Glossary / Physical hazards
Compressed gas
A compressed gas is a gas packaged under pressure in a cylinder or tank, including liquefied, dissolved and refrigerated forms. The container itself is a hazard because stored pressure can release violently if a cylinder is damaged or heated.
Explanation
The GHS groups gases under pressure into compressed gases, liquefied gases, refrigerated liquefied gases and dissolved gases. The pressure is a hazard whatever the contents are, which is why even nitrogen or argon cylinders carry the gas cylinder pictogram.
The greatest physical danger is a broken valve. A cylinder with its valve knocked off can accelerate like a rocket, and the force can pierce walls. Cylinders should be transported with caps on, secured with chains or stands, and never moved by rolling or dragging on their valve.
Contents add other risks. Gases may also be flammable, toxic, corrosive or oxidizing, or may displace oxygen in a closed room. Regulators must be matched to the gas, and equipment such as hoses and fittings must be rated for the pressure and compatible with the contents.
Storage practice includes keeping cylinders upright, away from heat and sources of ignition, and with full and empty cylinders separated and clearly labeled. Heat can raise pressure toward the relief setting, so cylinders should not sit in direct sun or near furnaces.
What to do and watch for
- Keep valve caps on during movement and storage, and secure every cylinder.
- Use the correct regulator and check for leaks after changing a cylinder.
- Store in ventilated areas, separate from incompatible gases.
Where it appears on an SDS
- Section 2: Hazard identification. The gas under pressure classification, gas cylinder pictogram and statements such as H280 or H281.
- Section 7: Handling and storage. Cylinder handling, securing and storage advice, including ventilation and temperature limits.
SDS content and wording vary by supplier. This page is general reference and does not replace the current SDS for your product.