What is 1,3-Butadiene?

1,3-Butadiene (C₄H₆) is a colourless, flammable, non-corrosive gas with a mild gasoline-like odour. It is slightly soluble in water, more soluble in methanol and ethanol, and highly soluble in organic solvents like cyclohexane. Produced through petroleum processing.

What is 1,3-Butadiene used for?

Mainly used in:

• Synthetic rubber production
• Plastic & acrylic manufacture
• Tyre products (e.g., hoses, belts, gaskets)
• Chemical intermediate (e.g., for fungicides, latex adhesives)
• Other applications: nylon carpet backing, paper coatings, electrical components, luggage
• Trace amounts in petrol

Sources of Emission & Route of Exposure

Sources of Emission

• Industry: Petroleum refining, synthetic material manufacturing, oil/gas extraction
• Natural: Emitted during incomplete combustion of biomass (bushfires, wood, tobacco)
• Transport: Vehicle exhaust
• Diffuse: Tobacco smoke, agricultural burning
• Consumer Products: Not present in finished goods, but released when burnt (e.g., plastic, rubber)

Routes of Exposure

• Inhalation of urban/suburban air (higher near facilities or in polluted cities)
• Workplace inhalation in chemical, rubber, or plastic plants
• Breathing air near car/truck exhausts, wood fires, or cigarette smoke
• Drinking contaminated water near production/waste sites
• Minor ingestion from plastic/rubber containers
• Skin contact and inhalation of gasoline fumes

Health Effects

Acute Effects

• Irritation: Eyes, nose, throat, lungs
• Neurological symptoms (at high levels): Headache, fatigue, blurred vision, vertigo
• Skin contact: May cause burning/frostbite sensation
• Animal studies: Low acute toxicity in rats and mice

Chronic Effects

• Humans: One epidemiological study reported that chronic (long-term) exposure
• to 1,3-butadiene via inhalation resulted in increased risk of cardiovascular disease. While other studies revealed possible blood disorders
• Animals: Effects on respiratory, cardiovascular, hepatic, and hematologic systems
• Chronic RfC (EPA): 0.002 mg/m³ (based on reproductive effects in mice)

Reproductive/Developmental Effects

• No human data
• Mice studies: Skeletal abnormalities, lower foetal weight, ovarian/testicular atrophy

Cancer Risk

• Epidemiology: Elevated leukaemia risk in synthetic rubber workers
• Other cancers: Respiratory, bladder, stomach, lymphatic (associations seen, causality unclear)
• Animals: Tumours at multiple sites from inhalation
• Mechanism: Metabolised into genotoxic compounds in animals & humans
• EPA Classification: Carcinogenic to humans (via inhalation)

Safety

First Aid Measures

• Eye Contact: Remove contact lenses if present. Rinse eyes with water for at least 15 minutes, lifting eyelids occasionally. Seek immediate medical attention.
• Skin Contact: Flush affected area with water for at least 15 minutes, removing contaminated clothing. Soak clothing with water first to prevent static ignition. Wash clothes before reuse. Seek immediate medical attention.
• Frostbite: Gently warm the affected area. Seek medical attention.
• Inhalation: Move person to fresh air. If not breathing, provide artificial respiration or oxygen (trained personnel only). Loosen tight clothing. Seek immediate medical help.
• Ingestion: Not applicable—product is a gas. Refer to inhalation protocol.
• Note for Rescuers: If fumes are suspected, use self-contained breathing apparatus (SCBA). Do not give mouth-to-mouth resuscitation without protection.

Fire Hazard Information

• Flammability: Extremely flammable
• Auto-ignition temperature: 419.85°C (787.7°F)
• Hazards: Ignites in presence of flames, sparks, static discharge, and oxidisers
• Combustion products: May release CO and CO₂
• Fire response:
  • Use water spray, foam, or dry chemical
  • If flow can't be shut off, allow gas to burn
  • Apply water to cool surrounding area
• Protective Equipment: Firefighters must wear SCBA and full protective gear

Exposure Controls & Personal Protection

Engineering Controls

• Ensure adequate ventilation
• Use process enclosures and local exhaust ventilation
• Maintain airborne levels below exposure limits
• Use explosion-proof ventilation equipment
• Keep gas/vapour below lower explosive limits

Personal Protective Equipment

• Eye Protection: Safety eyewear compliant with approved standards for splash/mist protection
• Skin Protection: PPE selected based on task-specific risk assessment (e.g., chemical-resistant clothing)
• Respiratory Protection: Use air-purifying or air-fed respirators when required, based on exposure level and hazard
• Hand Protection: Wear chemical-resistant gloves conforming to relevant standards
• Large Spill Response: Use a self-contained breathing apparatus (SCBA) to prevent inhalation of hazardous gas

Regulation

United States

OSHA: Occupational Safety & Health Administration has set a Permissible Exposure Limit (PEL) of 1ppm TWA for 1,3 butadiene and a short term exposure limit of 5 ppm

ACGIH: The American Conference of Governmental Industrial Hygienists has established a Threshold Limit Value (TLV) of 4.4mg/m3

Australia

Safe Work Australia: Eight-hour time weighted average (TWA) exposure limit for 1,3 butadiene is 10 parts per million in air. Safe Work Australia has determined that 1,3-Butadiene is a probable carcinogen.