In the absence of effective control measures, airborne particles are released into the workplace atmosphere by many industrial processes. Such particle clouds can be invisible under normal lighting conditions but may be made visible by the use of a high-intensity beam of light. This technique is commonly referred to as the dust lamp. The use of the lamp enables the existence of particle release at a process to be simply demonstrated, or the performance of an extractor system to be qualitatively assessed. The dust lamp is a simple qualitative tool for making fine particle clouds visible or enhancing the visibility of partially visible clouds. With a certain amount of experimentation, observations can be recorded on still or video film. The dust lamp is a powerful tool in experienced hands and can be used in a variety of ways to gain an understanding of how work processes cause exposure or controls fail to prevent emissions. The very fact that the technique makes the invisible visible explains the impact it can have on employers and employees so it can be used as an educational tool for hazard communication.