NIOSH Publication No. 2005-151:

NIOSH Pocket Guide to Chemical Hazards

September 2005

Pentaborane

CAS
19624-22-7

B5H9

RTECS
RY8925000
Synonyms & Trade Names

Pentaboron nonahydride
DOT ID & Guide
1380 / 135

Exposure
Limits

NIOSH REL: TWA 0.005 ppm (0.01 mg/m3) ST 0.015 ppm (0.03 mg/m3)
OSHA PEL†: TWA 0.005 ppm (0.01 mg/m3)
IDLH
1 ppm See: 19624227
Conversion
1 ppm = 2.58 mg/m3
Physical Description
Colorless liquid with a pungent odor like sour milk.
MW: 63.1
BP: 140°F
FRZ: -52°F
Sol: Reacts
VP: 171 mmHg
IP: 9.90 eV

Sp.Gr: 0.62
Fl.P: 86°F
UEL: ?
LEL: 0.42%

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

Oxidizers, halogens, water, halogenated hydrocarbons [Note: May ignite SPONTANEOUSLY in moist air. Corrosive to natural rubber. Hydrolyzes slowly with heat in water to form boric acid.]
Measurement Methods
None available
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, Quick drench
First Aid
(See procedures)
Eye: Irrigate immediately
Skin: Soap wash immediately
Breathing: Respiratory support
Swallow: Medical attention immediately
Respirator Recommendations
NIOSH/OSHA
Up to 0.05 ppm:
(APF = 10) Any supplied-air respirator
Up to 0.125 ppm:
(APF = 25) Any supplied-air respirator operated in a continuous-flow mode
Up to 0.25 ppm:
(APF = 50) Any supplied-air respirator that has a tight-fitting facepiece and is operated in a continuous-flow mode
(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 = 1000) Any supplied-air respirator 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 canister providing protection against the compound of concern/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; dizziness, headache, drowsiness, incoordination, tremor, convulsions, behavioral changes; tonic spasm face, neck, abdominal, limbs
Target Organs
Eyes, skin, central nervous system
See also: INTRODUCTION   See ICSC CARD: 0819