The Lake County Air Quality Management District would like to remind the public and agriculuralists that burning treated wood is VERY DANGEROUS TO YOU AND ILLEGAL. The smoke and ash is very hazardous to your health and the welfare of the community. When burned, treated wood releases toxic and carcinogenic components to the air and to the groundwater by leaching of the ash, mostly commonlys arsenic and dioxins.

Treated wood has chemicals applied, either on the surface or pressure treated  deep into the wood to prevent biological degradation (rot) while in contact with soil and/or water. While the chemicals used to treat wood are not harmful when intact in the wood product (studies have shown leaching to be minimal or nil), they can be very harmful, and even made worse, when burned in open fires. Treated wood should not be burned in stoves, fireplaces or outdoors because toxic chemicals are produced as part of the smoke and ash and can be harmful if inhaled. It is legal to dispose of treated wood in the landfill, although it's always best to find a way to re-use it. Some of the chemicals that are commonly used as a wood preservative are Chromated Copper Arsenate (CCA), Ammoniacal Copper Arsenate (ACA), creosote and pentachlorophenol. Some commonly used types of treated wood products are grapestakes, fence posts, railroad ties, foundation plywood, and pilings.

You should be able to recognize treated wood, in most instances, because it will have an end-tag marking it as such or an ink stamp on the wood product. Pressure treated wood typically has slit like surface markings and is often green or dark brown in color. Surface treated wood may have an exterior color different than the inside.

Any person who is found burning treated wood is guilty of a misdemeanor and is liable for severe civil penalties and/or fines.

Common applications and origins for specific chemical treatments

•   Pentachlorophenol is widely used for the treatment of utility poles, glue laminated beams and fresh water pilings and bridge timbers. "Penta" is prepared by reacting chlorine with phenol in the presence of a catalyst at high temperatures. Dioxins can be an additional by-product of burning. Dioxins are a designated carcinogen, meaning that exposure increases the risk of cancer.

•   Creosote is primarily used in railroad ties, utility poles and pilings. Creosote is derived from coal tar, which is a by-product of the cooking of the coal used in steel manufacturing.

•   Chromated copper arsenate (CCA) or ammoniacal copper arsenate (ACA). Their use includes the prevention of termites and decay both indoors and outdoors. Some common uses are grapestakes, fences, gazebos, playground equipment, landscaping applications and pilings. CCA contains chromium, copper and arsenic. By burning they are converted to highly oxidized forms i.e. hexavalent chromate and arsenate, and are made water soluble. These are also designated as carcinogens and through exposure can increase the risk of cancer in humans.

Contacts: Bob Reynolds or Megan Beall, Lake County Air Quality Management District (707) 263-7000.