Q – Where is the regulation that specifies the color of medical gas cylinders? Must the color of Nitrogen, NF cylinder be black?
A – There is no actual “regulation” that specifies the color of medical gas cylinders… however there are at least two published requirements:
1.   In 2003, the FDA published it’s latest thinking on Current Good Manufacturing Practices in the “Draft Guidance”. On page 16, the document states:
Color code examination: The following colors are used by the medical gas industry in the United States to aid in identifying a medical gas. We recommend manufacturers use them.
•   Carbon Dioxide - gray;
•   Helium - brown;
•   Medical Air - yellow;
•   Nitrogen - black;
•   Nitrous Oxide - blue;
•   Oxygen - green; and
•   Blends of medical gases use a combination of the corresponding color for each component gas. For example, oxygen and carbon dioxide would be green and gray.
2.   In addition, in 1989, the FDA published the “Compressed Medical Gases Guideline”. This document is still official, though in many cases, the 2003 Draft Guidance has replaced it as the latest agency thinking. In 1989, the FDA specified the pre-fill inspection requirements:
Page 7….. A check to determine that each container is of the proper color to correspond to any color-coding system employed, such as that recommended by the CGA in its pamphlet C-9, Standard Color Marking of Compressed Gas Cylinders Intended for Medical Use in the United States.
We highly recommend that GAWDA members download the latest copy of CGA C-9 and carefully review the proper colors for medical gases. The CGA pamphlets are available at no charge to GAWDA members.