Matthew Brewer 

Direct Dial : 202.837 .2304 

matthew.brewer@Iw.com 

LATHAM&WATKI NSLLP 

5a L1 a5 

0~~03_~~~ 10 MAY 17 

May 12, 2010 

VIA HAND DELIVERY 

Toni Krasnic 

c/o Mary Dominiak 

EPA/OCSPP/OPPT/CCD/ECB 

EPA East 

1201 Constitution Avenue, NW 

Room 4410 

Washington, DC 20004 

1 6: 03 

Re: Docket ID No. OPPT-2003-0012 

2009 FMG Annual Method Development Report 

Dear Mr. Krasnic: 

P. 1 

555 Eleventh Street . N.W., Suite 1000 

Washington, D.C . 20004-1304 

Tel: +1 .202.837 .2200 Fax: i1 .202 .637 .2201 

www.lw.com 

FIRM / AFFILIATE OFFICES 

Abu Dhabi Moscow 

Barcelona Munich 

Beijing New Jersey 

Brussels New York 

Chicago Orange County 

Doha Paris 

Dubai Riyadh 

Frankfurt Rome 

Hamburg San Diego 

Hong Kong San Francisco 

Houston Shanghai 

London Silicon Valley 

Los Angeles Singapore 

Madrid Tokyo 

Milan Washington, D.C. 

On behalf of the Fluropolymer Manufacturers Group of the Society of the Plastics 

Industry, I am submitting to you a copy of a report entitled "2009 Annual Report on Method 

Development for PFOA Generation Testing." This is a hard copy of the electronic copy already 

submitted to you by George Millet of Dyneon, LLC. I also include a copy of the cover email 

included with Mr. Millet's electronic submission. 

Sincerely, 

Attachment 

cc: EPA OPPT Docket Office 

e _.`° 

..,y 

w 

© 

CONTAINS NO CBI 

Matthew Brewer ,l-) 

T e_ TTY . 4:._, 

Or LA 1 HAM Ob W A CK1NJ LLY ° 

1301303314.1 
From : George H . Millet/DY-Dyneon/3M/US 

To: <Krasnic.Toni@epamail .epa.gov> 

Date : 05/12/2010 11 :40 AM 

Subject : Third Method Development Report 

Dear Toni, 

Attached please find an electronic copy of the third Generation Test Method 

Development Report. This third report on method development covers work carried out 

from May 2008 to July 2009, and presents information about the techniques used to 

develop the test method, and summarizes the results of those experiments. This work is 

being done on behalf of the SPI Fluoropolymer Manufacturers Group who made a 

voluntary agreement to develop this method and run the test. 

We have a meeting date with you at US EPA to discuss the contents on May 26. We 

invite you to circulate the report to those colleagues of yours who may have an interest 

in the work, or who intend to attend that meeting. In particular, would you be kind 

enough to ensure that Greg Fritz and Jim Willis receive copies. 

Also, in the interest of transparency, we invite you to post this document to the 

appropriate electronic docket so interested members of the public will have an 

opportunity to catch up on our progress . 

We will also be submitting a paper copy of the report to you. We also invite you or any 

of your colleagues to call me at 651-733-5637 if you have questions or points you want 

clarified before the meeting. 

Regards, 

George 

[attachment "Third Method Development Report 2010 05 12 .pdf'] 

D01303349.1 
2009 Annual Report on 

Method Development for 

PFOA Generation Testing 

David Ehresman - 3M Medical Department 

Jeremy Zitzow - 3M Medical Department 

Venkateswarlu Pothapragada - 3M Materials Resource Laboratory 

George Millet - Dyneon 
Table of Contents 

PaQe 

1. INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ., . . . . . . . . . . . . . . . . . . . . . 3 

II . KEY ASPECTS OF METHOD DEVELOPMENT EXPERIMENTS . . . . . . . . . . . . . . . . . . . 4 

A. Accelerated Solvent Extraction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 

B. Thermal Test Apparatus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 

1 . Single Reaction Flask and Impinger Train . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 

2. Dual Reaction Flask and Impinger Train . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 

3. Standard Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 

4. Other Conditions : . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 

C. Analytical Approach and Progress . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 

1 . Instrument Minimum Detectable Limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 

2. Minimum Detectable Limit (Method) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 

3. Lower Limit of Quantitation (LLOQ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 

4. Values between LLOQ and the minimum detectable limit 

(MDL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 

5. Blank Corrected Totals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 

6. Analyte Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7 

a. Perfluorooctanoic acid (PFOA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7 

b. Other perfluorocarboxylic acids (PFCAs) . . . . . . . . . . . . . . . . . . . . . . . . . . 7 

D. Test Substance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7 

1 . Test Substance 1 - "As Received" . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 

2. Test Substance 2 - "Remixed" Test Substance 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 

3 . Cryomilled Test Substance 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 

4. ASE Solvent-Washed Test Substance 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $ 

III. RESULTS OF METHOD DEVELOPMENT EXPERIMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . .8 

A. Accelerated Solvent Extraction (ASE). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 

1 . ASE extraction of Test Substance 1 and 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 

2. 100°C ASE test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10 

3. ASE solvent-washing of Test Substance 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11 

B. Thermal Test Apparatus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11 

1 . Single Reaction Flask Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 

i 
a. Steps to Optimize Test Apparatus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 

b. Evaluation of PFOA Standard Curve Recovery . . . . . . . . . . . . . . .13 

c . Results after Manipulation of Test Substance 2 . . . . . . . . . . . . . . .14 

(1) Thermal Test Experiments of Test Substance 2 and 

ASE Solvent-Washed Test Substance 2 . . . . . . . . . . . . . . .14 

(2) Washing with methanol, acetonitrile and 1 .ON 

Formic Acid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15 

(3) Cryogenic milling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 

(4) Vacuum Oven Results For Cryomilled Test 

Substance 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16 

d. Results for Thermal Test Periods Exceeding 24 hours . . . . .17 

e. Results for PFOA, With Other Homologous 

Perfluorocarboxylic Acids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 

2 . Dual Reaction Flask Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 

a. Thermal Test Apparatus "Re-design" . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 

b. Results for PFOA, With Other Homologous 

Perfluorocarboxylic Acids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 

IV. GLOSSARY OF TERMS AND ABBREVIATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 

V. REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 
I. INTRODUCTION 

Over the past 5 years, the Fluoropolymer Manufacturers Group of the Society of the 

Plastics Industry (FMG) has carried out a series of experiments to assess whether 

perfluorooctanoic acid (PFOA) is generated from the test substance (a PTFE composite) 

exposed to very high temperatures . These experiments included two main elements : first, 

the development of sample handling techniques to measure PFOA residuals in the test 

substance at sub part per billion levels, and second, the development of the thermal test 

method that included design of new equipment and procedures. This work was performed by 

3M Company and Dyneon LLC on behalf of the FMG. 

Since the beginning of this program, the FMG has informed EPA of the progress 

through reports and technical discussions. The first report was submitted to the US EPA in 

April 2007, and the second was submitted in September 2008. These reports covered work 

done from late 2005 through May 2008 . 

This third report on method development covers work carried out from May 2008 to 

July 2009, and presents information about the techniques used to perform the necessary 

experimentation, and summarizes the results of those experiments. Specifically, the report 

includes : 

=> A discussion of the protocol, procedures and results of accelerated solvent extractions 

(ASE) to determine whether background PFOA was present in the test substance used in 

the thermal tests, and 

~ The further development and final design of equipment to perform the thermal test, the 

results of some testing done with the original design of the test system, and the results of 

initial testing using the redesigned equipment. 

The test substance used in ASE and the thermal testing methods was a mixture of 

suspension grade PTFE supplied by the FMG member companies that was manufactured 

without using a PFOA emulsifier. Two types of suspension grade PTFE were included in the 

Test Substance, standard PTFE and modified PTFE. Experiments were performed on the test 

substance as received (Test Substance 1) and as re-mixed (Test Substance 2) as well as after 

the test substance had been ASE solvent washed and cryomilled . 

In addition, the thermal test apparatus was redesigned to include a simultaneous 

blank, which allowed for improvements in the analytical methodology to reduce the lower 

limit of quantitation (LLOQ). Data generated in this report and shown in Tables 14-19 were 

based on the redesigned test apparatus. Thermal test data in earlier Tables were generated 

using the original single reaction flask equipment configuration. 

This report details analytical results for each of the above-mentioned test substance 

types relative to PFOA and, for some experiments, also for other perfluorocarboxylic acids 

(PFCAs). To simplify the report, data are not always presented in chronological order. 
The overall goal of the work has been to develop a reliable method to assess whether 

PFOA would be released from the test substance, when heated to 315° C for 24 hours in a 

stream of humidified air. This necessitated developing the ability to quantify the amount of 

PFOA released . This program has required new analytical methodologies and unique 

concepts and equipment, and as a result, has presented significant challenges that have 

necessitated new approaches. 

Throughout this report the analytes of interest are referred to as "acids". This term is 

inclusive of both the free acid and various salts of the free acid, such as the ammonium salt . 

It should be noted that the actual species being quantified is the anion of the acid. In the case 

of PFOA, the anion is the perfluorooctanoate anion. In addition, testing was also performed 

for other homologues of PFOA, namely PFHxA, PFNA and PFDA. The analytical 

techniques used in this study are not able to identify the cation associated with the anion in 

its dissociated state. 

II. KEY ASPECTS OF METHOD DEVELOPMENT EXPERIMENTS 

A. Accelerated Solvent Extraction 

Accelerated solvent extraction (ASE) is a fully automated technique that uses 

common solvents to extract solid and semisolid samples rapidly. ASE operates at 

temperatures above the normal boiling point of most solvents, using pressure to keep the 

solvents in liquid form during the extraction process. Typically, ASE methods are completed 

in 15-25 min, while consuming only 15-50 mL of solvent. ASE was introduced in 1995 by 

Dionex Corporation and is recommended under US EPA Methods 3545 and 3545A for 

extraction of organophosphorus pesticides. In this method development the Test Substance 

was extracted using methanol as the solvent with the cells being maintained at 150 degrees C 

and 1500 pounds per square inch of pressure applied. 

B. Thermal Test Apparatus 

1 . Sin2le Reaction Flask and Imuin2er Train 

The single reaction flask and impinger train system is an instrument configuration 

that utilizes a single, pre-heated inlet gas source connected to a single reaction flask within 

the heated zone (oven) . This set up uses a glass transfer line from the reaction flask within 

the oven connected to a set of two impingers in series. The impingers are outside the heated 

zone and are maintained at zero degrees C by immersing the impingers in an ice bath. The 

impinger train exhaust was passed through an XAD resin trap placed in the exit air stream 

flow to collect any material of interest not captured in the aqueous matrix within the dual 

impingers. See Figures 1 & 2. 

