by Noel Kelsch, RDHAP
[email protected]
While recently waiting for a doctor’s appointment, I observed an assistant handing a patient a hospital-grade disinfecting wipe to wipe her face. I explained to the assistant that these were not intended for patient contact. She was surprised and said, “But they are in a baby wipe package.” Knowing the use of these great products and the precautions will prevent accidental exposure to chemicals. Every hospital-grade disinfectant comes with a Materials Safety Data Sheet. That sheet needs to be read and understood before the product is used.
Common germs such as staph can live up to three weeks on a dry surface. Vancomycin-resistant enterococci (VRE) can live up to four months. Knowing how to rid the environment of those organisms can be a matter of life and death. The proper use of alcohol quaternary ammonia wipes can contribute to the safety of the environment we work in and the quality of care we deliver to our patients.
Premoistened germicidal wipes contain biocidal agents for inactivating microorganisms.1 Many labels for germicidal wipes will include concepts such as bactericide and tuberculocide. The first part of the word is the type of microorganism. The second part (“-cidal” or “-cide”) refers to the killing action.2
A growing number of premoistened germicidal wipes are being manufactured with different chemical formulations that are classified as low or intermediate level disinfectants and are registered with the Environmental Protection Agency for hospital use. Chemical formulations typically are quaternary-ammonium compounds, alcohol-quaternary ammonium compounds, chlorine based, and hydrogen peroxide based. The most popular premoistened wipe is the alcohol-quaternary ammonium germicidal wipe.3
There is a difference between the effectiveness of products, and it is important to read the labels that list the products’ capabilities. The alcohol-quaternary ammonium germicidal wipe has many advantages:
- They do not leave residue on surfaces
- They are easy to use and effective when directions are followed
- They do not create aerosols
- They limit cross contamination that can occur when using a rag
- They require a very limited amount of time to be effective
- You can achieve cleaning and disinfection with one product
Both low- and intermediate-level disinfectants use the label claim of “hospital disinfectant,” which means the product is effective against the three test organisms, Salmonella enterica, Staphylococcus aureus, and Pseudomonas aeruginosa. Some low-level disinfectants may kill HIV and hepatitis B virus if stated on the label. They can be used as a cleaner on surfaces that are not visibly soiled with blood or other potentially infectious materials.2 Low-level disinfectants are limited to housekeeping surfaces and areas that have no possibility of being contaminated with blood.
Intermediate-level disinfectants include the same properties but go a step further in killing one of the most difficult organisms, Mycobacterium tuberculosis. They are used on surfaces contaminated with blood or other potentially infectious materials. Intermediate-level disinfectants effectively achieve disinfection with a single product.4
How do alcohol quaternary ammonium germicidal wipes work? Each wipe is saturated with an alcohol-based quat. Quat (quaternary ammonium chloride) is a cationic detergent with four organic groups (thus named quaternary) attached to a central nitrogen atom. The cleansing ability is related to the positively charged portion of the cation of the molecule. They are thought to affect the plasma membrane. This changes the cells’ permeability and causes a loss of essential cytoplasmic constituents such as potassium.2 Quat is great at killing gram-positive bacteria and less active against gram-negative bacteria. That is where the alcohol comes in; it is able to denature proteins. The combination of quat and alcohol is lethal to even some of the most tenacious organisms, including Mycobacterium tuberculosis.
The amount of quat can differ from product to product and is specified in parts per million (ppm). Each wipe is saturated with a specified number of ppm of active quaternary ammonium chloride (5,000 ppm or 2,500 ppm, for example).
The percentage of alcohol (usually isopropyl alcohol) may vary by manufacturer, and the percentage is listed in the product’s MSDS. Because alcohol has rapid action against microorganisms, the higher percentage of alcohol in the chemical formulation can contribute to the faster kill times.3 For example, a 55% isopropyl alcohol (w/w) and quaternary ammonium chloride formulation 0.5% (w/w) is fungicidal, bactericidal, virucidal, and tuberculocidal, killing 26 microorganisms in two minutes or less.
A study at the School of Pharmacy at Cardiff University in Wales clearly showed that following directions is a vital part of using antimicrobial wipes. The researchers found that current protocols have the potential to spread pathogens. Although some wipes can remove higher numbers of bacteria from surfaces than others, the wipes tested were unable to kill the bacteria with the methods clinicians were using. They were using a single wipe to clean and disinfect areas. As a result, high numbers of bacteria were transferred to other surfaces when reused.
According to the Cardiff study, one risk associated with the use of wipes is the transfer of microorganisms to other surfaces. The study actually found wipes to be superior to the use of spraying a cloth or paper towel and applying disinfectant as an aerosol. Wipes are a superior way of decreasing microbial bioburden on surfaces when used properly.5 It is vital that you use one wipe to clean and one wipe to disinfect. Most labels will instruct you to use one wipe to clean. Throw that wipe away, and then use one wipe to disinfect.
There are many risks in the dental environment. Understanding the use of alcohol quaternary ammonium germicidal wipes can make a difference in preventing the risk of spreading disease.
References
- Rutala W. Disinfection, Sterilization and Antisepsis Principles, Practices, Current Issues and New Research. APIC Conference Proceedings, 2006, APIC. Page 13.
- Microbiology: an Introduction, Gerard J. Tortura, Funke, Berdell R., Christine L. Case, 8th Ed.
- Infection Control Today June 2009: The Benefits of Alcohol-Quaternary Ammonium Germicidal Wipes, Jean Fleming, RN, MPM, CIC.
- OSAP. From policies to practice: OSAP’s guide to the guidelines. Workbook. Annapolis: OSAP, 2004.
- www.cardiff.ac.uk, accessed 12/09/09.
Noel Brandon Kelsch, RDHAP, is a syndicated columnist, writer, speaker, and cartoonist. She is a member of the Organization for Safety and Asepsis Procedures and has received many national awards. Kelsch owns her dental hygiene practice that focuses on access to care for all. She has devoted much of her 35 years in dentistry to educating people about the devastating effects of methamphetamine and drug use. She is immediate past president of the California Dental Hygienists’ Association, and is on the board of directors for the Simi Valley Free Clinic.
More things you need to know about wipes
Do not make your own wipes: Cotton and many other fibers can neutralize quats and other disinfectants; special materials are used in the manufacturing process that does not neutralize the quat.
Surface contact time: To achieve effective contact time, the surface area needs to remain wet for the appropriate contact time. Attempting to towel dry a surface that has been moistened by a disinfectant to speed up the drying process defeats the efficacy of disinfectant on that surface. Always wet the area you are disinfecting and allow the product to dry on its own. Do not dry the area with a towel. The process of drying is part of the process that needs to occur. In order for effective disinfection to occur, the contact time it vital.
Use caution with alcohol-based cleansers: They are flammable and should not be stored near flames or in areas where combustion may occur.
Never leave the container open: The evaporation of the liquid will render the product useless.
EPA-registered: Disinfectant products registered with the Environmental Protection Agency for hospital use are the only disinfectants that should be used in the dental environment. Most products found in stores do not fit into the qualifications discussed in this article.
PPE: This is one of the safest products on the market, but personal protective equipment must still be worn.
