What is Household Hazardous Waste (HHW)?

HHW is waste from your home that is toxic, corrosive, flammable, or reactive based on its chemical properties. Products such as batteries, paint, paint thinner, solvents, fertilizers, and poisons (pesticides) are considered hazardous waste. Learn about the multiple easy and free ways to safely remove HHW from your home here, including making an appointment for the next collection event. If a product label states Caution, Warning, Danger, or Poison, it’s classified as a hazardous waste.

IMPORTANT NOTICE: Nitrous oxide canisters are not accepted through the Household Hazardous Waste Program.

NEW! HHW Guide

Our new HHW Guide brings safe disposal options together in one place. Find out how to drop off items at a one-day event, take them to a local business, or use curbside battery programs. You’ll also find safer alternatives to hazardous cleaning products and information on what makes HHW hazardous. Read the Complete Guide to Household Hazardous Waste here.

It’s illegal and unsafe to dump this waste in the trash or down the drain. San Mateo County’s HHW Program helps residents reuse, recycle, or responsibly manage residential hazardous waste for free at local businesses that collect common HHW items such as batteries and fluorescent lights, and neighborhood collection events.

If you have questions, contact us at hhw@smcgov.org or (650) 372-6200.

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