Methylene diphenyl diisocyanate

4,4′-Methylene diphenyl diisocyanate
Names
	Preferred IUPAC name 1,1′-Methylenebis(4-isocyanatobenzene)
	Other names Bis(4-isocyanatophenyl)methane; 1-Isocyanato-4-[(4-isocyanatophenyl)methyl]benzene; 4,4′-Methylene diphenyl diisocyanate; 4,4′-Diphenylmethane diisocyanate; Bayer Desmodur 44; Methylene bis(4-phenyl isocyanate); Pure MDI;
Identifiers
CAS Number	101-68-8 ;
3D model (JSmol)	Interactive image; Interactive image;
ChEBI	CHEBI:53218 ;
ChemSpider	7289 ;
ECHA InfoCard	100.043.361
EC Number	4,4'-: 202-966-0;
PubChem CID	7570;
RTECS number	NQ9350000;
UNII	B0LO6BBS8C ;
	InChI InChI=1S/C15H10N2O2/c18-10-16-14-5-1-12(2-6-14)9-13-3-7-15(8-4-13)17-11-19/h1-8H,9H2 Key: UPMLOUAZCHDJJD-UHFFFAOYSA-N ;
	SMILES O=C=NC(C=C2)=CC=C2CC1=CC=C(N=C=O)C=C1; O=C=N\c1ccc(cc1)Cc2ccc(\N=C=O)cc2;
Properties
Chemical formula	C15H10N2O2
Molar mass	250.25 g/mol
Appearance	White or pale yellow solid
Density	1.230 g/cm3, solid
Melting point	40 °C (104 °F; 313 K)
Boiling point	314 °C (597 °F; 587 K)
Solubility in water	Reacts
Vapor pressure	0.000005 mmHg (20 °C)
Hazards
	GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H315, H317, H319, H332, H334, H335, H351, H373
Precautionary statements	P201, P202, P260, P261, P264, P271, P272, P280, P281, P285, P302+P352, P304+P312, P304+P340, P304+P341, P305+P351+P338, P308+P313, P312, P314, P321, P332+P313, P333+P313, P337+P313, P342+P311, P362, P363, P403+P233, P405, P501
Flash point	212–214 °C (Cleveland open cup)
	Lethal dose or concentration (LD, LC):
LD50 (median dose)	2200 mg/kg (mouse, oral)
LDLo (lowest published)	31,690 mg/kg (rat, oral)
LC50 (median concentration)	369 mg/m3 (rat, 4 hr); 380 mg/m3 (rat, 4 hr); 178 mg/m3 (rat);
	NIOSH (US health exposure limits):
PEL (Permissible)	C 0.2 mg/m3 (0.02 ppm)
REL (Recommended)	TWA 0.05 mg/m3 (0.005 ppm) C 0.2 mg/m3 (0.020 ppm) [10-minute]
IDLH (Immediate danger)	75 mg/m3
Related compounds
Related Isocyanates	Toluene diisocyanate; Naphthalene diisocyanate; Hexamethylene diisocyanate; Isophorone diisocyanate;
Related compounds	Polyurethane
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). verify (what is ?) Infobox references

Methylene diphenyl diisocyanate (MDI) is an aromatic diisocyanate. Three isomers are common, varying by the positions of the isocyanate groups around the rings: 2,2′-MDI, 2,4′-MDI, and 4,4′-MDI. The 4,4′ isomer is most widely used, and is also known as 4,4′-diphenylmethane diisocyanate. This isomer is also known as Pure MDI. MDI reacts with polyols in the manufacture of polyurethane. It is the most produced diisocyanate, accounting for 61.3% of the global market in the year 2000.