What is 1,3-Dichloropropene?

1,3-Dichloropropene (C₃H₄Cl₂) is a clear to straw-coloured liquid with a sharp, sweet, and irritating odour. It is moderately soluble in water and evaporates easily. This compound is primarily generated as a by-product during the chlorination of propene to produce allyl chloride.

What is 1,3-Dichloropropene used for?

1,3-Dichloropropene is widely used in agriculture as a preplant soil fumigant and nematicide, particularly in the United States. It is also employed in the synthesis of other chemicals. While still in use in several countries, it is being phased out across the European Union due to health and environmental concerns.

In the Environment

In the atmosphere, 1,3-dichloropropene breaks down rapidly within a few days. In soil and water, it either evaporates or undergoes degradation. Despite its breakdown rate, its widespread use raises concerns about air, water, and soil contamination, especially near hazardous waste sites.

Sources & Routes of Exposure

Sources of Exposure

• Occupational exposure during production or application
• Environmental exposure from air near waste sites
• Drinking water and soil near areas of use or disposal

Routes of Exposure

• Inhalation (primary route)
• Skin absorption
• Ingestion
• Eye/skin contact

Health Effects

Acute Effects

• Humans: Inhalation during a spill has led to coughing, mucous membrane irritation, chest pain, and breathing difficulty.
• Animals: Rats exposed by inhalation or ingestion show signs of emphysema, edoema, gastrointestinal bleeding, liver damage, and neurotoxicity. Toxicity ranges from moderate to high, depending on route and dose.

Chronic Effects

• Humans: Long-term dermal contact may lead to skin sensitisation.
• Animals: Chronic exposure has caused damage to the nasal mucosa, urinary bladder, forestomach, liver, and kidneys in rodents. Respiratory tract changes, weight loss, and epithelial degeneration have also been documented.
• Reference Values:
  • RfC (Inhalation): 0.02 mg/m³
  • RfD (Oral): 0.03 mg/kg/day

Reproductive/Developmental Effects

• Humans: No fertility impact observed in exposed male workers.
• Animals: No consistent evidence of developmental toxicity, although maternal toxicity has been noted at high exposures. Some studies reported fewer foetuses at high doses, likely linked to maternal effects.

Cancer Risk

• Humans: Limited evidence. A few cases of lymphoma and leukaemia were reported in emergency responders.
• Animals: Increased tumour rates in rodents, including liver, forestomach, urinary bladder, and lung.

EPA Classification: Group B2 – Probable Human Carcinogen

Safety

First Aid Measures

• Eye Contact: Immediately rinse eyes with plenty of water for at least 15 minutes, lifting upper and lower eyelids occasionally. Remove contact lenses during rinsing. Seek immediate medical attention.
• Skin Contact: Quickly remove any contaminated clothing. Wash skin thoroughly with soap and water. Seek medical advice if irritation persists.
• Inhalation: Move the affected individual to fresh air. If breathing has stopped, begin rescue breathing (using universal precautions). If the heart has stopped, initiate CPR. Promptly transfer the person to a medical facility.

Fire Hazards

• Flammable Liquid – 1,3-Dichloropropene poses a fire hazard.
• Use dry chemical, carbon dioxide, water spray, or foam to extinguish fires.
• Toxic gases, such as hydrogen chloride, may be released during combustion.
• Containers may explode if exposed to fire or heat.
• Use water spray to cool fire-exposed containers.
• Vapours are heavier than air and may travel to distant ignition sources, leading to flash fires or explosions far from the source.

Workplace Exposure Controls

Recommended Engineering Controls

• Enclose processes when handling highly irritating/corrosive substances.
• Use local exhaust ventilation for substances hazardous on short exposure.
• Maintain general ventilation to limit exposure to skin/eye irritants.

Recommended Work Practices

• Label all process containers clearly.
• Provide workers with hazard communication and training.
• Monitor airborne concentrations regularly.
• Implement engineering controls if levels exceed exposure limits.
• Install emergency eyewash stations and showers near chemical areas.
• Clean exposed skin promptly; always shower after a work shift.
• Change out of contaminated clothing—do not bring it home.
• Train staff on safe laundering of work garments.
• Avoid eating, smoking, or drinking in chemical handling zones.
• Always wash hands before eating, using cosmetics, or using the restroom.

Personal Protective Equipment (PPE)

The following personal protective equipment is recommended when handling 1,3-Dichloropropene:

• Gloves & Clothing: Wear PPE made from materials resistant to 1,3-dichloropropene. Consult PPE manufacturers for recommendations. Ensure clothing is clean, protective, and changed daily.
• Eye Protection: Use indirect-vent goggles resistant to impact and splash. Pair with a face shield when handling highly irritating or toxic materials. Do not wear contact lenses.
• Respiratory Protection: Use approved supplied-air respirators with a full facepiece in pressure-demand or positive-pressure mode when exposure exceeds 1 ppm. For added protection, combine with a self-contained breathing apparatus (SCBA). All respirator use must comply with a written respiratory protection programme, including medical exams and fit testing.

Regulation

United States

ACGIH: American Conference of Governmental Industrial Hygienists has set a Threshold Limit Value (TLV) of 1 ppm, 4.5 mg/m3 TWA (Skin); Appendix A4 (Not Classifiable as a Human Carcinogen) 

NIOSH: National Institute for Occupational Safety and Health has set a Recommended Exposure Limit (REL) of 1 ppm TWA; Potential carcinogen

Australia

Safe Work Australia: The recommended time weighted exposure limit is 1ppm over an 8-hour period.