Advisory Committee on Pesticides Annual Report 2001

Section E: UK Review Programme
protection requirements and the provision of further data. It also identified
a need for continuing monitoring of residues in food, particularly bran.
This need would be referred to the Pesticides Residues <strong>Committee</strong>.
Tolclofos-methyl
Tolclofos-methyl is an organophosphorus fungicide formulated in a range of
products approved for use on potato and various horticultural crops. There are
no products approved for amateur use. In January 2001, the ACP considered
a human health review of this active substance as part of a comprehensive
review of anticholinesterase compounds.
The <strong>Committee</strong> agreed that an ADI value should be set at 0.07 mg/kg bw/day
based on the NOAEL of 6.5 mg/kg bw/day for reduced brain cholinesterase
activity and increased absolute and relative kidney weights in a two-year
mouse carcinogenicity study, and applying a 100-fold assessment factor.
The <strong>Committee</strong> agreed that there were no acute or developmental effects on
which it was appropriate to set an ARfD.
In view of the usage patterns of tolclofos methyl, the <strong>Committee</strong> agreed that
both short-term and long-term systemic AOELs were appropriate to the
operator risk assessment. A short-term systemic AOEL of 0.13 mg/kg bw/day
was agreed for the operator risk assessment relating to seasonal uses (i.e. < 90
days’ operator exposure per year), based on the NOAEL for increased liver
weights, reduced bodyweight gain and increased alkaline phosphatase activity
in a six-month dog study. A long-term systemic AOEL of 0.042 mg/kg bw/day
was agreed for the operator risk assessment relating to more frequent usage
(i.e. > 90 days’ operator exposure per year), based on the same end point as
the ADI. For both of these reference values, a correction factor of 60 percent
was applied to take account of incomplete oral absorption, and a 100-fold
assessment factor was used.
51
The <strong>Committee</strong> considered that the estimates of exposure to operators,
workers and bystanders were acceptable, subject to additional operator
protection requirements, and the provision of confirmatory data.
On the basis of the residue data provided, the <strong>Committee</strong> considered that
estimates of consumer exposure were acceptable, although confirmatory data
were required.
The <strong>Committee</strong> agreed to advise Ministers that approvals should be allowed
to continue subject to the imposition of additional operator protection