Spring-cleaning season is around the corner, and soon we’ll be removing expired or seldom-used products from the garage, household cupboards, under the kitchen sink or bathroom vanity cabinet.

It might surprise us to learn that some of these products are considered household hazardous waste (HHW) – and require special methods of disposal. They should not be thrown in the regular weekly curbside trash pickup, taken to a landfill or flushed down the toilet.

Household hazardous waste is the leftover or unused portions of chemicals and products used to clean and maintain your home, garden and vehicles. HHWs can also be pharmaceuticals and electronic waste such as computer components. These materials are often labeled with terms such as Caution, Warning, Danger, Poison, Toxic, Flammable and Corrosive.

According to Amanda Roa, environmental compliance engineer at the Delta Diablo Sanitation District, “For safety and environmental reasons it is illegal to dispose of household hazardous waste in the garbage, landfill, sewers or storm drains. Improper disposal of hazardous products in our community does damage to our local watershed and Delta ecosystem.”

Roa encourages all East County residents to take advantage of the free Delta Household Hazardous Waste Collection Facility. The facility accepts HHWs such as prescription and non-prescription medications, used oil and filters, antifreeze, latex and oil-based paints and stains, batteries, light bulbs, cosmetics, pesticides, pool chemicals and household cleaners. The facility also accepts used fats, oils and grease.

A few wastes, however, are not accepted: large appliances, radioactive materials, asbestos, medical waste, controlled substances, explosives, tires, marine flares and compressed gas cylinders (except propane and helium tanks).

During 2010-11 more than 560 tons of hazardous waste were dropped off. Since it opened in 1996, the facility has reused, recycled or sent for proper disposal over 4,000 tons of hazardous waste. Some of the products stayed at the facility and became part of the Re-use Room, where residents are encouraged to take home perfectly good used (and sometimes new) household products such as paint, cleaners and pool chemicals.

For a full list of what is and isn’t accepted, visit www.ddsd.org, www.earth911.org or call 925-756-1990.

The Delta Household Hazardous Waste Collection Facility, 2550 Pittsburg-Antioch Highway in Pittsburg, is open Thursdays through Saturdays from 9 a.m. to 4 p.m. (except Nov. 22-24 and Dec. 27-29, 2012).