The Centre for Food Safety (CFS) took some 64,000 food samples for microbiological and chemical tests in 2006. The overall failure rate for both microbiological and chemical testing remained at a low level of 0.3%, same as that in 2005.
While microbiological tests covered pathogenic bacteria and viruses, chemical tests were conducted to detect natural toxins, food additives and contaminants in food samples.
For microbiological tests, about 21,000 food samples were analyzed. Among them, 41 samples were found to contain unacceptable levels of pathogens such as Bacillus cereus, Listeria monocytogenes, Staphylococcus aureus, Clostridium perfringens, Salmonella and Noroviruses, which amounted to an unsatisfactory rate of about 0.2%, compared with 0.1% in 2005. More than half of the unsatisfactory food samples were found to contain Bacillus cereus, which was detected mainly in starchy food such as rice, vermicelli and noodles.
The CFS would like to stress the importance of proper food handling and storage to avoid breeding of pathogens. To prevent food poisoning caused by Bacillus cereus, the CFS reminded the public to observe good personal and food hygiene, avoid cross contamination, cook food thoroughly to a core temperature of 75 degrees Celsius and keep cooked hot foods above 60 degrees Celsius and cold foods below 4 degrees Celsius.
Despite the persistence of low failure rate in past years, the CFS has maintained vigilance over the monitoring of food safety in Hong Kong. Coupled with the efforts of manufacturers and consumers' enhanced knowledge in food hygiene, the safety of foods on sale could be further ensured.
For chemical analyses, some 41,000 food samples were tested in 2006 and 156 (about 0.4%) samples were found to be unsatisfactory, representing an unsatisfactory rate same as that in 2005. They covered 64 samples containing non-permitted or excessive food additives, 55 containing non-permitted or excessive veterinary drug residues, 34 containing excessive chemical contaminants and three containing excessive natural toxins.
Non-permitted or excessive food additives
Regarding food additives, out of some 4,600 samples taken for preservative analysis in 2006, 45 were found to contain non-permitted/excessive preservatives, including sweetened lotus seed, fried dace, Chinese buns and beef ball.
Benzoic acid was found in 21 samples of food. Sixteen samples including fresh beef, sweetened lotus seed, dried shrimp, Chinese tea and dried conch slice were found to contain non-permitted or excessive sulphur dioxide. Other samples failing the tests, such as fish cake, seafood sauce and sausage, were found to contain non-permitted or excessive sorbic acid or propionic acid.
As for colouring matters, 13 out of 3,020 samples, including Chinese sausage, Chinese bun, jelly candy, yellow croaker, dried bean curb, pork rib, hen eggs and salted duck egg were found to contain non-permitted food colours.
Following the detection of non-permitted colour Sudan dyes in poultry eggs by the CFS in November 2006, control measures on importation of poultry eggs were stepped up since January 2007, including the requirement of health certificate for imported eggs from the Mainland and the voluntary enrolment scheme for egg importers, wholesalers and distributors,
Food trade is reminded to use only permitted food additives, follow good manufacturing practice and comply with legal requirements.
Non-permitted or excessive veterinary drug residues
Out of about 3,570 samples taken in 2006, there were 55 unsatisfactory results related to non-permitted or excessive veterinary drug residues. Among them, 36 samples of fish and fish product were found to contain malachite green, while 18 samples, including geoduck, fresh water fish and marine fish, were found containing antibiotics residues such as nitrofurans and chloramphenicol. Moreover, one sample of frozen pork was found to contain clenbuterol.
The CFS has taken follow-up actions against the vendors, including issuing warnings or summons.
Turning to chemical contaminants, 17 out of 22,300 vegetable samples were detected to contain a low level of methamidophos.
To reduce the risk posed by pesticide-contaminated vegetables, consumers are advised to soak vegetables in clean water for an hour or wash them well before cooking.
Besides, seventeen out of 1,150 samples taken in 2006 were found containing excessive amounts of heavy metals. They include samples of oysters, vermicelli, vegetables and peanut containing cadmium, and shrimps and egg samples with arsenic and mercury respectively.
Three out of 1,110 samples taken in 2006 were found unsatisfactory in terms of natural toxins such as ciguatoxin and PSP toxins.
All the exceedances/breaches were not serious and would not pose immediate health risks. Regarding the unsatisfactory samples, the CFS had arranged to take follow-up samples from the same sources for tests, and the follow-up samples taken were all found to be satisfactory. On the whole, Hong Kong's food safety remains at a high standard.