Diamond	Hazard	Value	Description
4 4 2	Health	4	Can be lethal.
	Flammability	4	Burns readily. Rapidly or completely vaporizes at atmospheric pressure and normal ambient temperature.
	Instability	2	Readily undergoes violent chemical changes at elevated temperatures and pressures.
	Special

A clear colorless liquid with a pungent odor like sour milk. Freezing point -52.9°F (-46.6°C). Boiling point 136.4°F (58°C). Decomposition temperature 302°F (150°C). Vapors toxic both under prolonged exposure to low concentrations and short exposure to high concentrations. Density 0.61 g / cm3. Under prolonged exposure to intense heat the containers may rupture violently and rocket.

• Strong Reducing Agent
• Pyrophoric

Highly flammable. May ignite spontaneously in air [Merck 11th ed. 1989]. Slowly decomposes in water.

Ignites spontaneously in air. Reacts violently with halogenated extinguishing agents. Boron hydrides present considerable fire and explosion hazard. They undergo explosive reaction with most oxidizing agents, including halogenated hydrocarbons. Fires tend to reignite. On decomposition, it emits toxic fumes and can react vigorously with oxidizing materials. Avoid dimethyl sulfoxide, water, most oxidizing agents (including halogenated hydrocarbons). Avoid direct sunlight and sources of ignition, decomposes very slowly at 302. Hazardous polymerization may not occur. (EPA, 1998)

May cause death or permanent injury after very short exposure to small quantities. (EPA, 1998)

PENTABORANE is an extremely reactive reducing agent. Can ignite spontaneously in contact with air and many other materials. Reactions with oxygen are often violently explosive. Reacts with ammonia to form a diammoniate. Is stabilized by the formation of complexes with N, O, P, or S. Is stable in hydrocarbon solvents, but forms shock sensitive solutions in most carbonyl containing solvents.

• Metal Hydrides, Metal Alkyls, Metal Aryls, and Silanes

No information available.

Excerpt from ERG Guide 135 [Substances - Spontaneously Combustible]:

IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids.

SPILL: See ERG Table 1 - Initial Isolation and Protective Action Distances on the UN/NA 1380 datasheet.

FIRE: If tank, rail tank car or highway tank is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2024)

Move container from fire area if you can do it without risk. Cool containers that are exposed to flames with water from the side until well after fire is out. For massive fire in cargo area, use unmanned hose holder or monitor nozzles; if this is impossible, withdraw from area and let fire burn. Wear positive pressure breathing apparatus and full protective clothing. Evacuation: if fire becomes uncontrollable or container is exposed to direct flame -- evacuate for a radius of 1,500 feet. If material is leaking (not on fire), downwind evacuation must be considered.

If material is on fire or involved in fire, do not extinguish unless flow can be stopped. Do not use water. Extinguish small fires with dry chemical or carbon dioxide. For large fires withdraw and let burn. (EPA, 1998)

Excerpt from ERG Guide 135 [Substances - Spontaneously Combustible]:

ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area. Do not touch or walk through spilled material. Stop leak if you can do it without risk.

SMALL SPILL: CAUTION: For spills of Xanthates, UN3342 and for Dithionite (Hydrosulfite/Hydrosulphite), UN1384, UN1923 and UN1929, dissolve in 5 parts water and collect for proper disposal. CAUTION: UN3342 when flooded with water will continue to evolve flammable Carbon disulfide/Carbon disulphide vapors. Cover with DRY earth, DRY sand or other non-combustible material followed with plastic sheet to minimize spreading or contact with rain. Use clean, non-sparking tools to collect material and place it into loosely covered plastic containers for later disposal. Prevent entry into waterways, sewers, basements or confined areas. (ERG, 2024)

Excerpt from NIOSH Pocket Guide for Pentaborane:

Skin: PREVENT SKIN CONTACT - Wear appropriate personal protective clothing to prevent skin contact.

Eyes: PREVENT EYE CONTACT - Wear appropriate eye protection to prevent eye contact.

Wash skin: WHEN CONTAMINATED - The worker should immediately wash the skin when it becomes contaminated.

Remove: WHEN WET (FLAMMABLE) - Work clothing that becomes wet should be immediately removed due to its flammability hazard (i.e., for liquids with a flash point <100°F).

Change: No recommendation is made specifying the need for the worker to change clothing after the workshift.

