© 2026 Sinochem Nanjing Corporation,
All Right Reserved
Chemical Name: Toluene-2,4-Diisocyanate
Common Synonyms: TDI, 2,4-TDI
Molecular Formula: C9H6N2O2
CAS Number: 584-84-9
Use: Manufacturing flexible polyurethane foams, coatings, elastomers, adhesives, and sealants
Appearance: Pale yellow liquid, sharp and pungent odor
Health Hazards: Strong respiratory irritant, contact can trigger asthma-like symptoms and sensitization. Severe eye and skin irritation possible, with blistering on contact. Inhalation at higher concentrations threatens lung function; low-level chronic exposure has a cumulative impact.
Environmental Concerns: Spills and leaks contaminate water sources and harm aquatic life, persistence leads to bioaccumulation.
Flammability: Vapor mixes with air, forming explosive atmospheres in closed spaces. Liquid ignites at moderate temperatures.
Regulatory Categories: OSHA hazardous chemical, subject to strict control in handling and reporting.
Main Ingredient: Toluene-2,4-Diisocyanate, concentration typically exceeds 99 percent by weight
Impurities: Trace amounts of isomeric Toluene-2,6-Diisocyanate, minor traces of toluene or phosgene residues depending on production methods
Inhalation: Move person to fresh air, avoid panic and keep airways clear, oxygen if breathing feels labored, medical care is urgent due to possible delayed lung inflammation.
Skin Contact: Take off contaminated clothing, shower skin with soap and water, don’t delay. Vigilance for delayed inflammation or rashes is warranted.
Eye Contact: Rinse eyes gently with water for at least 15 minutes, medical check for corneal injury is crucial.
Swallowing: Not typical, immediate medical attention recommended, do not induce vomiting without advice.
Extinguishing Media: Dry chemical, foam, or carbon dioxide works better than water streams due to risk of violent reaction with water.
Fire Hazards: Combustion creates irritating, toxic gases including nitrogen oxides and hydrogen cyanide. Personnel need proper breathing equipment.
Special Protection: Full protective gear, including chemical-resistant suit and self-contained breathing apparatus; hot surfaces can worsen vapor release.
Explosion Hazard: If confined vapor ignites, pressure build-up leads to explosion.
Spill Control: Keep people away, ventilate area. Wear adequate protection, including respirators.
Cleanup: Neutralize with a suitable decontamination blend, typically involving water, ammonia, and detergent—monitor for dangerous gas formation.
Containment: Stop leakage at source, dam spills with inert absorbents like sand or earth; avoid allowing chemicals to flow to water systems.
Waste Disposal: Collected residue requires disposal by licenced hazardous waste handler.
Handling: Keep containers closed, work in well-ventilated spaces or use local fume extraction; minimize skin and eye contact, double-check proper transfer procedures. Always ensure containers and pumps are grounded due to static electricity risk.
Storage: Hold in a cool, dry, well-ventilated area, away from water, alcohols, amines, and acids, as these trigger violent reactions. Clearly label, lock, and segregate from incompatible chemicals. Security and recordkeeping cut the risk of unauthorized use.
Personal Hygiene: No eating, drinking, or smoking near workspaces, wash hands thoroughly after handling.
Engineering Controls: Proper ventilation is obligatory, often both local exhaust and closed systems for transfer and mixing; routine air monitoring gauges vapor levels.
Personal Protective Equipment (PPE): No shortcuts—a full-face respirator, chemical-resistant gloves, coveralls, goggles, and boots come standard. In spaces with high concentrations, a supplied-air respirator or self-contained unit is chosen.
Exposure Limits: OSHA sets a Permissible Exposure Limit at 0.02 ppm (ceiling); chronic overexposure leads to lasting health setbacks.
Health Precaution: Pre-work and post-work medical checks not only safeguard employees but help identify undiagnosed sensitization early.
Physical State: Liquid at room temperature
Color: Colorless to pale yellow
Odor: Sharp, pungent, quickly noticeable at low levels
Boiling Point: Around 251°C
Melting Point: 20°C—solidifies just below normal room temperature
Vapor Pressure: Noticeable, especially in warm environments
Solubility: Reacts with water
Density: Close to 1.22 g/cm³
Reactivity with Other Materials: Reacts vigorously with water, acids, amines, alcohols, generating heat and gases
Chemical Stability: Remains stable only under dry, cool, well-ventilated storage, away from sunlight.
Incompatible Materials: Explosive or toxic reactions occur with water, strong bases or acids, amines, and alcohols. Many metals promote decomposition.
Hazardous Reactions: Uncontrolled reactions release carbon dioxide, possibility of rapid pressure increase in closed containers.
Decomposition Products: Toxic emissions, including nitrogen oxides, carbon monoxide, and hydrogen cyanide.
Acute Effects: Even short exposures make breathing difficult, inflame lungs and airway lining. High concentrations lead to pulmonary edema.
Chronic Effects: Sensitization for life occurs in some with repeated exposures—minute amounts later on may spark asthma attacks.
Skin and Eye Impact: Redness, blistering and possible burns if not washed away quickly.
Carcinogenicity: Classified by the International Agency for Research on Cancer as a possible human carcinogen.
Target Organs: Primarily affects respiratory tract; some risk for kidneys and liver after extreme exposure.
Aquatic Impact: Even minor releases poison fish and invertebrates, toxicity manifests in both acute and chronic exposure.
Persistence: Sticks around in water and soil, slow breakdown under natural conditions.
Mobility: Binds to soil, but water runoff can carry it over long distances.
Bioaccumulation: Potential to build up in aquatic food webs, presenting risk to larger species and humans.
Disposal Preference: Never dump into sewers or waterways, use only properly managed hazardous waste disposal sites.
Resource Management: Reduce waste at the source, capture spills and evaporation wherever possible.
Contaminated Gear: Bag and label protective equipment for special industrial disposal, avoid laundering gear at home.
Container Disposal: Empty drums still hold harmful residue; rinse with recommended neutralizer, then incinerate or deliver to hazardous waste site.
Legal Responsibility: Disposal must comply with environmental protection rules; random dumping leads to stiff penalties for operators.
Regulated Status: Transported as a dangerous good under international and domestic law, strict labeling and emergency documentation follow every shipment.
Packing Type: Leak-proof containers, ventilated vehicles, spill containment kits—always prepped for worst-case scenario.
Transit Risk: Longer journeys invite risk of exposure from vibration, impact, or heat, so best practice limits time and monitors conditions throughout.
Emergency Steps: Crews with hazard training and spill kits prevent minor leaks from becoming disasters.
Occupational Standards: OSHA, NIOSH, and ACGIH set exposure and handling limits; companies required to provide staff with information and safety measures.
Environmental Regulation: EPA classifies TDI as hazardous substance, subject to strict reporting and control during use and disposal.
Worker Protection: Training for handlers forms part of both regulatory compliance and basic ethics in safety.
Community Right-to-Know: Facilities storing or using TDI must notify local authorities, publish chemical inventories, and offer safety data to neighbors and first responders.
International Status: Movement subject to transport conventions; regulations similar across North America, Europe, and major Asian economies.
