Ethanol vs Isopropyl Alcohol: Which Works Better With CHG Applicator For Skin Preparation?
Chlorhexidine gluconate (CHG) antiseptic applicators are commonly used to disinfect the skin prior to medical procedures like placing IV lines or drawing blood. Traditionally, these applicators have contained a combination of CHG and isopropyl alcohol (also known as isopropanol or IPA). However, some newer CHG applicator products use ethanol alcohol rather than isopropyl alcohol as the solvent.
The aim of this article is to compare the effectiveness and safety of ethanol-based versus isopropyl alcohol-based CHG applicators for skin antisepsis. Specifically, we will evaluate the two alcohol types in terms of antimicrobial efficacy, skin effects like irritation and drying, cost, and evaporation time. By examining the evidence on both forms of alcohol, we can provide recommendations on which alcohol preparation works best for pre-procedure skin disinfection in conjunction with CHG.
I. Overview of Ethanol and Isopropyl Alcohol
Ethanol and isopropyl alcohol are both alcohols that are commonly used as disinfectants in healthcare settings.
Ethanol, also known as ethyl alcohol, is the type of alcohol present in alcoholic beverages meant for human consumption. It has two carbon atoms and is one of several types of alcohol with different chemical structures. Both ethyl alcohol and isopropyl alcohol are colorless liquids that can kill bacteria and other germs by disrupting cell membranes. They evaporate quickly, helping to achieve skin antisepsis.
Isopropyl alcohol, also called isopropanol or 2-propanol, is most commonly used at 70% concentration as a disinfectant. It is more effective against bacteria than viruses. A downside is that organic matter can interfere with isopropyl alcohol's disinfectant actions.
For disinfection purposes, ethanol and isopropyl alcohol are typically used at concentrations of 60-80%. This alcohol concentration has proven most effective for killing germs. Water acts as a catalyst and plays a key role in denaturing the proteins of gram-positive bacterial cell membranes. The water content slows the evaporation rate, thus increasing surface contact time and enhancing effectiveness. The ability to kill bacteria and other microbes decreases when using rubbing alcohol at higher concentrations above 80-85%.
II. Efficacy for Skin Disinfection
We have some key information on the efficacy about using ethanol and isopropyl alcohol as disinfectants:
1. A concentration of 60-80% of ethanol or isopropyl alcohol has been proven to be the most effective. Water acts as a catalyst and plays a key role in denaturing the proteins of gram-positive bacterial cell membranes. The water content slows evaporation, thus increasing surface contact time and enhancing effectiveness. The effectiveness as a disinfectant decreases when concentrations are higher than 80-85%.
2. Ethyl alcohol (ethanol) at concentrations of 60-80% is a potent virucidal agent that inactivates all enveloped viruses (e.g. herpes, vaccinia, influenza virus) and many non-enveloped viruses (e.g. adenovirus, enterovirus, rhinovirus, rotavirus) but not hepatitis A virus (HAV) or poliovirus. Hand sanitizer containing at least 60% ethanol alcohol is effective at killing germs.
3. Based on some studies, 60-80% isopropyl alcohol (IPA) is not as active against non-enveloped enteroviruses but is fully active against enveloped viruses. Studies have also demonstrated the ability of both ethyl and isopropyl alcohol to inactivate hepatitis B virus (HBV) and herpes virus.
4. A viral envelope ensures stability and infectivity of viral particles. Non-enveloped viruses are relatively easier to inactivate by chemical disinfectants.
5. Recommended contact time of at least 2-15 minutes for different concentrations of ethanol or isopropyl alcohol to achieve disinfecting effect.
6. Although differing in chemical structures, both alcohols can be used as disinfectants. Ethanol is more widely used in wet laboratories while isopropyl alcohol is preferentially used to disinfect electronic devices.
7. Neither ethanol nor isopropyl alcohol is formally approved by EPA and FDA as high-level disinfectants.
III. Impact on Skin Integrity
When applying antiseptic agents to skin, it’s important to consider their effects on skin health and integrity. The alcohol used in CHG preparation can influence skin irritation, dryness, and absorption.
