5.1.2 Other measures of toxicity and implications
From an operational point of view, acute toxicity is paramount, but other criteria are important - especially in food safety assessments. In order to register a pesticide, other toxicological information is required including:
- Chronic (sub-acute) toxicity over long periods (years) that include generation studies to find out if fertility has been impaired
- Carcinogenicity - whether the substance is likely to cause cancers
- Teratogenicity - whether the substance can damage embryos
- Genotoxicity - whether the substance damages genetic material
- Irritancy (especially for spray operators) and
- Metabolism - it is important to know how the substance is metabolised, into what (metabolites may be more toxic than the original pesticide) and how all metabolites are excreted.
Two important measures (and their associated terms) are especially prominent in legislation and debate. They are not actually linked to one another, but in some ways can be thought of as reflecting hazard and risk.
- ‘Toxicological measures’ based on known safety limits: including Acceptable Daily Intake (ADI: a key indicator for pesticide approval, described in section 5.3)
- Measures and limits of actual residues based on field studies: including Maximum Residue Levels (MRLs: practical specifications for food producers) for a given crop.
