Hong Kong's Centre for Food Safety has released its second Food Safety Report for 2007.
Announcing the results at a press conference, Assistant Director for Food Surveillance and Control of the CFS Dr Constance Chan said some 7,500 food samples were tested in March and April. Among them, some 2,200 samples were taken for microbiological tests and about 5,000 for chemical tests.
"The overall satisfactory rate is 99.2%, with only 57 samples failing the tests," Dr Chan said.
While microbiological tests cover pathogenic bacteria and viruses, chemical tests are conducted to detect chemicals such as antibiotics, anti-oxidants, sweeteners, preservatives, heavy metals, colouring matters and pesticides. Food samples tested included vegetables, fruits and products; poultry and products; aquatic products; milk, milk products and frozen confections; cereals, grains and products.
About 3,600 vegetable, fruit and their product samples were taken for microbiological and chemical tests. There were 10 unsatisfactory samples.
On pesticides, tests were conducted for four main types covering more than 100 pesticides (such as DDT, methamidophos, hexachlorocyclohexane and carbofuran). Four samples (including celery, garlic, Indian lettuce and Swiss chard) were found to contain trace amounts of methamidophos (from 2-3ppm). A tangerine sample was found to contain triazophos (1.2ppm).
For food additives, tests included the commonly-used sulphur dioxide, benzoic acid and sorbic acid. Five pickled radish samples were found to contain preservative benzoic acid (from 1,100-1,600ppm), three of which also found to contain preservative sorbic acid (from 1,100-1,200ppm), exceeding the permitted levels. For heavy metals, tests included cadmium, arsenic, and lead. All the results were satisfactory.
In response to public concerns about the suspected use of colouring matters in oranges, 25 samples were taken for testing. All the results were satisfactory.
CFS says it collected some 800 samples of meat, poultry and their products for microbiological and chemical tests. Apart from three unsatisfactory samples announced earlier, there were 14 other unsatisfactory results. A pork sample was found to contain clenbuterol (0.0086ppm) during tests on veterinary drug residues.
On preservatives, six pork samples were found to contain non-permitted sulphur dioxide (from 33-220ppm). Five samples of dried meat products (including dried sliced pork, dried pork floss, satay pork stick and beef nuggets) were found to contain sorbic acid (from 110- 500ppm). A sample of beef ball and a dried pork floss sample were found to contain benzoic acid, at levels of 59ppm and 100ppm respectively. Sorbic acid and benzoic acid are not permitted to be used in dried meat products and meat balls.
About 500 samples (including freshwater fish, seawater fish, shrimps and shellfish) were analyzed for micro-organisms, chemicals and natural toxins. Apart from 23 unsatisfactory samples announced earlier, there were five other unsatisfactory results.
Regarding tests on veterinary drug residues, including antibiotics (such as nitrofurans and chloramphenicol) and malachite green, two grass carp samples and a turbot fish sample were found to contain nitrofurans (0.0037ppm, 0.0085ppm and 0.01ppm respectively). On preservatives, two noodlefish samples were found to contain formaldehyde (150ppm and 430ppm respectively). Concerning tests on heavy metals (such as mercury, arsenic and cadmium), all the results were satisfactory.
Some 900 samples including snacks, dim sum, sushi, sashimi, condiments and sauces were tested. There were two unsatisfactory samples – one sample of rice with plain chicken and BBQ pork containing pathogen Staphylococcus aureus, and a steamed dumpling with preservative benzoic acid (64ppm).
"We observe that quite a number of unsatisfactory samples were related to the use of excessive or non-permitted preservatives and veterinary drug residues or pesticide residues," Dr Chan said.
She reminded the food trade not to use preservatives in fresh meat. As for other foods, she said the trade should use only permitted food additives, follow good manufacturing practice and comply with legal requirements. Dr Chan also advised people to thoroughly wash vegetables before cooking as most pesticides, such as methamidophos, were water soluble.
"Regarding the unsatisfactory samples, the CFS has taken follow-up actions, including tracing the source of food in question, asking concerned retailers to stop selling and to dispose of those food items, taking follow-up samples and issuing warning letters. If there is sufficient evidence, prosecution action will also be taken," she said.