Methylene bis(4-cyclohexylisocyanate)

Synonyms & Trade Names

Dicyclohexylmethane 4,4'-diisocyanate, DMDI, HMDI, Hydrogenated MDI, bis(4-Isocyanatocyclohexyl)methane, Reduced MDI, Saturated MDI

CAS No.

5124-30-1

RTECS No.

NQ9250000

DOT ID & Guide

Formula

CH₂[(C₆H₁₀)NCO]₂

Conversion

1 ppm = 10.73 mg/m³

IDLH

N.D.
See: IDLH INDEX

Exposure Limits

NIOSH REL

C 0.01 ppm (0.11 mg/m³)

OSHA PEL

none See Appendix G

Measurement Methods

NIOSH 5525;
OSHA PV2092
See: NMAM or OSHA Methods

Physical Description

Clear, colorless to light-yellow liquid.

Molecular Weight

262.4

Boiling Point

Freezing Point

<14°F

Solubility

Reacts

Vapor Pressure

(77°F): 0.001 mmHg

Ionization Potential

Specific Gravity

(77°F): 1.07

Flash Point

>395°F

Upper Explosive Limit

Lower Explosive Limit

Class IIIB Combustible Liquid: Fl.P. at or above 200°F.

Incompatibilities & Reactivities

Water, ethanol, alcohols, amines, bases, acids, organotin catalysts [Note: May slowly polymerize if heated above 122°F.]

Exposure Routes

inhalation, ingestion, skin and/or eye contact

Symptoms

irritation eyes, skin, respiratory system; skin, resp sensitization; chest tightness, dyspnea (breathing difficulty), cough, dry throat, wheezing, pulmonary edema; skin blisters

Target Organs

Eyes, skin, respiratory system

Personal Protection/Sanitation

(See protection codes)
Skin:Prevent skin contact
Eyes:Prevent eye contact
Wash skin:When contaminated
Remove:When wet or contaminated
Change:No recommendation
Provide:Quick drench

First Aid

(See procedures)
Eye:Irrigate immediately
Skin:Water flush immediately
Breathing:Respiratory support
Swallow:Medical attention immediately

Respirator Recommendations

NIOSH

Up to 0.1 ppm:
(APF = 10) Any supplied-air respirator*

Up to 0.25 ppm:
(APF = 25) Any supplied-air respirator operated in a continuous-flow mode*

Up to 0.5 ppm:
(APF = 50) Any self-contained breathing apparatus with a full facepiece
(APF = 50) Any supplied-air respirator with a full facepiece

Up to 1 ppm:
(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) Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode in combination with an auxiliary self-contained positive-pressure breathing apparatus

Escape:
(APF = 50) Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted organic vapor canister
Any appropriate escape-type, self-contained breathing apparatus

Important additional information about respirator selection

Methylene bis(4-cyclohexylisocyanate)

NIOSH REL

OSHA PEL

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