Which classification of lasers poses the least risk to skin and eyes?

Class 1 lasers pose the least risk to skin and eyes because they are designed to be safe under all conditions of normal use. These lasers emit low levels of radiation that should not cause harm to human tissues, making them inherently safe for the user and those nearby. The design and operational limits of Class 1 lasers ensure that the emitted radiation is within safe exposure limits, meaning individuals can be in the vicinity of these lasers without concern for injury.

In comparison, other classifications like Class 2, Class 3A, and Class 4 lasers have higher power outputs or capabilities that can pose potential risks. Class 2 lasers may cause harm if viewed directly for an extended period, and Class 3A lasers can be hazardous under specific conditions, such as when viewed through optics. Class 4 lasers are high-powered systems that can cause significant damage to both skin and eyes, making them the most hazardous of all classifications. Thus, the hierarchy of laser safety clearly positions Class 1 lasers as the safest option.