Airflow Indicators​

There isn’t a specific legal requirement to have air-flow indicators or similar fitted to an LEV system. But as an employer you do by law have to make sure your LEV systems keeps working properly. One of the main reasons why LEV’s fail to meet CoSHH standards is because the airflow is not acceptable and therefore control of the dust is lost. This could be for a number of reasons: build-up of material, damage to ducting etc.

One simple but effective way of checking this is the use of airflow indicators at the hood, this will provide you reassurance that the flow-rate is maintained, that the protection for employees is there and that you’re not wasting money. There are other ways of checking the airflow, such as using a pitot tube and anemometer. Visual inspections like using a dust lamp or a smoke tracer(with the work process running) can be used to check the dust is being controlled. However, an airflow indicator is currently the only method that will show the operator or supervisor immediately if there’s a problem, and HSE’s LEV guidance HSG 258[1] recommends these are fitted.