In the United States, there is no single federal standard that universally mandates the color coding of compressed gas cylinders. However, CGA C-9: Standard Color Marking of Compressed Gas Containers by the Compressed Gas Association (CGA) provides recommended guidelines for cylinder color coding. These recommendations are widely followed in the industry but are not legally binding.
Instead of relying solely on cylinder color, the primary means of identifying the gas inside a cylinder should always be the label or marking on the cylinder itself. This is because color schemes can vary between suppliers, and color alone is not a reliable method of identification.
For specific applications, other organizations may have additional guidelines:
- OSHA (Occupational Safety and Health Administration) requires that gas cylinders be clearly labeled with their contents per 29 CFR 1910.253 (for welding gases) and 29 CFR 1910.1200 (Hazard Communication Standard).
- DOT (Department of Transportation) regulates the transportation and labeling of hazardous gases under 49 CFR 172.