How temperature, microbes and time interact in food

One danger temperature does not describe every food. Assess product, exposure history and the measured profile together.

1 November 2021Updated 23 September 2026

Short answer

Refrigeration does not sterilise food; it can slow microbial growth depending on the food and organism. Do not decide safety from one universal temperature threshold after an excursion. Segregate the product, preserve its time-temperature record and batch details, and assess it against product conditions, the full exposure profile and guidance from the food safety lead.

Food spoilage and illness risk cannot be described by one temperature figure. Food type, initial microbial state, packaging and time all matter.

What cooling does and does not do

Cooling does not remove microorganisms. Growth rates vary by food and organism. Re-cooling does not erase earlier exposure history.

Review excursions against product information

Record product and batch, start and end times, measured maximum, duration, device ID and previous excursions. Assess the profile with the product’s storage information and the operator’s approved food-safety procedure. An average temperature alone can hide short extremes or earlier exposure.

A safety decision needs product-specific evidence and review by the responsible specialist; one general “danger-zone” duration cannot be applied to all foods.