# NIOSH Pocket Guide to Chemical Hazards
Morpholine | CAS 110-91-8
C4H9ON | RTECS QD6475000
Synonyms & Trade Names Diethylene imidoxide; Diethylene oximide; Tetrahydro-1,4-oxazine; Tetrahydro-p-oxazine | DOT ID & Guide 1760 154 (aqueous) 2054 132
Exposure Limits | NIOSH REL: TWA 20 ppm (70 mg/m3) ST 30 ppm (105 mg/m3) [skin]
OSHA PEL†: TWA 20 ppm (70 mg/m3) [skin]
IDLH 1400 ppm [10%LEL] | Conversion 1 ppm = 3.56 mg/m3
Physical Description Colorless liquid with a weak, ammonia- or fish-like odor. [Note: A solid below 23°F.]
MW: 87.1 | BP: 264°F | FRZ: 23°F | Sol: Miscible
VP: 6 mmHg | IP: 8.88 eV |  | Sp.Gr: 1.007
Fl.P(oc): 98°F | UEL: 11.2% | LEL: 1.4% |
Class IC Flammable Liquid: Fl.P. at or above 73°F and below 100°F.
Incompatibilities & Reactivities Strong acids, strong oxidizers, metals, nitro compounds [Note: Corrosive to metals.]
Measurement Methods NIOSH S150 (II-3)
Personal Protection & Sanitation Skin: Prevent skin contact Eyes: Prevent eye contact Wash skin: When contaminated Remove: When wet (flammable) Change: No recommendation Provide: Eyewash (>15%), Quick drench (>25%) | First Aid (See procedures) Eye: Irrigate immediately Skin: Water flush immediately Breathing: Respiratory support Swallow: Medical attention immediately
Respirator Recommendations NIOSH/OSHA Up to 500 ppm: (APF = 25) Any supplied-air respirator operated in a continuous-flow mode£/(APF = 25) Any powered, air-purifying respirator with organic vapor cartridge(s)£ Up to 1000 ppm: (APF = 50) Any chemical cartridge respirator with a full facepiece and organic vapor cartridge(s)/(APF = 50) Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted organic vapor canister/(APF = 50) Any powered, air-purifying respirator with a tight-fitting facepiece and organic vapor cartridge(s)£/(APF = 50) Any self-contained breathing apparatus with a full facepiece/(APF = 50) Any supplied-air respirator with a full facepiece Up to 1400 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
Exposure Routes inhalation, skin absorption, ingestion, skin and/or eye contact
Symptoms Irritation eyes, skin, nose, respiratory system; visual disturbance; cough; in animals: liver, kidney damage
Target Organs Eyes, skin, respiratory system, liver, kidneys
See also: INTRODUCTION