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1000
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Abstract/Summary
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The German Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area has re‐evaluated 4,4′‐methylenedimorpholine [5625‐90‐1], considering all toxicological endpoints. Available publications and unpublished study reports are described in detail. 4,4′‐Methylenedimorpholine is a formaldehyde releaser. The substance is corrosive to rabbit skin and induces local effects in the forestomach of rats after prolonged oral application. Therefore, the critical effect is presumably the local irritation in the respiration tract. Adequate data in humans and inhalation studies in animals to derive a maximum concentration at the work place (MAK value) is not available. Thus, the assignment of the substance to Section II b of the List of MAK and BAT Values is retained. A prenatal toxicity study in rabbits does not show any developmental toxicity up to the highest dose tested of 100 mg/kg body weight and day. 4,4′‐Methylenedimorpholine induces mutations in bacteria and is mutagenic and predominantly clastogenic to mammalian cells. The clastogenicity has, however, not been confirmed in vivo. Adequate carcinogenicity studies with 4,4′‐methylenedimorpholine are not available but the release of the local carcinogen formaldehyde has also to be taken into account for evaluating the carcinogenicity of 4,4′‐methylenedimorpholine. At work places where 4,4′‐methylenedimorpholine is used the mean air concentration of formaldehyde is about 2 µl/m3. As the difference between the MAK value of formaldehyde of 300 µl/m3 and the work place air concentration is sufficiently large, and the measured concentrations are in the range of the background levels, no classification into a Carcinogen Category is confirmed. Clinical data in humans reveal a skin sensitizing potential which is also due to the release of formaldehyde. The results of the animal experiments are negative but they are carried out at very low concentrations. 4,4′‐Methylenedimorpholine is designated with an “Sh” notation. Skin contact is not expected to contribute significantly to systemic toxicity.
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