and RH co nditions on formaldehyde emissions from hardwood ply wood with veneer core made with various resins. The motivation for this study was described in Chapter s 1 and 2, where a few references are mentioned highlighting the influence of temperature and relative humidity on formaldehyde emissions from wood composite panels. It is a clear presentation, logicall y organized, including sufficient data presented in appropriate tables and graph , which sustain the results , interpretation , and conclusions. In general, explanations are included that clarify the presentation and avoid confusion in interpretation of results (e.g
. , establishing the test matrix, presentation in details of statistical methodology

used i n data anal ys is, equivalency tests for large/small chamber comparison, experiments on the first batch of ULEF

- UF panels). The objectives of the study were achieved and the conclusions are technically sound , supported by all the technical data and statistical interpretation. **II. RESPONSE TO CHARGE QUESTIONS 1.**  **Is the study scientifically sound? Was it designed and conducted properly?** The study

i s technically

s ound and includes evidence for any statements or conclusions that it makes. The report contains accurate information on procedures, facilities, quality a ssurance and control, and results: **Procedure and facilities** :  Tests are performed according to standard methods recommended for this ty pe of product , ASTM D

- 6007

- 02

- small chamber and ASTM E

- 1333

- 96 (2002)

- large chamber, with a few exceptions mentioned and justified in the report (e.g. , lower concentrations for calibration curve, greater conditioning period for the small chamber). The study used adequate equipment to ensure operation within the parameters recommended by the standard methods;External Peer Review of EPA’s Draft Document : Measuring Formaldehyde Emissions from Low Emitting Hardwood Plywood Panels under Different Conditions of Temperature and Relative Humidity

17  Tests are performed b y an accredited TPC labo ratory approved b y CARB;  Tests were well conducted based on an equilibrated test design.  The products used were veneer core HWPW panels labeled as NAF and ULEF panels, selected b y EPA as representative for ULEF composite wood products category. **Quality Assurance/Quality Control:**  There were clearl y specified measures taken to ensure the results accuracy by the following: monitoring the equipment (measuring the chambers’ parameters), control in the process (accurate records of all measurements), precision and clarity on sampling and anal ys is (fresh solutions , consistent over time in the preparation of calibration curves), etc **. 2.**  **Are the results presented clearly and appropriately? Results:**   The results are clearl y presented with adequate reporting of statistics and appropriate use of tables.  Interpretations and expl anations are provided in detailed, mentioning also the unexpected results (large/small chamber comparison results at elevated T and RH conditions, ULEF
- PF behavior at 70% RH).  Tables and figure fa cilitate comparisons, better understanding of results and drawing conclusions.  The results are in reasonable agreement with the findings in literature. **III. SPECIFIC OBSERVATIONS Page**  **L ine**  **Comment or Question** 5 **Section 3.1**

- line 1 - Why

onl y v eneer core HW PW panels? What about the other category of HWPW

–

with composite core?

- Are the tested resins ULEF

- UF, PF and NAF

- acrylic representatives for the HWPW manufacturing?

- line 3

- 4
- How were the elevated test conditions chosen (30 0 C temperature ,

respective 85% relative humidity )?

- line 10

- Why

didn’t E1333 constitute the basic standard for tests instead ASTM D6007 ? 5
- 6 **Section 3.1.1**

- line 8, page 5 - This equivalency test made by

TPC on July

2012 can be used no matter the product ty

pes?

- Would be interesting to have these results of equivalency shown in a table as an annex or after Table 2 in C hapter 6, for comparison.

- line 12, page 6 (paragraph 3) - T he sample dimensions (for test in the large chamber) are not

given ; it is mentioned only the product loading ratio of 0.43 (m2 /m 3 ) (on page 8) as is recommended for In dustrial Hardwood Ply wood Panels;

- The sample for the large chamber was from the same batch as the boards tested in the small chamber? 8 **Section 3.2**

- line 5 - It was considered less important the use of th e same thickness for

all panels due to that only exposed surface areas were taken intoExternal Peer Review of EPA’s Draft Document : Measuring Formaldehyde Emissions from Low Emitting Hardwood Plywood Panels under Different Conditions of Temperature and Relative Humidity

18 **Page L**  **ine Comment or Question**  consideration in the emission rate
. The same unit measure for all thicknesses would have be better. 8 **Section 3.3.1**
- How long was the sample in the large chamber tested? The

standard mentions 16

- 20 hours! 11 **Section 4.3**

- line 1 - Itshould be noted that these low background levels are below the

values indicated in the ASTM E13 33 and D6007 methods (0.03 ppm respec tive 0.02 ppm); this note should be added in section 3.1 .1 page 6 line 3
. 13 **Section 6.1**

- line 9

- line 16 (end of page) - As I have already mentioned before, for comparison, it would be

better to add the results for equivalency o btained by

T PC in July 2012 for standard conditions.

- Requirements for that equivalency are referred only

for standard conditions. The equivalency large/small chamber for higher conditions cannot be applied. 15 **Section 6.2**

- line 4 - To clarify this issue with ULEF
- PF panel, the test at high RH should be repeated. 15 **Section 6.2.1**

- l ine 3 - To have a clear evidence of comparison made (for each pair of

resin ty pes), it should be added if possible, a t able with these results
.