Are Lasers Machine Dangerous? For visible-beam consumer lasers, there are four main classes. Each is described in more detail here: Class 2, Class 3R, Class 3B and Class 4. Exposure to intense laser beams or UV radiation can potentially harm the eyes and skin. It's important for individuals working with such sources to follow safety guidelines and use appropriate protective measures, such as safety goggles or glasses designed for the specific wavelengths involved.