Temperature extremes in storage can reduce the effectiveness of pesticides. Freezing of liquid pesticides can result in separation of the active ingredients from the solvents or emulsifiers, or inactivation of emulsifiers, which may lead to crystallization or coagulation of the pesticide. The freezing point of many pesticides is lower than 32 degrees F due to the hydrocarbon solvents or inert ingredients. Some pesticides may be thawed after being frozen, the container rolled, shaken or otherwise agitated to resuspend the contents. Call the manufacturer for advice on reusing specific pesticides if frozen.
Excessive heat can cause some pesticides to volatilize and drift away from the storage site.
Additionally, some pesticides are flammable. Temperature extremes can also damage the integrity of the pesticide container. Freezing temperatures can cause glass, metal and plastic containers to break. High temperatures can cause plastic containers to melt and some glass containers to explode. As a rule, wettable powders and granules are not affected by low temperatures.