Although they have similar-sounding names, polyethylene glycol and ethylene glycol are very different compounds. In controlled amounts, polyethylene glycol can be ingested. Ethylene glycol, by contrast, is very toxic. Polyethylene glycol is often found in medicines such as laxatives. Ethylene glycol is best known for its use in antifreeze and deicer solutions.
Polyethylene Glycol Characteristics
Polyethylene glycol is a polyether compound, meaning that it consists of multiple ether groups. Depending on its molecular weight, polyethylene glycol may have different appearances. Below a molecular weight of 700, it is an opaque liquid. At molecular weights between 700 and 900, polyethylene glycol is a semisolid. Over a molecular weight of 900, it can be a white waxy solid, flakes or a powder. Polyethylene glycol is used in a large range of chemical, biological, commercial, industrial, and medical applications.
Polyethylene Glycol Uses
The most common medical use of polyethylene glycol is as a laxative. Over-the-counter polyethylene glycol is typically known as MiraLAX. A more intense version of the same application is also used to create solutions for colonoscopy and barium-enema preparations. When combined with electrolytes to prevent dehydration, polyethylene glycol causes a watery diarrhea that clears out the colon, allowing doctors to get a clear view of the organ.
Ethylene Glycol Characteristics
Ethylene glycol is a toxic organic compound. At room temperature, it is in a liquid state. It is odorless and colorless and has a sweet taste. Even small amounts of this compound can be harmful. Ingestion of just 4 fluid ounces can be enough to kill a grown man. Ingesting this compound can lead to shock or even death.
Ethylene Glycol Uses
Ethylene glycol is found in many common household items, such as laundry and dishwasher detergents, cosmetics and paints. Ethylene glycol is also used as an antifreeze and a hydraulic brake-fluid additive in automobiles. In addition, it's used as a deicing agent for runways and planes. The use of this compound as a deicer and antifreeze agent leads to concerns of environmental contamination because of improper disposal and incidental runoff.