Hand sanitiser: a buyer’s guide to the label

Hand sanitiser is regulated in the United States as an over-the-counter drug. That is the most useful thing in this article, because it drags a labelling regime along with it. An OTC drug carries a Drug Facts panel with a fixed set of headings: Active ingredient, Purpose, Uses, Warnings, Directions, Other information and Inactive ingredients 5.

Read that last heading again. Every inactive ingredient has to be named, in a standard format, on the pack itself. A US cleaning product carries no such duty, which is why a bottle of hand soap can lawfully say less about its contents than the sanitiser next to it.

The other thing an OTC drug carries is a National Drug Code. Each finished drug product has a unique NDC in three segments: a labeler code assigned by the Food and Drug Administration, a product code and a package code identifying the size and type 6. It is a registration identifier, not an approval and not an endorsement, and its use to a shopper is that it names who is actually responsible for the bottle. The Purell gel below is listed under 21749-704 by GOJO Industries 8; the Germ-X original is listed under 83986-652 by UpLift Brands 9.

The Centers for Disease Control and Prevention recommends, for community settings, alcohol-based hand sanitiser products containing at least 60 per cent ethyl alcohol or 70 per cent isopropyl alcohol 3. The World Health Organization takes a different route to a similar place: its two recommended handrub formulations are ethanol at 80 per cent v/v and isopropyl alcohol at 75 per cent v/v, each with glycerol at 1.45 per cent and hydrogen peroxide at 0.125 per cent 2.

Below the threshold, the problem is not that nothing happens, it is that the evidence stops supporting the claim. The WHO review of hand hygiene preparations states that alcohol solutions containing 60 to 80 per cent alcohol are most effective, with higher concentrations being less potent, and gives the reason: proteins are not denatured easily in the absence of water 1. More alcohol is not better, and appreciably less is worse.

Two further limits sit in the same review and rarely make it onto a front label. Alcohols have virtually no activity against bacterial spores or protozoan oocysts, and very poor activity against some non-enveloped viruses 1. And check the basis of the percentage before comparing two bottles: the WHO figures are volume for volume, while the ATTITUDE product below states 62 per cent w/w 13, which is a weight basis and not the same measurement.

Both alcohols are in the WHO formulations, at different strengths, and both appear in the CDC recommendation at different thresholds: 60 per cent for ethanol, 70 per cent for isopropanol 3 2. The gap between those two numbers is the practical answer to which is stronger at equal concentration, and it is the only comparison either body puts in writing.

One detail is worth carrying away from the WHO formulations. The hydrogen peroxide in them is there to inactivate contaminating bacterial spores in the solution itself, and is not an active substance for hand antisepsis 2. An ingredient in the bottle is not necessarily an ingredient working on your hands, which is a habit of reading worth keeping.

The FDA final rule of 12/04/2019 on consumer antiseptic rubs found 28 active ingredients not eligible for evaluation under the OTC drug review, and deferred rulemaking on three: ethyl alcohol, isopropyl alcohol and benzalkonium chloride. For those three the agency made no determination that they are generally recognised as safe and effective 4. On monograph status, in other words, benzalkonium chloride stands exactly where the alcohols stand: unresolved, and still on the shelf.

The difference is in the guidance rather than the rulemaking. The CDC recommendation for community settings names ethanol and isopropanol thresholds and does not name benzalkonium chloride 3. The WHO review describes quaternary ammonium compounds as primarily bacteriostatic and fungistatic, more active against Gram-positive than Gram-negative bacteria, with relatively weak activity against mycobacteria and fungi, and records that benzalkonium chloride is prone to contamination, with outbreaks traced to contaminated preparations 1.

That is not a reason to treat an alcohol-free product as a mistake. People buy them for children, for skin that alcohol has already broken, and for places where a flammable liquid is a nuisance. It is a reason to know that you are buying a product with a different evidence base and a different regulatory status, and to notice that the Babyganics refill below publishes its ingredients on its page but no Drug Facts panel 14.

The methanol episode is the serious one. Methanol is not an approved active for hand sanitiser and appeared as a contaminant. Public health investigators recorded 15 cases of methanol poisoning in Arizona and New Mexico from ingestion of alcohol-based hand sanitisers during May and June 2020: four patients died, three were discharged with vision impairment, and four recovered without lasting complications. The FDA issued its consumer alert on 19/06/2020, and by 15/07/2020 had tested and identified 67 alcohol-based hand sanitiser products containing methanol 3.

Benzene came next, and it is a narrower story. On 24/03/2021 the analytical pharmacy Valisure petitioned the FDA after testing 260 batches from 168 brands and finding benzene in 44 of them, or 17 per cent, with the highest result at 16.1 parts per million against an FDA interim limit of 2 ppm for liquid hand sanitiser. The petition asked for recalls of the affected batches and for an exposure limit to sit alongside the concentration limit 7.

What a reader can do with a bottle today is unglamorous and effective. Find the NDC, check that the labeller named next to it matches the brand on the front, and look up the labelling published under that code, which is where the Purell and Germ-X entries in the table above came from 8 9. A product with no NDC, no labeller name and no Drug Facts panel is a product you cannot trace, and both of the episodes above ran through exactly that gap.

The WHO review is blunt about it: alcohols are not good cleansing agents, and their use is not recommended when hands are dirty or visibly contaminated with proteinaceous materials 1. Where small amounts of blood are present, alcohol may still reduce bacterial counts, but the review adds that this does not remove the need for handwashing with soap and water whenever such contamination occurs 1. The CDC frames the same point as a positive instruction, washing hands with soap and water for at least 20 seconds 3.

Put that together with the spore and non-enveloped virus limits above and the division of labour is clear. Sanitiser is the option for clean-looking hands away from a sink, and it was never presented as the better one by the bodies that recommend it.

A sanitiser that hurts to use does not get used, so the emollient line is a performance question rather than a comfort one. The WHO review states that frequent use of alcohol-based formulations tends to dry the skin unless humectants or other skin conditioning agents are added, that the drying effect can be reduced or eliminated by adding 1 to 3 per cent glycerol or another conditioning agent, and that alcohol-based solutions or gels containing humectants caused significantly less skin irritation and dryness than the soaps and antimicrobial detergents tested 1. The WHO formulations put glycerol at 1.45 per cent for that reason 2.

On the shelf, that is a line you can find. Dr. Bronner’s runs organic ethyl alcohol, water, organic glycerin and one organic essential oil, and nothing else 11. Purell lists glycerin, isopropyl myristate, caprylyl glycol and tocopheryl acetate among its inactives 8, and Touchland lists aloe and glycereth-26 10.

One last contrast. WHO advises that perfumes and dyes are not recommended in these formulations, on the grounds of allergic reaction risk 2. Several consumer products carry fragrance regardless: Purell lists Fragrance (Parfum) in its inactives 8, and the ATTITUDE product lists fragrance (Parfum) in its own 13. Neither is a rule broken, since that guidance is written for locally produced healthcare handrubs rather than for retail. It is the trade-off, printed, where you can find it.