Pesticides are chemical products designed to control pests, but they are not uniformly flammable. The risk of fire depends entirely on the product’s formulation, which is the combination of ingredients that makes the pesticide usable. While the active ingredient may not be flammable, the other components mixed with it can introduce a significant fire hazard. Therefore, the hazard ranges from negligible to highly combustible depending on the specific product.
The Chemical Factors Driving Flammability
The primary source of flammability in a pesticide product is not the active chemical that targets the pest, but the inert ingredients used as carriers or solvents. These components make the active ingredient dissolve, spread, or remain stable for application. Liquid formulations, particularly Emulsifiable Concentrates (ECs), often utilize petroleum distillates, such as xylene or kerosene, or other organic solvents which are inherently flammable liquids.
These solvent-based products pose the highest fire risk because they can easily release flammable vapors, especially when heated. Conversely, dry formulations like wettable powders (WPs), soluble powders (SPs), or granular (G) products are generally considered non-flammable. These dry types typically use non-combustible carriers like clay or talc, although the packaging itself can burn.
Identifying Flammability Hazards
Determining the fire hazard of a specific product requires consulting the documentation provided by the manufacturer. The product label will include a “Physical or Chemical Hazards” section that specifically warns if the contents are flammable, extremely flammable, or combustible. Look for cautionary statements such as “Keep away from heat and open flame.”
For a detailed analysis, examine the product’s Safety Data Sheet (SDS), which provides extensive hazard information. Section 9 of the SDS, titled “Physical and Chemical Properties,” will list the specific fire-related property known as the flash point. The flash point is the lowest temperature at which the liquid releases enough vapor to form an ignitable mixture with air near the surface of the liquid.
The flash point helps classify the hazard: a lower temperature indicates a higher fire risk. For instance, a liquid with a flash point between 80°F (27°C) and 150°F (66°C) is classified as combustible. One with a flash point below 80°F (27°C) is typically labeled flammable. Section 14, “Transport Information,” also indicates the hazard class, confirming the flammability level for shipping purposes.
Safe Handling and Storage
Proper storage of flammable pesticides is necessary to prevent the risk of fire and explosion. Flammable liquid products must be kept completely separate from any potential ignition source, including pilot lights, furnaces, water heaters, electric motors, and electrical outlets that could spark. Smoking must also be prohibited in or near the storage area.
Temperature control is a primary factor in safe storage because excessive heat significantly lowers the flash point, making the product more volatile. Most pesticides should be stored in a cool, dry area, ideally maintained between 40°F and 90°F, and protected from direct sunlight. Containers should never be placed near windows where solar heating can increase the internal temperature.
The storage area should be well-ventilated to prevent the accumulation of flammable vapors, which can form explosive mixtures with air. Flammable products should be stored in fire-resistant cabinets, separate from non-flammable pesticides and incompatible materials like fertilizers or oxidizing agents. A suitable fire extinguisher should be readily accessible near the storage unit. A plan should also be in place to contain contaminated water runoff, as water used to fight a pesticide fire can spread toxic chemicals into the environment.