MEG - Mono Ethylene Glycol

About This Product

Mono ethylene glycol, MEG or ethane-1,2-diol (CAS 107-21-1, EC 203-473-3, formula C2H6O2), is the simplest diol and one of the largest-volume organic chemicals. It is made by hydrating ethylene oxide, or through the ethylene carbonate route, and is a clear, colourless, slightly viscous, hygroscopic liquid that boils at about 197 °C and is fully miscible with water. Diethylene and triethylene glycol are co-products, which is why DEG content is one of the defining specification limits. MEG is sold in two broad qualities. Fibre grade, also called polyester grade, is the high-purity material used to make polyethylene terephthalate (PET), and it carries tight limits on purity, diethylene glycol, water, acidity, iron, aldehydes and ultraviolet transmittance, because trace impurities cause yellowing, haze and poor spinning in polyester. Industrial or antifreeze grade has looser limits and suits heat-transfer fluids, antifreeze and chemical uses where polymer-grade purity is not needed. The largest use by far is polyester: MEG reacts with purified terephthalic acid to make PET for textile fibre, film and bottles. Its second major use is antifreeze and engine coolant, where a 50:50 mixture with water protects to roughly −37 °C, and heat-transfer fluids for chillers, solar and process systems. MEG is also used in aircraft de-icing fluids, in unsaturated polyester and alkyd resins, as a humectant and freezing-point depressant in inks and adhesives, and as a hydrate inhibitor in natural gas pipelines. The parameters buyers agree for fibre grade are purity (typically 99.9% minimum), DEG, water, acidity as acetic acid, colour on the Pt-Co scale before and after heating with acid, iron, ash, aldehydes and ultraviolet transmittance at 220, 275 and 350 nm. For industrial grade, purity, water, DEG and colour are usually enough. Agree the grade and limits in writing and check each certificate of analysis. MEG is classified under CLP as harmful if swallowed (H302) and may cause damage to the kidneys through prolonged or repeated oral exposure (H373). Its sweet taste makes accidental poisoning a real risk, so never decant it into drinking containers. It is not regulated as dangerous goods for road, sea or air transport, but check section 14 of the safety data sheet. It is a registered substance under EU REACH; an importer into the EU or Great Britain should ask which registration covers the import and use under REACH or UK REACH. MEG absorbs water from the air, so store it in closed stainless steel, aluminium or lined mild steel tanks with a dry nitrogen blanket for fibre grade, and keep drums sealed. Avoid contact with strong oxidisers and strong acids. It is combustible at high temperature, with a flash point around 111 °C. When you enquire, state fibre or industrial grade, the key limits (purity, DEG, water, ultraviolet transmittance), the pack format (drum, IBC, flexitank or ISO tank), your volumes, the destination and your Incoterms.