Triethylene glycol is a colorless, viscous liquid with a slight odor. It is non-flammable, mildly toxic, and considered non-hazardous. It is a member of a homologous series of dihydroxy alcohols.

The main uses for triethylene glycol are based upon its hygroscopic quality. This means that it can absorb moisture from the air through absorption or adsorption. It is used as a dehydrating agent for natural gas pipelines where it removes the water from the gas before being condensed. The triethylene glycol can then be continually reused, although the by-product of benzene needs to be disposed of carefully. This process is useful as it prevents the gas from freezing, making the gas easier to transport and manage for end consumers.

Triethylene glycol can also be used as a mild disinfectant. Due to its low toxicity, antimicrobial properties, and low odour, it is commonly used for air disinfection in occupied areas where more aggressive disinfectants cannot be used. Due to these disinfectant properties and the dehydrating properties, it is an ideal dehumidifying agent in air-conditioning units.