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Description of the measure

Engineering measures may reduce occupational exposure. For instance, drift-reducing nozzles can lower exposure of the operator to the pesticide spray cloud. A closed cabin on a tractor, ventilated using a filter system, will reduce exposure of the operator. Closed-circuit pesticide pumping systems tend to greatly reduce the risk of exposure during mixing and loading of pesticides, and are applied for aerial and vehicle-mounted sprayers. And the proper design of backpack sprayers can reduce the risk of exposure during filling or if leakages would occur.

Conditions for effective implementation

The required reduced risk application equipment should be available to the user at an affordable cost.

In some countries, pesticide application equipment is being tested and certified to ensure it is of good quality and does not pose undue risks. Rather than making engineering controls a registration requirement for individual pesticides, application equipment certification can be an effective way to impose such controls.

Estimated risk reduction potential

The risk reduction potential of engineering measures is variable and depends on the type of equipment. For instance, European legislation stipulates that closed, filtered, tractor cabins to be used for pesticide spraying should be “Category 4” cabins, which means they protect against dusts, aerosols and vapours, with <2% leakage.

Potential constraints

The use of engineering controls is most likely to be implemented by larger commercial farmers and by pest control operators, who are in a position to make the necessary investments. Engineering controls are less likely to be applied by smallholder farmers with limited financial means.

A problem that may be encountered when engineering controls are applied (e.g. spraying using a closed tractor cabin) is that the operator does not use the necessary PPE anymore. This can lead to dangerous exposure to the pesticide, especially for activities that are not protected by the engineering control (e.g. mixing and loading, in the case of the closed cabin, which only protects against the spray cloud).

Further information

• FAO Guidelines on pesticide application equipment (various). 
• Engineering controls. Cornell University. 
• Agricultural tractors and self-propelled sprayers – Protection of the operator (driver) against hazardous substances. European Standard EN 15695-1/2 (2009)