Recent events in our business have highlighted the risk of personnel being exposed to Nitrogen Oxides (NOx) gas. NOx is generated through standard processes including blasting, waste gas formation in manufacturing, during unplanned events like overheating of concentrated nitric acid and improper mixing of bulk emulsion trace chemicals. NOx is a highly toxic, colourless to reddish brown gas above 21oC, and is made up of a range of nitrogen and oxygen compounds including Nitrogen Dioxide (NO2) and Nitric Oxide (NO).