According to OSHA, a compressed gas is “a gas or mixture of gases in a container having an absolute pressure exceeding 40 pounds per square inch (psi) at 70°F (21.1°C)”. Basically any compressed gas that we work with is contained in a cylinder or in a piped system. Not only is there a possible danger of the gas being toxic, corrosive, or flammable, there are hazards due to the container itself.
Some dangers include:
- Leakage of toxic gases
- Projectile caps due to pressure buildup
- Explosions due to reactive gases within the container
- Explosions due to high temperature and pressure buildup
- Heavy cylinders falling
To properly handle and store gas:
- Cylinders, full or empty, must always be stored upright
- Gas valves must always be closed when not in use
- Cylinders should never be rolled, dragged, or slid.
- Cylinders should be capped at all times and be transported in an approved cart
- Gas cylinders should be chained in such a way that they cannot tip over or slip.
- Gas lines should most preferably run overhead
Other than cylinders, some gases in reaction vessels can expand due to pressure, temperature, or the evolution of a gas due to a reaction. Care should be taken to make sure the reaction vessel is properly vented or can handle the compressed gas pressure. An example would include mixing solutions in a separatory funnel and forgetting to vent, causing gas and solution to shoot out the stopper. In times of emergency, you should leave the area, call emergency services, and pull the fire alarm. Standard lab operating procedure should already be in place to deal with certain compressed gas threats.
- Matheson Gas Guide to Safe Handling of Compressed Gases
- CGA P-1 Regulation (10 CFR 1910.101(b): Safe Handling of Compressed Gases
- (UW Madison EHS)
Page prepared by Allen Chen, Spring 2017
Person Interviewed in preparation of this material: Chris Kailhofer- MSE building manager and lab supervisor