2. Dual Reaction Flask and Imuinger Train 

The dual reaction flask and impinger train system is an instrument configuration that 

has a single, pre-heated inlet gas source connected to a stream splitter allowing two reaction 
flasks to be used in the oven. This set up uses two glass transfer lines from the reaction 

flasks within the oven connected to two separate sets of two impingers each connected in 

series . Both sets of impingers are maintained at zero degrees C by immersing the impingers 

in an ice bath. The impinger train exhausts through an XAD resin material trap placed in the 

exit air stream flow to collect any material of interest not captured in the aqueous matrix 

within the dual impingers. Two gas flow meters are attached to the exit air streams allowing 

operators to balance the flow equally through both reaction flasks and impinger sets. See 

Figure 4. 

3. Standard Conditions 

Many of the experiments were performed under the following standard conditions 

developed during dialogue between US EPA and the FMG: 

=> Temperature: The temperature for testing was set at 10 degrees C below the onset of the 

melting point of the test substance as determined by differential scanning calorimetry 

(DSC). This temperature was determined by triplicate testing using DSC to be 315 

degrees C. 

=> Time interval: The standard time interval was set at 24 hours duration. 

=> Percent relative humiditv: The percent relative humidity was set at 50% relative 

humidity. 

~ Carrier gas and flow rates: The standard test carrier gas was zero grade air maintained at 

a constant flow rate of 100 milliliters per minute. 

4. Other Conditions : 

Conditions other than the above standard conditions are described in the text as 

necessary and include all other operational conditions as described other than the standard 

operational conditions . 

C. Analytical Approach and Progress 

1. Instrument Minimum Detectable Limit 

Most analytical instruments produce a signal even when a blank (matrix without 

analyte) is analyzed. This signal is referred to as the noise level. The instrument detection 

limit is the analyte concentration that is required to produce a signal greater than three times 

the standard deviation of the noise level. This may be practically measured by analyzing 

eight or more standards at the estimated instrument detection limit and then calculating the 

standard deviation from the measured concentrations of those standards. This is then used to 

establish an instrument detection limit which does not include the matrix or the extraction 

variations of the method. As such, the instrument detection limit value is of limited value for 

purposes of meaningful quantitation . 
2. Minimum Detectable Limit-Method) 

The method minimum detectable limit (MDL) is affected by any additional steps 

completed during an analysis. These other necessary method steps (such as : dilutions, 

extractions, solution transfers, concentration steps) all add additional opportunities for error. 

Since detectable limits are defined in terms of error, this will naturally increase the measured 

detectable limit. This detectable limit (with all steps of the analysis included) is called the 

method minimum detectable limit (MDL). 

3. Lower Limit of Ouantitation (LLOO) 

The lower limit of quantitation (LLOQ) is the limit of concentration at which one can 

reasonably tell the difference between two different values . The LLOQ can vary 

dramatically between different labs . Overall, the LLOQ is approximately 5 times the 

minimal detectable limit (MDL) and is generally the lowest point that is fitted on the 

extracted standard curve where the curve itself produces acceptable regression values 

including that point. Specifically, in this project work the LLOQ is established by the lowest 

point included in the regression analysis of the matrix matched, full method extracted 

standard curve. 

4. Values between LLOO and the minimum detectable limit (MDL) 

Values less than the LLOQ can not be accurately quantitated as one can not 

distinguish between any two different values reasonably (within acceptable variation) by 

definition . Therefore, values falling between the LLOQ and MDL of the method can not be 

reported as concentration values . 

5. Blank Corrected Totals 

Tables that include "corrected total concentrations" have actual measured blank 

concentrations above the LLOQ. The results that have the value of the "blank" reaction flask 

result subtracted from that of the "test substance" reaction flask are considered "blank 

corrected" results. 

Results from the single reaction flask system all had blank runs completed where the 

results were less than 0.5 ng/g (the LLOQ). Therefore, all results in the tables completed 

using the single reaction flask instrument set-up have no blank correction applied to the 

resulting concentrations as reported since all blank extractions performed using the single 

reaction flask instrument configuration had measurable blank concentrations less than the 

LLOQ. 

With the implementation of the dual reaction flask instrument modifications the 

LLOQ was able to be adjusted to a lower value and blank corrected results were then able to 

be included in selected tables as reported . 
6. Analyte Description 

a. Perfluorooctanoic acid ( PFOA) 

Perfluorooctanoic acid .(PFOA), also known as C8 and perfluorooctanoate, is a 

synthetic, stable perfluorinated carboxylic acid and fluorosurfactant . One industrial 

application is as a surfactant in the emulsion polymerization of fluoropolymers . Generally 

accepted methods for the quantification of PFOA are based on high pressure liquid 

chromatography (HPLC) and triple stage mass spectrometry. This combination of 

instrumentation is also known as LC-MS/MS. These combined techniques are well 

recognized tools for measuring various fluorochemicals including but not limited to : 

perfluorooctanoic acid (PFOA) perfluorobutanoic acid (C4 acid), perfluorohexanoic acid (C6 

acid), perfluorononanoic acid (C9 acid) and perfluorodecanoic acid (C10 acid) at very low 

concentrations (Olsen et. al., 2007 EHP vol. 115, 1298-1305 and Ehresman et. al., Env Res 

vol. 103, 176-184). 

b. Other ruerfluorocarbozvlic acids (PFCAs) 

Other PFCAs identified, quantitated and specifically mentioned in this report include: 

perfluorobutanoic acid (C4 acid), perfluorohexanoic acid (C6 acid), perfluorononanoic acid 

(C9 acid) and perfluorodecanoic acid (C 10 acid) . 

D. Test Substance 

1 . Test Substance 1- "As Received" 

Test Substance 1 is a blended polytetrafluoroethylene (PTFE) powdered matrix as 

received and initially mixed by Dyneon LLC. It is comprised of equal portions of suspension 

grade PTFE products as supplied by the contributing FMG member company manufacturers. 

2. Test Substance 2 - "Remixed" Test Substance 1 

Test Substance 1 was mixed on a rotational mixer for an additional 24 hours by the 

laboratory performing the actual testing and labeled as Test Substance 2. 

3. Cryomilled Test Substance 2 

Cryomilled test substance is Test Substance 2 that was cryogenically ground to 

reduce the particle size . This process is also known as freezer milling, freezer grinding, and 

cryomilling. It is the act of cooling or chilling a material and then reducing it into a smaller 

particle size by using repeated physical interactions . When chilled by dry ice, liquid carbon 

dioxide or liquid nitrogen, thermoplastics can be finely ground to powders suitable for 

electrostatic spraying and other powder processes. In the cryomilling process, liquid nitrogen 

chilling and oscillating magnets were used to produce a very fine powder for analysis. 
4. ASE Solvent-Washed Test Substance 2 

Test Substance 2 was subjected to ASE conditions (minimum 3 cycles of ASE 

solvent-washing) and then harvested from ASE cells. Multiple cells containing ASE washed 

Test Substance 2 were pooled to provide adequate amounts of this matrix for further testing. 

III. RESULTS OF METHOD DEVELOPMENT EXPERIMENTS 

A. Accelerated Solvent Extraction (ASE) 

During ASE extractions of PFOA (Larsen et al., Analyst, 2005 vol. 130, 59-62.) the 

test substance is heated to 150°C for 24 hours prior to the initial methanol extraction. The 

test substance is then extracted using methanol and a Dionex ASE system. The automated 

system moves a stainless steel cell containing the test substance, and purified sand (Ottawa 

sand) in between special filter media, into an oven where the temperature is raised to 150°C. 

Methanol is then introduced into the cell and the cell pressure is raised to 1500 psi. After 

holding at this temperature and pressure for a set number of minutes, the methanol solvent is 

collected in 40 mL glass reservoirs . The "Method Development Test Program Guidance 

Document" specifies multiple extractions to the point where less than 5% of the initially 

recovered value remains. To date, this has required four complete cycles of preheating and 

extracting as recommended by Larsen et al . 

1. ASE extraction of Test Substance 1 and 2 

The primary goal for ASE work was to extract PFOA from the Test Substance 

exhaustively. The original "As Received" Test substance was referred to as Test Substance 

1 . Our first goal was to develop a procedure whereby a standard curve could be constructed 

using blanks and Test Substance 1 samples extracted and quantitated via the ASE. 

Fifteen ASE extraction cells were loaded with Ottawa sand and preconditioned with 

methanol. 10 ng/g PFOA IS (internal standard) was then added to all cells prior to the first 

elution cycle. Various amounts of PFOA were added to nine of the cells in order to create a 

standard curve ranging from 0.5 to 17.5 ng/g PFOA. In the next five cells, 2g aliquots of 

Test Substance 1 were placed in the center of the cells. The final two cells had no standards 

or samples added to them, and were the ASE blanks . All the cells were placed in an oven for 

24 hrs at 150°C. Next the cells were subjected to ASE with methanol as the extraction 

solvent (Cycle One). The five cells containing Test Substance 1 were again placed in an 

oven for 24 hrs at 150°C. These five cells were run through ASE a second time using 

methanol (Cycle Two). These five cells were then placed in an oven for a second 24 hrs at 

150°C. Subsequently, the five cells were run through the ASE a third time using methanol 

(Cycle Three). At the conclusion of this sequence, all collected volumes of methanol (each 

approximately 19-22 mL) were brought to a final volume of exactly 25 ml by transferring 

each to a 25 ml volumetric flask and "topping up" with methanol. 
An aliquot of 2.5 ml from each volumetric flask was then transferred to a new, clean, 

disposable polypropylene tube containing 500 uL of reagent grade H20. The methanol was 

evaporated from the tubes using a LabConco RapidVap, and the residual aqueous phase was 

then extracted through SPE. The resulting curve had a linear regression equation with an "R" 

value equal to 0.9992 . , 

The ASE blanks all had measured concentrations less than the LLOQ of 0.5 ng/g. The 

Cycle One Test Substance 1 samples had recoveries of 1 .1, 1 . 1, and 1 .2, 1 .0 and 1 .2 ng/g 

PFOA. In both Cycles Two and Three, the recovered amount of PFOA from each of the 'Test 

Substance 1 samples was less than the LLOQ (see Table 1) . In Table 1, "Absolute Area 

counts" of the raw data were collected and integrated by the LC-MS/MS instrument software. 

