[Federal Register Volume 87, Number 118 (Tuesday, June 21, 2022)]
[Notices]
[Pages 36848-36849]
[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.

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:<PHONE_NUMBER>; 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