NIOSH Publication No. 2005-151:

NIOSH Pocket Guide to Chemical Hazards

September 2005

Tetrahydrofuran

CAS
109-99-9

C4H8O

RTECS
LU5950000
Synonyms & Trade Names

Diethylene oxide; 1,4-Epoxybutane; Tetramethylene oxide; THF
DOT ID & Guide
2056 / 127

Exposure
Limits

NIOSH REL: TWA 200 ppm (590 mg/m3) ST 250 ppm (735 mg/m3)
OSHA PEL: TWA 200 ppm (590 mg/m3)
IDLH
2000 ppm [10%LEL] See: 109999
Conversion
1 ppm = 2.95 mg/m3
Physical Description
Colorless liquid with an ether-like odor.
MW: 72.1
BP: 151°F
FRZ: -163°F
Sol: Miscible
VP: 132 mmHg
IP: 9.45 eV

Sp.Gr: 0.89
Fl.P: 6°F
UEL: 11.8%
LEL: 2%

Class IB Flammable Liquid: Fl.P. below 73F and BP at or above 100F.
Incompatibilities & Reactivities

Strong oxidizers, lithium-aluminum alloys [Note: Peroxides may accumulate upon prolonged storage in presence of air.]
Measurement Methods
NIOSH 1609, 3800; OSHA 7
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

First Aid
(See procedures)
Eye: Irrigate immediately
Skin: Water flush promptly
Breathing: Respiratory support
Swallow: Medical attention immediately
Respirator Recommendations
NIOSH/OSHA
Up to 2000 ppm:
(APF = 25) Any supplied-air respirator operated in a continuous-flow mode
(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 = 25) Any powered, air-purifying respirator with 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
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, ingestion, skin and/or eye contact
Symptoms
Irritation eyes, upper respiratory system; nausea, dizziness, headache, central nervous system depression
Target Organs
Eyes, respiratory system, central nervous system
See also: INTRODUCTION   See ICSC CARD: 0578   See MEDICAL TESTS: 0070