1.800.858.7378 npic@ace.orst.edu
We're open from 8:00AM to 12:00PM Pacific Time, Mon-Fri
About us

Treated wood exposed to sun, wind, rain, soil, and water may release chemicals onto the wood’s surface. This process is called leaching. The chemical residues may transfer to the skin and clothing of people who touch the wood. The chemicals may also get into soil or water. There are a number of factors that influence leaching and environmental behavior.

The following factors affect the risk of leaching:

Metals used in treated wood such as copper and arsenic cannot be broken down. However, they may change their chemical form. This is called speciation. Environmental factors such as pH, temperature, soil moisture, and soil type can affect whether and how speciation occurs. The final form can affect chemical behavior and toxicity. For example, some forms of arsenic are more likely to move in soil and contaminate water than other forms.

You can reduce environmental risks when you need to use treated wood. Consider the following tips:

Additional Resources:

If you have questions about this, or any pesticide-related topic, please call NPIC at 800-858-7378 (8:00am - 12:00pm PST), or email us at npic@ace.orst.edu.

Last updated May 12, 2023