Medical Management Guidelines for Diborane
(B2H6)
CAS#: 19287-45-7
UN# 1911
PDF Versionpdf icon[170 KB]
Synonyms include boroethane, boron hydride, diboron hexahydride.
- Persons exposed only to diborane pose little risk of secondary contamination to personnel outside the Hot Zone.
- Diborane is a colorless highly flammable gas with a repulsive, sickly sweet odor. At high concentrations, it ignites spontaneously in moist air at room temperature. It reacts with water to form hydrogen and boric acid. Diborane vapors are heavier than air and may collect in low-lying areas.
- Diborane is highly irritant when it contacts moist tissues such as the eyes, skin, and upper respiratory tract and can cause thermal burns. Burns are caused by the exothermic reaction of hydrolysis. Ingestion of diborane is unlikely since it is a gas at ambient temperatures.
General Information
Description
At room temperature, diborane is a colorless
gas with a repulsive, sickly sweet odor. It is generally shipped
in pressurized cylinders diluted with hydrogen, argon, nitrogen,
or helium. It reacts with water to form hydrogen and boric
acid. It mixes well with air and explosive mixtures are easily
formed. At high concentrations, it will ignite spontaneously
in moist air at room temperature. The main toxic effect of
exposure to diborane is irritation of the respiratory airway,
skin, and eyes.
Routes of Exposure
Inhalation
Inhalation is the major route of exposure
to diborane. An odor threshold between 2 and 4 ppm has been
reported for diborane, which is higher than the OSHA permissible
exposure limit (PEL) of 0.1 ppm. Prolonged, low-level exposures,
such as those that occur in the workplace, can lead to olfactory
fatigue and tolerance of diborane's irritant effects. Odor
does not provide adequate warning of hazardous concentrations.
Diborane is heavier than air; exposure to concentrations exceeding
the PEL may result in skin, respiratory, and eye irritation
in poorly ventilated, enclosed, or low-lying areas.
Children exposed to the same levels of
diborane as adults may receive larger dose because they have
a greater lung surface area:body weight ratios and higher
minute volume:weight ratios. In addition, they may be exposed
to higher levels than adults in the same location because
of their short stature and the higher levels of diborane found
nearer to the ground.
Skin/Eye Contact
Direct contact with concentrated diborane
vapors may cause severe eye or skin burns, leading to cell
death and ulceration.
Ingestion
Ingestion is unlikely to occur because
diborane is a gas at room temperature.
Sources/Uses
Diborane is produced by the reaction
of lithium hydride with boron trifluoride catalyzed by ether
at 25ĀŗC.
Diborane is used in rocket propellants
and as a reducing agent, as a rubber vulcanizer, as a catalyst
for olefin polymerization, as a flame-speed accelerator, and
as a doping agent in the manufacture of semiconductor devices.
Standards and Guidelines
OSHA PEL (permissible exposure limit)
= 0.1 ppm
NIOSH REL (recommended exposure limit)
= 0.1 ppm
NIOSH IDLH (immediately dangerous to
life or health) = 15 ppm
AIHA ERPG-2 (maximum airborne concentration
below which it is believed that nearly all persons could be
exposed for up to 1 hour without experiencing or developing
irreversible or other serious health effects or symptoms that
could impair their abilities to take protective action) =
1 ppm.
Physical Properties - Calcium Hypochlorite
Description: Colorless gas at
room temperature
Warning properties: odor does
not provide adequate warning of hazard
Molecular weight: 27.7 daltons
Boiling point (760 mm Hg) = -135ĀŗF
(-92.8ĀŗC)
Freezing point: -264.8ĀŗF
(-164.9ĀŗC)
Specific gravity (liquid): 0.210
at 15ĀŗC
Vapor pressure: >1 atm at 20ĀŗC
Gas density: 0.965 (air = 1)
Water solubility: Decomposes in
water
Flammability: Highly flammable,
ignites spontaneously in air at 40-50ĀŗC
Flammable Range: 0.8% to 88% (concentration
in air)
Incompatibilities
Diborane is incompatible with oxidizers,
aluminum, halogens, and water.
