Diphenylmethane diisocyanate

1Identification

Name

Diphenylmethane diisocyanate

IUPAC name

1-isocyanato-4-[(4-isocyanatophenyl)methyl]benzene

CAS number

101-68-8

EC number

202-966-0

Molecular formula

C15H10N2O2

Molecular weight

250.25 g/mol

InChIKey

UPMLOUAZCHDJJD-UHFFFAOYSA-N

SMILES

C1=CC(=CC=C1CC2=CC=C(C=C2)N=C=O)N=C=O

PubChem CID

7570

Synonyms

4,4'-Diphenylmethane diisocyanate, Diphenylmethane diisocyanate, Bis(4-isocyanatophenyl)methane, 4,4'-Methylenebis(phenyl isocyanate), Isonate, Desmodur 44, p,p'-Diphenylmethane diisocyanate, 1,1'-Methylenebis(4-isocyanatobenzene), Methylbisphenyl isocyanate, 4,4'-Methylenediphenyl diisocyanate, 4,4'-Diisocyanatodiphenylmethane, Methylene bisphenyl isocyanate, diphenylmethane-4,4'-diisocyanate, Caradate 30

Recommended uses

• The commercial form of MDI is primarily used to produce polyurethane foams.
  EPA Hazardous Air Pollutants
• 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]
  Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
• Molding and Core Making [Category: Foundry] Metal Preparation and Pouring [Category: Foundry] Textiles (Fiber & Fabric Manufacturing) [Category: Industry] Painting (Pigments, Binders, and Biocides) [Category: Paint] Working with Glues and Adhesives [Category: Other] Plastic Composites Manufacturing [Category: Industry]
  Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
• Monomers Polymerization promoter Binder Intermediate Pigment
  EPA Chemical Data Reporting (CDR)
• Pigment Polymerization promoter
  EPA Chemical Data Reporting (CDR)

Description

• Diphenylmethane-4,4-diisocyanate is a light yellow colored solid. It is not soluble in water. It may be toxic by ingestion, inhalation, or skin absorption. If in a solution it may or may not burn depending on the nature of the material and/or the solvent. It is used to make plastics.
  CAMEO Chemicals
• 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 an allergen and a hapten. It derives from a hydride of a diphenylmethane.
  ChEBI
• The commercial form of 4,4'-methylenediphenyl diisocyanate (MDI) is used to produce polyurethane foams. Acute (short-term) inhalation of high concentrations of MDI may cause sensitization and asthma in humans. Acute dermal contact with MDI has induced dermatitis and eczema in workers. MDI has been observed to irritate the skin and eyes of rabbits. Chronic (long-term) inhalation exposure to MDI has been shown to cause asthma, dyspnea, and other respiratory impairments in workers. Respiratory effects have also been observed in animals. No adequate information is available on the reproductive, developmental, or carcinogenic effects of MDI in humans.
  EPA Hazardous Air Pollutants

2Hazard identification

Signal word

Danger

Pictograms

GHS07, GHS08

Classification source

Regulation (EC) No 1272/2008 of the European Parliament and of the Council

Precautionary statements

Other reported classifications

9 classification records exist across sources. Differences usually reflect purity, physical form or impurities.

Health hazards

• Breathlessness, chest discomfort, and reduced pulmonary function. (USCG, 1999)
  CAMEO Chemicals

Fire hazards

• Special Hazards of Combustion Products: Toxic vapors are generated when heated. Behavior in Fire: Solid melts and burns (USCG, 1999)
  CAMEO Chemicals
• Combustible. Gives off irritating or toxic fumes (or gases) in a fire.
  ILO-WHO International Chemical Safety Cards (ICSCs)

