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Important information from US EPA: CDC/ATSDR Toxicological Profile on Perfluoroalkyls

CDC/ATSDR Toxicological Profile on Perfluoroalkyls


The Agency for Toxic Substances and Disease Registry (ATSDR) is releasing a Toxicological Profile (Tox Profile) on Perfluoroalkyl Substances (PFAS) for public comment. This document will include minimal risk level values (MRLs) for Perfluoroalkyls.


Tox  Profile for Public Comment

ATSDR’s Federal Notice, “Availability of Draft Toxicological Profile: Perfluoroalkyls” (docket number ATSDR-2015-0004 or the document number 2018-13385), is posted onlineThe public can view the notice at

The document was officially publish in the Federal Register on Thursday, June 21st, 2018. The public can begin commenting on the notice electronic shortly after 9 am on Thursday, June 21st by visiting


Additional Information

To assist in answering questions, ATSDR has worked to develop an initial set of FAQs and additional web resources accessible on the website at: To learn more about PFAS, or to access PFAS-related materials, please visit: Media requests can be referred to



What is a Tox Profile?

Congress mandates that ATSDR produce Tox Profiles that include an examination, summary, and interpretation of available studies of the health effects of a hazardous substance. The primary users of these documents are expected to be researchers and health professionals, including health assessors at the regional and state level. Profiles go to peer review (shared with experts in the field) before they are released for public comment in the Federal Register. After the comment period, ATSDR considers all comments, revises the documents, and then finalizes the profile. If there are significant revisions as a result of the public comments, the profiles are again peer reviewed before releasing as a final.

To access all current Tox Profiles please visit:


What’s new in the PFAS Tox Profile?

This draft of the PFAS Tox Profile updates minimal risk levels (MRLs, explained below) for two PFAS chemicals (PFOA and PFOS)  and sets new MRLs for two additional PFAS chemicals (PFHxS and PFNA). Updated, reliable and sufficient data were published in scientific literature after the previous 2015 draft. All four MRLs in the updated version of the Tox Profile are considered draft until they have been finalized following the public comment period.


What are MRLs, and how are they used?

An MRL is an estimate of someone’s daily exposure to a hazardous substance that is likely to be without appreciable risk to their health. It looks at non-cancer health effects only. MRLs are derived for different exposure periods, including:  acute (about 1 to 14 days), intermediate (from 15-364 days), and chronic (exposure for more than 365 days).



MRLs are used as a screening tool that help identify exposures that could be potentially hazardous to human health. Exposure above the MRLs does not mean that health problems will occur. Instead, it is a signal to health assessors to look more closely at a particular site where exposures may be identified.


For more information on Minimal Risk Levels please visit:


What do we know about PFAS?

While the Perfluoroalkyls Tox Profile is available to the public, it is an in-depth scientific resource utilized primarily by public health professionals.

To help answer basic questions about Perfluoroalkyl Substances (PFAS), there are additional supplemental fact sheets, FAQs, and other consumer-oriented resources available at:


Patti Kay Wisniewski

Drinking Water Security Coordinator


Drinking Water Branch (3WP21)

1650 Arch Street

Phila, PA  19103



Cell: 215-514-7893


(note the hyphen appears in email only)

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