Wood preservation facilities, chromated copper arsenate: chapter B-4

4. Human Health Concerns

Chromium, copper and arsenic are elements that occur naturally in food, water and air. Although these elements are a natural part of our environment, and some are necessary micronutrients (chromium, copper), chromium and arsenic are carcinogens. Exposure to CCA or the individual constituents should be minimized to the maximum practical extent possible in the workplace.

One safety objective for the industrial use of any chemical (in this case, chromium, copper and arsenic formulations) is to minimize worker exposure. If safeguards are not provided or implemented, a variety of human health effects may occur depending on the duration and manner of exposure, concentration of chemicals, chemical forms (valence), and varying metabolic sensitivities of individual workers.

The PMRA’s Re-evaluation decision for the registration of the heavy duty wood preservatives creosote, pentachlorophenol, chromated copper arsenate and ammoniacal copper zinc arsenate, has granted continued registration of these products for sale and use in Canada. Potential risks from inhalation and dermal exposure were identified for some occupational tasks within wood-treatment facilities. The addition of new risk-reduction measures and the development of a Risk Management Plan for heavy duty wood preservatives will continue to lower the potential for occupational exposure for treatment facility workers (14).

Table 4 outlines the possible human health effects that may result from exposure to CCA solutions and its components. The following possible human health effects are estimated from risk from chromium as Cr+6 and arsenic as As+5. Extensive reviews of the potential health effects of individual elements are provided in documents from Health Canada (13), the World Health Organization (15), the International Labor Organization (16) and the United States Environmental Protection Agency (17).