Hand sanitizer
Hand sanitizer is a liquid, gel, or foam used to kill viruses, bacteria, and other microorganisms on the hands. It can also come in the form of a cream, spray, or wipe. While hand washing with soap and water is generally preferred, hand sanitizer is a convenient alternative in settings where soap and water are unavailable. However, it is less effective against certain pathogens like norovirus and Clostridioides difficile and cannot physically remove harmful chemicals. Improper use, such as wiping off sanitizer before it dries, can also reduce its effectiveness, and some sanitizers with low alcohol concentrations are less effective. Additionally, frequent use of hand sanitizer may disrupt the skin's microbiome and cause dermatitis.
Alcohol-based hand sanitizers, which contain at least 60% alcohol, are recommended by the United States Centers for Disease Control and Prevention when soap and water are not available. In healthcare settings, these sanitizers are often preferred over hand washing with soap and water because they are more effective at reducing bacteria and are better tolerated by the skin. However, hand washing should still be performed if contamination is visible or after using the toilet. Non-alcohol-based hand sanitizers, which may contain benzalkonium chloride or triclosan, are less effective and generally not recommended, though they are not flammable.
The formulation of alcohol-based hand sanitizers typically includes a combination of isopropyl alcohol, ethanol, or n-propanol, with alcohol concentrations ranging from 60% to 95% being the most effective. These sanitizers are flammable and work against a wide variety of microorganisms, but not spores. To prevent skin dryness, compounds such as glycerol may be added, and some formulations include fragrances, though these are discouraged due to the risk of allergic reactions. Non-alcohol-based versions are less effective and should be used with caution.
The use of alcohol as an antiseptic dates back to at least 1363, with evidence supporting its use emerging in the late 1800s. Alcohol-based hand sanitizers became commonly used in Europe by the 1980s and have since been included on the World Health Organization's List of Essential Medicines.
Uses
General public
Alcohol-based hand sanitizers may not be effective if the hands are slimy, greasy or visibly soiled. In hospitals, the hands of healthcare workers are often contaminated with pathogens, but rarely soiled or greasy.Some commercially available hand sanitizers have alcohol concentrations that are too low. This makes them less effective at killing germs. Poorer people in developed countries and people in developing countries may find it harder to get a hand sanitizer with an effective alcohol concentration. Fraudulent labelling of alcohol concentrations has been a problem in Guyana.
Schools
The current evidence that the effectiveness of school hand hygiene interventions is of poor quality.In a 2020 Cochrane review comparing rinse-free hand washing to conventional soap and water techniques and the subsequent impact on school absenteeism found a small but beneficial effect on rinse-free hand washing on illness related absenteeism.
Health care
Hand sanitizers were first introduced in 1966 in medical settings such as hospitals and healthcare facilities. The product was popularized in the early 1990s.Alcohol-based hand sanitizer is more convenient compared to hand washing with soap and water in most situations in the healthcare setting. Among healthcare workers, it is generally more effective for hand antisepsis, and better tolerated than soap and water. Hand washing should still be carried out if contamination can be seen or following the use of the toilet.
Hand sanitizer that contains at least 60% alcohol or contains a "persistent antiseptic" should be used. Alcohol rubs kill many different kinds of bacteria, including antibiotic resistant bacteria and TB bacteria. They also kill many kinds of viruses, including the flu virus, the common cold virus, coronaviruses, and HIV.
90% alcohol rubs are more effective against viruses than most other forms of hand washing. Isopropyl alcohol will kill 99.99% or more of all non-spore forming bacteria in less than 30 seconds, both in the laboratory and on human skin.
In too low quantities or concentrations, the alcohol in hand sanitizers may not have the 10–15 seconds exposure time required to denature proteins and lyse cells. In environments with high lipids or protein waste, the use of alcohol hand rubs alone may not be sufficient to ensure proper hand hygiene.
For health care settings, like hospitals and clinics, optimum alcohol concentration to kill bacteria is 70% to 95%. Products with alcohol concentrations as low as 40% are available in American stores, according to researchers at East Tennessee State University.
Alcohol rub sanitizers kill most bacteria, and fungi, and stop some viruses. Alcohol rub sanitizers containing at least 70% alcohol kill 99.9% of the bacteria on hands 30 seconds after application and 99.99% to 99.999% in one minute.
For health care, optimal disinfection requires attention to all exposed surfaces such as around the fingernails, between the fingers, on the back of the thumb, and around the wrist. Hand alcohol should be thoroughly rubbed into the hands and on the lower forearm for a duration of at least 30 seconds and then allowed to air dry.
Use of alcohol-based hand gels dries skin less, leaving more moisture in the epidermis, than hand washing with antiseptic/antimicrobial soap and water.