Health Effects
- Diborane gas is irritating to the eyes, skin, and respiratory
tract. It may cause burning of the eyes, nose, and throat;
cough and constriction and edema of the airway and lungs
can occur. Other possible effects include dizziness, headache,
weakness, and lack of coordination. Kidney and liver damage
may rarely occur.
- Local irritation is caused by the exothermic nature of
the hydrolysis reaction.
- Individuals with pre-existing respiratory diseases may
be more susceptible to exposure to diborane.
Acute Exposure
The toxic effects of diborane are primarily
due to its irritant properties. The local irritant action
of diborane is due to the heat released as a consequence of
its reaction with water and products formed by the hydrolysis
reaction, such as boron oxide. Symptoms may be apparent immediately
or delayed for a few hours.
Children do not always respond to chemicals
in the same way that adults do. Different protocols for managing
their care may be
needed.
Respiratory
Exposure to diborane can cause a sensation
of tightness of the chest leading to diaphragmatic pain, shortness
of breath, cough, and wheezing. These signs and symptoms,
which may be delayed for up to 24 hours, can be seen for 3
to 5 days after an exposure.
Children may be more vulnerable to gas
exposure because of higher minute ventilation per kg and failure
to evacuate an area promptly when exposed.
Dermal
Skin irritation manifested as reddened
skin may occur from exposure to diborane vapors.
Ocular/Ophthalmic
High concentrations of diborane can cause
eye irritation, pain, swelling, lacrimation, or photophobia.
Neurologic
Dizziness, headache, weakness, central
nervous system depression, and incoordination have been seen
following exposure to diborane.
Potential Sequelae
Weakness and fatigue may follow exposure
to diborane. Damage to liver and kidneys may occur in some
cases during metabolism and excretion.
Chronic Exposure
Chronic exposure to low concentrations
of diborane were reported to have caused seizures, convulsions,
fatigue, drowsiness, confusion, altered EEG responses, and
spasms of the voluntary muscles. Others have reported headache,
vertigo, chills, ans sometimes fever. Asthmatic bronchitis
can also occur.
Chronic exposure may be more serious
for children because of their potential for a longer latency
period.
Carcinogenicity
Diborane has not been classified for
carcinogenic effects.
Reproductive and Developmental Effects
No information is available regarding
reproductive or developmental effects of diborane in experimental
animals or humans. Diborane is not included in Reproductive
and Developmental Toxicants, a 1991 report published by
the U.S. General Accounting Office (GAO) that lists 30 chemicals
of concern because of widely acknowledged reproductive and
developmental consequences.
Prehospital Management
- Rescue personnel are at low risk of secondary contamination
from victims who have been exposed to diborane gas. However,
rescuers entering areas with potential high concentrations
should wear appropriate equipment to avoid self-exposure
to diborane. An air concentration of 15 ppm is considered
"immediately dangerous to life or health".
- Acute exposure to diborane gas causes chest tightness,
coughing, skin, eye and nose irritation, and lacrimation.
Respiratory impairment and noncardiogenic pulmonary edema
may occur.
- There is no specific antidote for diborane poisoning.
Treatment is supportive.
Hot Zone
Rescuers should be trained and appropriately
attired before entering the Hot Zone. If the proper equipment
is not available, or if rescuers have not been trained in
its use, assistance should be obtained from a local or regional
HAZMAT team or other properly equipped response organization.
Rescuer Protection
Diborane is a severe respiratory-tract
and skin irritant.
Respiratory Protection: Positive-pressure,
self-contained breathing apparatus (SCBA) is recommended in
response situations that involve exposure to potentially unsafe
levels of diborane.
Skin Protection: Chemical-protective
clothing should be worn because diborane gas can cause skin
irritation and burns.
ABC Reminders
Quickly establish a patent airway, ensure
adequate respiration and pulse. If trauma is suspected, maintain
cervical immobilization manually and apply a cervical collar
and a backboard when feasible. Apply direct pressure to stop
bleeding.
