Hydrogen

HYDROGEN
Source: Canadian Centre for Occupational Health and Safety

*** SECTION 1. CHEMICAL IDENTIFICATION ***

CHEMINFO RECORD NUMBER :148
CCOHS CHEMICAL NAME :Hydrogen gas
SYNONYMS:
*HYDROGEN
*HYDROGEN,COMPRESSED
*MOLECULAR HYDROGEN
CAS REGISTRY NUMBER :1333-74-0
PIN(UN\NA NUMBER(S) :1049
RTECS NUMBER(S) :MW8900005
MOLECULAR FORMULA :H2
STRUCTURAL FORMULA :H-H

***SECTION 2. DESCRIPTION ***

APPEARANCE AND ODOUR:
Colourless,odourless gas
WARNING PROPERTIES:
None
COMPOSITION\PURITY
May contain small amounts of helium and hydrocarbon gas such as
methane.
USES AND OCCURRENCES:
Hydrogenation of vegetable and animal oils and fats; prevention
of oxidation of metals; welding and cutting; petroleum refining;
production of ammonia,methanol, aniline and some inorganic acids;
fuel.

*** SECTION 3. HAZARDS IDENTIFICATION ***
** POTENTIAL HEALTH EFFECTS **

EFFECTS OF SHORT-TERM (ACUTE) EXPOSURE:
INHALATION:

Non-toxic at normal temperature and pressure. Can displace oxygen
which may lead to oxygen deficiency. Oxygen content of the
atmosphere must not be allowed to fall below 18%. Effects of
oxygen deficiency are: 12-16% oxygen in air breathing and pulse
rate increased, muscular coordination slightly disturbed: 10-14%:
emotional upset,abnormal fatigue, disturbed respiration: 6-10%
nausea and vomiting, collapse or loss of consciousness; below 6%
convulsive movements, possible respiratory collapse and death.

SKIN CONTACT:
No known effects

INGESTION:
Not applicable to gases

EFFECTS OF LONG-TERM (CHRONIC) EXPOSURE :
Long-term exposure to this gas no known health effects. Chronic
oxygen deficiency (below 18% oxygen in air) may affect the heart
and nervous system.

CARCINOGENICITY:
Not carcinogenic

TERATOGENICITY AND EMBRYO TOXICITY:
No specific reproductive effects

MUTAGENICITY:
Not mutagenic

***SECTION 4. FIRST AID MEASURES ***

INHALATION:
If the victim is unconscious or does not respond, take proper
precautions to ensure your own safety before attempting rescue;
e.g. wear appropriate protective equipment, use the”buddy” sys
tem. Remove source of contamination or move victim to fresh air.
If breathing has stopped, trained personnel should begin artifi
cial respiration or, if the heart has stopped, cardiopulmonary
resuscitation (CPR) immediately. Oxygen may be beneficial if
advice. Obtain medical attention immediately.

SKIN CONTACT:
Not applicable

EYE CONTACT:
Not applicable

INGESTION:
Not applicable

FIRST AID COMMENTS:
Provide general supportive measures(comfort,warmth,rest). Some
recommendations in the above sections may be considered medical
acts in some jurisdictions. These recommendations should be
reviewed with a physician and appropriate delegation obtained, as
required. All first aid procedures should be periodically re
viewed by a physician familiar with the material and its condi
tions of use in the workplace.

*** SECTION 5. FIRST FIGHTING MEASURES ***

FLASH POINT:
Flammable gas (burns at all ambient temperatures)

LOWER FLAMMABLE (EXPLOSIVE) LIMIT (LFL\LEL):
4.0%

UPPER FLAMMABLE (EXPLOSIVE) LIMIT (UFL\UEL):
75%

AUTO IGNITION (IGNITION) TEMPERATURE:
571.2 deg C(1060 deg F)

COMBUSTION AND THERMAL DECOMPOSITION PRODUCTS:
None
EXTINGUISHING MEDIA:
Dry chemical, carbon dioxide, water spray, foam, fog

FIRE FIGHTING INSTRUCTIONS:
Do not extinguish a leaking gas flame unless leak can be securely
plugged, Stop flow of gas and move containers from fire area if
without risk. Use water to keep fire-exposed containers cool.
Containers may explode in fire. For massive fire in large area,
use manned hose holder or monitor nozzles; if this is not possi
ble, withdraw deem area and allow fire to burn. Stay away from
ends of tanks. Withdraw immediately in case of rising sound from
venting safety device or any discolouration of tank or cylinder
due to fire.

** NATIONAL FIRE PROTECTION ASSOCIATION (NFPA) HAZARD INDEX***

NFPA – HEALTH :0-Exposure, under fire conditions,
would be no more hazardous than
ordinary combustible material.

