Glykolen

Glykolen, commonly known in English as glycol, refers to a class of organic compounds characterized by the presence of two hydroxyl (‑OH) groups on adjacent carbon atoms. The most widely recognized members are ethylene glycol (1,2‑ethanediol) and propylene glycol (1,2‑propane­diol), both of which are colorless, odorless liquids with high boiling points and hygroscopic properties. Glykolens molecular structure confers strong hydrogen‑bonding capability, making it an effective solvent and humectant.

In industrial and consumer applications, ethylene glycol is primarily employed as an antifreeze component in automotive cooling systems and as a heat‑transfer fluid in HVAC equipment. Its low freezing point and high heat capacity allow it to protect engines from freezing and overheating. Propylene glycol, considered less toxic, finds extensive use in food processing, cosmetics, and pharmaceuticals as a carrier, preservative, and moisture‑retaining agent. Both glycols serve as intermediates in the synthesis of polymers such as polyethylene terephthalate (PET) and polyurethanes.

Safety considerations vary between the two. Ethylene glycol is toxic if ingested, causing metabolic acidosis and renal failure; consequently, it is subject to strict handling regulations and often mixed with bittering agents to deter accidental consumption. Propylene glycol exhibits low acute toxicity and is generally recognized as safe (GRAS) for specified uses, though high concentrations can cause skin irritation.

Environmental impact is modest; glycols biodegrade readily under aerobic conditions, but large spills can affect aquatic life due to oxygen demand during degradation. Ongoing research aims to develop bio‑based glycol alternatives to reduce reliance on petroleum‑derived feedstocks.