September 30, 2021

European Chemicals Agency Proposes OELs for 1,4-Dioxane

A new scientific report (PDF) published by the European Chemicals Agency includes ECHA’s recommendations regarding occupational exposure limits for the solvent 1,4-dioxane. The agency recommends an OEL of 6 ppm (22 mg/m3) as an eight-hour time-weighted average and a short-term exposure limit of 20 ppm (73 mg/m3). The recommended STEL matches the current indicative OEL value for 1,4-dioxane at the European Union level. The European Agency for Safety and Health at Work describes indicative OEL values as “health-based, non-binding values, derived from the most recent scientific data available and taking into account the availability of reliable measurement techniques.”

“1,4-dioxane has in humans been reported to cause irritation of the nose, eyes, and throat at high concentrations,” ECHA’s report explains. “As local irritation effects of the nose may in the worst case be followed by inflammation, nasal hyperplasia, and formation [of] nasal tumors, limiting the short-term exposure is considered relevant.”

ECHA is also recommending a biological limit value, or BLV, using 2-hydroxyethoxyacetic acid in urine as a biomarker. The agency’s proposed BLV for 1,4-dioxane is 120 mg 2-hydroxyethoxyacetic acid/g creatinine in urine. And because “1,4-dioxane may be absorbed via the skin in significant amounts,” ECHA recommends a skin notation for the chemical.

The agency will accept public comments on its OEL proposal until Nov. 26. More information on submitting comments can be found on ECHA’s website. An “infocard” on 1,4-dioxane is also available.

Related: In July, ECHA announced the addition of 1,4-dioxane to its Candidate List of substances of very high concern for authorization. According to the agency, 1,4-dioxane was added to the list because of its carcinogenicity as well as concerns related to its “probable serious effects” to human health and the environment.