This paper covers the selection of gas cylinders; seamless steel cylinders, seamless steel tubes, welded steel
cylinders, and non-refillable or disposable steel cylinders, used for carbon monoxide and for carbon monox-
ide/carbon dioxide mixtures, (e.g. laser gases). Intentionally made mixtures containing less than 5 ppmV car-
bon monoxide or 5 ppmV carbon dioxide are not affected by this document.