2019.04.26_CCO.p14_LetterReDEQToxicity

Sheila Holman
April 29, 2019
Page 1

April 29, 2019

Sheila Holman Assistant Secretary for the Environment
N.C. Department of Environmental Quality
1601 Mail Service Center
Raleigh, N.C. 27699-1601
[e-mail]
Re: Chemours’ Proposed Work Plan for Toxicity Studies Pursuant to Consent Order
Paragraph 14.

Dear Asst. Secretary Holman:
We have reviewed Chemours’ proposed work plan for the toxicity studies pursuant to
paragraph 14 of the consent order and provide the following comments on behalf of Cape Fear
River Watch.
- Chemours has estimated that it will take approximately 1 year to produce 10-15 kg of
each compound, but has not provided a basis for that conclusion. See Work Plan at 5
(Dose Selection). Chemours must support that assumption.
- Chemours has proposed using dose levels of 0.1 mg/kg/day and 1 mg/kg/day. Work Plan
at 5 (Dose Selection). The higher dose does reflect the higher levels of contamination that residents of southeastern North Carolina have been exposed to over the last several
decades. Additional testing with higher doses that reflect likely historical exposure rates
should be conducted.
- Under the work plan, no further action would be taken if effects are not observed at a 1
mg/kg/day dose. Work Plan at 5 (Dose Selection). Given the historical levels of exposure and the reality that people are rarely exposed to a single PFAS at a time, demonstrating
no observable effect at 1 mg/kg/day is not sufficient.
- Chemours estimates that the first tests will begin in July 2020. Work Plan at 6 (Work
Plan and Schedule). It is our understanding that Nafion Byproduct 2 is available
commercially and, therefore, delay is unnecessary.
Thank you for your consideration of these comments.

Sincerely,

Geoffrey R. Gisler
Sheila Holman
April 29, 2019
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GRG/rgd

Cc (via email): Dana Sargent, CFRW
Kemp Burdette, CFRW
Bill Lane, DEQ
Francisco Benzoni, NCDOJ
Michael Abraczinskas, DAQ Michael Scott, DWM
Linda Culpepper, DWR
David Shelton, Chemours
Brian Long, Chemours
John Savarese, Wachtell, Lipton Joel Gross, Arnold & Porter