SAB
Says PFOA is a Likely Carcinogen
[Posted
1/31/06] The
Environmental Protection Agency’s (EPA) Science
Advisory Board (SAB), which reviewed EPA’s Risk
Assessment of Potential Human Health Effects
Associated with Perfluorooctanoic Acid (PFOA),
released a draft report stating that PFOA is “likely
to be carcinogenic” based on EPA guidelines for
carcinogen risk assessment. This is a stronger
stance than EPA’s own assessment that there is
“suggestive evidence of carcinogenicity, but not
sufficient to assess human carcinogenic potential.”
Several years ago, EPA started its investigation
into PFOA and its salts because of concerns
regarding its persistence in the environment and its
presence in the blood of the general U.S. population
at very low levels. Animal studies had shown that
PFOA can cause developmental defects and had other
adverse effects in laboratory animals.
The advisory board also recommended the further
research on PFOA to investigate or accomplish the
following:
-
Mode of action for liver tumor
induction.
-
Include cancer endpoints,
neurotoxicity, immunotoxicity, and hormonal effects
in the risk assessment, aside from those already
proposed by EPA.
-
Conduct occupational
biomonitoring to identify potential human health
effects.
-
Present a clear rationale on
the choice of internal dose metrics to come up with
the margins of exposure (MOE). The SAB suggested the
use of benchmark dose (BMD) method for the
calculation of No Observed Adverse Effect Level (NOAEL)
or Lowest Observed Adverse Effect Level (LOAEL).
-
Retain the default uncertainty
value for cross species extrapolation, since there
is still a substantial gap in knowledge from animal
and human biomonitoring studies.
-
Incorporate new data into its
risk assessment as it becomes available.
PFOA is a synthetic compound also known as "C8."
Companies like DuPont, maker of Teflon®,
use PFOA to make fluoropolymers that have numerous
important manufacturing and industrial applications.
Commonly-used products made with fluoropolymers
include non-stick cookware and breathable,
all-weather clothing.
DuPont immediately responded to the SAB’s draft
report and reiterated its position that the consumer
products using PFOA and related chemicals are safe;
there are no human health effects from exposure to
PFOA, and that EPA’s current risk assessment that
the chemical be classified as a “suggestive
carcinogen” be retained. Although EPA is free to
reject the SAB’s recommendations, it will probably
take its suggestions seriously.
EPA, in its 2003 Federal Register publication, asked
manufacturers of PFOA and companies using those
chemicals in their products to do further research
on PFOA through enforceable consent agreements,
memoranda of understanding, and voluntary
commitments. On January 25, 2006, EPA Administrator
Johnson invited those companies to participate in a
global stewardship program on PFOA and related
chemicals. EPA is asking participating companies to
reduce PFOA from emissions and product content by
95% no later than 2010, and to work toward
eliminating PFOA from emissions and product content
no later than 2015. DuPont has declared its
willingness to work towards those goals.
Related Link:
EPA Info on PFOA
SAB Draft Report
Federal Register Environmental Documents
DuPont News Release
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