These data are converted using the instrument calibration curve to ng/g. 

Counts that are below the LLOQ level are not converted into ng/g concentrations if 

they are below the LLOQ for this instrument curve. The absolute area integrated counts for 

the 0.5 ng/g standard in this experiment were 452,779 counts As indicated in Table 1, the 

integrated absolute area counts during subsequent extraction cycles (Cycles 2 and 3) were all 

less that the integrated counts for the 0.5 ng/g standard . This indicates that PFOA 

concentrations during extraction cycles 2 and 3 remain less than the LLOQ of 0.5 ng/g as 

established for this assay. 

M 

Sample 

PFOA Conc. 

(ng/g) 

ASE Cycle 1 

Abs. Area 

(counts) 

ASE Cycle 1 

Abs. Area 

(counts) 

ASE Cycle 2 

I 

Abs. Area 

(counts) 

ASE Cycle 3 

Sample #1 1 .1 503,129 155,915 134,445 

Sample #2 1 .1 600,784 192,553 167,416 

Sample #3 1 .2 579,599 144,243 161,273 

Sample #4 1 .0 608,422 168,221 121,464 

Sample #5 1 .2 601,714 176,021 149,466 

- PFOA Concentrations (ng/g) for ASE Cydes 2 & 3 were less than LLOQ of 0.5 ng/g 

- Absolute Area counts of 0.5 n / Standard : 452,779 

A duplicate experiment had recoveries with nearly the same results (see Table 2a). In 

this case, a large aliquot of the Test Substance was re-mixed to ensure even distribution of 

the different PTFE products making up the composite. The original composite was prepared 

from contributions of standard and modified suspension grades of PTFE acquired from the 

four companies sponsoring the generation test . The re-mixed Test Substance samples were 

blended and mixed at one of the company's laboratories . These "re-mixed Test Substance 

samples" will be referred to as "Test Substance 2" for the remainder of this report . 
Sample 

PFOA Conc. 

(nglg) 

ASE Cycle 1 

Abs. Area 

(counts) ASE 

Cycle 1 

Abs. Area 

(counts) ASE 

Cycle 2 

Abs. Area 

(counts) ASE 

Cycle 3 

Sample #1 1 .6 703,097 339,356 348,462 

Sample #2 1 .5 682,066 718,903" 326,216 

Sample #3 1 .9 586,733 357,578 355,102 

Average 1.7 

- Absolute Area (counts) in 0 .5 ng/g Std. = 495,128 

* Suspected contamination in li quid transfer 

Based on this work, the amount of PFOA extracted from the re-mixed Test Substance 

samples (Test Substance 2) was reduced to instrument background levels after one complete 

ASE extraction cycle. To ensure that the PFOA concentrations were reduced to background 

levels, a total of three cycles were run during each ASE experiment. 

2. 100°C ASE test 

PFOA and its salts, the ammonium salt in particular, are susceptible to thermal 

degradation. Because of this, it was speculated that the PFOA may not be completely 

extracted at 150°C using ASE, as this temperature is known to be the onset of thermal 

degradation for the ammonium salt (APFO) [Larsen, et al 2005 Analyst 130, 59-62.] . To 

avoid this complication another ASE experiment was conducted with Test Substance 2 under 

the same ASE conditions as before, but at 100°C instead of at 150°C. The oven temperature 

between cycles was held at 100°C as well. 

Once again, after the first cycle, we recovered 1 .1-1 .4 ng/g PFOA. After the second 

and third cycles through the ASE, the PFOA concentrations remained less than the LLOQ 

(see Table 2b). It appeared running the ASE experiment at 100°C instead of 150°C had little 

effect on the amount of PFOA that was able to be recovered from Test Substance 2. 

PFOA Conc. Abs. Area Abs. Area Abs. Area 

(ng/g) (counts) ASE (counts) ASE (counts) ASE 

Sample ASE Cycle 1 Cycle 1 Cycle 2 Cycle 3 

Sample #1 1 .1 671,879 357,602 283,464 

Sample #2 1 .2 714,343 309,400 291,504 

Sample #3 1 .4 776,682 293,737 259,042 

Average 1 .2 

- Absolute Area (counts) in 0.5 ng/g Std . = 519,091 

- LLOQ = 0.5 ng/g 

- ASE Blank Concentrations in ASE Cycle 1 all < 0.5 n 
3. ASE solvent-washi_ne of Test Substance 2 

The original testing sequence as agreed upon during discussions with EPA prior to 

the start of this method development work consisted of three steps: 

1 . ASE extraction of the sample to quantify the "baseline" level of PFOA in the 

Test Substance. 

2 . Thermal testing via exposure to high temperature with trapping of any PFOA 

released. 

3 . A second ASE extraction of the sample to quantify the level of PFOA in the 

Test Substance after the thermal test . 

The three data points were to be used in a mass balance approach to determine how 

much, if any, PFOA was released due to degradation of the Test Substance sample during the 

thermal test . 

It was decided that Test Substance 2 should be "ASE solvent-washed" prior to 

thermal testing to remove PFOA residual material . ASE solvent-washing was expected to 

reduce the uncertainty in the overall test, since we were finding measurable concentrations of 

PFOA near the LLOQ. It was also expected to help differentiate between PFOA released 

from the surface of the Test Substance 2 particles, versus release from the interior of the 

primary particle or potential degradation of Test Substance 2 during the thermal test cycle. 

The reason that this test would differentiate between PFOA on or near the surface or in the 

interior of the particles of Test Substance 2 is that the ASE solvent wets the surface well, but 

does not penetrate into the particle . Test Substance 2 is not soluble or swellable by the ASE 

solvent (methanol) or by any other commonly used solvent. 

ASE-solvent washing was carried out by subjecting Test Substance 2 to three ASE 

full cycles as described above in section III.A.1 . About 30g of Test Substance 2 was ASE 

solvent-washed and set aside for use in future thermal test experiments. 

B. Thermal Test Araaaratus 

The thermal test is the basis of the overall method being developed. The thermal test 

conditions being used in our method development work are as follows : Heat a sample of the 

Test Substance at 315°C for 24 hours in a stream of zero grade air humidified to 50% RH (at 

RT), and trap PFOA exiting the sample cell in an impinger train. This train consists of two 

impingers containing high purity water, backed up with an XAD resin cartridge on the end to 

trap any PFOA that may have migrated through the impingers. The impingers also cool the 

hot air stream exiting the oven in which the sample reaction flask is held. The sample 

reaction flask is a small conical flask whose interior is coated with a siloxane coating to 

minimize adsorption of PFOA onto the walls of the flask and the tubing exiting the flask. See 

Figure 1 for a view of the sample reaction flask, and Figure 2 for a view of the impinger 

train. 
Figure 1 . 

Figure 2. 

1 . Sinale Reaction Flask Testing 

a. Stens to Optimize Test Atnuaratus 

Over the course of the past year, the conditions have been optimized for thermal test 

method development work to the point that there is confidence that the results are 

consistently showing how much PFOA (perfluorooctanoic acid) is being transferred from the 

12 
sample cell to the impinger train. The first step in optimizing this system was to determine 

what background levels of PFOA were present in the system itself. These PFOA background 

levels may have been introduced into the thermal test system from air in the room in which it 

is located since low-level quantitative analysis for PFOA is commonly performed in the same 

lab. Over the course of eight months, nine separate "blank runs" were conducted to , 

determine the system's background PFOA. These blank runs were normally conducted 

before or after other experiments where actual testing of PFOA transfer occurred. The 

temperature cycle used with the thermal test system was always 315°C for 24 hours. In all 

nine of these blank runs, no single impinger or XAD resin concentration of PFOA exceeded 

the LLOQ of 0 .5 ng/g (see Table 3). Therefore, all blank runs completed were considered to 

be < 0 .5 ng/g. Based on the nine blank runs, our routine background PFOA levels should be 

less than 0.5 ng/g. 

Experiment 

Conc. (ng/g) 

in Im in er #1 

Conc. (ng/g) 

in Im in er #2 

Conc. (nglg) 

in XAD Resin 

Conc. (nglg) 

in Rxn Flask 

Total Conc. 

n 

Blank Run #1 < 0.5 < 0.5 < 0.5 < 0 .5 < 0.5 

Blank Run#2 <0.5 <0.5 <0.5 <0 .5 <0.5 

Blank Run#3 <0.5 <0.5 <0.5 <0 .5 <0.5 

Blank Run#4 <0.5 <0.5 <0.5 <0 .5 <0.5 

Blank Run#5 <0.5 <0.5 <0.5 <0.5 <0.5 

Blank Run#6 <0.5 <0.5 <0.5 <0.5 <0.5 

Blank Run#7 <0.5 <0.5 <0.5 <0.5 <0.5 

Blank Run#8 <0.5 <0.5 <0.5 <0.5 <0.5 

Blank Run#9 <0.5 <0.5 <0.5 <0.5 <0.5 

- LLOQ = 0.5 ng/g 

b. Evaluation of PFOA Standard Curve Recoverv 

We were able to introduce a PFOA standard into the sample flask and move it to the 

impinger train where it was collected and quantified. The standards were placed in the 

sample flask located in the oven. The oven was then heated to 315°C and held there for 24 

hours. The impinger train was located in an ice bath and had an XAD resin cartridge placed 

on the end to trap and collect any PFOA that may have migrated through the impingers. This 

impinger train setup was very efficient at collecting PFOA that was introduced into the 

sample flask. Five concentrations of PFOA were introduced, including 1 .0, 2.5, 5 .0, 7.5 and 

10 ng/g. Total recovery of these standards in the impinger train setup was between 60-92%, 

with an overall average recovery of approximately 79%. A curve was plotted of these 

standards, which had an R2 value of 0.9929 (see Table 4 & Figure 3). Based on this 

regression analysis we moved forward testing Test Substance samples. 
M 

Predicted 

Std. Conc. 

n 

Conc. (nglg) 

in im in er #1 

. 

Conc.(nglg) 

in im in er #2 

Conc. (ng/g) 

in XAD resin 

Conc. (nglg) 

in Rxn vessel 

Total Conc. 

n I 

Percent 

Recovery 

1 0.6 < 0.5 < 0.5 < 0.5 0.6 60 

2.5 1 .2 0.6 < 0.5 < 0.5 1 .8 72 

5 2.6 1 .3 0.6 < 0.5 4.5 90 

7.5 4.5 1 .8 0.6 < 0.5 6.9 92 

10 6.3 1 .6 <0.5 <0.5 7.9 79 

- LLOQ=0.5n /~ 

Figure 3. 

