Safety Precautions to be Observed with Cooled Premixed Gases

Abstract

The gas delivered from a cylinder of Entonox (50% nitrous oxide and 50% oxygen) may not contain adequate quantities of oxygen if the cylinder has been cooled and then allowed to warm up in a vertical position. The composition of gas delivered from cylinders cooled to not lower than –40° C. remains unaltered if the cylinders are rewarmed for 24 hours in a horizontal position at a temperature of not less than 5° C. Cylinders of Entonox delivered in cold weather should be stored in a horizontal position at 5° C. or more for at least 24 hours before use.