Several studies have found that ethanol-based CHG preparations cause less skin irritation and stinging compared to isopropyl alcohol mixtures. Patients report lower pain scores with ethanol solutions. This may lead to greater procedural and application compliance.
A paper explores the effects of different alcohols (ethanol, isopropanol and n-propanol) on skin enzymes, cells, and condition. The key findings are:
· n-propanol had the strongest denaturing effect on the skin enzymes kallikrein 5 and phospholipase A2 compared to isopropanol and ethanol in vitro.
· n-propanol also had the most severe effects on keratinocyte metabolic activity and cytokine secretion. Ethanol had the mildest effects.
· In a clinical study, n-propanol caused the most skin irritation, followed by isopropanol, and then ethanol.
· At high application frequencies, the alcohols had similar effects on skin barrier function (TEWL) and hydration (capacitance). But at low frequencies, n-propanol uniquely damaged these parameters.
· n-propanol and isopropanol also caused more visible skin redness compared to ethanol.
The study shows ethanol is somewhat better tolerated than isopropanol and especially n-propanol, and should be the alcohol of choice for skin sanitizers, particularly with high use.
IV. Recommendations for Use
Ethanol seems to be the preferred alcohol for use in CHG antiseptic applicators. Ethanol demonstrates broad antimicrobial efficacy against viruses, bacteria, and fungi. It maintains its disinfecting action even in the presence of organic matter. Studies show ethanol causes less skin irritation and stinging compared to isopropyl alcohol, which could lead to better compliance. The research indicates ethanol has milder effects on skin enzymes, cell metabolism, and condition compared to other alcohols like isopropanol and n-propanol.
However, there are some situations where isopropyl alcohol may be the better option:
· For disinfecting non-enveloped viruses like poliovirus or hepatitis A, isopropyl alcohol may have greater efficacy. Ethanol is not as effective against these virus types.
· Isopropyl alcohol is preferentially used to disinfect electronic devices, where the lower conductivity of isopropanol is advantageous. Ethanol's higher conductivity could damage electronics.
· In resource-limited settings, isopropyl alcohol may be more easily accessible or affordable than pharmaceutical-grade ethanol.
· Individual patient factors like skin sensitivity should be considered. A small proportion may experience more irritation with ethanol.
Overall, the evidence supports ethanol as the most effective alcohol for skin antisepsis when combined with CHG. However, isopropyl alcohol remains a reasonable option in some circumstances, based on virus type, application, cost, or patient factors. Healthcare facilities should consider the evidence and their specific needs in choosing between ethanol and isopropyl alcohol-based CHG preparations.
Recent analysis of the evidence demonstrates that ethanol provides broad-spectrum antimicrobial efficacy, maintains potency in the presence of organic matter, and shows improved skin tolerability compared to isopropyl alcohol. Mantacc's ethanol-based CHG antiseptic applicators fully capitalize on these benefits to deliver superior skin antisepsis prior to IV insertions, blood draws, and other invasive procedures. Mantacc applicators contain the ideal ethanol concentration to rapidly kill pathogens while gently caring for patients' skin. When choosing a CHG antiseptic for your facility, trust the evidence and choose Mantacc with ethanol for reliable efficacy and safety. Mantacc's ethanol-based CHG applicators provide the best defense against infections to help clinicians remain focused on delivering excellent patient care.
1. Cartner T, Brand N, Tian K, Saud A, Carr T, Stapleton P, Lane ME, Rawlings AV. Effect of different alcohols on stratum corneum kallikrein 5 and phospholipase A2 together with epidermal keratinocytes and skin irritation. Int J Cosmet Sci. 2017 Apr;39(2):188-196. doi: 10.1111/ics.12364. Epub 2016 Sep 22. PMID: 27578266.
2. Cartner T, Brand N, Tian K, Saud A, Carr T, Stapleton P, Lane ME, Rawlings AV. Effect of different alcohols on stratum corneum kallikrein 5 and phospholipase A2 together with epidermal keratinocytes and skin irritation. Int J Cosmet Sci. 2017 Apr;39(2):188-196. doi: 10.1111/ics.12364. Epub 2016 Sep 22. PMID: 27578266.
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