Some pesticides are more toxic than others.
In technical terms, pesticides that have a high acute or chronic toxicity, or hazard to the environment are called highly hazardous pesticides.6 Under the current prevailing condition of use in African countries, it is advisable to primarily avoid the use of highly hazardous pesticides. Fortunately, only a relatively small share of the products available on the market is highly hazardous and therefore farmers can learn to recognise them, and avoid their use.
Pesticide labels provide important information to recognise the toxicity of a product. This includes instructions for use, content including active ingredients, requirements for personal protective equipment, re-entry intervals, and first aid statements.
Farmers should look for:
Active ingredient – Products are sold with different commercial names, but the important information on the label is the actual chemical that provides the pesticidal action (the poison). This is called active ingredient.
Toxicity Colour code – Some countries have adopted a colour-coded toxicity label on pesticide containers.
Pesticides labelled with red and yellow should always be avoided, unless proper conditions of use can be ensured.
Hazard pictograms – Visuals warning about specific high hazard (toxicity) levels to human health and the environment.
Pictograms commonly-used on pesticide-labels under the Globally Harmonized System of Classification and Labelling of Chemicals indicate:
There is a common misconception among farmers that pesticide toxicity determines its efficacy (“the more toxic, the better”). However, important factors that influence pesticide performance are: choosing the right product for the pest, the time and mode of application, water quality, temperature, and more importantly the stage of the target pest (for instance, some insecticides will only be effective on very young larvae).