Freons (fluorocarbons and chlorofluorocarbons [CFCs]) historically have been widely used as aerosol propellants, in refrigeration units, in the manufacture of plastics, and in foam blowing, metal and electronics cleaning, mobile air conditioning, and sterilization. Although the use of CFCs is being phased out to avoid further depletion of stratospheric ozone, freons remain in older refrigeration and air conditioning systems, and illicit importation of freons occurs. Most freons are gases at room temperature, but some are liquids (freons 11, 21, 113, and 114) and may be ingested. Specialized fire extinguishers contain closely related compounds known as halons, which contain bromine, fluorine, and chlorine. HCFCs (hydrochlorofluorocarbons) and HFCs (hydrofluorocarbons) are being used as transitional refrigerants because they break down more easily in the atmosphere than CFCs. The multilateral Montreal Protocol will phase out CFC and HCFC consumption by 2030.

1. Freons are mild CNS depressants and asphyxiants that displace oxygen from the ambient environment. Freons are quickly absorbed by inhalation or ingestion and are usually rapidly excreted in the breath within 15-60 minutes.
2. Freons and halons may cause CNS depression by potentiating inhibitory and impeding excitatory neurotransmission.
3. Like chlorinated hydrocarbons, freons may induce cardiac arrhythmias by sensitizing the myocardium to the effects of catecholamines.
4. Direct freezing of the skin, with frostbite, may occur if the skin is exposed to rapidly expanding gas as it escapes from a pressurized tank.
5. Freons and halons are mild irritants and may produce more potent irritant gases and vapors (eg, phosgene, hydrochloric acid, hydrofluoric acid, and carbonyl fluoride) when heated to high temperatures, as may happen in a fire or if a refrigeration line is cut by a welding torch or electric arc.
6. Some agents are hepatotoxic after large acute or chronic exposure.

1. Inhalation. The toxic air level is quite variable, depending on the specific agent (see Table IV-3). Freon 21 (dichlorofluoromethane; TLV, 10 ppm [42 mg/m³]) is much more toxic than freon 12 (TLV, 2,000 ppm). In general, anesthetic or CNS-depressant doses require fairly large air concentrations, which can also displace oxygen, leading to asphyxia.
2. Ingestion. The toxic dose by ingestion is not known.

1. Skin or mucous membrane exposure can cause pharyngeal, ocular, and nasal irritation. Dysesthesia of the tongue is commonly reported. Frostbite may occur after contact with rapidly expanding compressed gas. Chronic exposure may result in skin defatting and erythema.
2. Respiratory effects can include cough, dyspnea, bronchospasm, hypoxemia, and pneumonitis.
3. Systemic effects of moderate exposure include dizziness, headache, nausea and vomiting, confusion, impaired speech, tinnitus, ataxia, and incoordination. More severe intoxication may result in coma or respiratory arrest. Ventricular arrhythmias may occur even with moderate exposures. A number of deaths, presumably caused by ventricular fibrillation, have been reported after freon abuse by “sniffing” or “huffing” freon products from plastic bags or air conditioning fluid. Hepatic injury may occur.

Is based on a history of exposure and clinical presentation. Many chlorinated and aromatic hydrocarbon solvents may cause identical symptoms.

1. Specific levels. Expired-breath monitoring is possible, and blood levels may be obtained to document exposure, but these procedures are not useful in emergency clinical management and are only available from specialty reference laboratories.
2. Other useful laboratory studies include venous or arterial blood gases or pulse oximetry, ECG monitoring, and liver enzymes.

1. Emergency and supportive measures
   1. Remove the individual from the contaminated environment.
   2. Maintain an open airway and assist ventilation if necessary.
   3. Treat coma and arrhythmias if they occur. Avoid epinephrine or other sympathomimetic amines that may precipitate ventricular arrhythmias. Tachyarrhythmias caused by increased myocardial sensitivity may be treated with propranolol, 1-2 mg IV, or esmolol infusion, 0.025-0.1 mg/kg/min IV.
   4. Monitor the ECG for at least 4-6 hours.
2. Specific drugs and antidotes. There is no specific antidote. Steroids have been used in inhalational exposure but have no proven benefit.
3. Decontamination
   1. Inhalation. Remove victim from exposure and give supplemental oxygen if available.
   2. Ingestion. Do not give charcoal or induce vomiting because freons are rapidly absorbed and there is a risk for abrupt onset of CNS depression. Consider gastric aspiration of contents using small bore nasogastric or orogastric tube if the ingestion was very large and recent (<30-45 minutes). The efficacy of activated charcoal is unknown.
4. Enhanced elimination. There is no documented efficacy for diuresis, hemodialysis, hemoperfusion, or repeat-dose charcoal.