Actual vs. Predicted Conc. Of PFOA Standards 

Recovered from Thermal Test Apparatus @ 315r 

o z a s a io 12 

Predicted Conc. (ng19) 

c. Results after Manipulation of Test Substance 2 

(1) Thermal Test Experiments of Test Substance 2 and 

ASE Solvent-Washed Test Substance 2 

The first thermal test experiments after efficient transfer of PFOA from the reaction 

flask to the impinger train as described above were conducted with Test Substance 2 under 

the standard conditions of 315°C, and 24 hours of constant 50% RH 100 ml/min airflow. 

The average amount of PFOA that collected from these samples was 9.6 ng/g (see Table 5) . 

14 
Since the blank runs were consistently at or under the LLOQ, they were not subtracted from 

the average total concentration. 

M 

Experiment 

Conc. (nglg) 

in Im in ers* 

Conc. (nglg) 

in XAD Resin 

Conc. (nglg) 

in Rxn Flask 

Total 

M 

Conc. 

n 

Sample #5 7.1 1 .4 < 0.5 8.5 

Sample #6 8.9 1 .7 < 0.5 10.6 

Average 9.6 

- LLOQ = 0.5 ng/g 

* The contents of Impinger #2 were added to Impinger #1, which was then extracted in a 

single step using SPE . 

The next series of thermal test experiments were conducted using ASE-solvent 

washed Test Substance 2 in the reaction flask, again under standard conditions . The average 

amount of PFOA that was recovered in these runs was 1 .4 ng/g (see Table 6). This was a 

decrease in PFOA concentration compared to the amount (9.6 ng/g) that was transferred from 

the non-ASE solvent-washed Test Substance 2 (Table 5). 

Experiment 

Conc. (nglg) 

in Impin er #1 

Conc. (nglg) 

in Impin er #2 

Conc. (nglg) 

in XAD resin 

Conc. (nglg) 

in Rxn flask 

Total Conc. 

n 

Sample #1 0.7 < 0.5 0.9 < 0.5 1.6 

Sample #2 0.9 *Added to #1 0.7 < 0.5 1 .6 

Sample #3 1 .9 *Added to #1 0.8 < 0.5 **2.7 

Sample #4 0.9 *Added to #1 < 0.5 < 0.5 0.9 

Average 1 .4 

* The contents of Impinger #2 were added to Impinger #1, which was then extracted in a single step 

using SPE. 

" Suspected contamination in liquid transfer 

- LLOQ = 0.5 n / 

(2) Washing with methanol, acetonitrile and 1.ON 

Formic Acid 

ASE extraction of Test Substance 2 resulted in the recovery of roughly 1 ng/g of 

PFOA, but seemed to reduce the amount subsequently recoverable by thermal test treatment 

by nearly 80% (1 .4 ng/g versus 9.6 ng/g, see Tables 5 and 6). Since the result of these two 

sets of experiments was markedly different, more tests were conducted on Test Substance 2, 

in an attempt to account for more of the PFOA not recovered by ASE. The first experiment 

was to extract Test Substance 2 in methanol at room temperature for 24 hours; the amount of 

PFOA that was extracted in this fashion was less than the LLOQ. 
The second test consisted of extracting Test Substance 2 in a 10:1 combination of 

acetonitrile and 1N formic acid. After shaking the contents for 24 hours, the amount of 

PFOA that was extracted was also below the LLOQ. 

(3) Cryogenic milling 

Since the extraction solvent wets but does not dissolve Test Substance 2, there was a 

possibility that PFOA was physically trapped within the Test Substance 2 particles, where the 

solvent could not access it . Cryogrinding Test Substance 2 was thought to make the PFOA 

more accessible by increasing the surface area of the particles. A large aliquot of Test 

Substance 2 was finely ground using a liquid nitrogen mill. This cryomilled Test Substance 

2 was shaken in methanol for 24 hours at room temperature; the results were promising, as 

0.9 ng/g of PFOA was extracted, compared to less than the LLOQ for the non-cryomilled 

Test Substance 2 extracted by the same method, shaking in methanol. This showed that 

some of the PFOA was protected from solvent extraction by physical trapping within the 

polymer particles. 

Several thermal tests were then conducted on this cryomilled Test Substance 2 under 

the standard thermal test conditions. Based on three runs, the average amount of PFOA 

collected from cryomilled Test Substance 2 was 9.0 ng/g (see Table 7). These PFOA 

concentrations were similar to the test results from the non-cryomilled Test Substance 2 

samples, 9.0 ng/g vs. 9.6 ng/g (see Table 5). 

M 

Sample 

Conc. (nglg) 

in Impin ers* 

Conc. (nglg) 

in XAD Resin 

Conc. (nglg) 

in Rxn Vessel 

Total 

M 

Conc. 

n ) 

Sample #8 6.5 1 .2 < 0.5 7.7 

Sample #9 7.8 2.1 < 0.5 9.9 

Sample #10 8.1 1 .4 < 0.5 9.5 

Average 9.0 

* The contents of Impinger #2 were added to Impinger #1, which was then extracted in a single 

step using SPE. 

- LLOQ = 0.5 n / 

(4) Vacuum Oven Results For Crvomilled Test 

Substance 2 

ASE extraction of the cryomilled Test Substance 2 was ruled out due to concerns that 

the finely ground material would cause excessive ASE system back pressure . Therefore, the 

cryomilled Test Substance 2 was placed in a vacuum oven in an attempt to remove PFOA. 

After heating to approximately 240°C in the vacuum oven for 24 hours, cryomilled Test 

Substance 2 was subjected to the thermal test cycle under standard conditions . This first 

experiment resulted in a noticeable decrease in recovered PFOA from approximately 9.0 ng/g 

to 5.0 ng/g of PFOA (see Table 8a). However, vacuum treatment under these conditions did 

not remove all of the PFOA contained in Test Substance 2. In a second experiment, the 

cryomilled Test Substance 2 was heated to 240°C in the vacuum oven for 72 hours, and then 
run through the thermal test under standard conditions. In this case, 1 .7 ng/g of PFOA was 

recovered from the impinger train (see Table 8b). In a third experiment, non-cryomilled Test 

Substance 2 was heated to 240°C in a vacuum oven for 72 hours, and then run through the 

thermal test under standard conditions, and this sample recovered 1 .6 ng/g of PFOA (see 

Table 8c). When compared to the cryomilled Test Substance 2 at 1 .7 ng/g, no significant 

difference was noted. 

Conc. (nglg) Conc. (ng/g) Conc. (ng/g) Total 

Sample in Impin ers* in XAD Resin in Rxn Vessel Conc. n I 

Sample #11 4.2 0.8 < 0.5 5.0 

Conc. (ng/g) Conc. (nglg) Conc. (nglg) Total 

Sample in Im in ers* in XAD Resin in Rxn Vessel Conc. n I 

Sample #12 1 .7 < 0.5 < 0.5 1 .7 

Conc. (nglg) Conc. (nglg) Conc. (ng/g) Total 

Sample in Im in ers* in XAD Resin in Rxn Vessel Conc. n I 

Sample #13 1 .6 < 0.5 < 0.5 1 .6 

* The contents of Impinger #2 were added to Impinger #1, which was then extracted in a single step 

using SPE . 

- LLOQ = 0.5 n / 

Cryomilling Test Substance 2 to reduce the particle size and increase surface area had 

no significant effect on increasing the recovery of PFOA from the particles using a simple 

methanol extraction. Cryomilling and heating under vacuum for 72 hours at 240°C did 

reduce the amount of PFOA recovered by subsequent thermal testing by approximately 80%. 

Though this cleaning method was designed to reduce the amount of PFOA in Test Substance 

2, measurable amounts of PFOA were still recovered by the subsequent thermal test . 

d. Results for Thermal Test Periods Ezceedine 24 hours 

Due to the results of the vacuum oven experiments in which measurable amounts of 

PFOA were released from heat treating Test Substance 2 after vacuum treatment for up to 72 

hours, the thermal test was extended for a longer period of time to see if a point could be 

reached where no measurable amount of PFOA remained in Test Substance 2. Test 

Substance 2 was then subjected to a thermal test in which the time was extended from 24 to 

56 hours. During this extended thermal test, the impingers and XAD resin were replaced 

with a new set after time intervals of 4, 8, 32 and 56 hours. The results indicated that most of 

the PFOA was recovered after 4 hours (5.4 ng/g) . However, there were still quantifiable 

levels of PFOA recovered at up to 56 hours (1 .7 ng/g) (see Table 9). 
M 

Time 

hours 

Conc. (nglg) 

In Im in er #1 

Conc. (nglg) 

in Im in er #2 

Conc. (ng/g) 

in XAD Resin 

Conc. (nglg) 

in Rxn Vessel 

0 

Total Conc. 

n I 

4 3.5 1 .1 0.8 N/A 5.4 

8 < 0.5 < 0.5 < 0.5 N/A < 0.5 

32 0.7 < 0.5 < 0.5 N/A 0.7 

56 1 .7 < 0.5 < 0.5 < 0 .5 1 .7 

Total Recovery 7.8 

- LLOQ = 0.5 ng/g 

- Im in er train was replaced after each time interval with a freshly silanized set 

Due to the differences observed in the recovery of PFOA between ASE and thermal 

testing, it was decided to run a series of ASE extractions on various samples that had been 

treated in different fashions to see if more PFOA could be recovered by ASE. Each ASE 

experiment that had been run on non-manipulated Test Substance 2 samples resulted in 

between 1 .0-1 .9 ng/g PFOA being recovered after the first cycle. Thereafter, no quantifiable 

levels above the LLOQ of PFOA were recovered during the second and third ASE cycles 

(See Tables 1 and 2). The extended thermal test (described in the previous section) resulted 

in approximately 7 .8 ng/g of PFOA being recovered. The series of ASE extractions proposed 

were: 

1 . ASE of Test Substance 2, to serve as a control 

2. Thermal test of ASE solvent-washed Test Substance 2, then ASE again 

3 . Thermal test of Test Substance 2, then ASE extracted 

4. ASE-solvent washed Test Substance 2, then ASE extracted again 

Series 2, re-running ASE on ASE solvent-washed Test Substance 2 stored at room 

temperature, was done to see if any PFOA in the particle interior diffused over time to the 

surface and could be recovered. The results showed that the amount of PFOA recovered by 

ASE extraction remained below the LLOQ in every experiment in this series (see Table 10 

below). The ASE solvent-washed Test Substance 2 had about 0.9 ng/g, which was in line 

with earlier results (see Tables 2a & 2b above) . 
PFOA Abs. Area Abs. Area Abs. Area Conc. (ng/g) (counts) (counts) (counts) Sam le In ASE Cycle 1 in ASE Cycle 1 in ASE Cycle 2 in ASE Cycle 3 

Sample #1 1 .0 262,031 76,475 62,687 

Sample #2 0.8 292,692 85,189 74,605 

Sample #3 0.8 415,115 240,333 208,506 

Sample #4 1 .0 450,502 252,647 251,890 

Ave ra e 0.9 

Sample #1 < 0.5 56,669 52,474 P 37,941 

Sample #2 < 0.5 37,504 57,701 38,007 

Sample #3 < 0.5 38,445 40,129 40,928 

Sam le #4 < 0.5 57,988 47,426 50,810 

Sample #5 < 0.5 227,534 190,044 195,299 

Sample #6 < 0.5 193,145 183,610 203,249 

Saamm le #7 < 0.5 209,458 194,308 190,023 

S 

mp 

ample #1 < 0.5 85,831 68,634 46,0600 

1 Sample #2 < 0.5 86,492 70,686 49,747 

Double Blank #1 < 0.5 196,780 281,704 287,503 

Double Blank #2 < 0.5 178,144 212,972 184,370 

Double Blank #3 < 0.5 242,264 215,432 186,936 

- LLOQ = 0.5 ng/g 

- The above results are from experiments run at different times, so the absolute area counts 

corres onding to the LLOQ in each experiment differ . 

