The word refrigerant typically refers to a liquid substance or mixture used in heat pumps or refrigeration cycles. Refrigerants are used in cars, air conditioners and home appliances and, most notably, refrigerators and freezers. Typically, the refrigerant, when used in a freezer, is converted from liquid to gas and then back again. These phase cycles allow it to cool the inside of the freezer, keeping the space at the desired temperature.
Dangers of Refrigerants
For human beings, the dangers of leaking refrigerants are numerous. Early refrigerants posed risks of toxicity if ingested and were also highly flammable. Exposure to leaked refrigerant gas can result in asphyxiation and death. Most of the early kinds of refrigerants were toxic and dangerous to human beings as well as being highly reactive. Chlorofluorocarbon (CFC) refrigerants were the first nonflammable refrigerants available. However, although these compounds posed a lower risk to human beings, the effects of CFCs on the environment was significant, particularly with regards to ozone depletion. By the time it was recognized that these chemicals had been eating away at the ozone layer, more than 50 years had passed. In an effort to mitigate the environmental damage done, scientists began to search for an ideal refrigerant.
Fluorocarbons, halons, chlorofluorocarbons and hydrochlorofluorocarbons were extremely popular refrigerants during the majority of the 20th century but are slowly being phased out due to the problematic effects they have on the environment and the threats to human beings as well. Scientists today have discovered better refrigerants that do not pose as much of a hazard.
Changes in Refrigerant
As CFCs and their ilk began to be phased out, scientists replaced these refrigerants with other chemical compounds like ammonia, propane and sulfur dioxide. While these do pose health risks to humans if ingested or inhaled for extended periods, they present significantly fewer environmental risks. As of 2010, a popular refrigerant known as Freon was discontinued, and a hydrofluorocarbon known as compound R-410A was introduced. This HFC is referred to by several brand names, including Puron, Suva or Genetron. This is the very first HFC that claims to be environmentally safe and doesn't contribute to ozone depletion. These compounds represent the future of refrigerant chemicals.
While scientists are still searching for what they believe could potentially be an ideal refrigerant, meaning one that has the desired thermodynamic properties, is easy to produce and poses zero human or environmental hazards, there's little hope for such a discovery.