2019.06.18_CCO.p11_NCDWRFollowUpLetterRE-MTP.MMF.DFSA.PPFAcid

The Chemours Company
Fayetteville Works
22828 NC Highway 87 W
Fayetteville, NC 28306

June 18, 2019

Linda Culpepper
Interim Director, Division of Water Resources
1611 Mail Service Center
Raleigh, NC 27699-1611
[e-mail]

Re: Laboratory Analyses for MTP, MMF, DFSA, and PPF Acid

Dear Ms. Culpepper,

I am writing to follow up on our June 10 letter and June 12 conference call with DEQ in
regard to the four PFAS compounds shown below:

Acronym Name Molecular
Formula
CASN Chemical Structure
MTP Perfluoro-2-
methoxypropanoic
acid
CH3-O-
CF2-CF2-
COOH
93449-
21-9
MMF Difluoromalonic
acid
HOOC-
CF2-
COOH
1514-
85-8

DFSA Difluoro-sulfo-
acetic acid
HOOC-
CF2-
SO3H
422-67-
3
PPF Acid Perfluoropropionic
acid
CF3-CF2-
COOH
422-64-
0

2

As we noted in our letter and discussed on our conference call, the laboratory analytical
methods for these four compounds are new and not refined (and previously did not exist), and
the resulting data quantifications are not accurate. Our external testing laboratories, Eurofins
Lancaster Laboratories (“Lancaster”) and TestAmerica, have prepared summaries of the
technical issues they have encountered, and these summaries are enclosed.

Accordingly, to prevent the collection and dissemination of inaccurate and misleading
data, we have instructed Lancaster and TestAmerica to stop analyzing and reporting for these
four compounds under their current laboratory analytical methods (referred to as “Table 3+”).
We will continue to work with these labs on analytical method development and finding an
appropriate testing methodology for these four compounds, and we will keep you apprised of our
progress.

Please let me know if you have any questions.

Sincerely,

Brian D. Long
Plant Manager
Chemours – Fayetteville Works

Enclosures
Lancaster Technical Summary
TestAmerica Technical Summary

3
Cc:
Sheila Holman, DEQ
William F. Lane, DEQ
Francisco Benzoni, NC DOJ
Michael Abraczinskas, DAQ
Michael Scott, DWM
David C. Shelton, Chemours
John F. Savarese, WLRK
Kemp Burdette, CFRW
Geoff Gisler, SELC