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Chemical Name: Terephthaloyl Chloride
Common Names: 1,4-Benzenedicarbonyl dichloride
Chemical Formula: C8H4Cl2O2
Appearance: White to faintly yellow solid, typically crystalline
Odor: Pungent, irritating
Industrial Use: Key ingredient in the production of aromatic polyamide fibers, especially for high-strength materials like Kevlar
Solubility: Decomposes in water, soluble in some chlorinated solvents
CAS Number: 100-20-9
Hazard Classification: Corrosive to skin, eyes, and respiratory tract; harmful if inhaled or ingested
Primary Dangers: Releases toxic hydrogen chloride gas upon contact with moisture, including air and human tissue
Irritation Potential: Severe skin burns and eye damage, chemical burns possible
Acute Health Effects: Shortness of breath, coughing, blisters, burns
Chronic Health Effects: Prolonged exposure may damage respiratory system, aggravate existing lung conditions, lead to chronic skin issues
Flammability: Not considered highly flammable, but may emit toxic gases in a fire
Labeling Requirements: Corrosive symbol, Health hazard symbol, Handling precautions
Main Component: Terephthaloyl Chloride (over 99%)
Impurities: Trace amounts of hydrochloric acid possible, often residue from production
Additives: Usually shipped pure, with no intentional additives
Subclass: No significant mixture with other chemicals at sale
Inhalation: Move the person to fresh air, loosen tight clothing, get medical attention immediately; support breathing if symptoms appear severe
Skin Contact: Remove contaminated clothing right away, rinse skin thoroughly for 15 minutes or longer, medical evaluation is a must due to risk of deep burns
Eye Contact: Flush eyes with water continuously for at least 15 minutes, ensuring eyelids are held open, immediate medical evaluation required
Ingestion: Do not induce vomiting, rinse mouth, provide water if person is conscious, immediate transport to medical facility advised
Special Advice to Doctors: Symptomatic treatment, respiratory support may be necessary, burns should be evaluated as chemical in nature
Suitable Extinguishing Media: Dry chemical powder, foam, or carbon dioxide; avoid direct use of water as it reacts and produces hydrogen chloride gas
Special Hazards: Combustion releases hydrochloric acid vapor and phosgene, exposure creates secondary risk
Protective Equipment: Full chemical protection suit, self-contained breathing apparatus needed for responders
Firefighting Considerations: Keep containers cool with sprays of water on outside, but do not allow water to touch contents, control run-off due to risk of environmental harm
Personal Precautions: Evacuate area, restrict access, ensure responders avoid skin and eye contact, ventilate spill area
Protective Equipment: Chemical-resistant gloves, safety goggles, face shields, and protective clothing, full-face respirators for large spills
Spill Response: Cover spill with inert, non-reactive absorbent such as dry sand; never use water, collect and seal residue safely
Environmental Precautions: Prevent runoff to drains or watercourses, notify local authorities if substantial material enters the environment
Cleanup: Clean area with suitable non-aqueous cleaners, ventilate until vapors have fully dissipated before permitting re-entry
Storage Conditions: Store in tightly sealed, corrosion-resistant containers in a cool, dry, well-ventilated space, away from water or dampness
Handling: Use only inside chemical fume hoods or controlled areas, containers should be clearly labeled, equipment must withstand corrosive vapors
Avoid: Any exposure to water vapor or humidity, open handling without proper PPE, storage alongside acids, bases, or reactive organics
Transfer Precautions: Handle with tools and dispensing setups that prevent splashing or powder dispersal
Engineering Controls: Rely on fume hoods, sealed lines, or glove boxes for operations, local exhaust ventilation required
Personal Protective Equipment: Heavy-duty chemical-resistant gloves (such as butyl rubber or neoprene), goggles with face shield, full protective suits, NIOSH-approved respirators where airborne dust or vapors may form
Hygiene Measures: Wash thoroughly after handling, never eat/drink/smoke near materials, remove and decontaminate clothing regularly
Exposure Limits: No established OSHA PEL, though ACGIH recommends minimizing inhalation and skin exposure due to corrosivity
Appearance: White or slightly yellow crystalline powder or flakes
Molecular Weight: 203.03 g/mol
Melting Point: 80–83°C
Boiling Point: 273°C at 760 mmHg (decomposition possible above 110°C)
Density: About 1.6 g/cm³
Solubility: Reacts vigorously with water, rapidly produces hydrogen chloride and terephthalic acid
Vapor Pressure: Low at room temperature
Odor Threshold: Pungent, irritating, easily detected
Partition Coefficient: Not readily available; not typically bioaccumulative
Stability: Stable under dry, cool, and airtight conditions
Reactivity: Reacts violently with water or moisture, releasing hydrogen chloride gas
Incompatible Materials: Strong bases, strong acids, water, alcohols, amines
Decomposition Products: Releases toxic, corrosive fumes such as hydrogen chloride and phosgene if heated or in fire conditions
Polymerization: Not subject to hazardous polymerization under recommended handling
Routes of Exposure: Inhalation, skin contact, eye contact, ingestion
Immediate Effects: Severe burns, blistering, possible pulmonary edema from inhalation, chemical conjunctivitis
Long-Term Risks: Chronic skin damage, possible respiratory impairment with repeated inhalation
Acute Toxicity Data: Data on specific LD50 is sparse; known to cause immediate corrosive injury at low doses
Sensitization: Not identified as a sensitizer, though repeated burns and scars can develop
Carcinogenic Status: Not classified as carcinogenic by major agencies, but not tested for all chronic effects
Aquatic Toxicity: Highly toxic to aquatic organisms due to rapid formation of hydrochloric acid and terephthalic acid
Persistence and Degradability: Hydrolyzes rapidly in water to terephthalic acid, which is less harmful, but hydrochloric acid is a persistent pollutant
Mobility: Tends to remain at the site of spillage due to rapid reactivity, though runoff acidifies soil and water
Bioaccumulation: Low expected, hydrolysis is fast
Environmental Fate: Can cause severe pH drop and kill aquatic life in streams and ponds
Special Notes: Spills should never be washed away with water due to formation of acid clouds
Waste Management: Must be disposed of as hazardous waste under controlled conditions
Inappropriate Disposal: Never dispose via drains, sewers, or surface water; avoid landfill without pretreatment
Recommended Procedures: Incinerate in specialized facilities with temperature and air pollution controls, or neutralize under expert supervision
Rinsate and Containers: All wash water and residue should be treated as hazardous, empty containers should be decontaminated or destroyed
Shipping Name: Terephthaloyl Chloride
Transport Risks: Corrosive, reacts with moisture, releases toxic gas
Packing: Must use airtight, corrosion-resistant containers, appropriately labeled
Accident Protocols: Spill kits, emergency showers, and eyewash stations should always be nearby during warehouse or transit handling
Regulated Transport Modes: Road, rail, sea, or air shipments require hazardous material documentation and handlers trained in chemical emergencies
Global Regulations: Regulated as a hazardous substance in major jurisdictions including the US, EU, Japan, and Canada
Relevant Restrictions: Subject to comprehensive reporting and containment requirements for occupational exposure
Workplace Safety: Facilities using the chemical need controls for spills, airborne exposure, and equipment decontamination
Environmental Laws: Notification of accidental releases to environmental agencies is mandatory above specified thresholds
