Substance fact sheet
The background information page contains information and concepts that will be useful in understanding some of the issues surrounding the NPI. It is strongly recommended that you read this before reading the information presented below.
For an explanation of some of the terms used in this page, see the Glossary
| Substance name | Methylenebis (phenylisocyanate) |
| CASR number | 101-68-8 |
| Molecular formula | C15H10N2 O2 |
| Synonyms | Isocyanic acid, methylenedi-p-phenylene ester mdi benzene, 1,1'-methylenebis(4-isocyanato)- (9ci) methylenebis (4-isocyanatobenzene) bis(p-isocyanatophenyl)methane 1,1-methylenebis(4-isocyanatobenzene) bis(1,4-isocyanatophenyl)methane methylenebis(p-phenylene isocyanate) methylenebis(4-phenylene isocyanate) bis(4-isocyanatophenyl)methane p,p'-methylenebis(phenyl isocyanate) caradate 30 desmodur 44 4,4'diisocyanatodiphenylmethane 4,4'-diphenylmethane diisocyanate diphenylmethane-4,4'-diisocyanate hylene m50 isonate 125m isonate 125mf methylenebis(p-phenyl isocyanate) methylenebis(4-phenyl isocyanate) 4,4'-methylenebis(phenyl isocyanate) 4,4'-methylenediphenyldiisocyanate methylenedi-p-phenylene diisocyanate methylenedi-p-phenylene isocyanate 4,4'-methylenediphenylene isocyanate nocconate 300 nci-c50668, MDI. |
Physical and chemical properties Physical properties: Insoluble brown liquid, yellow to white crystals or solid at normal temperatures. Melting Point (°C): 37.2 Boiling Point (°C): 196 Specific Gravity: 1.197 Vapour Density:8.6. Chemical properties: |
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Common uses Methylene bis (phenylisocyanate) is used in the making of polyurethane foams and other synthetic components of furniture, machinery and electrical components for a variety of household and other electrical appliances. It is used to bond rubber to other synthetic fibres such as rayon and nylon. Also used in specialised spray paints, surface coatings, man-made resin and artificial gum. Some printers' ink may contain the compound. It is used in metal foundries to bind materials in low-temperature curing of metal components. |
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Sources of emissions Point sources It may be emitted to air, land or water from locations that produce polyurethane foam, adhesives, resins and plastic coatings, or where large volumes of polyurethane spray paint are used such as, vehicle manufacturing and repair workshops, vehicle body shops and specialised marine dockyards. Diffuse sources, and point sources included in aggregated emissions data Trace amounts may enter the natural environment from the wide variety of uses and applications. Minute quantities may be derived from the widely distributed consumer products that use polyurethane foam, adhesives and coatings. Natural sources No natural sources. Mobile sources No mobile sources. Consumer products which may contain Methylenebis (phenylisocyanate) Polyurethane foam, surface coatings, sprays paint, synthetic components of household furniture and a variety of electronic components and accessories where polyurethane products are present. |
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Health effects How might I be exposed to Methylenebis (phenylisocyanate)? People may be exposed to very low levels of Methylene bis (phenylisocyanate) from direct contact with freshly manufactured or produced products that contain it. People working in or living near industries that produce or use it may be subject to low but persistent exposure to minute amounts of dust particles. Exposure is limited to areas where it is used or manufactured. By what pathways might Methylenebis (phenylisocyanate) enter my body? Can be inhaled as minute dust particles or in the form of a fine spray mist. May result in irritation when in contact with the skin or eyes. Relative health hazard On a health hazard spectrum of 0 - 3 Methylenebis (phenylisocyanate) registers 0.8. A score of 3 represents a very high hazard to health, 2 represents a medium hazard and 1 is harmful to health. Factors that are taken into account to obtain this ranking include the extent of the material's toxic or poisonous nature and/or its lack of toxicity, and the evaluation of its tendency to cause, or not cause cancer and/or birth defects. It does not take into account exposure to the substance. Human exposure is reflected in the NPI rank given to this substance (see comparative data below). A substance that scores highly as a health hazard is arsenic at 2.3 and one of the lowest scores is ammonia at 1.0.  Health guidelines Worksafe Australia: Time weighted average atmospheric exposure levels over an 8 hour period is suggested as 0.02 milligrams/cubic metre of air and short term exposure (15 minute interval) is limited to 0.07 mg/m3. The compound is recognised as one that can produce a skin rash or a reduction in immunity in some people. Individuals that respond to the substance in this fashion should avoid all further exposure. See the Additional Information page for current health information. The Australian NOHSC National Exposure Standards Database link is probably the most useful source of information. Note that the emissions data in the NPI database is not directly comparable with these guidelines. What effect might Methylenebis (phenylisocyanate) have on my health? This depends on how much methylene bis (phenylisocyanate) you have been exposed to, for how long, and your current state of health. In certain circumstances, even a brief exposure to very high levels of methylene bis (phenylisocyanate) can result in skin and other irritations and affect breathing capacity. Exposure can result in symptoms such as skin dermatitis, nose, throat, lung and eye irritations. If it is inhaled as a dust it can cause shortness of breath, wheezing, coughing and chest tightness, headache and nausea. |
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Environmental effects Environmental Fate It will remain as a solid at normal temperatures and may gradually breakdown as result of contact with organic compounds in the soil or atmosphere. It will give rise to carbon dioxide and other compounds of nitrogen, carbon, hydrogen and oxygen as result of slow gradual breakdown through contact with the atmosphere. Environmental Transport Methylene bis (phenylisocyanate) is a solid, or less commonly a sticky liquid, and will gradually react with acid or basic compounds in the atmosphere, or in the soil into less complex compounds such as urea, amine and carbon dioxide. It will generally be transported in the atmosphere as dust particles or as a component of an aerosol but that only occurs within or surrounding manufacturing or production plants where it is used. Relative hazard to the environment On an environmental spectrum of 0 - 3 Methylenebis (phenylisocyanate) registers 2. A score of 3 represents a very high hazard to the environment and 0 a negligible hazard. Factors that are taken into account to obtain this ranking include the extent of the material's toxic or poisonous nature and/or its lack of toxicity, and the measure of its ability to remain active in the environment and whether it accumulates in living organisms. It does not take into exposure to the substance. Environmental exposure is reflected in the NPI rank for this substance (see comparative data below). A substance that scores highly as an environmental hazard is oxides of nitrogen at 3.0 and one of the lower scores is carbon monoxide at 0.8.  Environmental guidelines See the Additional Information page for current environmental guidelines. No national guidelines. What effect might Methylenebis (phenylisocyanate) have on the environment? Methylene bis (phenylisocyanate) is known to result in lung damage to humans. Similar results are evident for some other animals but only where the compound has been inhaled as dust particles or an aerosol. |
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Comparative data NPI Rank Approximately 400 substances were considered for inclusion on the NPI reporting list. A risk ranking was given based on health and environmental hazard identification and human and environmental exposure to the substance. Some substances were grouped together at the same rank with 208 ranks in total. Methylenebis (phenylisocyanate) was ranked as 59 out of the 208 ranks. Total hazard score (human health + environmental criteria) = 2.8.  |
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Sources of information used in preparing this fact sheet
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