Hazards summary

• The commercial form of 4,4'-methylenediphenyl diisocyanate (MDI) is used to produce polyurethane foams. Acute (short-term) inhalation of high concentrations of MDI may cause sensitization and asthma in humans. Acute dermal contact with MDI has induced dermatitis and eczema in workers. MDI has been observed to irritate the skin and eyes of rabbits. Chronic (long-term) inhalation exposure to MDI has been shown to cause asthma, dyspnea, and other respiratory impairments in workers. Respiratory effects have also been observed in animals. No adequate information is available on the reproductive, developmental, or carcinogenic effects of MDI in humans.
  EPA Hazardous Air Pollutants
• 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.
  Haz-Map, Information on Hazardous Chemicals and Occupational Diseases

3Composition / information on ingredients

This page describes the pure substance. Commercial products may be solutions or mixtures. Check Section 3 of your supplier's SDS for concentrations and other ingredients.

4First-aid measures

• EYES: First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. IMMEDIATELY transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop. SKIN: IMMEDIATELY flood affected skin with water while removing and isolating all contaminated clothing. Gently wash all affected skin areas thoroughly with soap and water.
  CAMEO Chemicals
• (General first aid procedures) Eye: Irrigate immediately - If this chemical contacts the eyes, immediately wash (irrigate) the eyes with large amounts of water, occasionally lifting the lower and upper lids. Get medical attention immediately. Skin: Soap wash immediately - If this chemical contacts the skin, immediately wash the contaminated skin with soap and water. If this chemical penetrates the clothing, immediately remove the clothing, wash the skin with soap and water, and get medical attention promptly. Breathing: Respiratory support Swallow: Medical attention immediately - If this chemical has been swallowed, get medical attention immediately.
  The National Institute for Occupational Safety and Health (NIOSH)

Symptoms of exposure

• Headache. Nausea. Shortness of breath. Sore throat.
  ILO-WHO International Chemical Safety Cards (ICSCs)
• Redness.
  ILO-WHO International Chemical Safety Cards (ICSCs)
• Pain.
  ILO-WHO International Chemical Safety Cards (ICSCs)

5Fire-fighting measures

• Carbon dioxide or dry chemical.
  Hazardous Substances Data Bank (HSDB)
• If material on fire or involved in fire: Extinguish fire using agent suitable for type of surrounding fire. Material itself does not burn or burns with difficulty. Keep run-off water out of sewers and water sources. /Methylene diphenyl diisocyanate/
  Hazardous Substances Data Bank (HSDB)
• Where there is a fire involving isocyanates, carbon dioxide or powder extinguishers must be employed. Firemen must be equipped with self-contained breathing apparatus. /Isocyanates/
  Hazardous Substances Data Bank (HSDB)

6Accidental release measures

Isolation and evacuation

• Excerpt from ERG Guide 156 [Substances - Toxic and/or Corrosive (Combustible / Water-Sensitive)]: IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids. SPILL: Increase the immediate precautionary measure distance, in the downwind direction, as necessary. FIRE: If tank, rail tank car or highway tank is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2024)
  CAMEO Chemicals

Spill cleanup

• Evacuate danger area! Consult an expert! Personal protection: chemical protection suit including self-contained breathing apparatus. Sweep spilled substance into covered sealable containers. Carefully collect remainder. Then store and dispose of according to local regulations.
  ILO-WHO International Chemical Safety Cards (ICSCs)
• VENTILATE AREA OF SPILL OR LEAK. FOR SMALL QUANTITIES, ABSORB ON PAPER TOWELS. ... BURN THE PAPER IN SUITABLE LOCATION AWAY FROM COMBUSTIBLE MATERIALS. LARGE QUANTITIES CAN BE COLLECTED & ATOMIZED IN SUITABLE COMBUSTION CHAMBER EQUIPPED WITH APPROPRIATE EFFLUENT GAS CLEANING DEVICE. DISPOSAL METHODS: 1. BY ABSORBING ON VERMICULITE, DRY SAND, EARTH OR A SIMILAR MATERIAL & DISPOSING IN A SECURED SANITARY LANDFILL. 2. BY ATOMIZING IN SUITABLE COMBUSTION CHAMBER EQUIPPED WITH APPROPRIATE EFFLUENT GAS CLEANING DEVICE.
  Hazardous Substances Data Bank (HSDB)
• Environmental considerations - land spill: Dig a pit, pond, lagoon, holding area to contain liquid or solid material. Cover solids with a plastic sheet to prevent dissolving in rain or fire fighting water. Dike surface flow using soil, sand bags, foamed polyurethane, or foamed concrete. /Methylene diphenyl diisocyanate/
  Hazardous Substances Data Bank (HSDB)
• Environmental considerations - water spill: Use natural barriers or oil spill control booms to limit spill travel. Use natural deep water pockets, excavated lagoons, or sand bag barriers to trap material at bottom. Remove trapped material with suction hoses. /Methylene diphenyl diisocyanate/
  Hazardous Substances Data Bank (HSDB)

