Department of Toxic Substances Control Department of Toxic Substances Control
 

Treated Wood Waste

What is Treated Wood Waste?

Treated wood waste (TWW) comes from old wood that has been treated with chemical preservatives. These chemicals help protect the wood from insect attack and fungal decay while it's being used. Fence posts, sill plates, landscape timbers, pilings, guardrails, and decking, to name a few, are all examples of chemically treated wood.

Click on the report on the right to read more about how treated wood waste is managed in California.

 

 

 

TWW Cover

Is Treated Wood Waste Toxic?

TWW contains hazardous chemicals that pose a risk to human health and the environment. Arsenic, chromium, copper, creosote, and pentachlorophenol are among the chemicals used to preserve wood and are known to be toxic or carcinogenic. Harmful exposure to these chemicals may result from touching, inhaling or ingesting TWW particulate (e.g., sawdust and smoke).