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  Regulatory Requirements  l  Category I Pesticides - Storage & Signage  l

Thurston County's Involvement

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Pesticides on shelvesPesticide storage areas can pose serious health risks to workers, first responders, and the public if there is an accidental spill or release.

Although rare, catastrophes involving pesticide storage areas do happen, even in Thurston County. On June 16, 1987, a pesticide applicator’s storage shed caught fire, exploded, and sent up a 1,000-foot plume of toxic smoke and gas that spread through neighborhoods. Fifty residents were evacuated immediately and 200 more were advised of the situation and urged to evacuate.

Fortunately, no one was injured during the event, even though the fire department was not aware that pesticides were involved . . . the storage shed was not marked with any warning signs.

Fires that occur in pesticide storage areas present a special hazard to public health and the environment. Appropriate signage will help alert firefighters to the presence of the toxic pesticides stored in the structure.

Posted warnings also alert customers to stay out of the storage area and decrease the likelihood of accidental exposure. Additionally, signage reminds your employees about specific locations where pesticides must be stored.

Regulatory Requirements

The Washington State Department of Agriculture is responsible for enforcing pesticide regulations throughout the state, including the storage area posting requirements for Category I pesticides and their unrinsed containers (Washington Administrative Code 16-228-1220 (6) and (7)].

Other agencies, such as the Thurston County Fire Marshal and the Washington State Department of Labor and Industries, may have additional regulations that apply to businesses handling and storing pesticides.

Category I Pesticides—Storage and Signage

Category I pesticides are highly toxic and are identified by the signal words “DANGER" or "POISON” found on the product label. Category I pesticide products are generally only available to certified commercial applicators.

Storage locations for Category I pesticides and their unrinsed containers must be posted with warning signs in accordance with Washington State Department of Agriculture standards. Inadequately posted storage locations can pose a greater risk to emergency response personnel, customers, and employees.

Postings for Category I storage facilities must meet the Department of Agriculture’s standards for wording, size, and placement:

  • Wording — Placards must have the skull and crossbones symbol accompanied by the words “DANGER/POISON STORAGE AREA. KEEP OUT.” Instead of “DANGER/POSION” the words, “PESTICIDE” or “CHEMICAL” may be used.
  • Size — The letters must be large enough to be plainly legible at a distance of 30 feet.
  • Placement — See the following diagrams.

Example 1 - storage diagram

Example 2 - storage diagram

NOTE: It's also a good practice to keep a current inventory of the types and quantities of pesticides at your facility. Keep an updated copy of the list in an accessible place away from the storage area.

Thurston County's Involvement

Since several regulatory agencies have specific requirements for how storage areas must be placarded, Thurston County Public Health and Social Services Department, Environmental Health Division has taken on a new role to help homeowners and small businesses comply with regulations. The county offers education, collection, technical assistance, and compliance services to prevent hazardous waste pollution and public health exposures.

During 1999-2002, technical assistance campaigns for businesses that use and store pesticide products were conducted by the Hazardous Waste Program of the Environmental Health division. This fact sheet was developed to help businesses learn about the Washington State Department of Agriculture’s warning sign requirements for Category I pesticide storage areas.

For more information about disposal options for leftover or unwanted pesticide wastes, contact the Thurston County Business Pollution Prevention Program at 360-867-2664 or 360-867-2603 (TDD).

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This page last updated: 07/08/21