Cold Weather Storage of Pesticides

Jesse Fulbright, MSU Liberty County Extension

In the throes of winter, we all do our best to winterize and protect our homes, our equipment, and anything else that might suffer from being exposed to the elements.  For producers, this includes making sure that pesticides are stored in a secure location where hopefully they won’t freeze. 

Always read the pesticide product label to determine whether a pesticide can freeze with no adverse effects.  Even if the product seems usable after being frozen, the separation of active ingredients and inert carriers often occurs.  A previously frozen pesticide can plug spray equipment, have poor product performance and damage crops if the proper thawing and mixing procedures aren’t followed.

Before attempting to thaw a pesticide, the container should be checked to make sure it is not ruptured or cracked from the expansion of the frozen liquid.  If the container is cracked, place a waterproof container or bucket under the damaged pesticide product container prior to thawing.  If sound, the container should be brought to room temperature by placing the container in a heated room. The thawing process may take several days.  Once the liquid has thawed, the container should be agitated by rolling or shaking to return the contents to a uniform suspension.  The container should also be inverted several times to ensure the product is completely dissolved.  Pesticide manufacturers caution if a pesticide cannot be totally dissolved (crystals are still present) the pesticide should not be used.

In general, pesticides should be stored in a cool, dry location away from extreme temperatures, ignition sources, animals and children.  Always store pesticides in their original containers and do not reuse pesticide containers. 

 

Photo courtesy of University of Florida Extension

 

The MontGuide “Cold Weather Storage & Handling of Pesticides” has some examples of pesticide product storage recommendations.  This MontGuide is available online or at your local county Extension office.  Pesticides that cannot be frozen must be placed in a heated or adequately insulated area to avoid sub-zero temperatures.  Wettable powders and granules, as a rule, are not affected by low temperatures.  These formulations should be stored in a dry place as moisture may promote caking or lead to certain chemical changes, reducing their effectiveness.  Products formulated in water-soluble bags require special winter storage.  These bags have a high affinity for moisture and become brittle when frozen.  If handled when brittle, bags may break open.  It is important they are stored in heated facilities. 
 
For further questions about pesticides and cold weather storage, I would encourage you to visit with your local county Extension office.