PFOA
is perfluorooctanoic acid and is sometimes called C8
or C-8.
It is a man-made chemical and does not occur naturally in
the environment.
Perfluorooctanoic
acid (PFOA or C8)
CAS No: 335-67-1. Molecular
formula:
The "PFOA"
acronym is used to indicate not only perfluorooctanoic acid
itself, but also its principal salts.
The PFOA
derivative of greatest concern and most wide spread use is
the ammonium salt:
Ammonium
perfluorooctanoate (APFO or C8)
CAS
No. 3825-26-1. Molecular formula:
PFOA
is used as a processing aid in the manufacture of fluoropolymers
to produce hundreds of items such as non-stick surfaces on
cookware (TEFLON), protective
finishes on carpets (SCOTCHGUARD, STAINMASTER),
and clothing (GORE-TEX).
The
DuPont site where APFO is used as a reaction aid is the Washington
Works (Route 892, Washington, West Virginia 26181) located
along the Ohio River approximately seven miles southwest of
Parkersburg, West Virginia.
The
Little Hocking Water Association well field is located in
Ohio on the north side of the Ohio River immediately across
from the Washington Works facility. Consumers of this drinking
water have brought a Class Action suit against the Association
and DuPont for the contamination of their drinking water with
DuPont's APFO, which residents and media refer to as C8.
According
to the Environmental
Working Group, PFOA is not only used to manufacture Teflon,
but is also a breakdown product of chemicals used to coat
food packaging, including fast food like McDonald's,
and stain-resistant coatings for couches, carpets, and clothing.
PFOA is broadly toxic. It does not break
down in the environment, and is considered to be persistent
over geologic time scales. It nearly universally pollutes
human blood and has a half-life in the body of more than four
years. |
PFOS
is the perfluorooctane sulphonate anion and is not a substance
as such. The term PFOS-related substance is used to refer
to any or all of the substances which contain the PFOS moiety
(defined as the C8F17SO2 group) and may break down in the
environment to give PFOS.
The parent
sulphonic acid and some of its commercially important salts,
are:
Perfluorooctane
sulphonic acid (CAS No. 1763-23-1)
Potassium
salt (CAS No. 2795-39-3)
Ammonium
salt (CAS No. 29081-56-9)
Lithium
salt (CAS No. 29457-72-5)
and
Diethanolamine
(DEA) salt (CAS No. 70225-39-5)
-- no molecular structure available.
The use
of products containing these substances can lead to the direct
emission of PFOS to the environment.
According
to a September
2004 UK report PFOS
is:
• persistent and bioaccumulative
• has been detected in the serum
of occupational and general populations
• there appears to be an increased
risk of episodes for neoplasms of the male reproductive system,
the overall category of cancers and benign growths, and neoplasms
of the gastrointestinal track.
• highly toxic (acute) to honey
bees and bioconcentrates in fish
• detected in tissues of wild
birds and fish, in surface water and sediment, in wastewater
treatment plant effluent, sewer sludge and in landfill leachate.
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