In a continuation of previous experiments, Test Substance 2 that had not been 

solvent-washed by ASE was run first through thermal testing, and then run through three 

ASE cycles (see Table 5 and Table 10c for reference). No measurable levels of PFOA above 

the LLOQ were detected by ASE (as shown in Table lOc). These samples were then 

harvested from the ASE cells and run a second time through thermal testing under standard 

conditions for 24 hours. PFOA concentrations ranging from 0.8-1 .1 ng/g of PFOA were 

recovered from these samples during the second thermal test cycle (see Table 11). The 

average recovered concentration of PFOA was 0.9 ng/g. 
Conc. (ng/g) Conc. (ng/g) Conc. (ng/g) Total Conc. 

Sample in, Im in ers* in XAD Resin in Rxn Vessel n 

Sample #5 0.8 < 0.5 < 0.5 0.8 

Sample #6 0 .9 < 0.5 < 0 .5 0.9 

Sample #7 1 .1 < 0.5 < 0.5 1 .1 

Average 0.9 

* The contents of Impinger #2 were added to Impinger #1 , which was then extracted in a 

single step using SPE. 

- LLOQ = 0.5 ng/g 

- Results shown are after the second 24 hours of Thermal Testing under Standard Conditions 

e. Results for PFOA. With Other Homologous 

Perfluorocarboxvlic Acids 

These results led to two questions: 

1) Why were low levels of PFOA continuing to be recovered even after 56 hours at 

315°C? 

2) If PFOA was being released by heating Test Substance 2 at 315°C, were other 

perfluorocarboxylic acids (PFCAs) being released from Test Substance 2 as well? 

The reasoning behind question 2 was that the recovery of PFCAs other than PFOA 

might help identify the source of the PFOA recovered from Test Substance 2. One potential 

source of the PFOA in the Test Substance was contamination during manufacturing. Since 

PFOA is used at manufacturing plants that make the Test Substance constituents, and 

manufacturing equipment may be shared by different products, cross contamination is 

possible . If cross contamination by emulsifier grade PFOA occurred, other PFCAs were not 

expected to be present as contaminants since commercial PFOA does not contain significant 

concentrations of homologous perfluorocarboxylic acids. After this testing began it was 

learned that a second potential contamination source is fluorotelomer chemicals, since some 

fluoropolymer manufacturers also manufacture fluorotelomer products in the same plants . 

Therefore, a thermal test was run under standard conditions and tested for the 

presence of four other perfluorocarboxylic acids: PFBA (perfluorobutanoic acid) PFHxA 

(perfluorohexanoic acid), PFNA (perfluorononanoic acid) and PFDA (perfluorodecanoic 

acid) using LC-MS/MS instrumentation. The results showed 7.0 ng/g of PFOA was 

recovered, similar to our previous findings. In addition, quantifiable amounts of PFHxA (2. 

1 ng/g), PFNA (3.8 ng/g) and PFDA (3 .2 ng/g) were recovered from the impinger train. The 

amount of PFBA present was less than the LLOQ (see Table 12). 

As a result of this thermal test experiment, it was decided that future thermal test 

experiments would continue to test for the presence of these PFCAs (except PFBA) to see if 

any trends existed between the concentrations of each of these acids. 
Conc. In 

Impingers 

PFCA n 

Conc. in 

XAD Resin 

n 

Conc. In 

Rxn Vessel 

n 

M 

Total Conc. 

n / 

PFBA <0,5 <0.5 <0.5 < 0.5 

PFHxA 2.1 < 0.5 < 0.5 2.1 

PFOA 6.0 1 .0 < 0.5 7.0 

PFNA 3.2 0.6 < 0.5 3.8 

PFDA 2.6 0.6 < 0.5 3.1 

* The contents of Impinger #2 were added to Impinger #1, which was then extracted in a 

single step using SPE . 

- LLOQ = 0.5 ng/ 

Testing under wet or dry conditions and in the absence of oxygen was initiated. In all 

testing up to now, both oxygen and water were present during the thermal test, due to the use 

of humidified zero air as the carrier gas (as suggested by the EPA) . 

We first created a "dry" oxygen-free system with approximately 1 % RH by 

exchanging our zero air cylinder for a nitrogen cylinder, and bypassing the humidification 

chamber. A blank run experiment under I % RH 100 ml/min dry nitrogen flow for 24 hours 

at 315°C resulted in the recovery of no quantifiable amounts above the LLOQ (0 .5) for 

PFHxA, PFOA, PFNA and PFDA from the impinger train. 

An extended thermal test experiment was conducted, this time under 1 % RH 100 

ml/min dry nitrogen for 120 hours at 315°C. During this thermal test run, the impingers and 

XAD resin were replaced with a new set after 24, 48, 72, 96 and 120 hours. PFOA, PFHxA, 

PFNA, and PFDA were recovered from Test Substance 2; most of it in the first 24 hours (see 

Table 13a). 

We then switched the carrier gas for the thermal test system back to 50% RH zero air 

and re-tested the same sample used in the dry nitrogen experiment. This was done to see if 

the 50% RH zero air would cause the release of more PFOA, PFHxA, PFNA and PFDA. 

This second test was run under standard conditions (50% RH 100 MI/min zero air at 315°C) 

for 96 hours. During this run, the impingers and XAD resin were again replaced new sets 

after 24, 48, 72 and 96 hours. The compounds with the highest recoveries were PFOA and 

PFHxA (see Table 13b). Low levels of PFOA and PFHxA were recoverable from Test 

Substance 2 even after heating for another 96 hours under zero air at 315°C. 
Time Sample Name 

PFOA 

n 

PFHxA 

n 

PFNA 

n 

PFDA 

n 

24 hr Im in er#1 3.3 2.4 2.8 1,8 

Im in er #2 0.7 < 0.5 < 0.5 < 0.5 

XADResin <0.5 <0.5 <0.5 <0 .5 

Total 4.0 2.4 2.8 1 .8 

48 hr Im in er #1 < 0.5 0.5 < 0.5 < 0.5 

Im in er#2 <0.5 <0.5 <0 .5 <0.5 

XADResin <0.5 <0.5 <0.5 <0 .5 

Total < 0.5 0.5 < 0.5 < 0.5 

72 hr Im in er#1 <0.5 <0.5 <0.5 <0.5 

Im in er#2 <0.5 <0.5 <0.5 <0.5 

XADResin <0.5 <0.5 <0.5 <0.5 

Total < 0.5 < 0.5 < 0.5 < 0.5 

96 hr Im in er#1 <0.5 <0.5 <0.5 <0.5 

Im in er#2 <0.5 <0.5 <0.5 <0.5 

XADResin <0.5 <0.5 <0.5 <0.5 

Total < 0.5 < 0.5 < 0.5 < 0.5 

120 hr Im in er#1 <0.5 <0.5 <0.5 <0.5 

Impin er #2 0.5 < 0.5 < 0.5 < 0.5 

XADResin <0.5 <0.5 <0.5 <0.5 

Total 0.5 < 0.5 < 0.5 < 0.5 

Total Recovery 

( uncorrected )* 4.5 2.9 2.8 1 .8 

Reaction Flask 

after 120 hrs < 0.5 < 0.5 < 0.5 < 0.5 

- LLOQ = 0.5 ng/g for all compounds 

* In a previous blank run under dry nitrogen conditions, background levels of PFOA, PFHxA, PFNA and PFDA were < 0.5 nq/q. 

(Table 13 continued on next page) 
Time Sample Name 

PFOA 

n 

PFHxA 

n 

PFNA 

n 

PFDA 

n 

24 hr Im in er #1. 1 .2 1 .3 < 0.5 < 0 .5 

Im in er#2 0.7 <0.5 <0.5 <0.5 

XADResin <0.5 <0.5 <0.5 <0.5 

Total 1 .9 1.3 < 0.5 < 0.5 

48 hr Im in er #1 < 0.5 1 .0 < 0.5 < 0.5 

Impin er #2 < 0.5 < 0.5 < 0.5 < 0.5 

XAD Resin < 0.5 < 0 .5 < 0.5 < 0.5 

Total < 0.5 1 .0 < 0.5 < 0.5 

72 hr Im in er#1 <0.5 1 .4 <0.5 <0.5 

Im in er #2 0.6 < 0.5 < 0.5 < 0.5 

XAD Resin < 0 .5 < 0.5 < 0.5 < 0.5 

Total 0.6 1 .4 < 0.5 < 0.5 

96 hr Im in er #1 0.7 2.6 < 0.5 < 0.5 

Impin er #2 < 0.5 < 0.5 < 0.5 < 0.5 

XADResin <0.5 <0.5 <0.5 <0.5 

Total 0.7 2.6 < 0.5 < 0.5 

Total Recovery 

uncorrected 3.2 6.3 < 0.5 < 0.5 

Reaction Flask 

after 96 hrs < 0.5 < 0.5 < 0 .5 < 0.5 

- LLOQ = 0.5 n / for all compounds 

Approximately 4.0 ng/g PFOA was recovered in the first 24 hours of dry nitrogen 

thermal testing (See Table 13a). Subsequent testing of this same sample using zero air and 

50% RH released approximately an additional 1 .9 ng/g of PFOA in the first 24 hours, and a 

total of approximately 3.1 ng/g after 96 hours. Measurable amounts of PFOA and PFHxA 

continued to be recovered even after undergoing extensive heating with dry nitrogen for 120 

hours and humidified zero air for 96 hours (see Table 13b above) . 

