[Federal Register Volume 87, Number 118 (Tuesday, June 21, 2022)]
[Notices]
[Pages 36848-36849]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-13158]


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ENVIRONMENTAL PROTECTION AGENCY

[FRL 9855-01-OW]


Lifetime Drinking Water Health Advisories for Four Perfluoroalkyl 
Substances

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice of availability.

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SUMMARY: The Environmental Protection Agency (EPA) announces the 
release of health advisories for four perfluoroalkyl substances (PFAS), 
including interim updated lifetime drinking water health advisories for 
perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS), 
and final health advisories for hexafluoropropylene oxide (HFPO) dimer 
acid and its ammonium salt (together referred to as ``GenX chemicals'') 
and perfluorobutane sulfonic acid and its related compound potassium 
perfluorobutane sulfonate (together referred to as ``PFBS''). EPA's 
health advisories, which identify the concentration of chemicals in 
drinking water at or below which adverse health effects are not 
anticipated to occur, are: 0.004 parts per trillion (ppt) for PFOA, 
0.02 ppt for PFOS, 10 ppt for GenX chemicals, and 2,000 ppt for PFBS. 
Health advisories are non-regulatory and reflect EPA's assessment of 
the best available peer-reviewed science. The interim updated health 
advisories for PFOA and PFOS supersede EPA's 2016 health advisories for 
PFOA and PFOS.

[[Page 36849]]


FOR FURTHER INFORMATION CONTACT: Susan Euling, Health and Ecological 
Criteria Division, Office of Water (Mail Code 4304T), Environmental 
Protection Agency, 1200 Pennsylvania Avenue NW, Washington, DC 20460; 
telephone: (202) 566-2717; or email: [email protected].

SUPPLEMENTARY INFORMATION: 

I. What are PFAS, and specifically, what are PFOA, PFOS, GenX 
chemicals, and PFBS?

    PFAS are a large and diverse structural family of compounds used in 
myriad commercial applications due to their unique properties, such as 
resistance to high and low temperatures, resistance to degradation, and 
nonstick characteristics. Although PFAS have been manufactured and used 
broadly in commerce since the 1940s, particular concern over potential 
adverse effects on human health grew in the early 2000s with the 
discovery of PFOA and PFOS in human blood. Since that time, hundreds of 
PFAS have been identified in water, soil, and air. Many PFAS are 
environmentally persistent, bioaccumulative, and have long half-lives 
in humans, particularly the longer-chained carbon species such as PFOA 
and PFOS. Most uses of PFOA and PFOS were phased out by U.S. 
manufacturers in the mid-2000s although there are a limited number of 
ongoing uses. In addition, some currently used PFAS break down into 
PFOA and PFOS in the environment. PFAS with fewer carbon atoms, such as 
GenX chemicals and PFBS, were subsequently developed to replace PFOA 
and PFOS, respectively, and integrated into various consumer products 
and industrial applications because they have the desired properties 
and characteristics associated with this class of compounds but are 
more quickly eliminated from the human body than PFOA and PFOS.

