Arsenic-Treated Wood: Background and Overview

Publication Date: May 2004

Publisher: Library of Congress. Congressional Research Service

Author(s):

Research Area: Environment

Type:

Abstract:

Arsenic is a known human carcinogen. A preservative using chromated copper arsenate (CCA) has been the principal way to protect most commercially harvested wood from decay. Such wood has been used to build play structures, picnic tables, decks, gazebos, fences, and walkways. Arsenic and chromium can be released from the preserved wood. Since December 12, 2001, the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) Scientific Advisory Panel (SAP), a group designed to provide balanced expert assessment of pesticide-related issues to the Administrator of the U.S. Environmental Protection Agency (EPA) has recommended inter alia that CCA-treated wood be coated and recoated annually to reduce release of and exposure to arsenic, and that a biomonitoring study of children normally exposed to CCA-treated wood should be conducted. However, EPA does not believe there is any reason to remove or replace CCA-treated structures. On February 13, 2004, the SAP released its final report on EPO's draft preliminary probabilistic risk assessment of the potential risks to children associating with CCA-treated playsets and decks. The agency says it will carefully consider the SAP recommendations and revise the draft risk assessment as appropriate.

The wood treating industry, by January 1, 2004, voluntarily converted to nonarsenical preservatives for residential uses, including copper boron azole (CBA) and ammonia copper quaternary ammonia (ACQ), whose availabilities and costs are approximately those of CCA in the past. Labeling had been on all CCA products stating that no use of CCA would be allowed for the affected residential uses after December 31, 2003. Wood treated prior to that date can still be used in residential settings, and CCA-treated wood in extant built structures is not affected.

Disposal of extant CCA-treated wood, export and possible import of CCAtreated wood and wood products, determination of the best ways to reduce arsenic exposure from extant wood, and possible adverse effects from nonarsenic wood preservatives are continuing concerns.

Three bills (S. 337, H.R. 688, and H.R. 3629) have been introduced in the 108th Congress prohibiting other uses of or studying alternatives to CCA-treated wood. All bills had been referred to committees, as of May 2004.