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Pentaborane

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Synonyms & Trade Names
Pentaboron nonahydride
CAS No.
19624-22-7
RTECS No.
RY8925000
DOT ID & Guide
1380 135
Formula
B₅H₉
Conversion
1 ppm = 2.58 mg/m3
IDLH
1 ppm
See: 19624227
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) See Appendix G
Measurement Methods
None available
See: NMAM or OSHA Methods
Physical Description
Colorless liquid with a pungent odor like sour milk.
Molecular Weight
63.1
Boiling Point
140°F
Freezing Point
-52°F
Solubility
Reacts
Vapor Pressure
171 mmHg
Ionization Potential
9.90 eV
Specific Gravity
0.62
Flash Point
86°F
Upper Explosive Limit
?
Lower Explosive Limit
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.]
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
Personal Protection/Sanitation
(See protection codes)
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

See also
INTRODUCTION   ICSC CARD: 0819
Page last reviewed: October 30, 2019
Content source: National Institute for Occupational Safety and Health