Mono Ethylene Glycol (MEG) and Ethylene Glycol (EG) are the same chemical compound (CAS 107-21-1, C₂H₆O₂) with identical molecular structure and physical properties.
MEG and EG share the same molecular formula C₂H₆O₂ and the same CAS registry number 107-21-1, confirming they are the same substance in chemical classification systems used globally.
Both names refer to ethane-1,2-diol, which has fixed physical properties including a boiling point of 197.3°C, a melting point of -12.9°C, and a density of 1.113 g/cm³ at 20°C, with no measurable difference between MEG and EG.
The naming difference exists only for industrial classification: MEG is used in over 90% of glycol production output, mainly in polyester (PET) and antifreeze manufacturing, while EG is more commonly used in chemical databases, SDS documentation, and academic references.
MEG is part of the ethylene glycol family where MEG, DEG, and TEG represent one-, two-, and three-unit glycols respectively, and MEG is the primary commercial product due to its highest production volume in global petrochemical supply chains.