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Module 1: Hazards, issues and their control

Section 2: ACMSF recommendations for the control of Clostridium botulinum

This section covers the ACMSF’s views and recommendations for the control of non-proteolytic Clostridium Botulinum in chilled vacuum packed and modified atmosphere packed foods.

Further information can be found in Food Standards Agency guidance, which summarises ACMSF advice, on the hazards and controls associated with vacuum and modified atmosphere packed chilled foods. The guidance is essential reading for small businesses and local authority environmental health officers.

See Module 3 of this course for further information on the interaction of control factors.

Control factors for Clostridium botulinum

The ACMSF has recommended control factors to prevent the growth of non-proteolytic Clostridium botulinum in chilled foods where the organism has not been eliminated or is not sufficiently controlled by some other factor. The committee recommends that food manufacturers, caterers and retailers should take account of the time it takes for the organism to grow and/or produce toxin at the actual temperatures the food is expected to encounter during its shelf-life. This must take into account storage, transport, distribution, retail, catering and domestic stages, as appropriate.

It is recognised that certain bulk vacuum packaged foods are stored for a period under strictly-controlled conditions at temperature between -2ºC and 0ºC. These temperatures are sufficient to prevent growth and toxin production by non-proteolytic Clostridium botulinum.

However, the ACMSF does not believe it is realistic to maintain temperatures of 3ºC or less consistently during all the parts of the chill chain. The committee also does not believe it is acceptable to rely on chill temperatures as the only method of preventing growth of non-proteolytic strains of Clostridium botulinumin chilled foods that have an assigned shelf-life of more than ten days.

In addition to chill temperatures of less than 8ºC, the ACMSF recommends that prepared chilled foods with an assigned shelf-life of more than ten days should contain one or more controlling factors at levels that prevent growth and toxin production by strains of non-proteolytic Clostridium botulinum.

Control factors for Clostridium botulinum with a shelf-life of less than ten days

Key ACMSF recommendations

Authoritative industry guidance

Summary of control measures

The inherent risk of Clostridium botulinum