The “DO NOT ENTER” light serves to warn people in a cleanroom of potential dangers associated with entering certain workplaces, such as X-ray radiation or a high-power laser.

The do not enter light illuminates just before the start of a potentially hazardous activity and turns off only after it is completed. It is advisable to combine it, for example, with an electric door locking system to prevent people from entering the area during radiation exposure.

The light is mounted in a plasterboard partition panel above or near the door.