The main route of exposure of agricultural workers to paraquat is through skin, and the use of knapsack sprayers leads to a greater exposure than from tractor-mounted sprayers (IPCS 1984). The consequences from application of paraquat without protective clothing, use of leaking sprayers or careless handling leading to contamination may be fatal if spraying is not immediately interrupted in these cases. Sprayers must be leak-proof (tank and lever), contaminated clothing must be removed immediately and skin that was contaminated must be washed. While these measures appear to be common sense, more often than not they are likely to be ignored due to poor maintenance of equipment, lack of sanitary facilities in the field, ignorance of workers about the health risks or due to heavy workloads. Exposure of agricultural workers during spraying is associated with considerable acute and chronic risks to health, which can be reduced to a certain extent by good practice and use of protective clothing. However, a very large number of workers do not wear protective clothing, especially in countries in the South. Reasons for this are that workers can simply not afford adequate protective equipment and in tropical climate it is inapplicable to wear. Workers’ exposure to pesticides is usually measured with the aid of cotton pads attached to different parts of the body.