Process and Operations

MRO Q&A: What are the differences between sanitizing, disinfecting and sterilization?

MRO Q&A is a Food Processing series addressing maintenance, repair and operational issues in food plants.

Q. What are the differences between sanitizing, disinfecting and sterilization in food plant operations?

A. In food plant operations, sanitizing refers to the process of reducing the number of microorganisms on any surface to a level judged by public health standards to be safe. This safe level is known as a 5 log reduction or, 99.999%. Since microorganisms can number in the billions, a 99.999% reduction could still leave thousands of microorganisms on those surfaces, but this level has been determined to be the safe level for food health standards. Sanitizing your facility on a regular basis maintains this safe operational level.

If a specific food operation requires a 100 percent kill of a specific microorganism, then disinfectants and detergents are used to ensure the specific microorganism is totally removed. Even though a disinfectant may kill more than one specific microorganism, you must match the disinfectant with the microorganisms you wish to eliminate. When the microorganism senses the destruction of its environment, it will react to that threat by creating spores (endospores). The primary function of these spores is to ensure the survival of the microorganism through periods of environmental attack.

Sterilization is the process of eliminating 100 percent of the microorganism and its spores. Sterilization is usually achieved by maintaining a high-pressure environment and/or high temperatures over a longer period of time. Aseptic food processing refers to a procedure (such as filling) that is performed under sterile conditions. This sterile environment is free of all biological contaminants and can be employed to extend the shelf life of many dairy related products without using refrigeration.