Methanol in hand sanitisers
Following the USA FDA’s warning on methanol in hand sanitisers from Mexico, which has been publicised widely recently, on Friday 26th June, a member of the Chemical Regulations Self Help Group approached me about a (very cheap) alcohol based hand sanitiser which they were considering buying to decant and use on their chemical facility, on plant, in the warehouse, and in the offices.
However, section 3.2 of the SDS stated:
- Ethanol, >50%, ≤100%
- Glycerol, >1%, ≤ 2.5%
- Methanol, > 1% ≤ 2.5%
They said: “Not enough Methanol to trigger classification of the product, but its still there. Should we use it??”
This request rang alarm bells with me too, because when something toxic is present at sub-CLP classification levels, that does not automatically mean that it is safe to use, particularly when you consider the unusual case of hand sanitisers:
- this is the deliberate application of chemicals to the skin, which are likely to be absorbed into the body
- they are being used every day by people in industry, professional users and the general public
- the use has gone on for months, and is likely to go on for months more
I checked the guidance for people making hand sanitisers from the HSE is here https://www.hse.gov.uk/coronavirus/assets/docs/hand-sanitiser-manufacture-supply-coronavirus.pdf .
It does say “In making commercial decisions, manufacturers need to be mindful of maintaining high levels of safety and efficacy of the products they make available to the public and others” and “If you are supplying biocidal hand sanitiser products you must comply with general product safety regulations” .
However, there is no specific guidance on impurities such as methanol in hand sanitisers that I can find in the UK.
My next thought was that as this is for business use, we should carry out a COSHH assessment (Control of Substances Hazardous to Health, for our non-UK readers). The HSE provide a lot of information on this via COSHH essentials, and even have an online chemical risk assessment called the COSHH e-tool, but this does not appear to cover the deliberate application of chemicals to the skin.
What about Europe? I looked at the DNELs, the Derived No Effect Levels which are held in the REACH dossier for Methanol: https://echa.europa.eu/registration-dossier/-/registered-dossier/15569/7/1. There is also a European Occupational Exposure limit for methanol, which you can find below the Infocard for Methanol here: https://echa.europa.eu/substance-information/-/substanceinfo/100.000.599 .
The summary EU figures are:
- Long term OEL (8 hour exposure), 260 mg/m3/ 200 ppm methanol
- systemic worker DNEL 20 mg/kg bodyweight / day
- general population DNEL 4 mg/kg bodyweight / day
Obviously there are more detailed DNELs in the dossier, but methanol appears to be the type of substance where the route of exposure is relatively unimportant. (Presumably this is a reflection of short chain alcohols being absorbed through the skin, as they will dissolve fats).
I suggested that our Self Help Group member do a “quick and dirty” calculation on the amount of methanol which a worker might be exposed to, which we could then compare with either inhalation, skin absorption or even ingestion DNELs (unfortunately you have to consider ingestion because people occasionally drink hand sanitiser, e.g. if they are alcoholic, for a bet etc).
The “quick and dirty” calculation came back as follows:
Really quick calc…
assuming a 5ml or 5g squirt 20 times a day (not unreasonable at the moment)…
5g x 20 x 0.025 = 2.5g of methanol on the skin each day.
or 2.5g / 70 kg (me) = 36mg / kg bw / day
against a DNEL of 20 mg /kg bw / day
or a general population DNEL of 4 mg/kg bw / day
So the percentage of methanol looked to be too high, even for workers. You could, of course make this assessment slightly more sophisticated by asking the supplier the exact percentage of methanol present, and using the lightest weight of staff member, and possibly consider limiting the number of times they can use sanitiser per day. But would that really be good enough?
The reason for considering a general population DNEL instead of a workers DNEL is in case you have particularly sensitive people on site, e.g. pregnant women, people with long term health conditions etc. Not to mention the fact that hand sanitiser is the sort of thing which mysteriously finds its way into workers homes, where it could be used by anyone. (The Scots dialect word for pinching things from work is to “pauchle“, the ch is pronounced as in loch). So the general population DNEL is probably the most appropriate one to use.
The next step was to see if there was any more information available on the long term effects of methanol exposure, particularly via hand sanitiser use.
After all, we are in this unusual situation which we have not faced before, where many people are deliberately exposing themselves to the chemicals in hand sanitiser, and this is a classic situation where you can get previously unforseen problems aristing.
I discovered that the USA FDA have issued guidelines called “Policy for Temporary Compounding of Certain Alcohol-Based Hand Sanitizer Products During the Public Health Emergency Immediately in Effect Guidance for Industry” https://www.fda.gov/media/136118/download (“compounding” is the term used in the USA for “formulating” or making mixtures).
This provides a limit on the amount of methanol which is acceptable as being no more than 630 ppm (Table 1, page 12 of the document).
