Environmental Fate and Behaviour

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'Understanding the interacting processes that control the environmental dynamics of pesticides is essential in order to maximise their effectiveness while minimising the risk of environmental contamination.'

Proceedings of the British Crop Protection Council, 2001

Environmental fate and behaviour of pesticides can be thought of simplistically as the effect that the environment has on the pesticide, and where the pesticide and its breakdown products go in the environment after application.

Three key elements to assessing the potential environmental contamination from the pesticide are:

For authorisation of plant protection products within the European Regulatory system, the data requirements were first defined in Commission Directive 95/36/EC of 14 July 1995 amending Council Directive 91/414/EEC (see under M6 for specific fate and behaviour requirements).  Plant protection products  are regulated in the EU by Regulation (EC) No 1107/2009, which repealed and replaced Council Directive 91/414/EEC on 14 June 2011.

Environmental fate and behaviour data requirements under Regulation (EC) No 1107/2009 are as follows:

The information presented on this website, in conjunction with the information on other sites, is intended to assist applicants with applications for authorisation of Plant Protection Products in the UK with reference to the EU framework in the field of environmental exposure.  The information relates primarily to agricultural, horticultural and home garden pesticides (also known as plant protection products).  Applicants are advised to contact the HSE's Chemicals Regulation Division (CRD) for guidance to address fields of use or applications not covered by the available guidance or risk assessments at community level.  Non-agricultural (public hygiene) pesticides and biocides are also the responsibility of CRD. However, information about these products is held on the biocides website.

Applicants are advised to consider ALL the available guidance when preparing submissions, but applicants are invited to contact CRD if they have questions which cannot be answered by the available guidance.  HSE's Chemicals Regulation Division (CRD) contact details are found here.

The output from the fate and behaviour assessment is used to inform risk assessments performed by other specialist evaluators (for example ecotoxicology and consumer exposure).  These outputs are typically Predicted Environmental Concentrations (PEC's) in soil, surface water (water and sediment), groundwater and air.

A number of environmental exposure modelling tools and guidance documents for use in the EU have been produced by the FOCUS initiative, (FOrum for the Co-ordination of Pesticide Fate Models and their USe) whose goal has been to develop standardised worst-case scenarios, relevant to EU agriculture, for use with computer modelling, to provide exposure estimates in various environmental compartments.

The UK approach has evolved following much UK Research & Development Research and Development in this area.

Further information

Further information to guide applicants in providing suitable exposure calculations for Plant Protection Products in the range of Environmental compartments considered may be found by following the links below. A link is also provided to a range of Excel models to assist in PEC calculations.










Simple Fate PEC calculators (Excel)

Research & Development Reports


List of all Fate and Behaviour guidance pages


Updated 2020-09-04