The National Toxicology Program (NTP), part of the National Institute of Environmental Health Sciences, announced that it is evaluating the association between exposures to perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), and immunotoxicity. As part of the review, NTP requested information about ongoing studies on the immune-related health effects of PFOA and PFOS. (See 80 Fed. Reg. 48886-7 (8/14/15).) NTP also asked for nomination of scientific experts to potentially serve on an ad hoc expert panel that will draft a monograph based on the review. The deadline for receipt of information and nominations of scientific experts is September 30, 2015.
In the Federal Register announcement, NTP pointed out that the primary manufacturer of PFOS phased out production in 2002, that it is no longer manufactured in the U.S., and that eight companies that manufacture PFOA have committed to eliminate emissions and product content by 2015. However, NTP is conducting the study due to concerns about the bioaccumulation of both PFOA and PFOS, and it's continued persistence in the environment. While both of these substances were previously used as greaseproofing agents for food-contact materials, industry has since replaced perfluorinated compounds that were eight carbons in length or greater (C8-PFCs) with shorter-chained C6-based greaseproofing agents.
A study by a Food and Drug Administration staff member, Penelope A. Rice, showed that data from animal and epidemiological studies indicate that C6-PFCs are rapidly and completely excreted, and do not appear to accumulate in biological fluids. Her results were published in the March 2015 issue of Current Environmental Health Reports, in an article titled, "C6-Perfluorinated Compounds: The New Greaseproofing Agents in Food Packaging." She does point out that, "Although the existing toxicological database for the C6-PFCs is, as yet, comparatively sparse, these compounds do not appear to possess the biopersistence and potent systemic and reproductive toxicity that are characteristic of C8-PFCs as a class."