What is Allyl Chloride?

Allyl chloride is the organic compound with the molecular formula C3H5Cl. Allyl chloride is a colourless to light yellow liquid with a strong, unpleasant smell and it is highly flammable. Although allyl chloride is slightly soluble in water, it can mix with other liquids like alcohol, chloroform, ether, and petroleum ether. In the United States, allyl chloride is a federal hazardous air pollutant and was identified as a toxic air contaminant in April 1993.

What is Allyl Chloride used for?

Ally chloride is used as a chemical intermediate to manufacture pharmaceuticals, varnishes, epoxy resins, adhesives, plastics, gylcerol, and insecticides. It is also used in the synthesis of allyl compounds such as allyl alcohol, allyl amines, allyl esters, and polyesters. Additionally, almost all of the allyl chloride produced is used to make epichlorohydrin and glycerin.

Allyl Chloride Hazards

Sources of exposure

• Allyl chloride can be released into the air from production and processing facilities.
• Occupational exposure exists for people working with the production of allyl chloride, epichlorohydrin, and synthetic glycerin.
• Exposure can occur by breathing contaminated air or through skin contact.

Routes of Exposure

The main ways people can be exposed to allyl chloride are:

• Inhaling the chemical
• Absorbing it through the skin
• Ingesting it
• Contact with skin or eyes

Health Effects

Acute Effects

• Short-term exposure to high levels of allyl chloride can cause eye and respiratory irritation, and in severe cases, unconsciousness. 
• Intense exposure may lead to conjunctivitis, redening of eyelids, and corneal burn. 
• Acute animal tests in rats, mice, and guinea pigs have shown allyl chloride to have moderate toxicity from oral and inhalation exposure.

Chronic Effects

• Chronic inhalation exposure in humans mainly affects the liver and kidneys, but these effects may be reversible after the cessation or minimisation of exposure. 
• It can also damage the central nervous system, leading to motor and sensory neurotoxic damage, and affect the heart and lungs, potentially causing pulmonary oedema. 
• The reference concentration (RfC) is set at 0.001 mg/m³ based on effects observed in rabbits.
• EPA has not established a Reference Dose (RfD) for allyl chloride. 

Reproductive/Developmental Effects

• There is limited evidence on how allyl chloride affects human reproduction.
• Animal studies have shown that inhaling allyl chloride can lead to decreased maternal weight gain in rabbits.
• Rats that were injected with allyl chloride showed increased heart, liver, spleen and kidney maternal weights.

Cancer Risk

• No human cancer data are available for allyl chloride.
• Limited animal studies suggest that exposure to allyl chloride by gavage (directly placing the chemical into the stomachs of mice) increases the incidence of a rare type of forestomach tumor. Similar studies involving skin application have produced tumours at the application site.
• Allyl chloride is an alkylating agent and is structurally related to chemicals that are likely human carcinogens. 
• The EPA considers allyl chloride a possible human carcinogen (cancer-causing agent) and has classified it as a Group C chemical. 
• The EPA has not calculated an inhalation unit risk estimate for allyl chloride.
• The California Environmental Protection Agency (CalEPA) has established an inhalation unit risk estimate of 6.0 x 10^-6 (µg/m³)^-1 and an oral cancer slope factor of 2.1 x 10^-2 (mg/kg/day)^-1 for allyl chloride.

Allyl Chloride Safety

First Aid Measures

Eye Contact:

• Check for and remove any contact lenses.
• If allyl chloride gets into the eyes, immediately flush them with plenty of water for at least 15 minutes.
• Cold water can be used, but warm water must be used if available.
• Seek medical attention immediately.

Skin Contact:

• Immediately flush the skin with plenty of water if there is contact.
• Cover the irritated skin with an emollient.
• Remove any contaminated clothing and shoes.
• Wash clothing thoroughly before reuse, and clean shoes.
• Get medical attention.

Serious Skin Contact:

• Wash the affected area with disinfectant soap and apply an antibacterial cream.
• Seek immediate medical attention.

Inhalation:

• If inhaled, move the person to fresh air.
• If the person is not breathing, provide artificial respiration.
• If breathing is difficult, provide oxygen.
• Seek medical attention immediately.

Serious Inhalation:

• Evacuate the person to a safe area as soon as possible.
• Loosen tight clothing such as a collar, tie, belt, or waistband.
• If breathing is difficult, administer oxygen.
• If the person is not breathing, perform mouth-to-mouth resuscitation, but be aware of the hazards if the inhaled material is toxic, infectious, or corrosive.
• Seek immediate medical attention.

Ingestion:

• Do not induce vomiting unless directed by medical personnel.
• Never give anything by mouth to an unconscious person.
• If large quantities are ingested, call a physician immediately.
• Loosen tight clothing such as a collar, tie, belt, or waistband.

Fires & Explosion Information

• Allyl chloride is flammable.
• Auto-Ignition Temperature: 485°C (905°F)
• Closed cup flash point: -31.7°C (-25.1°F)
• Open cup flash point: -28.9°C (-20°F)
• It is highly flammable in the presence of open flames, sparks, or heat.
• It is a flammable liquid that can be soluble or dispersed in water.
• Use dry chemical powder to extinguish small fires.
• For large fires, use alcohol foam, water spray, or fog.

Allyl Chloride Safety Handling

Engineering Controls

• Use exhaust ventilation or other engineering controls to keep airborne concentrations of vapours below their threshold limit value.
• Ensure that eyewash stations and safety showers are near the workstation.

Personal Protective Equipment

When handling allyl chloride, the following PPE is recommended:

• Splash goggles
• Lab coat
• Vapour respirator (ensure it is an approved or certified respirator or equivalent).
• Gloves

Personal Protection in Case of a Large Spill

• Splash goggles
• Full protective suit
• Vapour respirator
• Boots
• Gloves
• Use a self-contained breathing apparatus to avoid inhalation of the product.
• Consult a specialist for additional protective clothing requirements before handling this product, as standard recommendations might not be sufficient.

Regulation

United States

• NIOSH (National Institute for Occupational Safety & Health) has established a Relative Exposure Limit (REL) for allyl chloride:
• OSHA (Occupational Safety & Health Administration) has set a Permissible Exposure Limit (PEL) for allyl chloride:
  • TWA: 1 ppm (3 mg/m³)
• ACGIH (American Conference of Governmental Industrial Hygienists) has set a time-weighted average Threshold Limit Value (TLV) for allyl chloride:

Australia

• Safe Work Australia has established a time-weighted average concentration of allyl chloride:
  • 3 mg/m³ for an 8-hour workday
  • Short-term exposure limit: 2 ppm (6 mg/m³) for a 15-minute period