Note in Table 13b that lesser amounts of PFOA, PFNA & PFDA were recovered (in 

total) when we completed thermal testing after first subjecting the Test Substance 2 sample to 

dry nitrogen instead of just humidified zero air (standard thermal test conditions) during the 

first 24 hours (compare to Table 12). The total amount of PFHxA recovered actually 

increased after subjecting the sample to dry nitrogen conditions before running the sample 

under standard conditions (2.1 ng/g to 6.3 ng/g). 

2. Dual Reaction Flask Testing 

a. Thermal Test Anuaratus "Re-design" 

All thermal tests are lengthy; many run for several days at a time. Because of this 

some variability in the values of the system blanks was experienced. An improved blank 

23 
testing method was needed to achieve more consistent results, an improved lower limit of 

quantitation (LLOQ, eliminate the effect of system contamination, and provide "real time" 

system blanks . These goals were achieved by splitting the heated transfer line in the oven 

providing airflow to both a sample test system and a blank system. A second impinger train 

was added to the new line to create an independent blank system. 

The amount of airflow through the heated transfer line into the oven was ramped to 

200 ml/min, so that both systems would have an equal airflow of 100 ml/min. Each test 

system, blank and sample, was equipped with its own sample holder, transfer line out of the 

oven, two impingers and an XAD resin cartridge. These systems were identical in every 

way. Both were treated with the same process for cleaning and silanization, and both shared 

a common oven. Both impinger trains were kept in the same ice bath (See Figure 4). 

Figure 4. 

Before each experiment was conducted, the airflow through each system was 

equilibrated by gas flow meters placed on the exits. This allowed adjustment to maintain the 

two systems to the same rate of airflow. Splitting the airflow between a continuous "blank 

test system" and the "sample test system" allowed the identification of any potential 

problems with background PFOA contamination in the thermal test. Quantifiable levels of 

PFOA and the other PFCAs found in the blank test system could be subtracted from that 

found in the sample test system. A double blank run measured less than 0.5 ng/g of PFOA 

24 
for each side of the redesigned test system under the standard conditions for 24 hours. Both 

sides of the airflow stream measured had comparable concentrations of PFOA. The amounts 

of PFHxA, PFNA and PFDA measured were less than the LLOQ. 

b. Results for PFOA. With, Other Homolmous 

Perfluorocarboxvlic Acids 

Once the redesigned test system was constructed, thermal test experiments 

commenced to develop and optimize the dual system. All method development work from 

this point forward was performed using the dual system. The first experiment was conducted 

using 2g of Test Substance 2 sample. This was placed in the sample holder and heated at 

standard conditions, a repeat of earlier tests. The amount of PFOA that was found in the 

experimental sample test system was 5.3 ng/g and the blank test system had a PFOA level 

below the LLOQ. The concentrations for the other PFCAs were as follows: PFHxA (3 .6 

ng/g), PFNA (5.0 ng/g) and PFDA (3 .3 ng/g) (see Table 14). The blank test system 

contained less than LLOQ amounts of PFHxA, PFNA and PFDA. 

Flask Sample Name 

PFOA 

n / 

PFHxA 

n 

PFNA 

n 

PFDA 

n 

Sample Flask Impinger #1 

Impinger #2 

XAD Resin 

Reaction Vessel 

3.9 

0.9 

0.5 

< 0.5 

3.6 

< 0.5 

< 0.5 

< 0.5 

4.3 

0.7 

< 0.5 

< 0.5 

2 .7 

0.6 

< 0.5 

< 0.5 

Total 5.3 3.6 5.0 3.3 

Blank Flask Impinger #1 < 0.5 < 0.5 < 0.5 < 0.5 

Impinger #2 < 0.5 < 0.5 < 0.5 < 0 .5 

XADResin <0.5 <0.5 <0.5 <0.5 

Reaction Vessel < 0.5 < 0.5 < 0.5 < 0.5 

Total < 0.5 < 0.5 < 0.5 < 0.5 

Corrected Total (sample - Blank) 5.3 3.6 5.0 3.3 

- LLOQ for all compounds = 0.5 ng/mL 

In the next experiment, 2g of Test Substance 2 was held at 315°C for 48 hours under 

1% RH (dry) nitrogen . Then the same 2g sample, in the same reaction flask, was held at 

315°C for 48 hours under 50% RH zero air. PFOA continued to be recovered in measurable 

amounts in 50% RH air even after 48 hours in dry nitrogen. The second 24 hours in zero air 

failed to recover further PFOA (see Table 15). 
Flask Sample Name 

PFOA 

n 

PFHxA 

n 

PFNA 

n 

PFDA 

n 

Sample Flask Im in er #1 

Im in er#2 

XADResin 

4.0 

<0.5 

<0.5 

3.9 

<0.5 

<0.5 

4.1 

<0.5 

<0.5 

2 .6 

<0.5 

<0.5 

Total 4.0 3.9 4.1 2.6 

Blank Flask IM in er #1 < 0.5 < 0.5 < 0.5 < 0.5 

Im pin er #2 < 0.5 < 0.5 < 0.5 < 0.5 

XADResin <0.5 <0.5 <0.5 <0.5 

Total < 0.5 < 0.5 < 0.5 < 0.5 

C 

imi 

orrected Total (Sample - Blank 

Flask Sample Name 

4.0 

PFOA 

n I 

3.9 

PFHxA 

n 

4.1 

PFNA 

n 

2.6 

PFDA 

n 

Sample Flask Im in er #1 0.8 0.9 0.6 0.5 

Im in er #2 < 0.5 < 0.5 < 0.5 < 0.5 

XADResin <0.5 <0.5 <0.5 <0.5 

Total 0.8 0.9 0.6 0.5 

Blank Flask Im in er #1 < 0.5 < 0.5 < 0.5 < 0 .5 

Im in er#2 <0.5 <0.5 <0 .5 <0.5 

XADResin <0.5 <0.5 <0.5 <0.5 

Total < 0.5 < 0.5 < 0.5 < 0.5 

Corrected Total (Sample - Blank) ~ 0.8 0.9 0.6 0.5 

(Table 15 continued on next page) 
PFOA PFHxA PFNA PFDA Flask Sample Name n / n n 

Sample Flask Im in er #1 1 .1 2 .2 0.6 0.4 

Im in er #2 0 .3 < 0.25 < 0.25 < 0.25 

XAD Resin 1 .3 2.6 0.9 0.7 

Total 2.7 4.8 1 .5 1.1 

Blank Flask Im in er #1 < 0.25 < 0.25 < 0.25 < 0.25 

Impin er #2 < 0.25 < 0.25 < 0 .25 < 0.25 

XAD Resin < 0.25 < 0.25 < 0.25 < 0.25 

Total < 0.25 < 0.25 < 0.25 < 0.25 

Corrected Total Sample - Blank 

Flask Sample Name 

2.7 

PFOA 

n 

4.8 

PFHxA 

n 

1 .5 

PFNA 

n 

1 .1 

PFDA 

n 

Sample Flask Im in er #1 0.5 0 .3 < 0.25 < 0.25 

Im in er #2 < 0.25 < 0.25 < 0.25 < 0.25 

XAD Resin 0 .3 0.5 < 0.25 < 0.25 

Total 0.8 0.8 < 0.25 < 0.25 

Blank Flask Im in er #1 0.3 < 0.25 < 0.25 < 0.25 

Impin er #2 0.4 < 0.25 < 0.25 < 0.25 

XAD Resin < 0.25 < 0.25 < 0.25 < 0.25 

Total 0.7 < 0.25 < 0.25 < 0.25 

Corrected Total sample - Blank 0.1 0.8 < 0.25 < 0.25 

- LLOQ for all compounds = 0.5 ng/mL for samples in Table 15a 

- LLOQ for all compounds = 0.25 ng/mL for samples in Table 15b 

Regarding the PFHxA recoveries, a total of 10.4 ng/g were recovered; this is more 

than the total amount of PFOA recovered (7.6 ng/g). Most of the PFCAs were trapped 

during the first 24 hours of heating, regardless of which carrier gas was used (see Table 15) . 

The conditions of the next experiment were modified slightly. 2g of Test Substance 2 

was held for 24 hours at 315°C in 1% RH dry nitrogen . After the first 24 hours under dry 

nitrogen, the sample was kept in the sample holder at room temperature for 24 hours. This 

sample was then run under 1% RH dry nitrogen for a second 24 hour period at 315°C. The 

sample was then held at room temperature for a second 24 hour period . Finally, the sample 

was held at standard conditions (315°C for 24 hours, 50% RH zero air) . Impinger trains 

were replaced after each 24 hour heating cycle. We were looking for any effects that would 

occur by resting the sample at room temperature in the middle of an extended heating 

process. The results of this experiment were not significantly different from previous 

extended thermal test experiments (see Table 16). Most of the PFCAs were recovered from 

the sample holder during the first 24 hours of heating using either the nitrogen or the zero air. 
It appears that the second and third sets of impingers used in this experiment may have been 

contaminated with small amounts of PFOA. 

After the second 24 hours under dry nitrogen, the recovered amount of all PFCAs is 

much less than after the first 24 hours. When this sample was exposed to humid air the 

recoveries of all PFCAs increased significantly compared to the second twenty four hours 

under nitrogen. The level of recovered PFHxA was higher than the amount of PFOA 

recovered under these conditions (see Table 16). 

