Classification of glycol ethers
The now obsolete European directives on classification and labelling were adapted into national laws of the EU member states but these are now in a process of transition to the new direct acting CLP regulation. Both the old directives and the new regulation have specified criteria for classifying the hazardous nature or otherwise of chemical substances and mixtures. As for all chemicals, all glycol ethers have been assessed against these criteria using all of the available data, including the results of research work carried out by the producers of these substances. Some key point of note are:
- For glycol ethers derived from ethylene oxide (the E series), 5 glycol ethers are classified “Toxic for reproduction” category 2 (category 1B under CLP) and are labelled with the following phrases: “May impair fertility” and “May cause harm to the unborn child”. Only 3 of them are produced commercially in the EU: ethylene glycol methyl ether (EGME), ethylene glycol dimethyl ether (EGDME) and diethylene glycol dimethyl ether (DEGDME). These classifications were derived using the results from experimental work carried out on animals in much higher concentrations than the exposure limits allowed in the work place.
- For glycol ethers derived from propylene oxide (the P series), none have shown any effects on reproduction in experimental studies, with the exception of 1-propylene glycol 2-methyl ether (1PG2ME) and its acetate (1PG2MEA). Neither of these two substances is available commercially as the pure substance. Both are classified as “Toxic for reproduction” category 2 (category 1B under CLP).
- One glycol ether is classified as “Toxic for reproduction” category 3 (category 2 under CLP). This substance is diethylene glycol methyl ether (DEGME). There is only limited evidence of reproductive effects in experimental studies and these effects are only seen at very high doses.
- Some 14 other glycol ethers are classified in the categories “Harmful” or “Irritant”. A few glycol ethers are classified as flammable. The remaining glycol ethers are not classified as hazardous.
- No glycol ethers are classified as category 1 “Toxic for reproduction” (category 1A under CLP), because no reliable evidence exists that demonstrates adverse effects on reproduction in humans.
- No glycol ether is classified as carcinogenic.