Oxygen can be dangerous if proper precautions aren’t taken. Display a warning oxygen sign to alert people that oxygen is in use. Yellow and black print on a white background. An exclamation mark and text reading, “Warning oxygen” get the message across. Made of high-quality plastic. Manufactured in the UK by Jalite. Photoluminescent, glow in the dark coating. Choose from two size options. 200mm x 150mm or 100mm x 300mm.