Which class of lasers are intermediate-powered lasers and may be hazardous under direct and specular reflection viewing, and/or diffuse reflection, but the probability of an injury is small, and they do not present a fire hazard?

• A. Class 2
• B. Class 1
• C. Class 4
• D. Class 3R

Answer: (D)

Understanding laser safety classifications means matching the exposure hazards to the beam power and how people might view it. An intermediate-powered laser is powerful enough that looking directly into the beam or at a mirror-like (specular) reflection can injure the eye, and reflections from surfaces can pose some risk, but the chance of injury is relatively low and there’s no fire hazard under normal use. This is the hallmark of Class 3R lasers. They are hazardous if viewed directly or through a strong reflection, yet diffuse reflections are much less dangerous, and they do not present a fire hazard. In contrast, safer classes like Class 1, or low-hazard Class 2, don’t carry this direct-beam risk profile, while higher classes (such as 3B or 4) carry greater eye/skin injury risk and fire hazards. So the description fits the intermediate Class 3R.