Pesticides are best stored in a locked, well-ventilated space. As an additional precaution, store away from pilot lights or other open flames, since the fumes could catch fire.
Always keep pesticides in their original containers. Never remove the labels. Never store garden chemicals in soft drink bottles, or any other container that could lead to anyone, especially a child, to mistake the contents for food or drink.
Make sure that pesticide containers are tightly sealed. Dry formulations such as wettable powders, dry flowables, granules, and dusts tend to cake when wet or kept in humid areas. Opened original containers can be placed in sealable plastic bags. This will reduce the absorption of moisture and will help prevent a spill if the original container tears.
Shelves used for pesticide storage should be strong, stable, and not too high to reach easily, but out of the reach of children. Keep all chemical containers back from the front edge of the storage shelf. Some liquid pesticides come in glass containers. Be especially careful and take extra care when handling and storing breakable containers.
Pesticides should not be stored with or near feed, seed, clothing, or similar articles. When possible, formulations of wettable powder, granular fungicides, and insecticides should be stored separately from herbicides to avoid possible contamination which could lead to later crop injury. Ideally, the storage room temperature should not fall below freezing. Products subject to “inversion” and similar breakdown as a result of freezing temperatures probably will not perform in a satisfactory manner the following gardening season if this occurs. In fact, crop injury may result from application of temperature altered pesticides.