We conduct a wide variety of trials in the field, which contribute
not only to both the human and environmental risk assessments for crop protection
products but also to the assessment of their efficacy.
Our Field Trials group has been conducting GLP field studies across
the world for more than ten years. We have a global network of GLP trained field
operatives, including our own field station in Spain.
The purpose of these trials is to establish what level of residue
will occur in food crops when a crop protection product is used exactly as it
would be in commercial practice. Where appropriate we can process the crop under
GLP conditions to provide processed commodity samples for analysis.
The aim of efficacy trials is to demonstrate that a pesticide
does the job it is designed to do. It is necessary to have Good Efficacy Practice
(GEP) certification in each country in which these trials are operated. We currently
have this certification in the UK and in Spain.
The exposure of operatives to crop protection chemicals is initially
estimated using a computer model, which takes data from toxicology and dermal
penetration studies. For some crop protection products, the estimated exposure
turns out to be unacceptably high. In these circumstances a controlled study
has to be performed in the field to find out more precisely what the level of
exposure will be in practice.
Not strictly speaking field trials, these studies still require
experience and expertise of running studies in the field as well as the specialist
analytical and environmental fate knowledge. These studies and their objectives
include:
- Soil dissipation / accumulation: To discover how fast an active substance and its metabolites will degrade
in soil and whether there is any potential for residues to accumulate during
repeated annual use
- Soil residues: To provide estimates
of soil residues at times such as sowing or planting and harvest of succeeding
crops
- Soil leaching / lysimeter: To
determine if the active substance or its metabolites have the potential for
mobility in soil and for leaching to groundwater
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