Agent Name

Hexamethylene diisocyanate

CAS Number

822-06-0

Formula

C8-H12-N2-O2

Major Category

Plastics & Rubber

Synonyms

1,6-Diisocyanatohexane; 1,6-Hexamethylene diisocyanate; 1,6-Hexanediol diisocyanate; 1,6-Hexylene diisocyanate; HDI; HMDI; Hexamethylendiisokyanat [Czech]; Hexamethylene-1,6-diisocyanate; Hexane 1,6-diisocyanate; Hexane, 1,6-diisocyanato-; Isocyanic acid, diester with 1,6-hexanediol; Metyleno-bis-fenyloizocyjanian [Polish]; Szesciometylenodwuizocyjanian [Polish]; TL 78; [ChemIDplus]

Category

Diisocyanates

Description

Clear, colorless to slightly yellow liquid with a sharp, pungent odor; [NIOSH]

Sources/Uses

Used as a cross-linking agent to manufacture dental materials, contact lenses, medical adsorbents, and polyurethanes; may be released during the spraying of polyurethane paints; Commonly used as a hardener in polyurethane automobile paints; [HSDB] Occupational asthma reported in a spray painter; [Malo] Used to make polyisocyanate products for curing agents in polyurethane paint systems (automobile, marine, industrial maintenance, and other high-performance coatings); [ACGIH]

Comments

"Isocyanate HP," a form of hypersensitivity pneumonitis, has been reported. [Rosenstock, p. 346] May cause skin sensitization; [ICSC] "1,6-Hexamethylene diisocyanate (HDI) is either conjugated or hydrolysed to the corresponding 1,6-hexamethylene diamine (HAD), which may then be conjugated to proteins, macromolecules, or acetyl groups, following absorption. . . . The recommended BEI of 15 ug HAD/g creatinine is based on the level of HAD expected with an exposure to the equivalent of the TLV-TWA of 0.005 ppm (0.034 mg/m3). The TLV-TWA is intended to protect workers from potential eye, nose, and upper respiratory tract irritation and respiratory sensitization." [ACGIH] See "DIISOCYANATES."

Reference Link

ATSDR - ToxFAQs - Hexamethylene Diisocyanate

Exposure Assessment
BEI

1,6-Hexamethylene diamine in urine (with hydrolysis) = 15 ug/g creatinine at end of shift; [TLVs and BEIs]

Skin Designation (ACGIH)

Insufficient data

TLV (ACGIH)

0.005 ppm

MAK

0.005 ppm

Vapor Pressure

0.5 mm Hg

Lethal Concentration

LCLo (rat) = 60 mg/m3/4h

Reference Link

Evaluation of pulmonary function in workers exposed to hexamethylene diisocyanate

Adverse Effects
Skin Sensitizer

Yes

Asthma

Yes

Fibrogenic

Yes

Links to Other NLM Databases
Health Studies

Human Health Effects from Hazardous Substances Data Bank:

Toxicity Information

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Chemical Information

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Biomedical References

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Related Information in HazMap
Diseases

Occupational diseases associated with exposure to this agent:

Processes

Industrial Processes with risk of exposure: