Introduction
The Pesticides Safety Directorate (PSD) (which became part of the Chemicals Regulation Directorate (CRD) from April 2009) and the Health and Safety Executive (HSE) have been re-assessing the safety of all anticholinesterase compounds (mainly organophosphorus and carbamate pesticides) approved under the Control of Pesticides Regulations 1986. The re-assessment ensures that these pesticide products are supported by appropriate safety studies that have been evaluated to modern standards.
Definition of Organophosphate (OPs) and Their Toxicology
PSD looked at products that fall within its area of regulation (products approved for use in agriculture, horticulture, forestry and the home garden) and the Health and Safety Executive similarly looked at non-agricultural products (mainly insecticides for use in the home or by professional users).
PSD and HSE's safety assessments have been considered by Advisory Committee on Pesticides (ACP). The Committee makes recommendations to Government Ministers who, after considering the advice, decide on any necessary regulatory action.
This work did not consider the use of these compounds for other purposes, for example use as human and veterinary medicines (such as use as sheep dips), as these are covered by other legislation.
Current Status of the Programme.
The start of the work was announced in 1998.
PSD completed re-assessments of the risks posed to people's health (risk to pesticide users, workers, bystanders and consumers) for the substances listed below:
- azamethiphos;
- carbosulfan;
- chlorpyrifos;
- chlorpyrifos-methyl;
- dichlorvos;
- dimethoate;
- ethephon (2-chlororethylphosphonic acid);
- fenpropimorph;
- malathion;
- methiocarb;
- oxamyl;
- pirimicarb;
- pirimiphos-methyl;
- thiodicarb;
- tolclofos methyl; and
- triazamate
These re-assessments were all submitted and considered by the ACP and Ministers:
Three anticholinesterase compounds were not considered as part of this programme:
- aldicarb - which was under first list EC review with the UK acting as rapporteur Member State, where a European decision has been taken for withdrawal.
- fosthiazate - which was considered by the ACP in 1998 as a new active substance in the UK and satisfactorily completed a European safety assessment.
- phorate - for which all approvals were revoked due to failure to support the compound in the EC Maximum Residue Level (MRL) setting process.
In addition to considering human health effects, PSD has also completed environmental evaluations for chlorpyrifos and chlorpyrifos methyl, both of which have been considered by the ACP.
Since the start of this work was announced, the European Commission has also further developed the European programme of pesticide re-assessment with the immediate focus also on the re-assessment of anticholinesterase compounds. As PSD (now CRD) is an active participant in regulation of pesticides at a European level, the national work is now integrated with the European programme.