There is also a scientific paper from 2018 called “Methanol as an Unlisted Ingredient in Supposedly Alcohol-Based Hand Rub Can Pose Serious Health Risk”, which you can find here: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6069146/ .
As a check on the FDA’s 630 ppm threshold, I carried out another “quick and dirty” calculation on it, and it equates to 6.4 mg ethanol per day, which is well below the DNEL of 4mg/kg bw/day. (Even a newborn baby weighs more than 1.5 kg, unless they’re severely premature).
It will come as no surprise to learn that our Self Help Group member has decided not to use this particular hand sanitiser.
Why is methanol present?
We think that the methanol may be present if ethanol which has been denatured with methanol has been used in the hand sanitiser (“methylated spirits”).
It is important to denature ethanol to prevent people drinking it, but the FDA document gives guidance on other, safer denaturing compounds, including recommended concentrations, although these are in USA customary units rather than metric units.
(Note that USA customary units are are sometimes the same as the old UK Imperial units, but the pint and gallon measures are different because the USA uses the old “wine pint” of 16 fluid ounces, that is the same weight as 1 lb, whereas our Imperial pint is 20 fluid ounces from a change made in 1824. A useful nugget of information I picked up from an Elizabeth David cookery book, of all places!)
What we are doing about this problem
Our Self Help Group member has passed this information on to their potential supplier, as they are presumably unaware of the risks of long-term use of methanol.
This is so they can either work-off the methanol-containing product in new batches to ensure that it is reduced to a safe level (which we consider to be the FDA threshold or lower), or they can destroy the product. The company is reputable, and our member is sure that they will act responsibly as soon as they realise what is happening.
Obviously I have sent the FDA information, and the link to the paper, to the HSE Helpdesk first thing this morning, to flag up the fact that methanol is being used in hand sanitisers in the UK, so that they can do something to prevent people being harmed through long term exposure to methanol.
I do not blame the HSE for not picking up on this issue, as they are extremely busy dealing with the current immediate problems around Coronavirus, and this is a longer term issue which has not arisen previously in the UK.
As well as informing everyone about this, and potentially issuing a set of thresholds for impurities in hand sanitiser, I hope the HSE will consider carrying out spot checks to ensure that companies (especially those new to the market) are genuinely in compliance.
Which hand sanitisers are safe to use?
The very best and safest way to clean your hands is with soap and water, or surfactant (e.g. liquid soap) and water.
If you are in a situation where this is impractical, there are basically two types of hand sanitiser which are in use during the Coronavirus crisis:
- alcohol based (including the WHO formulations)
- other biocide based formulations
The difference between the two sets of biocidal hand sanitiser is that alcohol based products break down the fats in the virus’s wall (or in bacterial cell walls), and therefore work physically, which means you can’t get resistance developing.
The other type of biocide either works on removing the fats, or works to poison the virus or bacteria, which can lead to resistance developing in the “arms race” as I’ve described previously.
The HSE provide some guidance on choosing hand sanitisers at https://www.hse.gov.uk/coronavirus/hand-sanitiser/choosing-hand-sanitiser-surface-disinfectant.htm .
This involves checking to see whether a product has been registered under BPR, or whether the company holds an official derogation under BPR.
Unfortunately, there is no requirement to have a BPR derogation for ethanol based hand sanitisers.
I would suggest that if you are considering using a hand sanitiser, you obtain the Safety Data Sheet first, to see whether it comes under BPR, and if it does, whether the manufacturer holds a full licence or a derogation. There are links on how to do this from the HSE page above. (I hope to write about this issue soon).
If the hand sanitiser is alcohol based, check to see if methanol is mentioned as an ingredient, and if it is, whether it is above the FDA threshold of 630 ppm, or 0.063% w/w, which you may want to use in the absence of any official guidance from the HSE.
Obviously other hazardous imputiries may also be present. The FDA document contains lists of other impurities, as well as methanol, in Table 1 (page 12), with a threshold of 300 ppm for all impurities. In cases where this 300 ppm limit is breached, a further detailed list of impurities and thresholds is given in Table 2, page 13.
You may also want to check that the overall CLP classification of the product is correct, based on the percentage and classification of each component (don’t forget to check whether the components hold Specific Concentration Limits).
I hope this information is useful for you, and will keep you posted on developments around hand sanitiser formulations in the UK.
Update, 14th July 2020: the HSE Biocides Helpdesk has confirmed that ethanol based hand sanitisers in the UK (and EU) should use ethanol which meets British Pharmacopeia standards. This includes a limit of 200ppm for methanol.
Unfortunately, the HSE are unable to take enforcement action against any company making hand sanitiser containing unsafe levels of methanol, as ethanol is still going through the biocides approval process, and it is in a legal limbo.
However, anyone who is concerned about a hand sanitiser containing methanol should contact their local Trading Standards office, as they are able to act against unsafe products.
Wishing you, your family and colleagues good health.
30th June 2020, updated 14th July 2020.
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