Victim Removal
If victims can walk, lead them out of
the Hot Zone to the Decontamination Zone. Victims who are
unable to walk may be removed on backboards or gurneys; if
these are not available, carefully carry or drag victims to
safety.
Consider appropriate management of anxiety
in victims with chemically-induced acute disorders, especially
children who may suffer separation anxiety if separated from
a parent or other adult.
Decontamination Zone
Victims exposed to diborane gas who have
no skin or eye irritation do not need decontamination. They
may be transferred immediately to the Support Zone. All others
require decontamination as described below.
Rescuer Protection
If exposure levels are determined to
be safe, decontamination may be conducted by personnel wearing
a lower level of protection than that worn in the Hot Zone
(described above).
ABC Reminders
Quickly establish a patent airway, ensure
adequate respiration and pulse. Stabilize the cervical spine
with a collar and a backboard if trauma is suspected. Administer
supplemental oxygen as required. Assist ventilation with a
bag-valve-mask device if necessary. Apply direct pressure
to control bleeding.
Basic Decontamination
Victims who are able may assist with
their own decontamination. Remove and double-bag contaminated
clothing and personal belongings.
Flush exposed skin and hair with copious
amounts of plain water for at least 15 minutes. Use caution
to avoid hypothermia when decontaminating victims, particularly
children or the elderly. Use blankets or warmers after decontamination
as needed.
Do not irrigate eyes that have sustained
frostbite injury. Otherwise, irrigate exposed or irritated
eyes with plain water or saline for no less than 30 minutes.
Eye irrigation may be carried out simultaneously with other
basic care and transport. Remove contact lenses if it can
be done without additional trauma to the eye. If pain or injury
is evident, continue irrigation while transferring the victim
to the support zone.
Consider appropriate management of chemically
contaminated children a the exposure site. Provide reassurance
to the child during decontamination, especially if separation
from a parent occurs.
Transfer to Support Zone
As soon as basic decontamination is complete,
move the victim to the Support Zone.
Support Zone
Be certain that victims have been decontaminated
properly (see Decontamination Zone above). Victims
who have undergone decontamination pose no serious risks of
secondary contamination to rescuers. In such cases, Support
Zone personnel require no specialized protective gear.
ABC Reminders
Quickly establish a patent airway and
ensure adequate respiration and pulse. If trauma is suspected,
maintain cervical immobilization manually and apply a cervical
collar and a backboard when feasible. Administer supplemental
oxygen as required and establish intravenous access if necessary.
Place on a cardiac monitor. Watch for signs of airway swelling
and obstruction such as progressive hoarseness, stridor, or
cyanosis.
Additional Decontamination
Continue irrigating exposed skin and
eyes, as appropriate.
Advanced Treatment
In cases of respiratory compromise, secure
airway and respiration via endotracheal intubation. If not
possible, perform cricothyrotomy if equipped and trained to
do so.
Treat patients who have bronchospasm
with an aerosolized bronchodilator such as albuterol.
Consider racemic epinephrine aerosol
for children who develop stridor. Dose 0.25-0.75 mL of 2.25%
racemic epinephrine solution, repeat every 20 minutes as needed
cautioning for myocardial variability.
Patients who are comatose, hypotensive,
or having seizures or who have cardiac arrhythmias should
be treated according to advanced life support (ALS) protocols.
If evidence of shock or hypotension is
observed, begin fluid administration. For adults with systolic
pressure less than 80 mm Hg, bolus perfusion of 1,000 mL/hour
intravenous saline or lactated Ringer's solution may be appropriate.
Higher adult systolic pressures may necessitate lower perfusion
rates. For children with compromised perfusion administer
a 20 mL/kg bolus of normal saline over 10 to 20 minutes, then
infuse at 2 to 3 mL/kg/hour.
If frostbite is present, treat by rewarming
in a water bath at a temperature of 102 to 108ĀŗF (40 to 42ĀŗC)
for 20 to 30 minutes and continue until a flush has returned
to the affected area.
