Bacterial sampling of food and work surfaces

These brief guidance notes are only intended to advise owners of food premises about general bacterial sampling results which may affect their business and staff.

Owners of all food premises have a responsibility to comply with the Food Safety Act 1990 and other regulations such as the Food Safety (General Food Hygiene) Regulations 1995.

Look elsewhere on the Internet for detailed information and advice regarding food hygiene and standards. It is the owner's responsibility to ensure that he/she and his/her staff act upon that information and comply with current legislation regarding food safety.

Action by the local authority

Under the Food Safety Act 1990, Environmental Health Officers from the local authority have powers to carry out bacterial sampling of food, food equipment and food handlers.

The local authorities will send samples off to a laboratory for microbiological analysis.

There are a number of courses of action open to the local authority if the results are unsatisfactory:

Taking further samples
Service of notices
Closure
Prosecution
Exclusion of food handlers from their food handling duties.

What will the laboratories look for?

Whilst there are a number of factors which might give rise to the presence of significant numbers and types of bacteria in food, the likely principal causes of unsatisfactory results are given in the table below.

Bacterial sampling	Cause
pH	Insufficient acetic acid contents in mayonnaise and similar products.
Total Count	Time/temperature controls poor. Preparation too far in advance of consumption or freezing. Cleanliness of general equipment and staff suspect. Inadequate cooking or heat processing.
Non faecal coliforms	General handling of food and cleanliness of food equipment poor Bactericides and sterilisation procedures suspect
Faecal coliforms	Lack of handwashing Cross contamination between raw and cooked foods. Inadequate cooking or processing.
Coagulase positive Staphylococci	Inadequate inspection of staff for uncovered boils, and septic lesions. Screening of nasal carriers inadequate. Human direct handling instead of tongs, spoons, gloves and such like Waterproof dressings unavailable Poor time and temperature controls
Salmonella	Cross contamination directly or indirectly between cooked items and raw meat/poultry Possibly food handler carrier Inadequate cooking or processing.
Clostridium perfringens	Poor time/temperature control. Inadequate cooking and processing Inadequate arrangements for sauce and stock cooling.
Bacillus cereus	Poor time and temperature of cooked rice and other starch products Cross contamination with other foods Excessive storage periods.
Vibrio parahaemolyticus	Inadequate cooking or processing of sea foods. Cross contamination between cooked and raw seafoods.