Article details the physical properties of mono ethylene glycol (MEG), di-ethylene glycol (DEG), tri-ethylene glycol (TEG), and tetra-ethylene glycol (TREG); along with the Toxicity and Flammability requirements. 

TOXICITY

Glycols as a class are of a low order of toxicity (with the exception of oral toxicity). They do not vaporize readily at normal temperatures and, therefore, do not constitute a hazard from inhalation. They are also not active skin irritants.

FLAMMABILITY

Glycols will burn and should be handled as if they were hydrocarbons.

Glycol MEG DEG TEG TREG
Formula HOC2H4OH HO(C2H4O)2H  HO(C2H4O)3H  HO(C2H4O)4H 
Molecular mass 62.07 106.12  150.17  194.32 
Boiling point 101.3 kPa (°C) 197 245 287 327
Freezing point (°C) -13  -8 -7.2  -6.2 
Density 20 °C (kg/m3) 1113 1116  1123  1246 
Viscosity 20 °C (mPa.s) 20.9 35.7 47.9 60.0
Degradation temperature (°C) 163  162 206  226