Methylene bisphenyl isocyanate

Synonyms

MDI; 1,1'-Methylenebis(4-isocyanatobenzene); 4,4'-Diisocyanatodiphenylmethane; 4,4'-Diphenylmethane diisocyanate; 4,4'-Diphenylmethanediisocyante; 4,4'-Methylenebis(phenyl isocyanate); 4,4'-Methylenedi-p-phenylene diisocyanate; 4,4'-Methylenediphenyl diisocyanate; 4,4'-Methylenediphenyl isocyanate; 4,4'-Methylenediphenylene isocyanate; 4-4'-Diisocyanate de diphenylmethane [French]; Benzene, 1,1'-methylenebis(4-isocyanato-; Bis(1,4-isocyanatophenyl)methane; Bis(4-isocyanatophenyl)methane; Bis(p-isocyanatophenyl)methane; Bis(para-isocyanatophenyl)methane; Caradate 30; Desmodur 44; Di-(4-isocyanatophenyl)methane; Difenil-metan-diisocianato [Italian]; Difenylmethaan-dissocyanaat [Dutch]; Diphenyl methane diisocyanate; Diphenylmethan-4,4'-diisocyanat [German]; Diphenylmethane diisocyanate; Diphenylmethyl diisocyanate; Hylene M50; Isocyanic acid, ester with diphenylmethane; Isocyanic acid, methylenedi-p-phenylene ester; Isonate; Isonate 125 MF; Isonate 125M; MDI; MDR; Methylbisphenyl isocyanate; Methylene di-p-phenylene isocyanate; Methylenebis(4-isocyanatobenzene); Methylenebis(4-phenyl isocyanate); Methylenebis(4-phenylene isocyanate); Methylenebis(p-phenyl isocyanate); Methylenebis(p-phenylene isocyanate); Methylenebis(para-phenyl isocyanate); Methylenebis(para-phenylene isocyanate); Methylenedi-p-phenylene diisocyanate; Methylenedi-para-phenylene diisocyanate; Nacconate 300; Rubinate 44; p,p'-Diphenylmethane diisocyanate; p,p'-Methylenebis(phenyl isocyanate); para,para'-Diphenylmethane diisocyanate; para,para'-Methylenebis(phenyl isocyanate); [ChemIDplus]

Category

Diisocyanates

Description

White to light-yellow, odorless flakes. [Note: A liquid above 99 degrees F.]; [NIOSH]

Sources/Uses

Pattern of use in 1974: coatings (28%); elastomers (22%); thermoplastic resins (22%); spandex fibers (19%); millable gums (9%); [HSDB] Occupational asthma reported in foundry; [Malo] Allergic contact dermatitis in shoemakers and other workers using glues; [Marks] Used in spray-on truck bed liners; [Reference #2]

Comments

Solid form can cause reddening of skin if left on clothes. [CHRIS] Cases of hypersensitivity pneumonitis (TDI HP and MDI HP) have been reported. [Rom, p. 388-90] "Tear drawing." Can cause skin sensitization and asthma; [ICSC] "Biological monitoring of exposure to 1,5-naphthalene diisocyanate and 4,4'-methylenediphenyl diisocyanate." [PMID 16506043] See "Methylenediphenyl diisocyanate."

Reference Link #1

Biomedical References

Insufficient data

0.051 mg/m3

Ceiling(OSHA) = 0.2 mg/m3

0.05 mg/m3, inhalable fraction

7 ppm

Excerpts from Documentation for IDLHs

Basis for original (SCP) IDLH: The chosen IDLH is based on an analogy with toluene diisocyanate, which has an IDLH of 10 ppm. [Note: A concentration of 10 ppm methylene bisphenyl isocyanate is equivalent to about 100 mg/m3.]

5E-06 mm Hg

0.39 ppm

LC50 (rat) = 369 mg/m3/4H

Explanatory Notes

Odor threshold from AIHA; VP from HSDB;

Reference Link #2

must be preheated

Not appropriate

5 mg/m3

55 mg/m3

Yes

Yes

Yes

Yes

Not classifiable

Diseases

Occupational diseases associated with exposure to this agent:

• Asthma, occupational
• Contact dermatitis, allergic
• Contact urticaria
• Isocyanate HP

Processes

Industrial Processes with risk of exposure:

• Metal Preparation and Pouring
• Molding and Core Making
• Painting (Pigments, Binders, and Biocides)
• Plastic Composites Manufacturing
• Textiles (Fiber & Fabric Manufacturing)
• Working with Glues and Adhesives

Activities

Activities with risk of exposure:

• Preparing and mounting animal skins (taxidermy)