Assessing the Risks of Ethanol

Ethyl alcohol, or ethanol, is found in many consumer products (household cleaning products, cleaning products, window cleaning solutions, liquid detergents, hygiene products, cosmetics, disinfectants, inks, paints and varnishes, flavourings, methylated spirits, deicing sprays, etc.). It is used in many applications as:

• a fuel (the French government officially launched E85 in late 2006, a blend of 85% ethanol and 15% petrol, as biofuel, available in hundreds of service stations since the end of 2007);
• a solvent (for extraction processes in laboratories and the manufacturing of paints, varnishes, inks, plastics, adhesives, explosives, perfumes, cosmetics, pharmaceuticals, etc.). Ethanol dissolves fats and many plastics particularly well;
• a disinfectant;
• a raw material for chemical synthesis (production of acetic acid, ethyl acrylate, ethyl acetate, glycol ethers, ethylamine, ethylene, ether oxides).

Ethanol’s Effects on Health

The effects of ethanol on health are observed in those who consume excessive alcoholic beverages: nausea, vomiting, dizziness, even respiratory paralysis. Apart from the symptoms of intoxication observed in the short term, excessive and regular alcohol consumption has proved hazardous to health in the medium and long term.

In fact, toxicologists and epidemiologists have acquired good knowledge of the effects and mechanisms of ethanol ingestion. Liver cirrhosis, cancers, nervous system disorders, and foetal alcohol syndrome are the most serious pathologies caused by excessive consumption of alcoholic beverages (INSERM, 2001).

It has also been recognised that inhalation of or skin contact with ethanol vapours can be a source of localised irritation.

For these reasons, the Agency has studied the risks resulting from inhalation of ethanol vapour and/or from skin contact for the general population as well as in the workplace.

The Agency’s work

The goal of the Agency’s work is to determine whether people who are exposed to ethanol, by skin contact and/or inhalation, at low concentrations at work or at home, have increased health risks (reproductive toxicity, neurotoxicity, etc.).

Therefore, for both the working population and the general population, this involves:

• assessing health risks;
• considering, if necessary, appropriate risk reduction measures;
• identifying possible substitutes for ethanol.

This work was carried out by the Agency’s Expert Committee on Assessment of the Risks Related to Chemical Substances, and a specific working group was formed that brought together ten expert toxicologists, doctors and chemists.

To accomplish this expert appraisal, three complementary projects were conducted:

• a summary of the health effects of ethanol, at low doses, both by inhalation and skin contact, was drawn up;
• to examine the situations of exposure to ethanol for working and general populations, the Agency collected information on ethanol supply chains, occupational activities using ethanol, and consumer products containing ethanol;
• to determine exposure levels in both populations, the values of occupational exposure to ethanol were collected from the scientific literature by identifying exposure levels observed in companies and by retrieving data contained in the COLCHIC database. Exposure of the general population was estimated by the working group on the basis of knowledge about the products and their methods of use, and from likely exposure scenarios. The risk assessment for ethanol in cosmetics was conducted by AFSSAPS and taken into account in the Agency’s studies. Acute exposure related to the application of a DIY product rich in ethanol (such as shellac or ‘French polish’) was also estimated, although its use by the general population is not common. Chronic exposure to ethanol was estimated from data of atmospheric concentrations measured in indoor and outdoor environments in Canada, due to the lack of French data. On this basis, the risk assessment was conducted by comparing measured or estimated exposure levels that could lead to potential health effects.

Finally, measures to reduce risks, including the possibility of ethanol substitutes, were compiled into a collection of best practices and experiences for workers.

Conclusions

Risk Assessment in the Workplace

Beyond alcoholic beverages, ethanol is found in many professional products: paints, varnishes and inks, alcohol-based products, and biofuels. More than 650,000 workers are potentially exposed to ethanol through skin contact and/or inhalation.

The toxic effects of ethanol (as a carcinogen, or on reproduction) associated with the consumption of alcoholic beverages are well known. The ethanol contained in alcoholic beverages is listed as carcinogenic to humans (Group 1) by the International Agency for Research on Cancer (IARC). Unlike ingestion, occupational inhalation does not lead to a significant increase in the concentration of ethanol in the blood, which is responsible for most of the toxic effects.

