Proper storage and identification of medical oxygen is essential. Medical oxygen is classified as a prescription drug by the FDA and a hazardous material by the DOT. 

Companies handling oxygen distribution are required to use signage to mark different storage areas at their facilities. The signage should be clear, well-maintained and convey the intended message effectively.

Required signs include:

Signage for Oxygen Distributors:

• Full: Cylinders with container closures installed and product inside, ready for customer delivery. 
• Empty: Cylinders returned from customers without container closures.
• Quarantine: Cylinders requiring repair or maintenance, often referred to as "dirty." 

Signage for Oxygen Manufacturers:

• Full: Cylinders with container closures installed and product inside, ready for customer shipment.
• Full Not Approved: Cylinders with container closures installed and product inside but not yet approved by Quality Control for customer delivery.
• Empty: Cylinders returned from customers without container closures.
• Quarantine: Cylinders needing repair or maintenance, failing an inspection during the filling process, also known as "dirty." 

Additionally, ensure that "No Smoking" signs are prominently displayed throughout the warehouse, especially at entryways and above cylinder storage areas.