What is the American Conference of Governmental Industrial Hygienists (ACGIH) recommended exposure limit for carbon dioxide gas?
TIME-WEIGHTED AVERAGE (TLV-TWA): 5,000 ppm
STEL: 30,000 ppm
TLV BASIS - CRITICAL EFFECT(S) : Asphyxiation
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
What are the fire and explosion dangers associated with carbon dioxide gas?
Carbon dioxide (CO2) does not burn and does not support combustion. However, cylinders or containers may rupture or explode in the heat of a fire. CO2 can displace air to the point where there is not enough oxygen to breath. It is slightly heavier than air and may accumulate in low areas posing a confined space hazard.
Is carbon dioxide gas stable when exposed to air, moisture, or heat?
CO2 is normally stable. In the presence of ultraviolet light or electrical discharges, CO2 decomposes to carbon monoxide and oxygen.
Are there any conditions to avoid when using carbon dioxide gas?
Temperatures higher than 52 deg C (approximately 125 deg F).
Does carbon dioxide gas have an odour threshold (at what level can I smell it)?
CO2 is odourless.
Is the odour of carbon dioxide gas reliable as a warning property?
NONE - colourless and odourless.
How can I work with carbon dioxide gas safely?
This material is a COMPRESSED GAS. Before handling, it is important that engineering controls are operating and that protective equipment requirements and personal hygiene measures are being followed. People working with this chemical should be properly trained regarding its hazards and its safe use. Use smallest, practical cylinder size in a well ventilated area separate from the storage area. Do not use with incompatible materials such as powdered metals.
Leave cylinder cap on cylinder until cylinder is secured and ready for use. Always secure cylinders to a wall, rack or other solid structure in an upright position. Do not handle cylinders with oily hands. Use the appropriate pressure regulator. Ensure equipment is compatible with cylinder pressure and contents. Follow supplier recommendations. Before connecting the cylinder for use, make sure that back-feed from the system into the cylinder is prevented.
Do not open cylinder if damaged. Never use excessive force when opening. Open cylinder valve slowly to prevent rapid decompression and damage to valve seat. Keep cylinder valves clean and free from contaminants (particularly oil and water). Make sure valves on gas cylinders are fully opened when gas is used. Open and shut valves at least once a day, while cylinder is in use, to avoid valve 'freezing'. Make sure cylinders are labelled clearly.
Avoid damaging cylinders. Move cylinders by hand truck or cart designed for that purpose. Do not drop cylinders or permit them to bank against each other. Do not lift cylinders by the cap or with a lifting magnet.
Shut flow off at cylinder valve and not just at the regulator after use. Replace outlet caps or plugs and cylinder caps as soon as cylinder is disconnected from equipment. Keep empty cylinders under slightly positive pressure. Do not use cylinders as rollers or for any other purpose than to contain the gas as supplied. Regularly check cylinders for evidence of corrosion or leakage.
Follow handling precautions on Material Safety Data Sheet. Have suitable emergency equipment fore fires, spills and leaks readily available. Practice good housekeeping. Maintain handling equipment. Comply with applicable regulations.
What can be done to control hazardous conditions?
Engineering control methods to reduce hazardous exposures are preferred. Provide sufficient local exhaust and general (dilution) ventilation to maintain the oxygen concentration of the air above 18%. Administrative controls and personal protective equipment may also be required.