Transport to Medical Facility
Only decontaminated patients or those
not requiring decontamination should be transported to a medical
facility. "Body bags" are not recommended.
Report to the base station and the receiving
medical facility the condition of the patient, treatment given,
and estimated time of arrival at the medical facility.
Multi-Casualty Triage
Consult with the base station physician
or the regional poison control center for advice regarding
triage of multiple victims.
Patients with evidence of significant
exposure (e.g., severe or persistent cough, dyspnea, or chemical
burns) should be transported to a medical facility for evaluation.
Patients who have minor or transient irritation of the eyes
or throat may be discharged from the scene after their names,
addresses, and telephone numbers are recorded. They should
be advised to seek medical care promptly if symptoms develop
or recur (see Patient Information Sheet below). The
development of serious respiratory symptoms may be delayed
for up to 24 hours.
Emergency Department Management
- Hospital personnel are at minimal risk of secondary contamination
from patients who have been exposed to diborane gas. However,
hospital personnel in an enclosed area can be secondarily
contaminated by vapors off-gassing from heavily contaminated
clothing or skin.
- Acute exposure to diborane initially causes coughing,
eye and nose irritation, lacrimation, and a burning sensation
in the chest. Airway constriction and noncardiogenic pulmonary
edema may occur.
- Diborane irritates the skin and can cause burning pain,
inflammation, and blisters. Exposure to liquefied diborane
can result in frostbite.
- There is no specific antidote for diborane poisoning.
Treatment requires supportive care.
Decontamination Area
Unless previously decontaminated, all
patients with skin or eye irritation require decontamination
as described below.
Be aware that use of protective equipment
by the provider may cause anxiety, particularly in children,
resulting in decreased compliance with further management
efforts.
ABC Reminders
Evaluate and support airway, breathing,
and circulation. In cases of respiratory compromise secure
airway and respiration via endotracheal intubation. If not
possible, surgically secure an airway.
Treat patients who have bronchospasm
with an aerosolized bronchodilator such as albuterol.
Consider racemic epinephrine aerosol
for children who develop stridor. Dose 0.25-0.75 mL of 2.25%
racemic epinephrine solution, repeat every 20 minutes as needed
cautioning for myocardial variability.
Patients who are comatose, hypotensive,
or having seizures or cardiac arrhythmias should be treated
in the conventional manner.
Basic Decontamination
Patients who are able may assist with
their own decontamination. Remove and double bag contaminated
clothing and personal belongings.
If skin and eye contact with liquified
diborane occurred, handle frostbitten with caution. Place
frostbitten skin in warm water, about 108ĀŗF (42ĀŗC).
If warm water is not available, wrap the affected part gently
in blankets. Let the circulation reestablish itself naturally.
Encourage the victim to exercise the affected part while it
is being warmed.
Flush exposed skin and hair with plain
water for no less than 15 minutes. Use caution to avoid hypothermia
when decontaminating victims, particularly children or the
elderly. Use blankets or warmers after decontamination as
needed.
Do not irrigate frostbitten eyes. Otherwise,
begin irrigation of exposed eyes. Remove contact lenses if
it can be done without additional trauma to the eye. Continue
irrigation while transporting the patient to the Critical
Care Area.
Critical Care Area
Be certain that appropriate decontamination
has been carried out.
ABC Reminders
Evaluate and support airway, breathing,
and circulation as in ABC Reminders above under Decontamination
Zone. Establish intravenous access in seriously ill patients
if this has not been done previously. Continuously monitor
cardiac rhythm.
Patients who are comatose, hypotensive,
or having seizures or cardiac arrhythmias should be treated
in the conventional manner.
Inhalation Exposure
Administer supplemental oxygen by mask
to patients who have respiratory symptoms. Treat patients
who have bronchospasm with an aerosolized bronchodilator such
as albuterol.
Consider racemic epinephrine aerosol
for children who develop stridor. Dose 0.25-0.75 mL of 2.25%
racemic epinephrine solution, repeat every 20 minutes as needed
cautioning for myocardial variability.