Hand sanitizers containing a minimum of 60 to 95% alcohol are efficient germ killers. Alcohol rub sanitizers kill bacteria, multi-drug resistant bacteria, tuberculosis, and some viruses and fungi. Alcohol rub sanitizers containing 70% alcohol kill 99.97% of the bacteria on hands 30 seconds after application and 99.99% to 99.999% of the bacteria on hands 1 minute after application.
Drawbacks
There are certain situations during which hand washing with soap and water are preferred over hand sanitizer, these include: eliminating bacterial spores of Clostridioides difficile, parasites such as Cryptosporidium, and certain viruses like norovirus depending on the concentration of alcohol in the sanitizer. In addition, if hands are contaminated with fluids or other visible contaminates, hand washing is preferred as well as after using the toilet and if discomfort develops from the residue of alcohol sanitizer use. Furthermore, CDC states hand sanitizers are not effective in removing chemicals such as pesticides.Safety
Fire
Alcohol gel can catch fire, producing a translucent blue flame. This is due to the flammable alcohol in the gel. Some hand sanitizer gels may not produce this effect due to a high concentration of water or moisturizing agents. There have been some rare instances where alcohol has been implicated in starting fires in the operating room, including a case where alcohol used as an antiseptic pooled under the surgical drapes in an operating room and caused a fire when a cautery instrument was used. Alcohol gel was not implicated.To minimize the risk of fire, alcohol rub users are instructed to rub their hands until dry, which indicates that the flammable alcohol has evaporated. Igniting alcohol hand rub while using it is rare, but the need for this is underlined by one case of a health care worker using hand rub, removing a polyester isolation gown, and then touching a metal door while her hands were still wet; static electricity produced an audible spark and ignited the hand gel. Hand sanitizer should be stored in temperatures below 105 °F and should not be left in a car during hot weather due to risk of flammability. Fire departments suggest refills for the alcohol-based hand sanitizers can be stored with cleaning supplies away from heat sources or open flames.
Skin
Researchers have not thoroughly studied the implications of hand sanitizer use for the body and the microbiome. Studies of healthcare workers have correlated high rates of hand eczema with hand sanitizer use.The alcohol in hand sanitizer strips the skin of the outer layer of oil, which may have negative effects on barrier function of the skin. A study also shows that disinfecting hands with an antimicrobial detergent results in a greater barrier disruption of skin compared to alcohol solutions, suggesting an increased loss of skin lipids.
Frequent use of alcohol-based hand sanitizers can cause dry skin unless emollients and/or skin moisturizers are added to the formula. The drying effect of alcohol can be reduced or eliminated by adding glycerin and/or other emollients to the formula. In clinical trials, alcohol-based hand sanitizers containing emollients caused substantially less skin irritation and dryness than soaps or antimicrobial detergents. Allergic contact dermatitis, contact urticaria syndrome or hypersensitivity to alcohol or additives present in alcohol hand rubs rarely occur. The lower tendency to induce irritant contact dermatitis became an attraction as compared to soap and water hand washing.
Ingestion
In the United States, the U.S. Food and Drug Administration controls antimicrobial handsoaps and sanitizers as over-the-counter drugs because they are intended for topical anti-microbial use to prevent disease in humans.The FDA requires strict labeling which informs consumers on proper use of this OTC drug and dangers to avoid, including warning adults not to ingest, not to use in the eyes, to keep out of the reach of children, and to allow use by children only under adult supervision. According to the American Association of Poison Control Centers, there were nearly 12,000 cases of hand sanitizer ingestion in 2006. If ingested, alcohol-based hand sanitizers can cause alcohol poisoning in small children. However, the U.S. Centers for Disease Control recommends using hand sanitizer with children to promote good hygiene, under supervision, and furthermore recommends parents pack hand sanitizer for their children when traveling, to avoid their contracting disease from dirty hands.
Denaturants are an ingredient added to hand sanitizers, such as Purell, that is used to stop the liquid gel from being digested. This chemical adds a taste to the gel that makes it less enticing to consume. It is especially helpful in keeping younger children away because of the different smells and colors of hand sanitizers that tend to attract children.
People with alcoholism may attempt to consume hand sanitizer in desperation when traditional alcoholic beverages are unavailable, or personal access to them is restricted by force or law. There have been reported incidents of people drinking the gel in prisons and hospitals to become intoxicated. As a result, access to sanitizing liquids and gels is controlled and restricted in some facilities. For example, over a period of several weeks during the COVID-19 pandemic in New Mexico, seven people in that U.S. state who were alcoholic were severely injured by drinking sanitizer: three died, three were in critical condition, and one was left permanently blind.
In 2021, a dozen children were hospitalized in the state of Maharashtra, India, after they were mistakenly orally administered hand sanitizer instead of a polio vaccine.