Over the years, rebreather divers have used many products as breathing loop cleaners, often with questionable safety, uncertain efficacy, and poor material compatibility. Some products recommended by non-US rebreather manufacturers are not available in the US because they do not meet the regulatory criteria of the Environmental Protection Agency (EPA), U.S. Public Health Service (USPHS), and the U.S. Food and Drug Administration (FDA).
Dive Gear Express has recommended two different types of antimicrobial agents for cleaning SCUBA equipment: RelyOn®, a disinfectant, and later Steramine™, a sanitizer. RelyOn (sold outside the US under the name Virkon) and Steramine are both suitable for use in the food service industry where they are proven safe and effective. (The assumption being if they are safe and effective under conditions of repeated exposure to food service workers, are not harmful to equipment, and incidental amounts that get in the food are benign then they should be suitable for cleaning dive gear.) The actual difference between the terms disinfectant and sanitizer is largely a matter of legal definitions based on which government agency is regulating what industry.
- A disinfectant is a chemical that completely destroys all specific test organisms on non-living surfaces within 10 minutes under conditions of the AOAC Use Dilution Test. The health care industry is most interested in disinfectants. A dilute solution of sodium hypochlorite (aka 'liquid bleach') is widely used as a disinfectant in health care and common household applications. However, NEVER use bleach to disinfect SCUBA gear because it has unsatisfactory compatibility with some seal materials commonly used in rebreathers and regulators.
- A sanitizer is a chemical that reduces the number of microorganisms on non-living surfaces to a safe level. Sanitizers are required to kill 99.999 percent of the specific test organisms present within 30 seconds under conditions of the Weber & Black Test. The food service industry is most interested in sanitizers, particularly because they are fast acting.
- An antiseptic is applied to living skin or tissue to prevent infection. Antiseptics are not as suitable for cleaning rebreathers because in this application they are significantly less effective and some may have material compatibility concerns. There are also concerns about unknown safety of antiseptic residue that might remain in a regulator second stage or CCR breathing loop after cleaning.
A very limited study of rebreather disinfection concluded soaking with Steramine is the most effective antimicrobial agent and cleaning method among those studied. What the study clearly demonstrated is that cleaning of equipment with an effective antimicrobial agent is required and that simply rinsing with ordinary tap water is neither sufficient nor effective.