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Household Hazardous Waste


Household Hazardous Waste


Household hazardous waste events (HHW) may be canceled due to poor air quality.

As of June 4th, 2020 only HHW events in San Mateo have resumed. HHW events in additional locations will resume when all safety protocols for both staff and the public can be put in place.


San Mateo County’s HHW Program helps residents reuse, recycle, or responsibly manage residential hazardous waste for free. County residents may drop-off a full range of HHW at collection events year-round every Thursday, Friday, and Saturday (except major holiday weekends).

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 paint thinner, toilet bowl cleaner, batteries, and rat bait are considered hazardous waste. It’s illegal and unsafe to dump this waste in the trash or down the drain. Manage household hazardous waste safely by using the HHW Program.


Make an HHW Drop-Off Appointment

IMPORTANT NOTICE: As of June 4th, 2020 only Household Hazardous Waste events in San Mateo have resumed. Household Hazardous Waste events in additional locations will resume when all safety protocols for both staff and the public can be put in place.

Any County resident may make an appointment at any location. Drop-off events are held Thursday – Saturday in San Mateo. To view a list of events, click here.

General information

Accepted Waste

The Household Hazardous Waste (HHW) Program is a free recycling and disposal service for San Mateo County residents only. Residents must make an appointment and limit waste to 10 gallons or 50 pounds per appointment. These requirements are due to storage capacity limits, state regulations, and for your safety. 

Empty containers are not hazardous waste and can be disposed of in the garbage. Leave the lids off so waste haulers can see that the container is empty and non-hazardous.

General information



Why do I need an appointment?

We are limited to how many cars we can handle at each collection site. The appointments allow us to manage this limit, as well as minimize your wait in line. 

Why do you need my contact information?

We send you an appointment confirmation that includes the address and driving directions to the drop-off location.


Recycle Batteries Right

Discarded rechargeable and single-use batteries, in all shapes and sizes from AAA, AA, C, button cell, 9-volt, and lithium-ion batteries are hazardous waste and must be recycled right to protect our community and the environment.

Prepare Batteries Properly

1. Collect batteries in a plastic zip-top bag.

2. Tape the terminals of lithium-ion and 9-volt batteries

3. Zip the bag when it’s about 1/2 way full.

General information

Where to Recycle Fluorescent Lights

Fluorescent lights save electricity and are a good choice for energy conservation. However, all fluorescent lights contain a very small amount of mercury sealed within the glass tubing. This means the lights are toxic and can’t be put in the trash.