NFPA- FLAMMABILITY :4 – Will rapidly or completely vapor
vaporize, or readily disperse in air
and burn.

NFPA – REACTIVITY : 0 Normally stable under fire condi-
tions, and not reactive with water.

***SECTION6. ACCIDENTAL RELEASE MEASURES ***

PRECAUTIONS:
Restrict access to area until completion of clean-up. Ensure
clean-up is conducted by trained personnel only. Wear adequate
personal protective equipment. Extinguish or remove all ignition
sources. Ventilate area.

CLEAN-UP:
Stop leak if it can be done without risk. Use water spray to
reduce vapour. Isolate area until gas has dispersed.

*** SECTION 7. HANDLING AND STORAGE ***

HANDLING:
Do not use near welding operations, flames or hot surfaces.
Move cylinders by hand-truck or cart designed for that purpose.
Do not lift cylinders by their caps. Do not handle them with
oily hands. Secure cylinders in place in an upright position at
all times. Do not drop cylinders or permit them to bang against
each other. Leave valve cap on cylinder until cylinder is secured
and ready for use. Close all valves when not in actual use.
Ground all cylinders containing flammable gases.
Use smallest possible amounts in designated areas with adequate
ventilation. Have emergency equipment (for fires, spills, leaks,
etc.) readily available.

STORAGE:
Comply with all applicable regulations for the storage and han
dling of compressed gases and flammable materials
Store at or above ground level, in a cool, dry, well-ventilated
area, out of direct sunlight and away from heat and ignition
sources. Cylinder temperature should never exceed 51 deg.C (125
deg.F).
Store away from flammable/combustible materials or materials that
support combustion. Use non-sparking ventilation systems and
electrical equipment that does not provide a source of ignition.
Store cylinders upright on a level,fireproof floor, secured in
position and protected from damage. Keep cylinder valve cover
on. Label empty cylinders. Store full cylinders separately from
empty ones. Empty containers may be hazardous due to residual
material.

Limit quantity of material in storage. Restrict access to storage
area.

Post appropriate warning signs. Keep storage area separate from
populated work areas. Inspect storage area regularly. Consider
leak detection and alarm equipment for storage area.

*** SECTION 8. EXPOSURE CONTROLS/PERSONAL PROTECTION ***

NOTE: Exposure to this material can be controlled in many ways.
The measures appropriate for a particular work site depend on how
this material is used and on the extent of exposure. This gener
al information can be used to help develop specific control
measures.

Ensure that control systems are properly designed and maintained.
Comply with occupational, environmental,fire and other applicable
regulations.

SAMPLING AND ANALYSIS:

The appropriate instrumentation and sampling strategy (location,
timing,duration, frequency and number of samples). Interpretation
of the sampling results is related to these variables and the
analytical method.

CALORIMETRIC-INDICATING (DETECTOR) TUBES: Commercially available
DIRECT READING INSTRUMENTS: Combustible gas indicator can be used
for hydrogen.

Monitoring of the oxygen concentration in the workplace air may
be necessary.

ENGINEERING CONTROLS:
Engineering control methods to reduce hazardous exposures are
preferred.
Methods include mechanical ventilation (dilution and local ex
haust), process or personnel enclosure, control of process condi
tions and process modification (e.g. substitution of a less
hazardous material).
Administrative controls and personal protective equipment may
also be required. Provide adequate local exhaust and dilution
(general) ventilation to control airborne hydrogen below 4000 ppm
(10% of the lower explosive limit). Use a non -sparking, grounded
ventilation system separate from other exhaust ventilation sys
tems. Exhaust directly to the outside. Supply sufficient re
placement air to make up for air removed by exhaust systems.

PERSONAL PROTECTIVE EQUIPMENT:
Respiratory protective equipment is not ordinarily required If
engineering controls,work practices and administrative controls
are not effective in controlling exposure to hydrogen, then wear
suitable personal protective equipment including approved respi
ratory protection. Have appropriate personal protective equipment
available for use in emergencies such as spills or fire. If
respiratory protection is required, institute a complete respira
tory protection program including selection, fit testing, train
ing,maintenance and inspection. Refer to the CSA Standard 294.4-
M1982,”selection, Care and use of Respirators,”available from the
Canadian Standards Association, Rex dale, Ontario, M9W 1R3.

RESPIRATORY PROTECTION GUIDELINES:
EMERGENCY OPR PLANNED ENTRY IN UNKNOWN CONCENTRATION OR HYDROGEN
CONCENTRATION GREATER THAT THE LOWER EXPLOSIVE LIMIT(LEL) OF 4%
OR IN AREAS OF OXYGEN DEFICIENCY: Any self-contained breathing

apparatus (SCBA) with full face piece and operated in a pressure-
demand or other positive-pressure mode, or any supplied-air
respirator with a full faceoiece and operated in pressures-demand
or other positive-pressure mode in combination with an auxiliary
SCBA operated in pressure-demand or other positive-pressure
mode.

