U.S. EPA registers three types of disinfec- tants based on the type of ecacy data sub- mitted by the manufacturer: 1) limited, 2) general (or broad spectrum), and 3) hospital. 1. Limited: A limited disinfectant is eec- tive against only a specific major group of microorganisms such as Gram-positive (e.g., Staphylococcus aureus ) or Gram- negative (e.g., Salmonella enterica ) bacte- ria. It can also be eective against fungi, amoebas, and mold. The limited disinfec- tants are generally quaternary ammonium compounds (QUAT) and are best suited for use in public areas such as waiting rooms, dining rooms, rest rooms, public transit, childcare settings, and on common-touch hard surfaces. 2.General or Broad Spectrum: These inter- mediate level disinfectants are eective against both Gram-positive and Gram- negative bacteria, fungi, and viruses. They have a wide variety of uses in resi- dential, commercial, institutional, and other sites including healthcare settings where they are used to disinfect critical surfaces and workwear that could have come in contact with infectious materi- als. These disinfectants are also appropri- ate for use on surfaces used for body art, diaper changing stations, toilet training, or cleaning up accidents involving bodily fluids. The most common disinfectants in this class include QUAT and alcohol blends, bleach, and bleach and hydrogen peroxide blends. They require the use of personal protective equipment (PPE) when used. 3. Hospital: A hospital disinfectant is a heavier duty broad spectrum disinfectant that is also designed to be eective against Pseu- domonas aeruginosa , a nosocomial bacterial pathogen. These high-level disinfectants are used on semicritical items (where ste- rility is not required) that will come into contact with either mucous membranes or nonintact skin. They are designed for use in hospitals, clinics, dental oces, or other healthcare-related facilities to kill endo- spore-forming bacteria (e.g., Clostridioides di cile ). These disinfectants might also be kept in low-risk facilities in case bacterial resistance or a disease outbreak occurs. High-level disinfectant products are typi- cally a combination of bleach and hydrogen peroxide or a blend of peracetic acid and
hydrogen peroxide. According to the Centers for Disease Control and Prevention, some of the most common active ingredients include peracetic acid, hydrogen peroxide, glutar- aldehyde, hypochlorous acid, hypochlorite, and ortho- phthalaldehyde. Since these prod- ucts include toxic ingredients, special tech- niques and skills are required when handling them. Individuals who handle these products should have extensive training and readily available PPE and spill kits. Sanitizer According to U.S. EPA, a product will only be registered as a nonfood contact surface sani- tizer if it reduced the bacterial population in the inanimate environment by significant numbers (≥3 log10 reduction or ≥99.9%) but does not destroy or eliminate all bacteria. U.S. EPA also stipulates that sanitizers are not intended to kill fungi and viruses. Around 1950, it became obvious that the conditions of use of disinfectants in pub- lic health were dierent from the uses in hospitals. The public health community realized that it needed something dierent from disinfectants—something to destroy harmful organisms, or if they could not be totally destroyed, at the least to bring them to a “safe” level where they do not pose a sig- nificant threat to health. The public health community realized that tests based on 10 minutes of contact time could not be sat- isfactorily interpreted. An assumption was that in most cases, a 30-second contact time was a reasonable expectation. To achieve this expectation, the Ocial Detergent Sanitizer Test was developed in which bacteria are actually counted, as opposed to the AOAC Use Dilution Test, which indicates the pres- ence of bacteria but yields no counts. A 99.999% or 5-log reduction in 30 seconds is expected with chlorine or QUATs when used with practical cleaning agents. This number was accepted for the intended application and was therefore adopted as a standard. To distinguish these products from disinfec- tants, they were called sanitizers. Most recently, this 5-log reduction rule of sanitizing took on a dierent meaning when it is applied to newer methods for getting sur- faces biologically clean (e.g., steam, ozone). We now recognize that a 5-log reduction in organisms can be achieved through the phys- ical act of cleaning. Since microbial removal
is part of particulate cleanliness, sanitization is met by validating surface cleanliness with particle counting and adenosine triphosphate (ATP) sampling. We can readily measure the bioburden of a surface in negative log num- bers by simply increasing the sampling area. This process works particularly well where a chemical residue is not welcomed, such as in a clean room, research laboratory, phar- maceutical and medical manufacturing, and with ultraclean technologies. The Label Is the Law You might encounter some products that are U.S. EPA registered for both disinfecting and sanitizing. These products will have dierent directions for each use. Typically, the label will specify dierent contact times and prod- uct concentrations depending on the claim, and to ensure that the product is used cor- rectly for its intended purpose. One thing to keep in mind: These products are evaluated in vitro, under controlled con- ditions. Their performance can vary in the field for any number of reasons. Sanitizers and disinfectants are designed to help reduce the risk of food and environmentally medi- ated diseases. This means use as directed by the product label . It is the law. Baseline information on the label of these products includes a wealth of information. All have a statement to clean surfaces before sanitization or disinfection. This direction simply makes sense. Besides listing the prod- uct name, manufacturer, and U.S. EPA regis- try and establishment number, the label has a list of ingredients and intended use. Please be aware that not all products are suitable for all environments. In addition to the directions for use, the label provides the recommended dilutions allowed for specific applications and types of soiling (e.g., oils and greases, body fluids), as well as the contact times for the various listed target organisms, which is the definitive guide. Safety, storage, and dis- posal information are also detailed. This information may all seem quite intui- tive, but in the real world, few actually read the label. In the real world, the “glug/pour” is more often than not the rule rather than the exception. During your inspections, please take the time and review the disinfec- tants and sanitizers at the inspected facility to assure that they are appropriate for the appli- cation, that they will not cause harm when
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June 2024 • Journal of Environmental Health
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