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. the world health organization (who) and the cdc recommends "persistent" antiseptics for hand sanitizers. 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 waste water 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 waste water biodegrades by both photolytic or natural biological processes or is removed due to sorption in waste water 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. automatic hand sanitizer hand sanitizer liquid in poland alcohol free hand sanitizer types alcohol-based hand rubs are extensively used in the hospital environment as an alternative to antiseptic soaps. hand-rubs in the hospital environment have two applications: hygienic hand rubbing and surgical hand disinfection. alcohol based hand rubs provide a better skin tolerance as compared to antiseptic soap. hand rubs also prove to have more effective microbiological properties as compared to antiseptic soaps. the same ingredients used in over-the-counter hand-rubs are also used in hospital hand-rubs: alcohols such as ethanol and isopropanol, sometimes combined with quaternary ammonium cations (quats) such as benzalkonium chloride. quats are added at levels up to 200 parts per million to increase antimicrobial effectiveness. although allergy to alcohol-only rubs is rare, fragrances, preservatives and quats can cause contact allergies. these other ingredients do not evaporate like alcohol and accumulate leaving a "sticky" residue until they are removed with soap and water. the most common brands of alcohol hand rubs include aniosgel, avant, sterillium, desderman and allsept s. all hospital hand rubs must conform to certain regulations like en 12054 for hygienic treatment and surgical disinfection by hand-rubbing. products with a claim of "99.99% reduction" or 4-log reduction are ineffective in hospital environment, since the reduction must be more than "99.99%". the hand sanitizer dosing systems for hospitals are designed to deliver a measured amount of the product for staff. they are dosing pumps screwed onto a bottle or are specially designed dispensers with refill bottles. dispensers for surgical hand disinfection are usually equipped with elbow controlled mechanism or infrared sensors to avoid any contact with the pump. composition consumer alcohol-based hand sanitizers, and health care "hand alcohol" or "alcohol hand antiseptic agents" exist in liquid, foam, and easy-flowing gel formulations. products with 60% to 95% alcohol by volume are effective antiseptics. lower or higher concentrations are less effective; most products contain between 60% and 80% alcohol. in addition to alcohol (ethanol, isopropanol or n-propanol), hand sanitizers also contain the following: additional antiseptics such as chlorhexidine and quaternary ammonium derivatives, sporicides such as hydrogen peroxides that eliminate bacterial spores that may be present in ingredients, emollients and gelling agents to reduce skin dryness and irritation, a small amount of sterile or distilled water, sometimes foaming agents, colorants or fragrances. who formulations the world health organization has published the following formulations to guide to the production of large quantities of hand sanitizer from chemicals available in developing countries, where commercial hand sanitizer may not be available: formulation 1 ingredient volume required (10-l prep.) active ingredient % (v/v) ethanol 96% 8333 ml 80% glycerol 98% 145 ml 1.45% hydrogen peroxide 3% 417 ml 0.125% distilled water added to 10000 ml 18.425% formulation 2 ingredient volume required (10-l prep.) active ingredient % (v/v) isopropyl alcohol 99.8% 7515 ml 75.15% glycerol 145 ml 1.45% hydrogen peroxide 3% 417 ml 0.125% distilled water added to 10000 ml 23.425% production covid-19 pandemic a notice about hand sanitizer coronavirus shortages at a cvs pharmacy on 17 march 2020 in 2010 the world health organization produced a guide for manufacturing hand sanitizer, which received renewed interest in 2020 because of shortages of hand sanitizer in the wake of the covid-19 pandemic. dozens of liquor and perfume manufacturers switched their manufacturing facilities from their normal product to hand sanitizer. in order to keep up with the demand, local distilleries started using their alcohol to make hand sanitizer. distilleries producing hand sanitizer originally existed in a legal grey area in the united states, until the alcohol and tobacco tax and trade bureau declared that distilleries could produce their sanitizer without authorization. in the beginnings of the pandemic, because of hand sanitizer shortages due to panic buying, people resorted to using 60% to 99% concentrations of isopropyl or ethyl alcohol for hand sanitization, typically mixing them with glycerol or soothing moisturizers or liquid contain aloe vera to counteract irritations with options of adding drops of lemon or lime juice or essential oils for scents, and thus making diy hand sanitizers. however, there are cautions against making them, such as a wrong measurement or ingredient may resulting in an insufficient amount of alcohol to kill the coronavirus, thus rendering the mixture ineffective or even poisonous. additionally, some commercial products are dangerous, either due to poor oversight and process control, or fraudulent motive. in june 2020, the fda issued an advisory against use of hand sanitizer products manufacture by eskbiochem sa de cv in mexico due to excessive levels of methanol – up to 81% in one product. methanol can be absorbed through the skin, is toxic in modest amounts, and in substantial exposure can result in "nausea, vomiting, headache, blurred vision, permanent blindness, seizures, coma, permanent damage to the nervous system or death". products suspected of manufacture by eskbiochem sa with excessive methanol have been reported as far away as british columbia, canada. in august 2020, the fda expanded the list of dangerous hand sanitizers.