7Handling and storage

• Separated from food and feedstuffs and incompatible materials. See Chemical Dangers. Cool. Dry. Keep in the dark.
  ILO-WHO International Chemical Safety Cards (ICSCs)
• Isocyanates are transported in railroad tank cars, tank trucks, tanks in ships, containers, and drums. They are stored in steel tanks and processed in steel equipment. For long-term storage stainless steel is recommended. To avoid contamination by atmospheric moisture, a dry air or inert gas blanket is essential. /Isocyanates/
  Hazardous Substances Data Bank (HSDB)

8Exposure controls / personal protection

Personal protective equipment

• Excerpt from NIOSH Pocket Guide for Methylene bisphenyl isocyanate: Skin: PREVENT SKIN CONTACT - Wear appropriate personal protective clothing to prevent skin contact. Eyes: PREVENT EYE CONTACT - Wear appropriate eye protection to prevent eye contact. Wash skin: WHEN CONTAMINATED - The worker should immediately wash the skin when it becomes contaminated. Remove: WHEN WET OR CONTAMINATED - Work clothing that becomes wet or significantly contaminated should be removed and replaced. Change: DAILY - Workers whose clothing may have become contaminated should change into uncontaminated clothing before leaving the work premises. (NIOSH, 2024)
  CAMEO Chemicals
• MASK OR RESPIRATOR OF TYPE APPROVED BY USA BUREAU OF MINES (ABOVE 135 °C); CLEAN RUBBER GLOVES; CHEMICAL GOGGLES; CLEAN WATERPROOF OR FRESHLY LAUNDERED PROTECTIVE CLOTHING (COVERALLS, RUBBER BOOTS, CAP, ETC).
  Hazardous Substances Data Bank (HSDB)
• Wear appropriate personal protective clothing to prevent skin contact.
  Hazardous Substances Data Bank (HSDB)
• Wear appropriate eye protection to prevent eye contact.
  Hazardous Substances Data Bank (HSDB)

Respirator recommendations

• NIOSH Up to 0.5 mg/m3 : (APF = 10) Any supplied-air respirator* Up to 1.25 mg/m3 : (APF = 25) Any supplied-air respirator operated in a continuous-flow mode* Up to 2.5 mg/m3 : (APF = 50) Any self-contained breathing apparatus with a full facepiece (APF = 50) Any supplied-air respirator with a full facepiece Up to 75 mg/m3 : (APF = 2000) Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode Emergency or planned entry into unknown concentrations or IDLH conditions: (APF = 10,000) Any self-contained breathing apparatus that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode (APF = 10,000)…
  The National Institute for Occupational Safety and Health (NIOSH)

9Physical and chemical properties

10Stability and reactivity

Reactivity

• Isocyanates and thioisocyanates, such as DIPHENYLMETHANE-4,4'-DIISOCYANATE, are incompatible with many classes of compounds, reacting exothermically to release toxic gases. Reactions with amines, aldehydes, alcohols, alkali metals, ketones, mercaptans, strong oxidizers, hydrides, phenols, and peroxides can cause vigorous releases of heat. Acids and bases initiate polymerization reactions in these materials. Some isocyanates react with water to form amines and liberate carbon dioxide. Base-catalysed reactions of isocyanates with alcohols should be carried out in inert solvents. Such reactions in the absence of solvents often occur with explosive violence, [Wischmeyer(1969)].
  CAMEO Chemicals
• It is not soluble in water.
  CAMEO Chemicals

