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. 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. 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 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.
Absorption On 30 April 2015, the FDA announced that they were requesting more scientific data based on the safety of hand sanitizer. Emerging science suggests that for at least some health care antiseptic active ingredients, systemic exposure (full body exposure as shown by detection of antiseptic ingredients in the blood or urine) is higher than previously thought, and existing data raise potential concerns about the effects of repeated daily human exposure to some antiseptic active ingredients. This would include hand antiseptic products containing alcohol and
triclosan.
Surgical hand disinfection Hands must be disinfected before any surgical procedure by hand washing with mild soap and then hand-rubbing with a sanitizer. Surgical disinfection requires a larger dose of the hand-rub and a longer rubbing time than is ordinarily used. It is usually done in two applications according to specific hand-rubbing techniques, EN1499 (hygienic handwash), and German standard DIN EN 1500 (hygienic hand disinfection) to ensure that antiseptic is applied everywhere on the surface of the hand.
Alcohol-free Some hand sanitizer products use agents other than alcohol to kill microorganisms, such as
povidone-iodine,
benzalkonium chloride or
triclosan. Persistent activity is defined as the prolonged or extended antimicrobial activity that prevents or inhibits the proliferation or survival of microorganisms after application of the product. This activity may be demonstrated by sampling a site several minutes or hours after application and demonstrating bacterial antimicrobial effectiveness when compared with a baseline level. This property also has been referred to as "residual activity." Both substantive and nonsubstantive active ingredients can show a persistent effect if they substantially lower the number of bacteria during the wash period. Laboratory studies have shown lingering benzalkonium chloride may be associated with
antibiotic resistance in
MRSA. Tolerance to alcohol sanitizers may develop in fecal bacteria. Where alcohol sanitizers utilize 62%, or higher, alcohol by weight, only 0.1 to 0.13% of benzalkonium chloride by weight provides equivalent antimicrobial effectiveness. Triclosan has been shown to accumulate in
biosolids in the environment, one of the top seven organic contaminants in
wastewater according to the
National Toxicology Program Triclosan leads to various problems with natural biological systems, and triclosan, when combined with chlorine e.g. from tap water, produces
dioxins, a probable
carcinogen in humans. However, 90–98% of triclosan in wastewater
biodegrades by both photolytic or natural biological processes or is removed due to
sorption in
wastewater treatment plants. Numerous studies show that only very small traces are detectable in the effluent water that reaches rivers. A series of studies show that
photodegradation of triclosan produced
2,4-dichlorophenol and 2,8-dichlorodibenzo-p-dioxin (2,8-DCDD). The 2,4-dichlorophenol itself is known to be biodegradable as well as photodegradable. For DCDD, one of the non-toxic compounds of the dioxin family, a conversion rate of 1% has been reported and estimated half-lives suggest that it is photolabile as well. The formation-decay kinetics of DCDD are also reported by Sanchez-Prado et al. (2006) who claim "transformation of triclosan to toxic dioxins has never been shown and is highly unlikely." Alcohol-free hand sanitizers may be effective immediately while on the skin, but the solutions themselves can become contaminated because alcohol is an in-solution preservative and without it, the alcohol-free solution itself is susceptible to contamination. However, even alcohol-containing hand sanitizers can become contaminated if the alcohol content is not properly controlled or the sanitizer is grossly contaminated with microorganisms during manufacture. In June 2009, alcohol-free Clarcon Antimicrobial Hand Sanitizer was pulled from the US market by the FDA, which found the product contained gross contamination of extremely high levels of various bacteria, including those which can "cause opportunistic infections of the skin and underlying tissues and could result in medical or surgical attention as well as permanent damage". Gross contamination of any hand sanitizer by bacteria during manufacture will result in the failure of the effectiveness of that sanitizer and possible infection of the treatment site with the contaminating organisms. == Types ==