Routine and regular checks on an LEV system that ensure it is working properly (controlling exposure). May involve the use of airflow indicators. Should be carried out in addition to the thorough examination and test, by acompetent person
Health and Safety Executive (HSE), Glossary of Terms: Local Exhaust Ventilation, HSE, Merseyside, England, UK 2012. www.hse.gov.uk/lev/glossary.htm, (Hlth and Sfty - Brit) {704}