Incompatible materials and hazardous reactions

• Strong alkalis, acids, alcohol [Note: Polymerizes at 450 degrees F].
  Hazardous Substances Data Bank (HSDB)
• Strong alkalis, acids, alcohol [Note: Polymerizes at 450 °F.]
  The National Institute for Occupational Safety and Health (NIOSH)

11Toxicological information

Target organs

• Nervous Respiratory
  EPA Integrated Risk Information System (IRIS)
• Eyes, respiratory system
  The National Institute for Occupational Safety and Health (NIOSH)

Short-term exposure effects

• Lachrymation. The substance is irritating to the eyes, skin and respiratory tract. The substance may cause effects on the lungs. This may result in impaired functions.
  ILO-WHO International Chemical Safety Cards (ICSCs)

Long-term exposure effects

• Repeated or prolonged contact may cause skin sensitization. Repeated or prolonged inhalation may cause asthma.
  ILO-WHO International Chemical Safety Cards (ICSCs)

12Ecological information

Not available in the public sources we compile. Check Section 12 of the supplier's SDS.

13Disposal considerations

• SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in soil or water; effects on animal and plant life; and conformance with environmental and public health regulations.
  Hazardous Substances Data Bank (HSDB)
• SRP: Wastewater from contaminant suppression, cleaning of protective clothing/equipment, or contaminated sites should be contained and evaluated for subject chemical or decomposition product concentrations. Concentrations shall be lower than applicable environmental discharge or disposal criteria. Alternatively, pretreatment and/or discharge to a permitted wastewater treatment facility is acceptable only after review by the governing authority and assurance that "pass through" violations will not occur. Due consideration shall be given to remediation worker exposure (inhalation, dermal and ingestion) as well as fate during treatment, transfer and disposal.
  Hazardous Substances Data Bank (HSDB)

14Transport information

DOT label

• Poison
  CAMEO Chemicals

Not available in the public sources we compile. Check Section 14 of the supplier's SDS.

How DOT hazard classes work →

15Regulatory information

• This action promulgates standards of performance for equipment leaks of Volatile Organic Compounds (VOC) in the Synthetic Organic Chemical Manufacturing Industry (SOCMI). The intended effect of these standards is to require all newly constructed, modified, and reconstructed SOCMI process units to use the best demonstrated system of continuous emission reduction for equipment leaks of VOC, considering costs, non air quality health and environmental impact and energy requirements. Methylene diphenyl diisocyanate is produced, as an intermediate or a final product, by process units covered under this subpart.
  Hazardous Substances Data Bank (HSDB)
• Persons in charge of vessels or facilities are required to notify the National Response Center (NRC) immediately, when there is a release of this designated hazardous substance, in an amount equal to or greater than its reportable quantity of 5000 lb or 2270 kg. The toll free number of the NRC is (800) 424-8802. The rule for determining when notification is required is stated in 40 CFR 302.4 (section IV. D.3.b).
  Hazardous Substances Data Bank (HSDB)
• Section 8(a) of TSCA requires manufacturers of this chemical substance to report preliminary assessment information concerned with production, exposure, and use to EPA as cited in the preamble in 51 FR 41329. Effective date: 10/29/90; Reporting date: 12/27/90.
  Hazardous Substances Data Bank (HSDB)

Overview of SDS regulations (OSHA HazCom, WHMIS, REACH/CLP) →

16Other information

Compiled from PubChem CID 7570 and the sources it aggregates (attributed inline). Data retrieved 2026-10-12. This summary describes the pure substance and is not a supplier SDS.