Which class of laser is any laser system containing a laser that cannot emit laser radiation at levels that are known to cause eye or skin injury during normal operation?

• A. Class 1M
• B. Class 1
• C. Class 2
• D. Class 4

Answer: (B)

Laser safety classifications sort devices by potential hazard under normal operation. The category described is the one where emission stays below injury levels during normal use, usually because the beam is enclosed or the output power is so low that even direct exposure cannot reach harmful levels. This makes the device inherently safe to observe and handle without protective measures. In practice, the maximum exposure remains below the thresholds that could cause eye or skin injury, even with typical viewing conditions.

Other classes carry higher risks and have conditions that permit exposure under specific circumstances: some may be safe only when viewed with protective optics or require precautions due to potential for accidental or reflected exposure, while others involve high-power beams that can cause injury or start fires even with indirect exposure.