August, 1998
Preliminary OP reports released; TRAC in home stretch
Nine preliminary risk assessments released in August by the Environmental Protection
Agency offer an early hint at the future of organophosphates under the Food Quality
Protection Act.
A public docket was established on August 10 for EPA to receive comments on the nine
assessments. The OPs under evaluation are Guthion, Prefar, Nemacur, Dibrom, Thimet,
Counter, Ethion, Curacron and Ostanol. The comment period lasts 60 days. EPA will
issue similar risk assessments on 31 other OPs, including seven on Sept. 9, and will seek
public comment on those as well.
EPA has also made available its recommendations for applying the 10X safety factor
for infants and children. The report comes from the FQPA Safety Factor Committee,
which is evaluating hazard and exposure data for all of the OPs.
The report recommends removal of the 10X safety factor from 18 OPs. They include Guthion,
Orthene, Prefar, Diazinon, Mocap, Nemacur and Malathion. Ten more OPs would have
the safety factor reduced to 3X. Among them are Monitor, Thimet and Counter. Nine
OPs would retain the full 10X safety factor. Among them are Lorsban, methyl parathion
and Metasystox-R.
The Tolerance Reassessment Advisory Committee (TRAC) has been meeting since late May.
The committee, with members from all sectors affected by pesticides, is looking at
how FQPA will be implemented and studying how a transition period for agriculture
would work.
TRAC has completed its August meetings as a full panel and in its work groups. One
work group is the Safety Factor Committee which prepared the report on the nine Ops.
This group is also working on a "plain English" document designed to explain FQPA
in understandable language.
The second work group is tackling cumulative risk assessment, which is the combined
risk of exposure to multiple chemicals. The group is recommending EPA continue to
work on individual OPs while determining how they will do the cumulative assessments.
The agency believes it will be able to conduct cumulative assessments of at least dietary
risk by June of 1999.
"The problem is that they don't have a methodology identified as to how they're going
to do that," said Constance Jackson, director of regulatory affairs for Ohio Farm
Bureau. "We're hoping they hold off on that until they have a methodology that is
sound."
The final TRAC meeting was supposed to be held in August, but a September 15-16 meeting
has been added. This meeting will give committee members their last chance to speak
on science policies, preliminary risk assessments, a "plain English" guide to the
EPA risk assessment process, risk management principles, tolerance reassessment principles
and transition strategy.
At the June 22-23 TRAC meeting, EPA announced it has conducted a preliminary risk
assessment on most of the 40 organophosphate pesticides that must be evaluated before
August 1999. Twenty-four of the 40 were tested for acute (one-day) dietary risk,
and 28 of the 40 for chronic dietary risk. In each case, EPA assumed that residues remained
on the crop at the tolerance level and that 100% of the crop had been treated.
Using this method 16 of the 24 OPs in the acute test exceeded their risk cup and 25
of the 28 in the chronic test exceeded the cup.
EPA then conducted a "refined" assessment on eight of the OP materials tested for
acute exposure and 22 of the chronic. The agency plugged in percentage of crop treated
and average field residue data. This method resulted in lower risk assessments for
all the pesticides. However, four of the materials overflowed the cup in the acute test
and 12 did in the chronic test.
While using actual residue and use data always lowers the level of material inside
the risk cup, other factors work to raise it back up again. EPA has not yet added
in exposure data from water, residential or occupational exposures, as FQPA requires
it to do. In lieu of data, EPA will devote 20% of the risk cup to these exposures. This
means that if a pesticide passes the dietary risk assessment by a narrow margin,
adding the additional exposures will overflow the cup again.
FQPA gives EPA the discretion to add the 10X safety factor to protect infants and
children. The National Resources Defense Council has petitioned the agency to use
this safety factor in all cases. That would shrink the risk cup by 90%.
EPA is evaluating its policy of "non-detects," the term it uses when no residue is
found. In this case, the agency assumes residues are present but can't find them.
It then plugs in a number half the limit of the detection rather than the accurate
number, which is zero. EPA says 25% of all existing tolerances are based on this non-detect
formula.
The Implementation Working Group is a coalition of farm, food, manufacturing and pest
management organizations which has submitted its own "road map" of how FQPA should
be implemented. While holding out hope the TRAC process will result in a more science-based approach, IWG is concerned that EPA will not use real data or give growers enough
of a transition period to newer materials.
"If EPA continues to use this approach, it will inevitably lead to the revocation
of large numbers of tolerances for many pesticides and uses," said the IWG's road
map report. "If a large number of tolerances are revoked in 1999, it may result in
extremely costly disruptions of fruit and vegetable production and major problems with pest
outbreaks in field crops."
The Great Lakes Fruit
Growers News