Can Hairy Crabs with Trace Amounts of Dioxins be Sold ?
Mid-Autumn Festival is coming soon (in less than two months) again! Apart from mooncakes, hairy crabs are also a seasonal delicacy for the festival every year. As one may recall, last year the Centre for Food Safety (CFS) announced that hairy crabs imported from China were detected with dioxins. The incident once sparked strong repercussions in the community. A hairy crab retailer was even prosecuted for selling “food unfit for human consumption”.
The retailer was acquitted after trial last month. The magistrate thought that the hairy crabs sold were already accompanied with an official health certificate issued by the Mainland government, and therefore in no event shall the retailer be liable for the incident. He added that it’s difficult to judge whether the tainted crabs are really “unfit for human consumption” because most people unlikely consume hairy crabs exceeding the amount that may lead to an adverse health effect in one season (47 crabs and 10 crabs in maximum for ordinary consumers and high risk consumers respectively).
I think the court judgement may somehow affect the CFS risk assessment of a food in the future. We should know no countries / territories including Hong Kong would specify legal limits of all potential food hazards in all types of food. On one hand, it is impossible to do so (lack of scientific data to set safety limits for all hazards in all foods). On the other hand, it is not necessary (not all hazards will be necessarily found in all foods).
If a food is found to contain a hazard (e.g. dioxins, pesticides, heavy metals, toxins, plasticizers, etc.) without a legal limit in the end-product, the CFS will conduct an internationally recognized risk assessment to evaluate the potential health risk associated with the consumption of the problem food (e.g. maximum no. of tainted crabs that a person can consume), and then determine whether the food is unfit for human consumption and/or sale.
From time to time, you should have heard a CFS spokesman said, “Based on the level of a “hazard” detected in the food sample, adverse health effects will not be caused under usual consumption”. Even so, if the hazard found is highly toxic (e.g. carcinogenic), the CFS generally would request the food trade to remove the problem food from the shelves and/or initiate a recall, even the level of the hazard is very low.
Using the incident of malachite green in fish imported from Mainland in 2005 as an example, the food law back then did not specify any tolerance limit of malachite green in food (including fish). HK government announced that adverse health effect would occur only if one had consumed more than 7 kg eel or 290 kg malachite green-containing fish every day for a long period of time. Isn’t the risk level same as the one posed by hairy crabs with trace amounts of dioxins? An ordinary man of course will not consume so many tainted fish per day. Even so, the food trade still worked in line with the government and agreed to stop selling the problem fish in 2005.
However, based on the court judgement last month, what if upcoming hairy crabs are again detected with dioxins, provided that an official health certificate is still available and risk assessment result again indicates that adverse health effects occur only if huge amount of hairy crabs are consumed? Will the CFS consider such tainted crabs as “fit for human consumption” and allow continued marketing of the crabs? From the consumer perspective, will citizen accept government to do so? Will the government be blamed of not safeguarding the public health?
To solve this problem or future problems arising from other food hazards, the CFS should probably turn all the internal “action levels” set for food hazards into “legal limits”. By doing so, both the government and the food trade can rapidly and clearly determine whether a food is “satisfactory” and “can be sold”. Compared with using “safety reference value” (tolerable daily / weekly / monthly intake of a chemical without appreciable health risk) in risk evaluation, legal limit can minimize disputes about whether a food with a hazard of concern is problematic or not.
Remarks: Regarding the difference between legal limit and safety reference value, please refer to my previous blog article “How come food exceeding legal limits do not cause adverse health effects?”
Some say that since current Hong Kong food law does not mandate a food trade to test for dioxins in hairy crabs, provision of a health certificate is already “sufficient” and there’s no need for the food trade to conduct product testing themselves. HK government might expect food trade shall verify the quality of her imported food by testing. However, this is merely a bit naive and wishful thinking. If it is not a legal requirement, who will devote to doing “extra quality assurance work” adequately? It is normal that many people would act only after a food incident occurs.
In contrast, Taiwan authority has long been aware of the duties of safeguarding food safety should not be limited to food testing by government only. Last year Taiwan strengthened legislation to increase the legal responsibility of certain food trade in self-management. The food trade are legally required to establish their own food safety monitoring programs by phases, so that hygiene and safety of foods sold in Taiwan can be better assured. The practice can serve as a very useful reference for Hong Kong.
by Food Safety Specialist
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