Chloroethane

Chloroethane (also known as ethyl chloride, or spray poppers, and under various trade names such as Maximum Impact® and Black Max®) is a volatile organic solvent which produces rapid-onset intoxication when its vapors are inhaled. It is toxic and lethal in high concentrations. Recreational use is extremely dangerous due to the essentially unmitigable risk of sudden death.

Chloroethane

Other names	Ethyl chloride, spray poppers
Health risk	Critical
Addiction risk	Moderate
Legal risk	Moderate
External links	PsychonautWiki Erowid

Background

Medical uses

Chloroethane was previously used as an inhalational anesthetic to produce general anesthesia. However, its flammability, toxicity, and pharmacokinetics have led to it being replaced by more modern agents such as sevoflurane. It is still sometimes used as a local anesthetic due to the chilling effect produced by topical evaporation.

Mechanism of action

Chloroethane is thought to produce intoxication primarily through GABA receptor agonism, similar to other volatile anesthetics.

Physical properties

Chloroethane is a volatile organic compound which boils at room temperature. When sprayed from a pressurized bottle in liquid form, it rapidly converts to a gas producing a very high concentration of chloroethane near where it was sprayed.

Appeal

Chloroethane is capable of producing a sensation similar to alcohol intoxication which can become extremely powerful and result in the rapid loss of consciousness.

Dosing

The effects of chloroethane primarily depend on the concentration of gas being inhaled and the duration of exposure. If used repeatedly, chloroethane will accumulate in the body until the concentration being inhaled reaches equilibrium with the concentration in the body. The concentration in the body represents the "dose" of the drug, and produces the following effects:

• <1%: Usually no symptoms
• 3-5%: Symptoms similar to alcohol intoxication
• 6-8%: Amnesia, partial or complete loss of consciousness, shallow breathing, myocardial depression
• 9-12%: Apnea (cessation of breathing), complete unresponsiveness, involuntary activation of reflexes (laryngospasm, bronchospasm, gagging), vomiting (which can cause aspiration of stomach contents into the lungs)
• >12%: Cardiac arrest and rapid death

Chloroethane is administered recreationally through an aerosol spray, often onto a cloth or into a bag for huffing. The sprays can discharge >3 mL/sec of chloroethane liquid which will rapidly evaporate, creating high concentrations of the gas. With doses as little as 3 mL being able to make someone unconscious when sprayed on a cloth, or less in a closed system like a bag. This results in an extremely small margin for a recreational dose compared to an amount which will make someone unconscious or cause sudden death.

Risks

Chloroethane, along with other volatile anesthetics, is extremely dangerous to use recreationally and presents an example of essentially unmitigable risk due to the inability to reliably monitor or control the concentration of gas that is being inhaled. When chloroethane is sprayed into the environment, it immediately boils into a gas. This causes extremely high concentrations of gaseous chloroethane far beyond potentially fatal levels, especially if the liquid is sprayed into a material which will capture the gas and slow the boiling process (e.g. into a rag).

Cardiac arrest

The difference in dose of chloroethane between the desired recreational effects and cardiac arrest is very small (<10% difference in the concentration of gas). Because chloroethane boils into a gas at room temperature, it is possible to produce extremely high concentrations of gas (>50%) if it is inhaled from a confined space such as a rag. Furthermore, it is practically impossible to accurately monitor and control the concentration of chloroethane being inhaled. These characteristics mean that cardiac arrest can rapidly occur without warning during any use.

Airway reflex activation

One major risk of chloroethane is the involuntary activation of airway reflexes, including laryngospasm (closure of the vocal cords), or bronchospasm (closure of the lower airways), resulting in partial or complete blockage of airflow to and from the lungs. Normally, these reflexes are protective and are triggered to prevent liquids or solids from entering the lungs. However, when unconsciousness is caused by an anesthetic agent, these reflexes can activate inappropriately even when no triggering stimulation was present, and may not relax once activated.

If laryngospasm occurs, it can sometimes be treated with Larson's maneuver (using fingers to apply firm inward pressure to the soft tissue directly underneath the ear lobe on both sides of the head). If a bag-valve-mask is present, positive pressure with a high inspiratory pressure may also resolve the episode. However, some cases of laryngospasm will not resolve until death occurs and can only be managed by trained experts with access to specialized medications and equipment.

Aspiration

Chloroethane may cause uncontrollable retching and vomiting which can lead to aspiration of the stomach contents into the lungs. Aspiration is especially likely if the individual is unconscious or physically positioned such that they are unable to clear vomit from their mouth.

If aspiration occurs and the airway is not immediately cleared, death by drowning will occur. If the airway is cleared but some vomit was inhaled, the individual is still at risk for complications and should be evaluated in an emergency room. Some examples include:

• Aspiration pneumonitis, which is lung inflammation and dysfunction caused by an aspiration event which may not initially be obvious, but leads to increasingly worsening symptoms over the next 24 to 48 hours, followed by rapid improvement.
• Aspiration pneumonia, which is a lung infection that requires treatment with antibiotics.

Drug interactions

Chloroethane will synergistically interact with other depressants and reduce the dose required to produce each of the listed effects above.

Addiction

Users of chloroethane have reported experiencing compulsive redosing during use.

Risk mitigation

Due to the risks described above, the use of any amount of chloroethane carries risk of sudden death which is unmitigable in nearly any circumstance.

Similar to other substances causing unconsciousness, additional overdosing may occur when the user loses consciousness and is unable to stop the supply of chloroethane. For example, if chloroethane is inhaled from a rag, the rag may stay over the mouth when the user passes out. Using a method of supply which requires constant active effort may reduce the risk of extreme and continued overdose after consciousness is lost when using chloroethane.

Limiting dosage to quick sprays <0.1 seconds in duration (such as flicking or tapping the spray cap instead of holding it down, then the bottle placed down) which are repeated periodically can reduce the amount of chloroethane which has the potential to be inhaled at a given time, only reapplying after it has been fully used up. This can help avoid excess unevaporated chloroethane liquid from continuing to be present in the event of unconsciousness.

Known incidents

Medical case reports

• Death attributed to ethyl chloride (1993)
• Death due to inhalation of ethyl chloride (2000)
• A Fatal Case of Ethyl Chloride Sniffing Using Head-Cleaning Spray (2004)
• Is old stuff back? A fatal case of ethyl chloride sniffing (2019)