NIOSH Pocket Guide to Chemical Hazards

Toluene-2,4-diisocyanate CAS 584-84-9
CH3C6H3(NCO)2 RTECS CZ6300000
Synonyms & Trade Names
TDI; 2,4-TDI; 2,4-Toluene diisocyanate
DOT ID & Guide
2078 156
NIOSH REL: Ca See Appendix A
OSHA PEL†: C 0.02 ppm (0.14 mg/m3)
IDLH Ca [2.5 ppm] Conversion 1 ppm = 7.13 mg/m3
Physical Description
Colorless to pale-yellow solid or liquid (above 71°F) with a sharp, pungent odor.
MW: 174.2
BP: 484°F
MLT: 71°F
Sol: Insoluble
VP(77°F): 0.01 mmHg
IP: ?

Sp.Gr: 1.22
Fl.P: 260°F
UEL: 9.5%
LEL: 0.9%

Class IIIB Combustible Liquid: Fl.P. at or above 200°F.
Incompatibilities & Reactivities
Strong oxidizers, water, acids, bases & amines (may cause foam & spatter); alcohols [Note: Reacts slowly with water to form carbon dioxide and polyureas.]
Measurement Methods
NIOSH 2535, 5521, 5522; OSHA 18, 33, 42
Personal Protection & Sanitation
Skin: Prevent skin contact
Eyes: Prevent eye contact
Wash skin: When contaminated/Daily
Remove: When wet or contaminated
Change: Daily
Provide: Eyewash, Quick drench
First Aid (See procedures)
Eye: Irrigate immediately
Skin: Soap wash immediately
Breathing: Respiratory support
Swallow: Medical attention immediately
Respirator Recommendations NIOSH
At concentrations above the NIOSH REL, or where there is no REL, at any detectable concentration: (APF = 10,000) Any self-contained breathing apparatus that has a full facepiece and is operated in a pressure- demand or other positive-pressure mode/(APF = 10,000) Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode in combination with an auxiliary self-contained positive-pressure breathing apparatus
Escape: (APF = 50) Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted organic vapor canister/Any appropriate escape-type, self-contained breathing apparatus
Exposure Routes inhalation, ingestion, skin and/or eye contact
Symptoms Irritation eyes, skin, nose, throat; choke, paroxysmal cough; chest pain, retrosternal (occurring behind the sternum) soreness; nausea, vomiting, abdominal pain; bronchitis, bronchospasm, pulmonary edema; dyspnea (breathing difficulty), asthma; conjunctivitis, lacrimation (discharge of tears); dermatitis, skin sensitization; [potential occupational carcinogen]
Target Organs Eyes, skin, respiratory system

Cancer Site [in animals: pancreas, liver, mammary gland, circulatory system & skin tumors]