Combined toxicity risk assessments for birds and mammals

The UK regulatory authority have recently issued new advice on combined toxicity risk assessments for birds and mammals as follows: “Many plant protection products contain more than one active substance. Authorisation requires consideration of the product and hence the combined effects of any active substances within them. Active substances may have the same mode of action and/or cause the same toxic effects within test organisms. In such cases a combined assessment is required for acute and long-term effects on birds and mammals. Applicants should note that this is relevant for all formulation types i.e. seed treatments, granules and foliar sprays.

CRD propose a screening step as combined risk assessments are not required in every case:

• Is one active substance clearly driving the risk assessment?
• Does the Tier I risk assessment for all active substances within the formulation pass with a margin of safety?
• Did the mammalian toxicology assessment identify that a combined assessment was not required?

If the answer to any of these is yes, a combined risk assessment may not be required and a reasoned case should be presented. Otherwise, a combined risk assessment is required.

The risks from combined toxicity should also be considered for other species e.g. aquatic organisms, earthworms, etc in consultation with the formulation guidance document until further notice.”

Please contact JSC If you require further advice on this type of regulatory risk assessment or on any other area of pesticides risk assessment: +44(0)1423 520245, enquiries@jsci.co.uk