Chloroform is no longer used in medicine but remains important in industrial chemistry and appears in trace amounts in treated drinking water.
Industrial production of refrigerants
Most chloroform produced today is used to make refrigerants. It reacts with hydrogen fluoride to create HCFC-22, a transitional refrigerant once widely used in air conditioning and refrigeration systems. Although the Montreal Protocol phased out ozone-depleting CFCs, HCFCs like HCFC-22 were adopted as temporary replacements. Chloroform is a key starting material in this process, even as newer, more environmentally friendly refrigerants gradually take over.
Manufacturing of fluoropolymers
Chloroform plays a supporting role in producing fluoropolymers such as polytetrafluoroethylene (PTFE), commonly known as Teflon. It acts as a solvent or intermediate in certain chemical processes used to make these materials. Because fluoropolymers are used in non-stick coatings, aerospace components, and medical devices like catheters, chloroform indirectly supports high-tech industries.
Use in chemical research
In laboratories, deuterated chloroform (CDCl₃) is a standard solvent for nuclear magnetic resonance (NMR) spectroscopy. Its ability to dissolve many organic compounds and produce a simple, predictable signal makes it ideal for analyzing molecular structure. Due to its toxicity, it is handled under fume hoods with strict safety protocols, and its use is limited to controlled research environments.
Presence in drinking water
Chloroform is not added to consumer products but can form as a byproduct when chlorine disinfects water. It is one of several trihalomethanes (THMs) created when chlorine reacts with organic matter such as decaying leaves. The U.S. Environmental Protection Agency (EPA) limits chloroform in drinking water to 80 micrograms per liter. Most municipal water supplies stay below this level, and the health risk from these small amounts is considered low compared to the danger of untreated water.
Why it’s no longer used in medicine
Chloroform was once used as an anesthetic in the 1800s but was phased out by the early 20th century due to safety concerns. It can cause fatal heart rhythms and liver damage, with little margin between effective and dangerous doses. Modern anesthetics like propofol and sevoflurane are much safer and more predictable. No reputable hospital uses chloroform for anesthesia today.