Don't use treated woods

By Gary Sliworsky
Ag. Rep.

The Canadian Food Inspection Agency (CFIA) recently released an advisory to the Canadian livestock industry. They are advising livestock producers across Canada not to use chemically-treated wood structures near livestock feed or food-producing animals because they can transfer potentially harmful levels of chemicals into animal products, such as meat, milk and eggs.
As part of the CFIA’s residue monitoring program, dioxin levels higher than background were detected in raw milk from two British Columbia dairy operations. The dioxin was found at levels that are not considered an immediate health risk by Health Canada. The levels found did, however, trigger follow-up action to identify and eliminate the source of contamination, in line with Canada’s approach to managing dioxin in the food supply. Dioxins are released into the environment through natural and industrial processes and are commonly found in low levels throughout the food chain around the world.
The CFIA and the Province of British Columbia are collaborating on this issue. The CFIA is also working with other provinces and territories to ensure this advice reaches all livestock producers. The investigation indicated that chemically-treated wood used in some silage bunkers (animal feed containers) may, in large part, be the source of the dioxin detected. Exposure to wood treated with chemicals, such as pentachlorophenol (PCP), has been shown to result in higher than background levels of dioxins in livestock feed, which can then transfer into animal products. Further follow-up after precautionary measures were implemented indicated lowered levels of dioxin.
Producers should ensure that livestock feed is not stored where it can come into direct contact with chemically-treated wood structures. Animals should also not be allowed to come into contact with chemically-treated wood, including sawdust or shavings that could be used for bedding. At a minimum, bunker silos containing this wood should be lined with a plastic tarp and untreated lumber. Gloves should be worn when handling any treated wood and scraps must be disposed of in accordance with provincial/territorial and municipal regulations.
For more information on dioxins, visit the Health Canada Web site at http://www.hc-sc.gc.ca/iyh-vsv/environ/dioxin_e.html or the CFIA Web site at www.inspection.gc.ca