Pictogram 6: Gas Cylinder

The sixth of OSHA's eight pictograms is the Gas Cylinder pictogram.

The Gas Cylinder pictogram identifies the class of chemicals called "gases under pressure."

So-called "gases under pressure" are defined as "gases which are contained in a receptacle (container) at a pressure of 200 kPa (kilopascals) or 29 psi (pounds square inch gauge) or more, or which are liquefied or liquefied and refrigerated."

OSHA separates gases under pressure into four categories: compressed gases, liquefied gases, dissolved gases, and refrigerated liquefied gases. The Society for Chemical Hazard Communication created a fact sheet defining gases under pressure. The definitions are as follows:

• Compressed gases: A gas that when under pressure is entirely gaseous at minus 50°C (minus 58°F), including all gases with a critical temperature less than or equal to (≤) minus 50°C (minus 58°F).
• Liquefied gases: A gas that when under pressure is partially liquid at temperatures above minus 50°C (minus 58°F).
• Dissolved gases: A gas that when under pressure is dissolved in a liquid phase solvent.
• Refrigerated liquefied gases: A gas that is partially liquid because of its low temperature.

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