Provide:
• EYEWASH - Eyewash fountains should be provided in areas where there is any possibility that workers could be exposed to the substances; this is irrespective of the recommendation involving the wearing of eye protection.
• QUICK DRENCH - Facilities for quickly drenching the body should be provided within the immediate work area for emergency use where there is a possibility of exposure. [Note: It is intended that these facilities provide a sufficient quantity or flow of water to quickly remove the substance from any body areas likely to be exposed. The actual determination of what constitutes an adequate quick drench facility depends on the specific circumstances. In certain instances, a deluge shower should be readily available, whereas in others, the availability of water from a sink or hose could be considered adequate.] (NIOSH, 2024)

No information available.

Signs and Symptoms of Pentaborane Exposure: Inhalation of low concentrations of pentaborane causes behavioral changes, loss of recent memory, poor judgement, nausea, vomiting, drowsiness, and difficulty in focusing. Inhalation of higher concentrations may cause headache, dizziness, nervous excitation, muscular pain, loss of muscle coordination, cramps, muscle spasms, tremors, convulsions, coma, and death due to central nervous system poisoning. Pentaborane may irritate or burn the skin, eyes, and mucous membranes.

Emergency Life-Support Procedures: Acute exposure to pentaborane may require decontamination and life support for the victims. Emergency personnel should wear protective clothing appropriate to the type and degree of contamination. Air-purifying or supplied-air respiratory equipment should also be worn, as necessary. Rescue vehicles should carry supplies such as plastic sheeting and disposable plastic bags to assist in preventing spread of contamination.

Inhalation Exposure:
1. Move victims to fresh air. Emergency personnel should avoid self-exposure to pentaborane.
2. Evaluate vital signs including pulse and respiratory rate, and note any trauma. If no pulse is detected, provide CPR. If not breathing, provide artificial respiration. If breathing is labored, administer oxygen or other respiratory support.
3. Obtain authorization and/or further instructions from the local hospital for administration of an antidote or performance of other invasive procedures.
4. Rush to a health care facility.

Dermal/Eye Exposure:
1. Remove victims from exposure. Emergency personnel should avoid self-exposure to pentaborane.
2. Evaluate vital signs including pulse and respiratory rate, and note any trauma. If no pulse is detected, provide CPR. If not breathing, provide artificial respiration. If breathing is labored, administer oxygen or other respiratory support.
3. Remove and isolate contaminated clothing as soon as possible.
4. If eye exposure has occurred, eyes must be flushed with lukewarm water for at least 15 minutes.
5. Wash exposed skin areas thoroughly with water.
6. Obtain authorization and/or further instructions from the local hospital for administration of an antidote or performance of other invasive procedures.
7. Rush to a health care facility.

Ingestion Exposure:
1. Evaluate vital signs including pulse and respiratory rate, and note any trauma. If no pulse is detected, provide CPR. If not breathing, provide artificial respiration. If breathing is labored, administer oxygen or other respiratory support.
2. Obtain authorization and/or further instructions from the local hospital for administration of an antidote or performance of other invasive procedures.
3. Vomiting may be induced with syrup of Ipecac. If elapsed time since ingestion of pentaborane is unknown or suspected to be greater than 30 minutes, do not induce vomiting and proceed to Step
4. Ipecac should not be administered to children under 6 months of age. Warning: Ingestion of pentaborane may result in sudden onset of seizures or loss of consciousness. Syrup of Ipecac should be administered only if victims are alert, have an active gag-reflex, and show no signs of impending seizure or coma. If ANY uncertainty exists, proceed to Step
4. The following dosages of Ipecac are recommended: children up to 1 year old, 10 mL (1/3 oz); children 1 to 12 years old, 15 mL (1/2 oz); adults, 30 mL (1 oz). Ambulate (walk) the victims and give large quantities of water. If vomiting has not occurred after 15 minutes, Ipecac may be readministered. Continue to ambulate and give water to the victims. If vomiting has not occurred within 15 minutes after second administration of Ipecac, administer activated charcoal.
4. Activated charcoal may be administered if victims are conscious and alert. Use 15 to 30 g (1/2 to 1 oz) for children, 50 to 100 g (1-3/4 to 3-1/2 oz) for adults, with 125 to 250 mL (1/2 to 1 cup) of water.
5. Promote excretion by administering a saline cathartic or sorbitol to conscious and alert victims. Children require 15 to 30 g (1/2 to 1 oz) of cathartic; 50 to 100 g (1-3/4 to 3-1/2 oz) is recommended for adults.
6. Rush to a health care facility. (EPA, 1998)

• BORANE (B5H9)
• BORON HYDRIDE (B5H9)
• NONAHYDROPENTABORANE
• PENTABORANE
• PENTABORANE (B5H9)
• PENTABORANE(9)
• PENTABORON NONAHYDRIDE
• (9)-PENTABORON NONAHYDRIDE