University of Missouri Extension

IPM1012, New March 2002

Temperature Effects on Storage of Greenhouse, Ornamental and Turf Pesticides

Fred Fishel
Department of Agronomy

Temperature extremes in the pesticide storage facility pose several problems. The normal temperature range recommended for storing liquid pesticides is usually 40 to 100 degrees Fahrenheit, although some pesticide labels state a specific temperature range for maintaining optimal shelf life. The purpose of this guide is to provide a quick reference for specific storage information and temperature requirements, if relevant, for many commonly used greenhouse, ornamental and turf pesticides.

Temperature extremes in storage can reduce the effectiveness of pesticides. Freezing of liquid pesticides can result in the active ingredients separating from the solvents or emulsifiers, which may lead to crystallization or coagulation of the pesticide. Some pesticides may be thawed and reused after being frozen by rolling, shaking or otherwise agitating the container to resuspend its contents. Call the manufacturer for advice on reusing specific pesticides that have frozen. Also note that the freezing point of many pesticides is lower than 32 Fahrenheit due to the hydrocarbon solvents and inert ingredients present. At the other extreme, excessive heat can cause pesticides to volatilize and drift away from the storage site. 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 glass containers to explode.

As a rule, wettable powders and granules are not affected by low temperatures. Moisture is the greatest factor affecting their storage as it can cause caking that may reduce the effectiveness of the pesticide. Products formulated in water-soluble packets have a high affinity for moisture and become brittle when frozen. Brittle packets may break open when handled, so store these products in a warm, dry area.

Before storing pesticides, read the "storage and disposal" section of the pesticide label. Many pesticide labels provide specific storage information. The following precautions should be used in the storage of all pesticides:

If storage information cannot be found on the label, contact the manufacturer of the pesticide. The following information was taken from the "storage and disposal" section of the respective pesticide labels.

Fungicides

Insecticides

Herbicides

The author gratefully acknowledges the Purdue University Pesticide Program and MU publication MX328, Applying Pesticides Correctly, in preparing this publication.

IPM1012, new March 2002

IPM1012 Temperature Effects on Storage of Greenhouse, Ornamental and Turf Pesticides | University of Missouri Extension

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