If pulmonary edema develops, maintain
ventilation and oxygenation and evaluate with frequent arterial
blood gas or pulse oximetry monitoring. Early use of PEEP
and mechanical ventilation may be needed. Prophylactic antibiotic
therapy may reduce the chances of respiratory infection.
Skin Exposure
If the skin was in contact with diborane,
thermal burns may occur. Treat thermal burns by assuring that
affected area is cool by flushing with cool water, then apply
dry sterile dressings. If the patient is burned on the face,
neck head, or chest, assume that the airway may also have
been burned.
If the liquefied diborane gas contacts
the skin, frostbite may result. If a victim has frostbite,
treat by rewarming affected areas in a water bath at a temperature
of 102 to 108ĀŗF (40 to 42ĀŗC) for 20 to 30 minutes
and continue until a flush has returned to the affected area.
Eye Exposure
Diborane-exposed eyes should be irrigated
for at least 15 minutes. Test visual acuity and examine the
eyes for corneal damage and treat appropriately. Immediately
consult an ophthalmologist for patients who have corneal injuries.
Antidotes and Other Treatments
There is no specific antidote for diborane.
Treatment is supportive.
Laboratory Tests
The diagnosis of acute diborane toxicity
is primarily clinical, based on respiratory difficulties and
irritation. However, laboratory testing is useful for monitoring
the patient and evaluating complications. Routine laboratory
studies for all exposed patients include CBC, glucose, and
electrolyte determinations. Patients who have respiratory
complaints may require pulse oximetry (or ABG measurements)
and chest radiography. Massive inhalation may be complicated
by hyperchloremic metabolic acidosis; in addition to electrolytes,
monitor blood pH.
Disposition and Follow-up
Consider hospitalizing patients who have
a suspected significant exposure or have eye burns or serious
skin burns.
Delayed Effects
Symptomatic patients complaining of persistent
shortness of breath, severe cough, or chest tightness should
be admitted to the hospital and observed until symptom-free.
Pulmonary injury may progress for several hours.
Patient Release
Asymptomatic patients and those who experienced
only minor sensations of burning of the nose, throat, eyes,
and respiratory tract (with perhaps a slight cough) may be
released. In most cases, these patients will be free of symptoms
in an hour or less. They should be advised to seek medical
care promptly if symptoms develop or recur (see the Diborane--Patient
Information Sheet below).
Follow-up
Obtain the name of the patient's primary
care physician so that the hospital can send a copy of the
ED visit to the patient's doctor.
Follow up is recommended for all hospitalized
patients because long-term respiratory problems can result.
Respiratory monitoring is recommended until the patient is
symptom-free. In addition, long-term follow-up should seek
neuropsychiatric abnormality. Kidney and liver tests are also
indicated.
Patients who have skin or corneal injury
should be re-examined within 24 hours. Anyone who had significant
dermal exposure should be followed for several months.
Reporting
If a work-related incident has occurred,
you may be legally required to file a report; contact your
state or local health department.
Other persons may still be at risk in
the setting where this incident occurred. If the incident
occurred in the workplace, discussing it with company personnel
may prevent future incidents. If a public health risk exists,
notify your state or local health department or other responsible
public agency. When appropriate, inform patients that they
may request an evaluation of their workplace from OSHA or
NIOSH. See Appendix III for a list of agencies that may be
of assistance.
Patient Information Sheet
This handout provides information and
follow-up instructions for persons who have been exposed to
diborane.
Print this handout only.pdf icon[45.7 KB]
What is diborane?
Diborane is a colorless gas with a repulsive,
sweet odor. It is used in rocket propellants and as reducing
agent, as a rubber vulcanizer, as a catalyst for olefin polymerization,
as a flame-speed accelerator, and as a doping agent. Because
diborane is a gas a ambient temperature, the most likely exposure
routes are inhalation and dermal.
What immediate health effects can be caused by exposure to diborane?
Even small exposures to diborane may
cause immediate irritation of the eyes, nose, and throat,
and shortness of breath, as well as coughing, wheezing, shortness
of breath, and tearing of the eyes. Some of these signs and
symptoms may develop several hours after exposure occurred.
