Harmonised classification of ethanol

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Your very good health?

Alcoholic drinks are not subject to classification and labelling under the CLP Regulation. But considering the harms caused and the potential for the classification of ethanol, we may see a time when booze is properly labelled with health warnings, as happened with cigarettes.

Overconsumption of alcohol causes liver disease. During pregnancy it can cause birth defects.

If alcohol is known to cause such effects, should it be properly classified for them? Should labelling of alcoholic products, such as hand-sanitiser gels, not alert users to these effects? This may happen in the coming years.

The Greek authorities have submitted a proposal for harmonised classification of alcohol (chemical name ethanol) in the EU, that would mandate the warnings: ‘Suspected of damaging the unborn child’, ‘may cause harm to breast-fed children’, and ‘may cause damage to organs through prolonged or repeated exposure’.

Are these hazard statements justified? What would be the consequences of this harmonised classification? Will alcohol-based hand gel need such warnings?

In this article, Mel Cooke of Alchemy Compliance looks at the proposed harmonised classification for alcohol and the case for labelling products with warnings for these effects.

The chemical classification system is crude, and it may be wise to make an exception for the classification of ethanol, rather than make a dogmatic classification that undermines the seriousness of warning symbols and text for other chemicals.

Check out our handy glossary of definitions and abbreviations of technical terms used in this article.

Is alcohol toxic to reproduction?

Drinking alcohol during pregnancy risk exposing the developing baby to alcohol, with potential to cause harm. Severe cases result in impaired development of the foetus, called foetal alcohol syndrome.

The effects on development can persist during the lifetime of the offspring, and include distinctive facial features, learning difficulties, and adverse effects on organs.

There is no doubt that alcohol can cause reproductive toxicity.

Alcohol consumed during breastfeeding period can find its way into breast milk, although the amount a baby takes in through breastmilk is very small. Estimates range from 2 to 5% of the alcohol consumed by the mother.

Alcohol can induce a temporary decrease in milk production in the mother, and adversely effect the child’s sleep.

Alcohol and liver damage

Alcohol-related liver disease (ARLD) is caused by excessive alcohol intake. It often does not cause symptoms until the liver has been severely damaged. Symptoms can include: weight loss, jaundice, swelling, and internal bleeding.

This effect is an example of specific target organ toxicity, repeated exposure (STOT-RE), as defined in the CLP Regulation (1272/2008).

Proposed classification and labelling of ethanol

The UK has promised to take into account any EU harmonised classifications in its own list of mandatory classification and labelling (GB MCL) list, but could decide to ignore this proposal.

UK and EU chemical regulation is designed to protect workers and the public from the harmful effects of chemicals.

Firstly, chemical products undergo hazard classification, based on a comprehensive search for information on their hazardous properties. Secondly, the classification is converted to product labelling and safety data sheets (SDSs) to communicate to the users the hazards posed by the product.

Ethanol has a current harmonised classification of Flam Liq 2 (highly flammable liquid and vapour). Industry has supplemented this with Eye Irrit 2 (causes serious eye irritation).

The current proposal [1] by the Greek authorities is for a harmonised classification of: Flam Liq 2, H225; Eye Irrit 2, H319; Repr 2, H361d; Lact, H362; STOT SE 3, H336; STOT RE 2, H373.

The proposal includes new mandatory classification for ethanol for reproductive effects, effects on or via lactation, and specific target organ toxicity (ie targeted damage to the liver).

Classification for reproductive effects

The Greek proposal is interesting in recommending a classification as Toxic to Reproduction, Category 2 (abbreviated as Repr 2), H361d (suspected of damaging the unborn child), rather than Category 1.

Category 2 classification is indicated where there is evidence from humans or experimental animals of an adverse effect on development, and the following criteria are met:

  • The evidence is not sufficiently convincing to place the substance in Category 1.
  • The developmental effects are not considered to be a secondary, non-specific consequence of the other toxic effects.

Substances are classified in Category 1 when they are known to produce an adverse effect on development in humans. The evidence from human experience, as outlined above, suggests that that Category 1 is appropriate.

Classification for lactation effects

This classification is appropriate for substances which can be absorbed by the mother, and have been shown to interfere with lactation, or which may be present in breast milk in amounts sufficient to cause concern for the health of a breastfed child.

This classification can be assigned after assessment of the following:

  • Human evidence indicating a hazard to babies during the lactation period.
  • Studies in animals which show an adverse effect in the offspring, either due to transfer of the substance in milk, or due to a reduction in the quality of the milk.
  • Absorption, metabolism, distribution and excretion (ADME) studies indicating that the substance may be present in harmful levels in breast milk.

The human evidence for the effect of alcohol consumption of breast-feeding babies indicates this classification is justified.

Specific target organ toxicity, repeated exposure (STOT RE)

The STOT RE hazard class applies to substances causing specific toxic effects on target organs (eg liver or kidneys) occurring after repeated exposure. The repeated, lower dosing is more relevant to workplace or environmental exposures than the single, high dose used for acute toxicity or single-exposure assessment.

The criteria for STOT RE include health effects in humans, such as the function or appearance of an organ, and which are relevant for human health. Additionally, the doses at which the adverse effect occur should be considered.

For classification as STOT-RE, Category 2, the CLP Regulation gives a guidance dose for a 90-day repeated-dose study in the rat of 10 to 100 mg/kg, giving a crude estimate of the dose for a 70 kg human, taking into account species differences and lifetime exposure, of 140 to 1400 grams alcohol/day, say 0.5 to 5 bottles of spirits per day.

Based on the human evidence for the effect of alcohol consumption on the liver, this classification is justified.

Classification and routes of exposure

Classification of substances is traditionally regarded as purely hazard based.

