Of the samples assessed, 900 were collected for microbiological tests, some 1,600 were taken for chemical tests and the remaining 6,700—including about 6,400 taken from food imported from Japan—were collected to test radiation levels.
The tests covered pathogens and hygienic indicators, while the chemical tests aimed at detecting pesticides, preservatives, metallic contaminants, colouring matters and veterinary drug residues across all food segments.
Of the four unsatisfactory samples, two were of vegetable that had pesticide residues exceeding the legal limits; one mud crab was found to contain a veterinary drug, chloramphenicol; and a roast beef sample was suspected to be contaminated with Listeria monocytogenes.
The CFS has taken follow-up action to remove substandard items from the market and traced their sources, the centre said in a statement.
Since new residue regulations came into effect in August 2014, the CFS has taken 97,600 samples of imported, wholesale and retail items for pesticide testing, with an overall failure rate of less than 0.2%.