April 19, 2006 |
EPA-HQ-OPP-2006-0253 |
Proposed
Revocation of Pesticide Inert Ingredient Tolerance Exemption.
The existing tolerance exemption under 40 CFR 180.920 for
the inert ingredient mono- and bis-(1H, 1H, 2H, 2H- perfluoroalkyl)
phosphates where the alkyl group is even numbered and in the
C6-C12 range allows for its use as a defoaming agent at not
more than 0.5% of pesticide formulation. Due to potential
risk from use of these perfluoroalkyl phosphates EPA is proposing
to revoke the tolerance exemption at 180.920 under FFDCA section
408(e)(1) because the Agency is unable to determine that the
tolerance exemption meets the safety requirements of FFDCA
section 408(c)(2).
It has been demonstrated that
compounds containing perfluoroalkyl chains (PFAC), such as
the perfluoroalkyl phosphates described in Sec. 180.920 will
undergo degradation (chemical, microbial, or photolytic) of
the non-fluorinated portion of the molecule leaving the remaining
perfluorinated acid untouched (Ref.:
A. Remde and R. Debus, Biodegradability of Fluorinated Surfactants
Under Aerobic and Anaerobic Conditions, Chemosphere, 32(8),
1563-1574 (1996)). Among the degradation
compounds that can be produced is perfluorooctanoic acid (PFOA).
Further degradation of the perfluoroalkyl residual compounds
is extremely difficult.
EPA has received significant and troubling
data on PFOA. Biological sampling recently revealed the presence
of PFOA in fish, birds, and mammals, including humans, across
the United States and in other countries. The widespread distribution
of the chemical suggests that PFOA may bioaccumulate.
PFOA has shown liver, developmental, and reproductive toxicity
at very low dose levels in exposed laboratory animals (Ref.:
(AR226-1093) Seed, Jennifer. Hazard Assessment of Perfluorooctanoic
Acid and Its Salts-USEPA/EPA/RAD. Washington, DC. November
4, 2002.).
On March 7, 2006, EPA published a proposal
to amend the polymer exemption rule to exclude certain perfluorinated
polymers (71
FR 11484, March 7, 2006, FRL-7735-5). EPA believes this
change to the current regulation is necessary because, based
on recent information, including the data on PFOA and the
potential for these perfluorinated polymers to degrade to
PFOA, EPA can no longer conclude that these polymers will
not present an unreasonable risk to human health or the environment,
which is the determination necessary to support an exemption
under section 5(h)(4) of TSCA, 15 U.S.C. 2604(h)(4), such
as the Polymer Exemption Rule. Because (1) PFOA and other
PFACs are produced from the degradation of the perfluoroalkyl
phosphates described in Sec. 180.920 and (2) the potential
risks to human health and the environment associated with
PFOA, EPA is unable to determine that there is a reasonable
certainty that no harm will result from exposure residues
of the perfluoroalkyl
phosphates described in Sec. 180.920. Therefore, the tolerance
exemption does not meet requirements of FFDCA section 408(c)(2),
and EPA is proposing to revoke this tolerance exemption in
Sec. 180.920 in accordance with FFDCA section 408(e)(1). |