What is the difference between bacteriostats, sanitizers, disinfectants and sterilizers?

The EPA classifies public health antimicrobials as bacteriostats, sanitizers, disinfectants and sterilizers based on how effective they are in destroying microorganisms. Bacteriostats inhibit bacterial growth in inanimate environments. Sanitizers are substances that kill a certain percentage of test microorganisms in a given time span. Disinfectants destroy or irreversibly inactivate all test microorganisms, but not necessarily their spores. Sterilizers destroy all forms of bacteria, fungi, and other microorganisms and their spores.

Disinfectants can be further categorized as broad or limited spectrum agents. A broad-spectrum disinfectant destroys both gram-negative and gram-positive bacteria. A limited-spectrum disinfectant must clearly specify the specific microorganisms against which it works.

Antibacterials are definitely effective in killing bacteria, however, there is considerable controversy surrounding their health benefits. The non-residue producing agents have been used for many years and continue to be effective agents for controlling disease organisms in a wide variety of healthcare and domestic settings. When used under strict guidelines of application, the residue-producing agents have proven effective at controlling bacterial and fungal infection in clinical settings such as hospitals, nursing homes, neonatal nurseries and other health care facilities where there may be a high risk of infection.

A certain few consumer products have demonstrated effectiveness for specific conditions: antibacterial toothpaste helps control periodontal (gum) disease; antibacterial deodorants suppress odor-causing bacteria, and antidandruff shampoos help control dandruff. However, to date, there is no evidence to support claims that antibacterials provide additional health benefits when used by the general consumer.