Methylene bis(4-cyclohexylisocyanate)

Synonyms & Trade Names

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

Physical Description

Clear, colorless to light-yellow liquid.

Incompatibilities & Reactivities

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

Symptoms

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

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