Non-Hazardous Area (dust) : Area in which combustible dust-air mixtures are not expected to be present in hazardous quantities and in which special precautions for the construction and use of apparatus are not required
Solutions Fire Safety Ltd, Fire Safety Glossary: An A - Z of definitions regarding fire safety terms and vocabulary, Solutions Fire Safety Ltd, UK 2012. http://solutionsfire.co.uk/Fire-literatures-PDF/Fi re-Safety-Glossary.pdf, (Fr Sfty - Brit) {465}