Flask Sample Name 

PFOA 

n 

PFHxA 

n 

PFNA 

n 

PFDA 

n 

Sample Flask Im in er #1 

Im in er #2 

XAD Resin 

3.2 

0.7 

0 .4 

1 .1 

< 0.25 

< 0.25 

3.4 

0.5 

0.4 

2.6 

0.3 

0.4 

Total 4.3 1 .1 4.4 3.3 

Blank Flask Im in er #1 0.4 < 0.25 < 0.25 < 0.25 

Im in er #2 0.2 < 0.25 < 0.25 < 0.25 

XAD Resin < 0.1 < 0.25 < 0.25 < 0.25 

Total 0.6 < 0.25 < 0.25 < 0.25 

Corrected Total (Sample - Blank) 

Flask Sample Name 

3.7 

PFOA 

n 

1 .1 

PFHxA 

n 

4.3 

PFNA 

n 

3.3 

PFDA 

n 

Sample Flask Im in er #1 1 .0 0.4 0 .6 0.6 

Im in er #2 0.3 < 0.25 < 0.25 < 0.25 

XAD Resin 0.2 < 0.25 < 0.25 < 0.25 

Total 1 .5 0.4 0.6 0.6 

Blank Flask Im in er #1 0.4 < 0.25 < 0.25 < 0.25 

Im in er #2 0.7 < 0.25 < 0.25 < 0 .25 

XAD Resin 0.3 < 0.25 < 0.25 < 0.25 

Total 1 .3 < 0.25 < 0.25 < 0.25 

Corrected Total (sample - Blank) 0.2 0.4 0.6 0.6 

(Table 16 continued on next page) 
Flask Sample Name 

PFOA 

n 

PFHxA 

n 

PFNA 

n 

PFDA 

n 

Sample Flask Im in er #1 5.0 9.7 4.0 3.4 

Imp ~in er #2 2.0 0.8 0.3 < 0.25 

XAD Resin 1 .1 0.8 0.3 0.3 

Total 8.1 11 .3 4.6 3.7 

Blank Flask Im in er #1 0.5 < 0.25 < 0.25 < 0.25 

Im in er #2 1 .9 < 0.25 < 0.25 < 0.25 

XAD Resin 0.8 < 0.25 < 0.25 < 0.25 

Total 3.2 < 0.25 < 0.25 < 0.25 

Corrected Total (Sample - Blank) 4.9 11.3 4.6 3.7 

- LLOQ for PFOA = 0.1 ng/mL for all samples 

- LLOQ for PFHxA, PFNA & PFDA = 0.25 ng/mL for all samples 

Similar amounts of all of the PFCAs were recovered using 50% RH and zero air 

regardless of resting the test material between heating cycles under dry nitrogen conditions . 

The similar amounts for all PFCAs recovered were observed after: 1) heating with nitrogen 

for 24 hours at 315°C, resting for 24 hours at room temperature and heating again for 24 

hours with nitrogen, or 2) uninterrupted heating for 48 hours using dry nitrogen. Due to the 

lengthy nature of these experiments, it was decided not to repeat these tests a second time. 

The next set of experiments involved using dry nitrogen for 24 hours followed by a 

second and third 24 hour period with humidified nitrogen (See Table 17). Comparing these 

wet nitrogen results to the results discussed above and detailed in Table 16, a significant 

difference was noted. When the sample was exposed to humidified zero air after exposure to 

dry nitrogen (N2), more PFOA and the other PFCAs were recovered from the test system 

than were recovered when using humidified nitrogen. Based on these experimental results it 

would appear that more PFCAs are recovered when oxygen (OZ) is present in the air stream. 

(Compare Table 16 to Table 17). 
p. 33 

Flask Sample Name PFOA n I PFHxA n ~PFNA n PFDA n I 

Sample Flask Impinger #1 2.8 1 .5 2.2 1 .6 

Impinger #2 0.9 0.3 0.7 0.5 

XAD Resin 0.3 0.1 0.2 0.2 

Total 4.0 1 .9 3.1 2.3 

Blank Flask Impinger #1 0.1 < 0.1 < 0.1 < 0.1 

Impinger #2 0.1 < 0.1 < 0.1 < 0.1 

XAD Resin 0.2 < 0.1 < 0.1 < 0.1 

Total 0.4 < 0.1 < 0.1 < 0.1 

Corrected Total (Test - Blank) 

Flask Sample Name 

3.6 

PFOA n / 

1 .9 

PFHxA n I 

3.1 

PFNA NOg/al n 

2.3 

M PFDA n 

Sample Flask Impinger #1 0.7 0.4 0.5 0.5 

Impinger #2 0.2 < 0.1 < 0.1 < 0.1 

XAD Resin 0.2 < 0.1 < 0.1 < 0.1 

Total 1 .1 0.4 0.5 0.5 

Blank Flask Impinger #1 0 .1 < 0.1 < 0.1 < 0.1 

Impinger #2 0 .2 < 0.1 < 0.1 < 0.1 

XAD Resin 0 .1 < 0.1 < 0.1 < 0.1 

Total 0.4 < 0.1 < 0.1 < 0.1 

Corrected Total (Test -Blank) 

Flask Sample Name 

0.7 

PFOA n / 

0.4 

PFHxA n 

0.5 

PFNA n 

0.5 

PFDA n 

Sample Flask Impinger #1 0.4 0.2 0.3 

_ 

0.3 

Impinger #2 0.2 < 0.1 0.1 0.2 

XAD Resin 0.2 < 0.1 < 0.1 < 0.1 

Total 0.8 0.2 0.4 0.5 

Blank Flask Impinger #1 NQ < 0.1 < 0.1 < 0.1 

Impinger #2 0.1 < 0.1 < 0.1 < 0.1 

XAD Resin 0.1 < 0.1 < 0.1 < 0.1 

Total 0.2 < 0.1 < 0.1 < 0 .1 

Corrected Total (Test -Biank) 0.6 0.2 0.4 0.4 

OVERALL TOTAL 4.9 2.5 4.0 3.2 

- LLOQ = 0.1 ng/g for all compounds 

- In this experiment, only one sample flask and one blank flask were used 

- Impingers & XAD resins were changed between each 24-hour period 

- While switchin g from d nitrogen to wet nitro~en, oven temperature was maintained at 315 9C 
Experiments were designed to find the optimal temperature for PFCA recovery from 

Test Substance 2 during the thermal test . At 100°C, 2g of Test Substance 2 was run under 

100 ml/min 50% relative humidity airflow for 24 hrs. The same 2g sample was run 

sequentially at 150°C for 24 hrs, at 200°C for 24 hrs, at 250°C for 24 hrs and finally at 300°C for 24 hours. In this experiment, only. one sample holder and one blank sample holder were used. Impingers and XAD resins were changed between each temperature level. Between 

temperature levels, the oven was ballistically ramped to the next temperature. It was noted 

that an increase in concentrations of each of the compounds were recovered when 

temperatures exceeded 250°C with the maximum occurring at 300°C (see Table 18). 

Flask Sample Name 

PFOA 

n 

PFHxA 

n 

PFNA 

n 

PFDA 

n 

Sample Flask Im in er #1 0.7 < 0.1 < 0.1 < 0.1 

Im in er#2 0.1 <0.1 <0.1 <0.1 

XAD Resin 0.1 < 0.1 < 0.1 < 0.1 

Total 0.9 < 0.1 < 0.1 < 0.1 

Blank Flask Im in er #1 0.1 < 0.1 -<O. 1 < 0.1 

Im in er#2 0.2 <0.1 <0.1 <0.1 

XAD Resin 0.1 < 0.1 < 0.1 < 0.1 

Total 0.4 < 0.1 < 0.1 

_ 

< 0.1 

Corrected Total (Test - Blank) 

Flask Sample Name 

0.5 

PFOA 

n 

< 0.1 

PFHxA 

n 

< 0.1 

PFNA 

n 

< 0.1 

PFDA 

n 

Sample Flask Im in er #1 0.3 < 0.1 0.1 0.2 

Im in er#2 0.1 <0.1 <0.1 <0.1 

XAD Resin 0.1 < 0.1 < 0.1 < 0.1 

Total 0.5 < 0.1 0.1 0.2 

Blank Flask Im in er #1 < 0.1 < 0.1 < 0 .1 < 0.1 

Im in er#2 <0.1 <0.1 <0.1 <0.1 

XADResin <0.1 <0.1 <0.1 <0.1 

Total < 0.1 < 0.1 < 0.1 < 0.1 

Corrected Total (Test - Blank) 0.5 < 0.1 0.1 0.2 

(Table 18 continued on next page) 
Flask Sample Name 

PFOA 

n 

PFHxA 

n 

PFNA 

n 

PFDA 

n 

Sample Flask Im in er #1 0.6 0.3 0.8 0 .7 

Im in er#2 <0.1 <0.1 <0.1 <0.1 

XAD Resin < 0.1 < 0.1 < 0.1 < 0.1 

Total 0.6 0.3 0.8 0.7 

Blank Flask Im in er #1 < 0.1 < 0.1 < 0.1 < 0.1 

Im in er#2 <0.1 <0.1 <0.1 <0.1 

XADResin <0.1 <0.1 <0.1 <0.1 

Total < 0.1 < 0.1 < 0.1 < 0.1 

Corrected Total (Test - Blank) 

Flask Sample Name 

0.6 

PFOA 

n I 

0.3 

PFHxA 

n 

0.8 

PFNA 

n 

0.7 

PFDA 

(n 

Sample Flask Im in er #1 1 .4 0.8 2.0 1 .6 

Im in er#2 <0.1 <0.1 <0.1 <0.1 

XAD Resin 0 .2 < 0.1 0.1 0.2 

Total 1 .6 0.8 2.1 1 .8 

Blank Flask Im in er #1 < 0.1 < 0.1 < 0.1 < 0.1 

Im in er#2 <0.1 <0.1 <0.1 <0.1 

XAD Resin < 0.1 < 0.1 < 0.1 < 0.1 

Total < 0.1 < 0.1 < 0.1 < 0.1 

Corrected Total Test - Blank 

Flask Sample Name 

1 .6 

PFOA 

n 

0.8 

PFHxA 

n 

2.1 

PFNA 

n 

1 .8 

PFDA 

n I 

Sample Flask Im in er #1 2 .1 1 .3 1 .8 

_ 

1 .9 

Im in er #2 0.2 0.4 0.1 < 0.1 

XAD Resin 0.9 1 .3 0.7 0.7 

Total 3.2 3.0 2.6 2.6 

Blank Flask Impin er #1 < 0.1 < 0.1 < 0.1 < 0.1 

Im in er#2 <0.1 <0.1 <0.1 <0.1 

XADResin <0.1 <0.1 <0.1 <0.1 

Total < 0.1 < 0.1 < 0.1 < 0.1 

Corrected Total Test - Blank 3.2 3.0 2.6 2.6 

Cumulative Total 6.4 4.1 776- 7 5.3 

- LLOQ = 0.1 ng/g for all compounds - 

- Impingers & XAD resins were swapped out between each temperature level 

- Between temperature levels, oven was ballistically ramped to next temperature 

Experiments were run at 225°C, 250°C, 275°C and 315°C to refine the optimal 

temperature level. Separate thermal test experiments were conducted at each temperature, 

where 2g of Test Substance 2 was run under 100 ml/min 50% relative humidity airflow for 

24 hrs. Table 19 presents the results, which seem to indicate that as the temperature of the 

32 
sample is increased, more of each of the PFCAs are recovered from the impinger train up to 

at least 315°C (see Table 19). 

