Disinfectants and Antiseptics
Chemical germicides including disinfectants and antiseptics are used in a variety of applications from sterilizing medical instruments at hospitals to cleaning a household kitchen counter. They provide a convenient method of inactivating a variety of potentially harmful microorganisms.
Chemical germicides are known by several names, including antimicrobials, disinfectants, sporicides, sanitizers and sterilants, just to name a few. They are designed to destroy a variety of pathogenic microorganisms such as viruses, bacteria, bacteria spores, molds and fungi. They are divided into sterilants, disinfectants and antiseptics.
Sterilants kill microorganisms on medical equipment and devices as well as surfaces. This includes bacterial spores, which can survive other germicides. The EPA regulates disinfectants.
Disinfectants—which can be classified as high-, medium-, or low-level depending on the strength required—kill nearly all microbial life on objects or surfaces except for bacterial spores.
Antiseptics are used to inactivate or destroy organisms on skin or living tissue.
Deciding which category of germicide you want to use depends on the function of the device or surface that is being considered. Steam autoclaving or ethylene oxide sterilization might damage certain instruments, so use chemical germicides in those processes. Critical devices—such as endoscopes, forceps and hemodialyzers—that enter sterile areas of the body or protrude into the blood barrier must be sterilized. Semi-critical devices—such as fiber-optic endoscopes, vaginal specula, and dental and ophthalmic devices—that only contact mucous membranes and don't penetrate body tissues can be sterilized or cleaned with a high-level disinfectant, depending on the application. Non-critical devices that only contact intact skin—such as stethoscopes, blood-pressure cuffs, electrodes and measuring devices—may be cleaned with a low-level disinfectant. Equipment surfaces including handles, knobs or carts, as well as housekeeping surfaces—such as sinks, counters or floors—may also be cleaned with a low-level disinfectant.
Many factors influence the effectiveness of germicides, including the:
- shape of the object being cleaned, including its surface texture and whether it is flat or has cracks
- amount of microbiologicals on the surface
- resistance of the microbiologicals to the germicide
- amount of additional soil buildup on the object, including blood, mucous or tissue
- chemical composition of the germicide
- time of exposure to the germicide
- temperature of the germicide
Generally, bacterial spores—including Bacillus subtilis—have the most resistance to germicides, followed by mycobacteria such as Mycobacterium tuberculosis, non-lipid viruses such as poliovirus, fungi such as Cryptococcus, vegetative bacteria such as Salmonella choleraesuis, and lipid viruses such as human immunodeficiency virus with the least resistance.
Because of the many factors that affect germicides, each object that is to be cleaned must be analyzed for the best method and germicide to use. It is of great importance to read and understand the manufacturer's instructions to know which application the product is designed for as well as the instructions for its proper use.
This chart features the common active ingredients in many germicides. It shows the normal concentrations of each ingredient, along with the activity level expressed as high (H), medium (M) and low (L) as an indicator of its disinfecting strength.
|Chlorine mixtures||none||500 to 5000mg |
|Formaldehyde||6% to 8%||1% to 8%||H, M, L|
|Hydrogen Peroxide||6% to 30%||3% to 6%||H, M|
|Iodophor mixtures||none||40 to 50mg |
|Phenolic mixtures||none||0.5% to 3%||M, L|
|Quaternary ammonium mixtures||none||0.1% to 0.2%||L|
The Environmental Protection Agency's office of pesticides oversees disinfectants. Manufacturers are required to test products using pre-established test procedures on product stability, toxicity to people and microbial activity. If the product passes these requirements, it is registered by the agency and ready for trade. The Food and Drug Administration oversees sterilants and germicides that are required for a specific medical device. The manufacturers must submit specific microbial activity data to the FDA before a pre-market notification or 510(k) being issued. Once the 510(k) is issued, the product is ready for trade. The FDA also regulates antiseptics or drugs used on or in the human body. This includes antimicrobial soaps, antiseptics, scrubs and wound protectants, which are simply categorized by an advisory panel that scrutinizes non-prescription germicidal products. Manufacturers can voluntarily submit information on these products.
|Q.||Are chemical germicides required by any OSHA regulation?|
|A.||Yes. The bloodborne pathogens standard, 29 CFR 1910.1030, requires germicides. Housekeeping requirements mandate decontamination and disinfection procedures for all equipment and working surfaces when they contact blood or other potentially infectious materials. In addition, general work practices require that handwashing facilities be made available. If they are not feasible, an antiseptic hand cleanser and towels or antiseptic towelettes must be available. For more information on the bloodborne pathogens standard, see Quick Tips #105: OSHA's Bloodborne Pathogens Standard, 29 CFR 1910.1030.|
|Q.||Can antiseptics be used as disinfectants and vice versa?|
|A.||No. Disinfectants are designed for objects and surfaces and might be too strong for skin or tissue. Conversely, antiseptics might not be strong enough to provide a thorough disinfection of surfaces and objects.|
"Disinfection, Sterilization, and Antiseptics in the Hospital", Martin S. Favero and Walter W. Bond, Manual of Clinical Microbiology, American Society of Microbiology, Washington DC, Chapter 24, pp. 183-200, 1991.
Occupational Safety and Health Administration, 29 CFR 1910.1030, Bloodborne Pathogens.
"Guidelines for Handwashing and Hospital Environmental Control", Revised by Julia S. Gardner, R.N., M.N. and Martin S. Favero, PhD, U.S. Department of Health & Human Services and Center for Disease Control and Prevention, 1987.
Find even more information you can use to help make informed decisions about the regulatory issues you face in your workplace every day. View all Quick Tips Technical Resources at www.grainger.com/quicktips.
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The content in this newsletter is intended for general information purposes only. This publication is not a substitute for review of the applicable government regulations and standards, and should not be construed as legal advice or opinion. Readers with specific compliance questions should refer to the cited regulation or consult with an attorney.
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