How safe is DR technology?

Class 1 Lasers are safe under reasonable foreseeable conditions of operation, Beam can be looked into with the naked eye or with optical devices,

Trimble's Class 1 laser:
5600 DR 200+/300+ & S6 without visible laser pointer

Class 2 These lasers are visible (400 nm to 700 nm). They are safe provided the blink or aversion responses operate.

Trimble's Class 2 lasers:
3300, 3600, and 5600 DR Standard
5600 & S6 visible laser pointer