Atmospheric concentrations of ethanol in the workplace are generally well below (6 to 20 times) the French occupational exposure limit over an eight hour period (1900 mg.m-3 currently in force). However, concentrations over that limit can be observed in certain jobs, particularly in industrial distillation and winemaking. For information, the concentrations of ethanol in the blood (ethanolaemia) resulting from the inhalation of ethanol in a working environment are generally much lower (50 to 250 times) than the threshold set by the French legal driving limit (0.5 g.L-1).

Symptoms of intoxication associated with acute occupational exposures to high concentrations of ethanol vapour cannot be excluded.

The results of the expert appraisal did not find any evidence of chronic health risks specifically related to occupational exposure by inhalation or skin contact. In fact, the values estimated for ethanolaemia in occupational environments with the greatest exposure are indistinguishable from basal ethanolaemia (amount naturally present in the body without any ingestion of ethanol).

Risk Assessment for the General Population

Among the most common activities with the greatest exposure in the short term, experts first identified the use of alcohol-based products and cosmetics. These uses lead to maximum exposure values estimated at 758 and 230 mg.m-3, respectively.

The use of household cleaning products, an ethanol fireplace or filling a car tank with biofuel resulted in lower exposures to ethanol.

The combination of all these exposures could result in a maximum ethanol level of nearly 0.9 mg.L-1 (approximately 50 times less than the threshold set by the French Highway Code).

Among the scenarios studied, the application of shellac or French polish is the activity with the greatest exposure to ethanol. In fact, the maximum exposure concentrations modelled were between 1450 and 2500 mg.m-3. This exposure would result in an ethanolaemia of between 5 and 9 mg.L-1.
All the ethanolaemia values presented above are below those reported for the first known acute effects of ethanol (neurotoxic effects), observed between 100 and 200 mg.L-1.

Thus, no excessive risk can be demonstrated in the case of exposure to ethanol in the short term for the general population.

The levels of chronic ethanol exposure for the general population are estimated in indoor air between 0.05 and 0.1 mg.m-3, with a maximum of 2 mg.m-3. The ethanol concentrations in outdoor environments are ten times lower than inside homes.

The ethanol levels induced through chronic exposure to ethanol in indoor air are so low that no health risk (carcinogenic or developmental) is expected for the general population exposed to ethanol by inhalation.

Identifying Possible Substitutes

The possibilities for substituting ethanol in consumer products were indicated for cosmetics and cleaning products and disinfectants. The information collected in 2008 confirms that ethanol is primarily used as a substitute for other more hazardous chemicals. In the particular case of perfume components, the substitution of ethanol was considered but proved inconclusive for manufacturers.

Recommendations

In light of this assessment, ANSES recommends:

For Occupational Risk Prevention

• reinforcing the application of preventive measures based on the regulations for preventing chemical hazards applicable to ethanol;
• updating the classification of the dangers of ethanol in accordance with procedures currently in force;
• re-examining the occupational exposure limit values for ethanol in light of scientific knowledge acquired since 1982, with a view to providing better protection against potential acute toxic effects (irritation of the ocular and respiratory mucous membranes, headaches, fatigue, vertigo, etc.) which are also potential factors in occupational accidents;
• improving our knowledge of occupational exposure to ethanol, particularly by undertaking individual measurement campaigns among the producers of crude ethanol and in the winemaking industry.

For Risk Prevention among the General Population

Taking precautions when using any DIY product containing volatile substances, such as applying these products in a well-ventilated area and if necessary, wearing appropriate respiratory protection.

Improving Scientific Knowledge

• acquiring knowledge on the chronic effects of low doses of ethanol in order to have adequate data for establishing toxicity reference values (TRVs) by inhalation and to document the basal ethanolaemia in the French population;
• using experimental data on ethanolaemia resulting from inhalation exposure to refine the existing physiologically-based toxicokinetic model (an ongoing study funded by ANSES).