Malachite Green a Mystery for Canadian Officials
This week, Canadian food-safety officials gave Creative Salmon Co. and Marine Harvest Canada the green light to resume harvesting salmon from their Vancouver Island, British Columbia, farms after numerous fish samples tested negative for malachite green, a fungicide banned for use in food production because it's a potential carcinogen. But the companies are struggling to determine why fish samples the U.S. Food and Drug Administration tested at the border more than a month ago contained traces of malachite green ï¿½" proof that pinpointing the source of the chemical is thornier than it may appear.
''I'm flabbergasted,'' Spencer Evans, general manager of Creative Salmon, which raises antibiotic- and hormone-free king salmon in Clayoquot Sound, told SeaFood Business yesterday. ''Weâ??ve never used the product.''
Tests have ruled out that malachite green was used at the farms and processing facilities of both Creative Salmon and Marine Harvest. The companies are now investigating whether the salmon came into contact with the fungicide while in distribution.
There are numerous possibilities: The salmon could have been transported in equipment treated with malachite green. The fish could have been handled with green gloves or aprons dyed with malachite green. The FDA's tests could have been false positives. Is it simply a coincidence that the agency found traces of malachite green in salmon from farms on opposite sides of Vancouver Island on the same day?
Rachel Ellner, a freelance journalist who has reported on malachite green, points out in an e-mail to SeaFood Business published in today's Feedback that it's pretty easy to detect the chemical at very low levels using a chromatograph, because there's a sharp, wide peak at about 600 nanometers, the wavelength thatâ??s green. Visible light ranges in wavelengths from 400 nm (deep violet) to 700 nm (deep red), she explains.
The possibility also exists that the contamination originated from the environment. But thatâ??s doubtful, says Evans, because Creative Salmon's FDA-tested fish samples contained 2.868 parts per billion of malachite green, too high to speculate that the farm's surrounding waters are the source.
Despite the predicament, there have been no cancelled orders or supply interruptions, and customers are understanding of Creative Salmon's situation, notes Evans. Still, ''this is a pain,'' he says bluntly.
That it is. Hopefully, the source of the contamination will be discovered soon so Creative Salmon and Marine Harvest can put the malachite green mystery to rest.