Disinfect vs. Sanitize

Disinfection, Sterilization, and Preservation. Edited by Seymour S. Block.  In Chapter 3, Dr. Block defines the terms:


A disinfectant is an agent that frees from infection, usually a chemical agent but sometimes may be a physical one, such as x rays or ultraviolet light, that destroys disease or other harmful microorganisms but may not kill bacterial spores.  It refers to substances applied to inanimate objects.

The legal definition (Reddish, 1957) is similar but more detailed:  An agent that frees from infection; usually a chemical agent that destroys disease germs or other harmful microorganisms or inactivates viruses.  The term is most commonly used to designate chemicals that kill the growing forms, but not necessarily the resistant spore forms of bacteria, except when the intended use is specifically against an organism forming spores or a virus, in which case the spores, too, must be killed or the virus inactivated.  Proper use of a disinfectant is contingent upon the purpose for which it is employed or the type of infectious agent that there is reason to suspect may be present.


A sanitizer is an agent that reduces the number of bacterial contaminants to safe levels as judged by public health requirements.  It is commonly used with substances that are applied to inanimate objects.

This term is associated with the cleaning of eating and drinking utensils and dairy equipment and is restricted to cleaning operations, as in the case of a detergent/sanitizer, which combines both cleaning and antibacterial properties.  According to the official sanitizer test, a sanitizer is a chemical that kills 99.999% of the specific test bacteria in 30 seconds under the condition of the test.”

A disinfectant to US EPA is a sanitizer that can be used both as a cleaner
and a sanitizer, as one step.

When chemco’s go to EPA for pesticide registration, they can opt to test
their “sanitizer” with a 5% bovine serum to act as a bioburden, or not.  If
they pass the AOAC test method with the bioburden added, then they get to
claim they are a disinfectant.  IF they pass without a bioburden, they claim
they have a sanitizer.

Its silly. Organics inactivate sanitizers and with hugely variable
bioburdens how does any reasonable science based person accommodate this

Everyone knows you cannot sanitize that which is unclean.

You either clean first to remove foreign organics and then sanitize, or you
are just contributing to the profitability of chemco without predictable
reductions of RISK.