II. What health effects are associated with exposure to PFOA, PFOS, 
GenX chemicals, and PFBS?

    The interim updated health advisories for PFOA and PFOS are based 
on human epidemiology studies in populations exposed to these 
chemicals. Human studies have found associations between PFOA and/or 
PFOS exposure and effects on the immune system, the cardiovascular 
system, human development (e.g., decreased birth weight), and cancer. 
The most sensitive non-cancer effect and the basis for the interim 
updated health advisories for PFOA and PFOS is suppression of vaccine 
response (decreased serum antibody concentrations) in children. While 
there is evidence that PFOA is likely to be carcinogenic to humans, EPA 
has not derived a cancer risk concentration in water for PFOA at this 
time. There is suggestive evidence of carcinogenic potential of PFOS in 
humans. Cancer analyses are ongoing for both PFOA and PFOS.
    EPA's final health advisories for GenX chemicals and PFBS are based 
on animal toxicity studies following oral exposure to these chemicals. 
GenX chemicals have been linked to health effects on the liver, the 
kidney, the immune system, and developmental effects, as well as 
cancer. The most sensitive non-cancer effect and the basis for the 
final health advisories for GenX chemicals is a liver effect 
(constellation of liver lesions). There is suggestive evidence of 
carcinogenic potential of oral exposure to GenX chemicals in humans, 
but data are insufficient to derive a cancer risk concentration in 
water for GenX chemicals at this time. Animal studies following oral 
exposure to PFBS have shown health effects on the thyroid, reproductive 
organs and tissues, developing fetus, and kidney following oral 
exposure. The most sensitive non-cancer effect and the basis for the 
final health advisory for PFBS is a thyroid effect (decreased serum 
total thyroxine). There are no known studies evaluating potential 
cancer effects of PFBS and so the potential for cancer effects after 
PFBS exposure could not be evaluated.

III. What are drinking water health advisories?

    Under the Safe Drinking Water Act, EPA may publish health 
advisories for contaminants that are not subject to any national 
primary drinking water regulation. 42 U.S.C. 300g-1(b)(1)(F)). EPA 
develops health advisories to provide information on the chemical and 
physical properties, occurrence and exposure, health effects, 
quantification of toxicological effects, other regulatory standards, 
analytical methods, and treatment technology for drinking water 
contaminants. Health advisories describe concentrations of drinking 
water contaminants at which adverse health effects are not anticipated 
to occur over specific exposure durations (e.g., one-day, ten-days, and 
a lifetime). Health advisories serve as technical information to assist 
Federal, state and local officials, as well as managers of public or 
community water systems in protecting public health. They are not 
regulations and should not be construed as legally enforceable Federal 
standards. Health advisories may change as new information becomes 
available.

IV. What are EPA's interim health advisories for PFOA and PFOS?

    EPA is releasing interim updated health advisories for PFOA and 
PFOS based on data and draft analyses that indicate that the levels at 
which negative health effects could occur are much lower than 
previously understood when the agency issued its 2016 health advisories 
for PFOA and PFOS (70 parts per trillion or ppt). Human studies have 
found associations between PFOA and/or PFOS exposure and effects on the 
immune system, the cardiovascular system, development (e.g., decreased 
birth weight), and cancer. These data and draft analyses, which were 
released publicly in November 2021, are currently undergoing EPA 
Science Advisory Board (SAB) review. EPA is concerned about the public 
health implications of these preliminary findings and is therefore 
issuing interim updated health advisories for PFOA and PFOS. The 
interim updated health advisories for PFOA and PFOS are 0.004 ppt and 
0.02 ppt, respectively. The interim updated health advisories replace 
the 2016 final health advisories for PFOA and PFOS which were both set 
at 70 ppt. EPA is reviewing and will respond to the SAB comments as the 
Agency moves forward to develop Maximum Contaminant Level Goals (MCLGs) 
to support the Safe Drinking Water Act National Primary Drinking Water 
Regulation for PFOA and PFOS, which is expected to be proposed later 
this year.

V. What are EPA's final health advisories for GenX chemicals and PFBS?

    EPA is also releasing final health advisories for GenX chemicals 
and PFBS for the first time, based on EPA's 2021 final toxicity 
assessments for these PFAS. In chemical and product manufacturing, GenX 
chemicals are considered a replacement for PFOA, and PFBS is considered 
a replacement for PFOS. Animal toxicity studies following oral exposure 
to GenX chemicals have reported health effects in the liver, kidney, 
immune system, development, as well as cancer. For PFBS, animal studies 
have reported health effects on the thyroid, reproductive system, 
development, and kidney following oral exposure. The final health 
advisories for GenX chemicals and PFBS are 10 ppt and 2,000 ppt, 
respectively.

Radhika Fox,
Assistant Administrator.
[FR Doc. 2022-13158 Filed 6-17-22; 8:45 am]
BILLING CODE 6560-50-P


