It is estimated that up to 30,000 workers are exposed to 1,4-dioxane in the EU. Typical workplaces, where 1,4-dioxane is used, are in the rubber and chemical industry. It can also occur as a by-product in the cosmetics industry. Workers are mainly exposed through airborne contamination and by dermal contact, although oral exposure is possible as well. 1,4-dioxane is classified as category 1B carcinogen according to CLP legislation (Carc. 1B) and is suspected to contribute to carcinomas in the nose as well as tumors in the liver and kidneys. In addition, 1,4-dioxane causes severe eye irritation and may cause respiratory irritation; repeated exposure to the skin may cause dryness or cracking.

Where risk occur

Occupational exposure occurs during the production, processing, and use of 1,4-dioxane, via inhalation or dermal exposure. 1,4-Dioxan is often used as a solvent, in laboratories (e.g., mobile phase in chromatography) and at industrial sites in polymerisation processes. Cleaning and maintenance activities are also important to consider regarding exposure.

More about the substance

1,4-dioxane is a clear, colourless liquid, readily mixed with other solvents. Because of its inertness it is mainly used as solvent itself. It is highly flammable and may form explosive peroxides. 1,4-dioxane is an anthropogenic chemical that does not occur naturally in the environment. It is a known by-product of industrial ethoxylation processes and can thus bepresent as contaminant in cosmetics and personal care products, where its concentration is strictly regulated. 1,4-Dioxane has also been found as residue in articles of plastic and rubber (e.g., gloves, boots, clothing, rubber handles, gear lever, steering wheels).

1,4-dioxane is stable in water and does not break down. Compounds in the air can break down 1,4-dioxane into different compounds rapidly. There is contamination in the environment (groundwater) related to the disposal of chemical solvents containing 1,4-dioxane and from disposal of 1,4-dioxane itself.

How symptoms can affect you

1,4-Dioxane is rapidly and almost completely absorbed after inhalation and oral exposure. The absorption via skin is also relevant. After inhaling 1,4-dioxane, upper abdominal pain and vomiting, as well as irritation of the eyes and respiratory tract may occur. Other symptoms of 1,4-dioxane intoxication include liver and kidney damage, convulsions and coma. In this context, a simultaneous dermal absorption of the substance should be taken into account. Besides, repeated dermal exposure to 1,4-dioxane can lead to skin damage.
Additionally, in animal studies effects on the liver and kidneys as well as on the central nervous system like staggered gait, narcosis, paralysis and coma were observed. It should be noted, that the main target organs are the respiratory system, liver and kidneys after long-term exposure.

What you can do

Substitution should be considered in applications where feasible. If alternatives are not available or 1,4-dioxane might occur as by-product, perform proper exposure measurements periodically so it is known when and where actions should be taken. To avoid adverse health effects it is, therefore, of utmost importance to reduce exposure below the health-based limit value. In industrial processes, examples of technical control measures are enclosed systems, general exhaust and local exhaust ventilation. Even when working with closed systems, exposure can occur e. g. during sampling tasks. Measurements and control measures are of relevance there. Other recommended work practices include providing employees with hazard information and training, and general working hygiene standards for chemical handling areas. Workers in maintenance and cleaning should be trained as well. Investigate if workers report early symptoms. It is recommended to involve an occupational physician. Be aware that for 1,4-dioxane the exposure assessment can be supported with biomonitoring, if applicable under national legislation. Workers need to be aware of the effects of exposure. Personal protective equipment should only be used as a last resort, after introducing the possible engineering solutions.

Sources: BAuA, CLP, German MAK-commission, RAC