Advisory Committee on Pesticides Annual Report 2001

Section E: UK Review Programme
products containing pirimiphos-methyl, both of which are approved for use
by professionals only. They are an emulsifiable concentrate insecticide/wood
preservative and a dusting powder insecticide for professional use against
flying and crawling insects.
A human health review of pirimiphos-methyl had been undertaken by PSD
and considered by the <strong>Committee</strong> earlier in the year (see page 50). The
<strong>Committee</strong> then considered a review of the human health and efficacy issues
associated with the non-agricultural use of pirimiphos-methyl. The <strong>Committee</strong>
noted that it had already agreed a NOAEL of 0.25 mg/kg/bw/day for repeated
exposure. In addition, it had agreed values for the dermal absorption of
pirimiphos-methyl of one percent from an emulsifiable concentrate and a
100 g/l dilution, five percent for a 1 g/l dilution and one percent for the
dermal absorption of pirimiphos-methyl from a dustable powder.
The <strong>Committee</strong> agreed that the predicted exposure of those using products
was generally acceptable but gave cause for concern when exposures at the
95 th percentile level were considered. It considered that the use of personal
protective equipment (PPE) would mitigate exposure of workers and asked for
further consideration of the way in which data had been used to predict highlevel
exposures. The <strong>Committee</strong> noted that the operator exposure assessments
for agricultural products used the 75 th percentile and, for comparative
purposes, asked HSE to present exposure predictions on the same basis.
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The <strong>Committee</strong> considered that, once surface residues were dry, further
dislodging of active substance from treated surfaces was highly unlikely. Also,
there would be a provision for the exclusion of people and animals during
application of the pesticide. The predicted long-term exposure to pirimiphosmethyl
after treatments had been carried out gave some cause for concern,
although the exposure predictions were not well-established and were based
on a series of assumptions in the absence of actual data. The <strong>Committee</strong>
agreed that its concerns should be communicated to the approval holder, who
should be asked to comment on the current exposure predictions and provide
assurance that exposures of children and adults would be acceptable.
The <strong>Committee</strong> agreed that further clarification was required from the
approval holder regarding the possible photodegradation of pirimiphosmethyl.
It also asked HSE to consider further various issues relating to the
efficacy of the products and to liase with PSD regarding the consumer risk
assessment for stored food.