NIOSH Publication No. 2005-151:

NIOSH Pocket Guide to Chemical Hazards

September 2005

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
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] See: 110918
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 73F and below 100F.
Incompatibilities & Reactivities

Strong acids, strong oxidizers, metals, nitro compounds [Note: Corrosive to metals.]
Measurement Methods
NIOSH S150 (II-3)
See: NMAM or OSHA Methods
Personal Protection & Sanitation
(See protection)
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
Important additional information about respirator selection
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   See ICSC CARD: 0302