Level Disinfectants

Critical instruments come into direct contact with the patient s bloodstream or other sterile areas of the body. Examples of critical instruments include needles, surgical instruments used within the body, IV catheters, peritoneal endoscopes, and kidney dialysis membranes. Semicritical instruments must be free of pathogenic organisms. Examples of semicritical instruments are gastrointestinal endoscopes, bronchoscopes, vaginal speculums, respiratory care devices, and anesthesia equipment. Semicritical instruments must, at a minimum, require high-level disinfecting. 

Examples of noncritical instruments or surfaces include floors, countertops, patient furniture, instrument housings and control knobs, blood pressure cuffs, diagnostic electrodes, wheelchairs, and most physical therapy equipment. Keep these surfaces clean and sanitary. 

These agents can kill mycobacterium (TB), many, but not all, types of virus s fungi, and vegetative bacteria. These disinfectants can t kill bacterial spores in any practical exposure time. Examples of intermediate-level disinfectants include phenols, alcohols, iodophors, and combinations of isopropanol and QACs. Noncritical instruments and environmental surfaces may require disinfection with intermediate-level disinfectants. The correct application of intermediate-level disinfectants is for such noncritical items as floors and countertops, patient room furniture, instruments that contact only intact skin, and plastic or metal machine housings that do not directly contact patients. 

These substances do not kill bacterial spores, mycobacterium (TB), or all viruses. Low-level disinfectants can kill vegetative bacteria, fungi, and some lipid-coated viruses such as HIV. Use low-level disinfectants such as QACs on floors, countertops, furniture, and plastic or metal housing of machines. QAC disinfectants contain their active ingredients as n-alkyl dimethyl ethylbenzyl 

Chlorine The dilutions should fluctuate depending on the job. On a clean surface, a dilution of 1 10 works against many spores, mildews, viruses, molds, and bacteria. Bleach can pose risk for people with lung and heart problems. 

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Phenols are considered to be low-to-intermediate level disinfectants, appropriate for general disinfection of noncritical and semicritical areas. They are not sporicidal and should not be used when sterilisation is required. They are dispensed in aqueous formulations or in mixed water—alcohol solutions. Levels of 400—1300 ppm in the diluted formulation are typical. 

Treatment Secondary treatment, filtration and disinfection Oxidized, coagulated, filtered and disinfected Secondary treatment, filtration and high-level disinfection Oxidized, filtered and disinfected Secondary treatment and disinfection NS Oxidized, coagulated, filtered and disinfected... 

Walsh, S.E., Maillard, J.-Y. and Russell, A.D. (1999) Ortho-phthalaldehyde a possible alternative to glutaraldehyde for high level disinfection. ]. Appl. Microbiol., 86 (6), 1039-1046. 

Formaldehyde is available as a 40% w/v solution in water (100% formalin). An 8% formaldehyde solution in water has a broad spectrum of activity against bacteria, fungi, and viruses. Sporicidal activity may take as long as 18 hours. Its rapidity of action is increased by solution in 70% isopropanol. Formaldehyde solutions are used for high-level disinfection of hemodialyzers, preparation of vaccines, and preservation and embalming of tissues. The 4% formaldehyde (10%... 

Equipment used in medical practice for disease diagnosis, which come into contact with the body, must be sterilized. Nonsterilizations can cause transmission of infection from one person to other. Commonly, 2% glutaraldehyde solution is used. Instruments must be kept in the solution for at least 3 hours, but high-level disinfection is achieved in 20 to 30 minutes for most. Glutaraldehyde is an irritant and may cause sensitization. Alternatively, paracetic acid, chlorine dioxide, and superoxidized water are used for this purpose. 

The safety and biocidal efficacy of glutaral has led to its endorsement by the CDC and WHO as a substitute for formaldehyde in high-level disinfection and cold sterilization (1,2). Glutaral is used in a 2% aqueous solution buffered to a pH of about 8 for sterilization of endoscopic and dental equipment and for other equipment that cannot be sterilized by heat. 

Development of vastly improved antimicrobial formulations that have broad-spectrum activity, high-level disinfection capability, and persistence such that log reductions that meet or exceed performance minimums can be obtained with a very high frequency of occurrence. 

Carbonated beverages are often sold as concentrated syrups syn. beverage extracts that are subsequently mixed with water, sweeteners, and other components at bottling facilities. In addition to the flavour, colours, preservatives, and other constituents, these syrups contain acidulants acids that give a tart flavour, maintain pH levels, disinfect, and perform other functions. Acidulants include phosphoric, citric, ascorbic, tartaric, adipic, and malic acids. 

These substances, widely used as disinfectants, do not work effectively against tuberculosis and gram-negative bacteria. Central sterile, environmental services, patient care areas, and clinical services use quaternary compounds for general low-level disinfecting tasks. These compounds may cause contact dermatitis and nasal irritation but less irritating to hands than other types of substances. 

High-level disinfection processes can expect to destroy all microorganisms with die exception of high numbers of bacterial spores. 

Intermediate-level disinfection, which inactivates M. tuberculosis, vegetative bacteria, most viruses, and most fungi but does not necessarily kill bacterial spores. 

Low-level disinfection, which can kill most bacteria, some viruses, and some fungi but does not kill resist t microorganisms such as tubercle bacilli or bacterial spores. 

Which federal agency regulates liquid chemical sterilants and high-level disinfectants ... 

Wipe floors, countertops, furniture, and machinery housing with an intermediate- or low-level disinfectant to remove soil. Then rewipe with fresh disinfectant to complete the killing of microbes. Never rinse enviromnental surfaces unless the label directs or a surface might come into contact with eyes. 

Food and Drug Administration. Guidance for Industry and FDA Reviewers Content and Format of Premarket Notification [5I0(k)] Submission Chemical Sterilants/High Level Disinfectants. Rockville, MD US Department of Health and Human Services, Food and Drug Administration, 2000. 

Glutaraldehyde is also used for high-level disinfection of biopsy forceps [301], peak flow meters [302] and, as an alternative to formaldehyde, of hae-modialyzers [303-305], though there is continued criticism of the latter practice due to an increased risk of infection and chronic exposure of patients to aldehydes [303, 306]. Glutaraldehyde is the only chemical found to be effective in the disinfection of composite polishing instruments in dentistry [307],... 

Clean up and decontamination must be done with appropriate disinfectants which include diluted bleach solutions and EPA-registered tuberculocides (List B), sterilants (List A), or products registered against HIV/HBV(List D). The lists of these EPA registered products are available from the National Antimicrobial Information Network at (800) 447-6349 or its website at (http //ace.orst.edu/info/nain/lists.htm). OSHA allows the use of these products provided the surfaces have not become contaminated with agents, volrunes, or concentrations for which higher level disinfection is recommended. 

CIDEX OPA Solution (containing 0.55% ort/io-phthalaldehyde, OPA, 1) has become the preferred choice over glutaraldehyde (GTA, 2) as a high-level disinfectant for hospital instrument processing. 

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