EYE/FACE PROTECTION:
no specific requirement, but it is good practice to wear chemical
safety goggles.

SKIN PROTECTION:
No specific requirement

RESISTANCE OF MATERIALS FOR PROTECTIVE CLOTHING:
Not applicable.

**EXPOSURE GUIDELINES **
*threshold limit values (TLVs) /AMERICAN CONFERENCE OF GOVERNMEN
TAL INDUSTRIAL HYGIENISTS (ACGIH)/1992-93*

TIME-WEIGHTED AVERAGE (TLV-TWA): Simple asphyxiant

TLV COMMENTS:
SIMPLE ASPHYXIANTS: Primary health concern is displacement of
oxygen in air. Ensure that oxygen content remains above 18% by
volume. NOTE: In many Canadian jurisdictions, exposure limits are
similar to the ACGIH TLVs. Since the manner in which exposure
limits are established, interpreted and implemented can vary,
obtain detailed information from the appropriate government
agency in each jurisdiction.

*PERMISSIBLE EXPOSURE LIMITS (PELs)/
FINAL RULE LIMITS / OCCUPATIONAL
SAFETY AND HEALTH ADMINISTRATION (OSHA)*

TIME WEIGHTED AVERAGE (PEL-TWA): Not established

NOTE: The OSHA PEL Final Rule Limits are currently non-
enforceable due to a court decision. The OSHA PEL Transitional
Limits are now in force.
*PERMISSIBLE EXPOSURE LIMITS (PELs)
TRANSITIONAL LIMITS /OCCUPATIONAL
SAFETY AND HEALTH ADMINISTRATION (OSHA)*
TIME WEIGHT AVERAGE (PEL-TWA) : Not established.

***SECTION 9. PHYSICAL AND CHEMICAL PROPERTIES ***

MOLECULAR WEIGHT : 2.016

CONVERSION FACTOR:
1ppm=0.082 mg/m3; 1mg/m3=12.2 ppm at 25 deg C
MELTING POINT :-259.2 deg C (-434.6 deg F)
BOILING POINT: -252.8 deg C (-423.0 deg F)

RELATIVE DENSITY (SPECIFIC GRAVITY):
Not applicable

SOLUBILITY IN WATER :
Slightly soluble (1.8% v/v at 20 deg C)
SOLUBILITY IN OTHER LIQUIDS:
Slightly Soluble in Ethanol,ether
VAPOUR DENSITY : 0.0695 (air=1)
VAPOUR PRESSURE: Not applicable
SATURATION VAPOUR CONCENTRATION : Not applicable
EVAPORATION RATE : Not applicable
PH VALUE : Not applicable
CRITICAL TEMPERATURE : -239.9 deg C (-399.8 deg F)

*** SECTION 10. STABILITY AND REACTIVITY ***

STABILITY :
Stable
HAZARDOUS POLYMERIZATION :
Does not occur
HAZARDOUS DECOMPOSITION PRODUCTS :
None
INCOMPATIBILITY -MATERIALS TO AVOID:
HALOGEN COMPOUNDS (e.g. bromine, chlorine, fluorine)-react explo
sively PLATINUM-finely divide platinum and some other metals will
cause hydrogen to react explosively with oxygen in air LITHIUM-
burns in gaseous hydrogen NITROGEN TRIFLUORIDE -reacts explosive
ly when ignited OXYGEN DIFLUORIDE-reacts explosively when ignited

CORROSIVITY TO METALS:
Not corrosive

*** SECTION 11. TOXICOLOGICAL INFORMATION ***

No numerical toxicity data is available.

*** SECTION 12. ECOLOGICAL INFORMATION ***

NOTE: This section is under development.

*** SECTION 13.DISPOSAL CONSIDERATIONS ***

Allow gas to dissipate safely into the atmosphere or use as
fuel.

