What category of lasers poses a potential fire hazard?

Class 3B and Class 4 lasers pose a potential fire hazard due to their higher power outputs and the ability to produce significant energy levels. These categories of lasers can emit enough energy to ignite flammable materials or cause serious burns upon exposure. Class 3B lasers can cause skin and eye injuries when not properly safeguarded. Class 4 lasers, which are even more powerful, can not only injure but also start fires if they come into contact with combustible substances, making them particularly hazardous in environments where flammable materials are present.

In contrast, Class 1 lasers are considered safe under all operating conditions, as they emit very low levels of laser radiation. Class 2 lasers, although they can be hazardous if viewed directly for extended periods, are less likely to pose fire risks due to their limited power. Class 3A lasers have some potential for exposure concerns but are still lower in risk compared to Class 3B and Class 4 lasers. Understanding these classifications is crucial for assessing safety and ensuring appropriate precautions are adhered to in environments where lasers are used.