4,4'-METHYLENEBIS(PHENYL ISOCYANATE) Property

Melting point:

42-45℃

Density 

1.18

storage temp. 

2-8°C

form 

Flakes

color 

White

CAS DataBase Reference

26447-40-5(CAS DataBase Reference)

EPA Substance Registry System

Diphenylmethane diisocyanate (26447-40-5)

Safety

Hazard Codes 

Xn

Risk Statements 

20-36/37/38-42/43

Safety Statements 

23-36/37-45

RIDADR 

UN 2811

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Danger

Hazard statements

H315Causes skin irritation

H317May cause an allergic skin reaction

H319Causes serious eye irritation

H332Harmful if inhaled

H334May cause allergy or asthma symptoms or breathing difficulties if inhaled

H335May cause respiratory irritation

H351Suspected of causing cancer

H373May cause damage to organs through prolonged or repeated exposure

Precautionary statements

P201Obtain special instructions before use.

P202Do not handle until all safety precautions have been read and understood.

P260Do not breathe dust/fume/gas/mist/vapours/spray.

P261Avoid breathing dust/fume/gas/mist/vapours/spray.

P264Wash hands thoroughly after handling.

P264Wash skin thouroughly after handling.

P271Use only outdoors or in a well-ventilated area.

P272Contaminated work clothing should not be allowed out of the workplace.

P280Wear protective gloves/protective clothing/eye protection/face protection.

P281Use personal protective equipment as required.

P285In case of inadequate ventilation wear respiratory protection.

P302+P352IF ON SKIN: wash with plenty of soap and water.

P304+P340IF INHALED: Remove victim to fresh air and Keep at rest in a position comfortable for breathing.

P304+P341IF INHALED: If breathing is difficult, remove victim to fresh air and keep at rest in a position comfortable for breathing.

P305+P351+P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.

P308+P313IF exposed or concerned: Get medical advice/attention.

P312Call a POISON CENTER or doctor/physician if you feel unwell.

P314Get medical advice/attention if you feel unwell.

P321Specific treatment (see … on this label).

P332+P313IF SKIN irritation occurs: Get medical advice/attention.

P333+P313IF SKIN irritation or rash occurs: Get medical advice/attention.

P342+P311IF experiencing respiratory symptoms: call a POISON CENTER or doctor/physician.

P362Take off contaminated clothing and wash before reuse.

P363Wash contaminated clothing before reuse.

P405Store locked up.

P501Dispose of contents/container to..…

4,4'-METHYLENEBIS(PHENYL ISOCYANATE) Chemical Properties,Usage,Production

Storage

Cool, ventilated, strictly waterproof, moisture-proof, avoid direct sunlight, and keep away from fire and heat sources. The storage temperature should not exceed 20℃ during long-term storage.

Description

Methylene diphenyl diisocyanate (MDI) is a white, odorless diisocyanate that may also occur in crystalline form. It exists in three isomers, (2,20-MDI,2,40-MDI, and 4,40-MDI), however, the primary technical/commercial form of MDI is actually polymeric MDI, which is a mixture that contains 25–80% monomeric 4,40-MDI as well as oligomers containing three to six rings and other minor isomers, such as the 2,20-isomer the 4,40 isomer. MDI is most widely used and accounted for 62% of the global market in 2000.

Uses

MDI is used to produce polyurethane foams for application in a wide range of retail, commercial, and industrial uses to protect cement, wood, fiberglass, steel, and aluminum surfaces such as truck beds, trailers, boats, foundations, and decks. MDI is also used as a high strength adhesive in industrial and consumer applications.

Definition

ChEBI: Diphenylmethane-4,4'-diisocyanate is a diisocyanate consisting of diphenylmethane with two isocyanate groups at the 4- and 4'-positions. It has a role as a hapten and an allergen. It derives from a hydride of a diphenylmethane.

Environmental Fate

MDI is the least hazardous of the commonly available isocyanates, however, it is not without toxicity. It has low vapor pressure, which reduces hazards during handling compared to the other major isocyanates, e.g., TDI, HDI. The complex nature of MDI composition and reactions in the environment often makes interpretation difficult. Release of MDI to the atmosphere is low due to its low volatility and since MDI readily degrades to inorganic compounds in the presence of hydroxyl radicals, its atmospheric half-life is short. High exposures involving MDI in ambient environments are expected to be rare. There is no information about levels of various forms of MDI in the ambient air. When MDI is released to water, it reacts readily with water to form mixtures of diisocyanates and amines, which then readily react with more MDI to produce inert, solid, insoluble polyurea. MDI has a transient existence due to its reaction with the water to produce predominantly insoluble polyureas. The evidence indicates that MDI accumulation through the aquatic food chain is extremely unlikely, as might be expected considering the very low solubility and high reactivity of MDI with hydroxyl radicals in aqueous solution.

Toxicity evaluation

A definitive mechanism of MDI toxicity is unknown; however, it is speculated that humoral and cellular immunity may be involved in the pathogenesis of hypersensitivity due to isocyanate sensitization responses of both animals and humans.