This means that other factors, such as the likelihood of the effect, the lack of exposure, or the route of exposure are not taken into account during assessment of the classification.

However, some hazard classes, particularly carcinogenicity and STOT-RE, allow the inclusion of specific routes of exposure to be specified, if effects via other routes can be ruled out, eg for titanium dioxide [carcinogenicity, Category 2 (by inhalation) (Carc 2, H351i)] where the effects on the lung are caused only through inhalation.

Although regular heavy boozing may cause serious health effects, other products containing alcohol, such as hand sanitisers, are unlikely to be regularly ingested.

Studies suggest that skin absorption of alcohol through using hand sanitiser gels is not significant, but some effects are possible via inhalation [2]. It is therefore unlikely that the classification can be modified to specify that the hazards only occur via ingestion.

The International Agency for Research on Cancer (IARC) designate ‘alcoholic beverages’ as ‘carcinogenic to humans’, and this has been adopted in the label declaration requirements in California’s Proposition 65. It is interesting that the effect is ascribed to beverages, rather than the ethanol, in an attempt to distinguish from other alcohol-based products, and to stress that the oral route is considered the only source of harm.

Consequences of classification

Labelling of ethanol-based products

Generally, ethanol and mixtures containing it as an ingredient would require classification and labelling for specific hazards at the following concentration thresholds:

  • 0.3 wt% for effects via lactation (may cause harm to breast-fed children).
  • 3 wt% for Repr 2 (suspected of damaging the unborn child).
  • 10% for STOT RE 2 (may cause damage to organs through prolonged or repeated exposure).

These are the generic concentration limits given for the hazard classes in the CLP regulation. The EU authorities can choose to give specific concentration limits if supported by the safety assessment.

A label showing pictograms, signal word, hazard statements and precautionary statements for a mixture with the proposed classification for ethanol is given below. See here for the Guide to Labelling of Chemical Products.

Label elements for a typical ethanol-based mixture with the proposed classification

Bringing the classification system into disrepute?

The move to classify ethanol for reproductive toxicity, lactation effects, and STOT-RE may bring the hazard classification system into disrepute.

As indicated above, the criteria given in the CLP Regulation gives good grounds for classifying ethanol for these effects.

However, people understand alcohol, and are comfortable with the risks it poses. Requiring scary pictograms and hazard warnings on products such as hand gel, which people regard as safe, risks trivialising the warnings on more hazardous products used in the workplace or home.

The difficultly with the classification is that ethanol is a unique substance in that is consumed in relatively large quantities by many people over a long period.

There are clearly serious consequences of this for individuals and society, but the deliberate consumption of ethanol is fundamentally different from incidental exposures to other chemical substances in the home, workplace, or through their environment.

The chemical classification system is crude, and it may be wise to make an exception for the classification of ethanol, rather than make a dogmatic classification that undermines the seriousness of warning symbols and text for other chemicals.

Others may disagree. The CHRIP/NITE classification recommendations [3] issued by the Japanese authorities, and influential in Asia, includes the following hazard categories for ethanol:

  • Carcinogenicity, Category 1A (may cause cancer).
  • Reproductive toxicity, Category 1A (may damage fertility or the unborn child)
  • Specific target organ toxicity, repeated exposure, Category 1 (liver), Category 2 (central nervous system).

These hazard categories reflect the impartial application of GHS and CLP classification criteria to the health data for ethanol.

In this context, the Greek proposal may already be seen as a compromise, reducing the severity of the classification for pragmatic purposes.

Regulatory consequences of the proposed classification

Ethanol has a multitude of uses, as a common solvent used in labs, coatings and fragrance products.

Hand sanitisers containing 70% alcohol are universal owing to the Covid pandemic. These are an example of biocidal products, ie those controlling harmful organisms, which cannot be authorised if they contain a reproductive toxicant. This would require a legal fix.

Cosmetic products, particularly perfumes, frequently contain ethanol. Although finished cosmetics destined for the consumer are not subject to classification under the CLP Regulation, bulk or occupational use (eg in a salon) would require the labelling as above.

Many fragrances and essential oils are supplied as alcohol solutions and would require extra labelling.

Classification of ethanol for developmental effects and effects on or via lactation would require employers would need to revise workplace assessment (COSHH assessment in the UK), particularly regarding pregnant or breastfeeding workers. Employers are obligated to prevent the exposure of these workers to any agents that may have adverse health effects on either mother or child.

Alcoholic drinks are not subject to classification and labelling under the CLP Regulation. But considering the harms caused and the potential for the classification of ethanol, we may see a time when booze is properly labelled with health warnings, as happened with cigarettes.

Conclusions

The classification of ethanol has long been debated. There are clear grounds for classification for reproductive and STOT RE effects, based on the criteria given in the GHS and CLP Regulation.

So far, the EU has shied away from such classification, because the widespread implications for the labelling of many products, and the perceived devaluation of hazard warnings that might ensue.

The current proposal might be more sympathetically received by the EU Risk Assessment Committee this time around, in line with recent controversial harmonised classifications. Certain forms of titanium dioxide, widely used in consumer products such as cosmetics and paints, was recently classified for carcinogenicity.

The UK has promised to take into account any EU harmonised classifications in its own list of mandatory classification and labelling (GB MCL) list, but could decide to ignore this proposal.

References

[back to Proposed classification] [back to classification system into disrepute] [back to Routes of exposure]

[1] Registry of CLH intentions until outcome; ethanol; European Chemicals Agency website.

[2] Is Alcohol in Hand Sanitizers Absorbed Through the Skin or Lungs? Implications for Disulfiram Treatment; Colin Brewer and Emmanuel Streel; Alcohol Alcohol; 55(4): 354–356; June 2020.

[3] Chemical Risk Information Platform (CHRIP); National Institute of Technology and Evaluation (NITE); website.