Exposure to diborane can also cause dizziness, headache, drowsiness,
and lack of coordination. Breathing large amounts of diborane
may cause the lining of the throat and lungs to swell, making
breathing difficult. Generally, the more serious the exposure,
the more severe the symptoms.
Can diborane poisoning be treated?
There is no antidote for diborane, but
its effects can be treated and most exposed persons get well.
Persons who have experienced serious symptoms may need to
be hospitalized.
Are any future health effects likely to occur?
A single small exposure from which a
person recovers quickly is not likely to cause delayed or
long-term effects. After a serious exposure, symptoms may
worsen for several hours and respiratory and neurologic alterations
may persist for long time.
What tests can be done if a person has been exposed to diborane?
Specific tests for the presence of diborane
in blood or urine generally are not useful to the doctor.
If a severe exposure has occurred, blood and urine analyses
and other tests may show whether the upper respiratory airways
and lungs or brain have been injured. Testing is not needed
in every case.
Where can more information about diborane be found?
More information about diborane can be
obtained from your regional poison control center, your state,
county, or local health department; the Agency for Toxic Substances
and Disease Registry (ATSDR); your doctor; or a clinic in
your area that specializes in occupational and environmental
health. If the exposure happened at work, you may wish to
discuss it with your employer, the Occupational Safety and
Health Administration (OSHA), or the National Institute for
Occupational Safety and Health (NIOSH). Ask the person who
gave you this form for help in locating these telephone numbers.
Follow-up Instructions
Keep this page and take it with you to
your next appointment. Follow only the instructions
checked below.
Print instructions only.pdf icon[45.7 KB]
[ ] Call your doctor or the Emergency
Department if you develop any unusual signs or symptoms within
the next 24 hours, especially:
- coughing or wheezing
- difficulty breathing, shortness of breath, or chest pain
- increased pain or a discharge from injured eyes
- increased redness or pain or a pus-like discharge in the
area of a skin burn
[ ] No follow-up appointment is necessary
unless you develop any of the symptoms listed above.
[ ] Call for an appointment with Dr.____
in the practice of ________.
When you call for your appointment, please
say that you were treated in the Emergency Department at _________
Hospital by________and were advised to be seen again in ____days.
[ ] Return to the Emergency Department/Clinic
on ____ (date) at _____ AM/PM for a follow-up examination.
[ ] Do not perform vigorous physical
activities for 1 to 2 days.
[ ] You may resume everyday activities
including driving and operating machinery.
[ ] Do not return to work for _____days.
[ ] You may return to work on a limited
basis. See instructions below.
[ ] Avoid exposure to cigarette smoke
for 72 hours; smoke may worsen the condition of your lungs.
[ ] Avoid drinking alcoholic beverages
for at least 24 hours; alcohol may worsen injury to your stomach
or have other effects.
[ ] Avoid taking the following medications:
________________
[ ] You may continue taking the following
medication(s) that your doctor(s) prescribed for you: _______________________________
[ ] Other instructions:
____________________________________
_____________________________________________________
- Provide the Emergency Department with the name and the
number of your primary care physician so that the ED can
send him or her a record of your emergency department visit.
- You or your physician can get more information on the
chemical by contacting: ____________ or _____________, or by
checking out the following Internet Web sites:
___________;__________.
Signature of patient _______________ Date ____________
Signature of physician _____________ Date ____________
Where can I get more information?
If you have questions or concerns, please contact your community or state health or environmental quality department or:
For more information, contact:
Agency for Toxic Substances and Disease Registry
Division of Toxicology and Human Health Sciences
4770 Buford Highway
Chamblee, GA 30341-3717
Phone: 1-800-CDC-INFO 888-232-6348 (TTY)
Email: Contact CDC-INFO
ATSDR can also tell you the location of occupational and environmental health clinics. These clinics specialize in recognizing, evaluating, and treating illnesses resulting from exposure to hazardous substances.