*** SECTION 14. TRANSPORT INFORMATION ***
TRANSPORTATION OF DANGEROUS GOODS (TDG) SHIPPING INFORMATION **

SHIPPING NAME AND DESCRIPTION: Hydrogen,compressed or Hydrogen
PRODUCT IDENTIFICATION NUMBER (PIN):1049
CLASSIFICATION: 2.1 – Flammable gas
SPECIAL PROVISIONS: 56,90,99,102
IMO CLASSIFICATION: 2.1.
ICAO CLASSIFICATION: 2,3
PACKING GROUP: X

*** SECTION 15. REGULATORY INFORMATION ***
* WORKPLACE HAZARDOUS MATERIALS INFORMATION SYSTEM (WHMIS) **

PROPOSED WHMIS CLASSIFICATION :
A – Compressed gas
BI – Flammable and combustible material – Flammable gas
WHMIS HEALTH EFFECTS :
Does not meet criteria
WHMIS INGREDIENT DISCLOSURE LIST:
Does not meet criteria
DETAILED WHMIS CLASSIFICATION ACCORDING TO CRITERIA:
CLASS A – COMPRESSED GAS: Meets criteria; critical temperature:
-239.9 deg c
CLASS B – FLAMMABLE & COMBUSTIBLE MATERIAL: Meets criteria for
“Flammable Gas”; TDG 2.1
CLASS C – OXIDIZING MATERIAL: Does not meet criteria
CLASS D – POISONOUS AND INFECTIOUS MATERIAL. DIVISION 1 – IMME
DIATE AND SERIOUS TOXIC EFFECTS: Does not meet criteria. Acts as
a “simple asphyxiant” gas.
CLASS D – POISONOUS AND INFECTIOUS MATERIAL. DIVISION 2 – OTHER

TOXIC EFFECTS: Does not meet criteria. Acts as a “simple asphyx
iant” gas.

CLASS E CORROSIVE MATERIAL: Does not meet criteria
CLASS F – DANGEROUSLY REACTIVE MATERIAL: Does not meet criteria
OSHA HAZAED COMMUNICATION EVALUATION :

Meets criteria for hazardous material, as defined by 29 CRF
1910.1200.

***SECTION 16. OTHER INFORMATION ***

SELECTED BIBLIOGRAPHY :
(1) Matheson gas data book. 6th ed. Matheson, 1980. p. 365-371
Information on chemicals reviewed in the CHEMINFO database is
drawn from a number of publicly available sources. A list of
general references used to compile CHEMINFO RECORDS IS available
in the database Help.

REVIEW/PREPARATION DATE
REVISION INDICATORS : :1987-06-23
PEL-TWA;1993-03
NFPA (health):1993-03
NFPA(flammability): 1993-03
NFPA(reactivity): 1993-03
REGULATORY INFORMATION: 1993-03
Trans PEL-TWA; 1993-04
________________________________________________________________

SAFETY WITH HYDROGEN

* Hydrogen is referred to H2 It is a colourless,odourless and
tasteless gas. It is non-toxic, but does not support life and
acts as an asphyxiant. It is the lightest gas known.

* Hydrogen is highly flammable and most mixtures of hydrogen and
air will burn or even explode. It ignites more easily than any
other common gas and a high pressure leak can even ignite itself.
If burns with a hot and almost invisible flame. Thus, when
approaching a hydrogen leak,hold some readily combustible materi
al such as a newspaper in from of you.

* Hydrogen fires are extremely difficult to extinguish: sound the
alarm immediately. The most effective way to fight a hydrogen
fire is to shut off the source of hydrogen, provided that this
can be done safely. If the hydrogen supply cannot be shut off,
it may be dangerous to extinguish the fire as this may create a
gas cloud which can explode. If this is the case,keep nearby
equipment cool by drenching with water and allow the gas to burn
itself out.

* No valves should be left cracked open to prevent the possibili
ty of any leakage. All valves must be operated very cautiously
and slowly.

* High pressure hydrogen should not be vented directly to at
mosphere but can be made to bubble through water.

* Hydrogen should never be released or vented into buildings for
confined spaces. Vent lines which may contain air or hydrogen
should be of copper.

* Buildings in which hydrogen is handled or stored must always be
well ventilated at high and low levels to prevent the built-up of
an explosive atmosphere: do not block any ventilation openings.

* Equipment must always be purged with nitrogen before admitting
hydrogen,of before opening for maintenance.

* Smoking and the bringing of matches of lights into a plant
where hydrogen, is manufactured, stored or used is not permitted.

* Earthing systems must not be tampered with or damaged, as they
are provided to prevent the accumulation of static electric
charges which could act as a source of ignition.

* It is not permitted to bring on to a hydrogen installation any
unauthorised electrical,eg, non-safety torch,radio, power tool
etc.

* Hot work, eg, cutting,grinding, welding,soldering, etc can only
be carried out when authorised by the issue of s Work Permit.

* Hydrogen cylinders should not be shifted. Clean the socket
with a jet of nitrogen or air.

* Hydrogen trailor and storage system must be at same potential
and connected through purpose designed cable.

* Wear antistatic clothing.

* Earth yourself at entrances before touching any plant.

* Do not allow strangers to enter areas when hydrogen is manufac
tured or stored.

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