Flask Sample Name PFOA n I PFHxA n PFNA n PFDA n 

Sample Flask Im in er #1 1 .7 0.5 1 .4 0.9 

Impin er #2 0 .5 < 0.1 0.2 0.1 

XAD Resin 0.4 < 0.1 0 .1 0.1 

Total 2.6 0.5 1 .7 1 .1 

Blank Flask Im in er #1 0.2 < 0.1 < 0.1 < 0.1 

Impin er #2 0.2 < 0.1 < 0.1 < 0.1 

XAD Resin 0.2 < 0.1 < 0.1 < 0.1 

Total 0.6 < 0.1 < 0.1 < 0.1 

Corrected Total Test - Blank 

Flask Sample Name 

2.0 

PFOA n / 

0.5 

PFHxA n 

1 .7 

PFNA n 

1 .1 

PFDA n 

Sample Flask Impin er #1 2.5 0.8 2.2 1 .2 

Im in er #2 0.5 < 0.1 0.3 0.2 

XAD Resin 0.5 < 0.1 0.2 0.1 

Total 3.5 0.8 2.7 1 .5 

Blank Flask Im in er #1 0.4 < 0.1 < 0.1 < 0.1 

Impin er #2 0.2 < 0.1 < 0.1 < 0 .1 

XADResin 0.3 <0.1 <0.1 <0.1 

Total 0.9 < 0.1 < 0.1 < 0.1 

Corrected Total Test - Blank 

Flask Sample Name 

2.6 

PFOA n I 

0.8 

PFHxA n 

2.7 

PFNA n I 

1 .5 

PFDA n 

Sample Flask Im in er #1 2.7 1 .1 1 .9 1 .0 

Impin er #2 1 .0 < 0.1 0.7 0.4 

XAD Resin 0.5 0.1 0.3 0.2 

Total 4.2 1 .2 2.9 1 .6 

Blank Flask Im in er #1 0.6 < 0.1 < 0.1 < 0.1 

Im in er#2 0.3 <0.1 <0.1 <0.1 

XAD Resin 0.2 < 0.1 < 0.1 < 0.1 

Total 1 .1 < 0.1 < 0.1 < 0.1 

Corrected T otal (Test - Blank) 3.1 1 .2 2.9 1 .6 

(Table 19 continued on next page) 
Corrected Total (Test - Blank) I 5.3 3.6 5.0 3.3 

- LLOQ = 0.1 ng/g for all compounds tested except for the 315 9C sample where LLOQ = 0.5 

- A different sample flask and blank flask was used at each temperature level 

- Impingers & XAD resins were swapped between each 24 hr period 

- The experiment was run under continuous 50% RH zero air 

IV. GLOSSARY OF TERMS AND ABBREVIATIONS 

Accelerated Solvent Extraction (ASE) - An automated instrument that uses a combination 

of high temperature and high pressure solvent in an extraction process. This instrument was 

designed to increase recovery of selected compounds from semi-solid and/or solid materials. 

Ammonium perfluorooctanoate (APFO) - Ammonium perfluorooctanoate is the ammonia 

salt of perfluorooctanoic acid (PFOA), having the chemical formula C7F15COZNH4. APFO is 

identified by CAS# 3825-26-1 . See also PFOA. 

Differential Scanning Calorimetry (DSC) - a thermo-analytical technique in which the 

difference in the amount of heat required to increase the temperature of a sample and a 

reference mass are measured as a function of temperature. The main application of DSC is in 

studying phase transitions, such as melting, glass transitions, or exothermic decompositions. 

These transitions involve energy changes or heat capacity changes that can be detected by 

DSC with great sensitivity. 

Framework Test Program Guidance - a document entitled "Framework for Test Method 

for Measurement of Perfluorooctanoic Acid Generated from Thermal Degradation of 

Fluoropolymers ." 

Lower Limit of Quantitation (LLOQ) - the lowest amount of an analyte in a sample that 

can be quantitatively determined with suitable precision and accuracy. The LLOQ of the 

analytical methods used for PFOA analysis in the PSE and TGT methods is equal to the 

lowest calibration standard actually used in establish in the actual calibration curve. 

Method Development Test Program Guidance - a document entitled "Method 

Development for Testing Generation of Perfluorooctanoic Acid from Thermal Degradation 

of Fluoropolymers ." 

Modified PTFE - refers (for the purposes of this study) to those grades of 

polytetrafluoroethylene that are made: 1) by a suspension polymerization process (Drobny, 

Technology of Fluoropolymers), 2) typically without using PFOA, and 3) contain a second 

comonomer. The comonomers are typically perfluorinated vinyl ethers, and are present in 

low amounts (-0.1% or less) in the final polymer. Modified PTFE is identified by CAS# 

3825-26-1, or by CAS# 26655-00-5 . 

PFOA n I PFHxA n PFNA n I PFDA n 
Part per million (ppm) and parts per billion (ppb): Parts-per notation is used, especially 

in science and engineering, to denote relative proportions in measured quantities ; particularly 

in low-value (high-ratio) proportions at the parts-per-million (ppm) 10-6 and parts-per-billion 

(ppb) 10-9 level . One part in one million equal parts is a part per million, one part in one 

billion equal parts is a part per billion. 1 nanogram / gram (ppb) of PFOA would be 

0.000000001 grams of PFOA in 1 .0 grams of material (such as the test substance) . 

Perfluorooctanoic acid (PFOA) - Perfluorooctanoic acid is a fully fluorinated carboxylic 

acid, having the chemical formula C7F,SC02H. PFOA is identified by CAS# 335-67-1 . 

When the term PFOA is used in this Protocol, it is inclusive of both PFOA and APFO. More 

specifically, the perfluorooctanoate anion is the chemical species detected by the analytical 

methods used in this study. 

Polytetrafluoroethylene (PTFE) - refers, for the purposes of this study, to those grades of 

polytetrafluoroethylene made by a suspension polymerization (Drobny, Technology of 

Fluoropolymers) processes and typically not using PFOA. PTFE made by this process is 

also known as "granular PTFE" by the fluoropolyrner processing industry. PTFE is 

identified by CAS# 3825-26-1 . 

Solid Phase Extraction (SPE) - A technique that is a separation process by which 

compounds that are dissolved or suspended in a liquid mixture are separated from other 

compounds in the mixture according to their physical and chemical properties. Analytical 

laboratories use solid phase extraction to concentrate and purify samples for analysis. Solid 

phase extraction can be used to isolate analytes of interest from a wide variety of matrices, 

including urine, blood, water, beverages, soil, and animal tissue . SPE uses the affinity of 

solutes dissolved or suspended in a liquid (known as the mobile phase) for a solid through 

which the sample is passed (known as the stationary phase) to separate a mixture into desired 

and undesired components. The result is that either the desired analytes of interest or 

undesired impurities in the sample are retained on the stationary phase. The portion that 

passes through the stationary phase is collected or discarded, depending on whether it 

contains the desired analytes or undesired impurities. If the portion retained on the stationary 

phase includes the desired analytes, they can then be removed from the stationary phase for 

collection in an additional step, in which the stationary phase is rinsed with an appropriate 

eluent . 

Test Sponsors - collectively, AGC Chemicals Americas, Inc. ; Daikin America, Inc . ; Dyneon 

LLC; and E.I . du Pont de Nemours and Company. 

Test Substance - the industry PTFE composite sample specified in Section II of this 

Protocol. 

Trifluoroacetic acid (TFA) - a strong carboxylic acid with the formula CF3C02H. 

Thermal Test - the thermal test is a test conducted using a special-purpose device developed 

by the Test Sponsors. This test subjects a sample of the Test Substance to a specified 

temperature under specified conditions for a specified time interval. Clean, moisturized air 

passes through the device in a controlled and reproducible manner. The outlet air stream is 

sampled to collect PFOA potentially released from the polymer. 

35 
XAD - a highly absorbent ion-exchange resin used in continuous sampling of organic 

materials, especially for monitoring of pollutants in gas streams . It is used for collecting 

specific compounds in air because it traps and retains compounds of interest even in the 

presence of other compounds, doesn't alter the compound of interest, and allows the 

collected compounds to be readily extracted for analysis. 

Zero Grade Air (or Zero Air) - Commercially purchased compressed air that has met 

standards for hydrocarbon content at less than 0.1 part per million (ppm) . Every cylinder of 

zero grade air is supplied with an individual certificate of analysis to insure the quality 

required was provided. Zero Grade Air as certified is required to have oxygen content 

between 20 and 21 percent, less that 5 ppm residual water and less that 1 ppm of the 

following contaminates: carbon monoxide, carbon dioxide, and sulfur dioxide. 

V. REFERENCES 

Framework for Test Method for Measurement of Perfluorooctanoic Acid Generated from 

Thermal Degradation of Fluoropolymers (April 24, 2006). 

Method Development for Testing Generation of Perfluorooctanoic Acid from Thermal 

Degradation of Fluoropolymers . (April 24, 2006). 

Drobny, J. George. Technology of f uoropolymers; CRC Press LLC: Boca Raton, FL, 2001 . 

Ehresman, D.J . ; Froehlich, J.W. ; Olsen, G.W. ; Chang, S. ; Butenhoff, J.L. "Comparison of 

human whole blood plasma and serum matrices for the determination of 

perfluorooctanesulfonate (PFOS), perfluorooctanoate (PFOA), and other fluorochemicals." 

Environmental Research, 2007, Vol. 103, pp 176-184. 

Larsen, B.S. ; Kaiser, M.A. ; Botelho, M. ; Bachmura, S.F. ; Buxton, L.W. "Comparison of 

pressurized solvent and reflux extraction methods for the determination of perfluorooctanoic 

acid in polytetrafluoroethylene polymers using LC-MS/MS". Analyst, 2005, 130, 59-62. 

Larsen, B.S. ; Kaiser, M.A. ; Botelho, M. ; Bachmura, S.F. ; Buxton, L.W. "Efficient `total' 

extraction of perfluorooctanoate from polytetrafluoroethylene fluoropolymer." Analyst, Vol. 

131, pp 1105-1108, 2006. 

Olsen, G.W. ; Burris, J.M. ; Ehresman, D.J . ; Froehlich, J.W. ; Seacat, A.M. ; Butenhoff, J.L. ; 

Zobel, L.R. "Half-life of serum elimination of perfluorooctanesulfonate, 

perfluorohexanesulfonate, and perfluorooctanoate in retired fluorochemical production 

workers." EHP, 2007, Vol. 115, pp 1298-1305.