The spraying of crops using light aircraft or helicopters poses a number of problems or hazards to the agricultural aviation industry. The toxicity hazard to humans and to neighbouring crops, due to drift, have already been considered in detail in previous symposia and much information is available on this subject. Another hazard which has not received much prominence, possibly due to the lack of incidents, or the reporting of them, and which is associated with the handling of flammable liquids is that of a fire or explosion risk. This is particularly true for spraying operations; incidents arising from aeroplane or helicopter crashes are rather obvious and these are not considered in this paper. The paper attempts to describe hazardous conditions and what steps can be taken to minimise fire and explosion risks.