Chloroethane, also called ethyl chloride, is a colorless gas used primarily as a topical pain-relieving spray in medicine and as a chemical building block in industrial manufacturing. It boils at just 12.3°C (about 54°F), meaning it evaporates almost instantly on contact with skin, which is the property that makes it medically useful.
How It Works as a Pain Relief Spray
The most common use of chloroethane today is as a spray-on anesthetic. When sprayed onto skin, it evaporates so quickly that it drops the surface temperature enough to temporarily numb the area. This effect, called cryoanalgesia, lasts only seconds to minutes, but that’s long enough to be useful in several settings.
Sports medicine is one of the biggest areas where you’ll encounter it. Athletic trainers spray it directly onto sore muscles during games or practices to relieve spasms and allow athletes to keep moving. It’s also used in clinics and emergency rooms to numb skin before minor procedures like draining small abscesses, starting IVs, or removing splinters. Outside of traditional medicine, tattoo and piercing shops sometimes use it to reduce the sting of needles. You can buy ethyl chloride spray over the counter, and it’s widely available online.
Industrial and Chemical Applications
Beyond medicine, chloroethane serves as a solvent and refrigerant in chemical manufacturing. Its extremely low boiling point makes it effective for processes that require rapid cooling. It also functions as a starting ingredient or intermediate compound in the synthesis of other chemicals, including certain types of dyes, pharmaceuticals, and specialty materials.
Historically, the single largest use of chloroethane was in producing tetraethyl lead, the additive that made leaded gasoline work. According to the Government of Canada, industrial production of chloroethane dropped drastically once leaded gasoline was phased out worldwide. That shift fundamentally changed the scale at which this chemical is manufactured, and today’s production is a fraction of what it once was.
Safety and Flammability
Chloroethane is classified as an extremely flammable gas. It earns the highest fire rating on the NFPA hazard diamond (a score of 4 out of 4), meaning it vaporizes rapidly at normal temperatures and ignites easily. The U.S. Department of Transportation classifies it as a Division 2.1 flammable gas for shipping purposes. In medical and industrial settings, it needs to be kept away from open flames, sparks, and heat sources.
Health Risks From Overexposure
Brief skin contact with chloroethane spray, as intended for pain relief, is generally safe. The risks increase significantly with inhalation, especially deliberate inhalation. Breathing in small amounts can produce a feeling of intoxication, which is one reason it has become a substance of abuse. At higher concentrations, the effects escalate quickly: dizziness, slurred speech, delayed reactions, tremors, hallucinations, and unconsciousness. In severe cases, inhaling chloroethane can cause death.
Other symptoms of overexposure include stomach cramps, nausea, vomiting, and eye irritation. Animal studies have found that chloroethane exposure during pregnancy delayed skull bone development in baby mice, and breathing large amounts affected the reproductive systems of female mice and dogs. The CDC’s Agency for Toxic Substances and Disease Registry flags intentional inhalation as particularly dangerous because the line between intoxication and life-threatening overdose is thin.
Recreational misuse has been called a rising trend. Because ethyl chloride spray is sold over the counter as a muscle treatment, it’s easy to obtain, and some people inhale it for its intoxicating effects. This carries all the risks of other inhalant abuse, including sudden cardiac events.
Environmental Breakdown
Chloroethane released into the air breaks down relatively quickly compared to many industrial chemicals. It reacts with naturally occurring molecules in the lower atmosphere and has a half-life of about 40 days, meaning half of any given release degrades within that window. Because it breaks down before reaching the upper atmosphere, less than 1% of released chloroethane ever makes it to the ozone layer. It poses minimal risk to the ozone compared to longer-lived chlorinated compounds like CFCs.