The LASER system falls into class 3B or 4 and the beam is free (the LASER beam is mounted on a manually steerable handpiece; the manufacturer did not embed it into a housing; e.g. hand-held LASER handpieces as in an aesthetic or hospital setting, industrial LASERs that require the presence of the operator in the immediate proximity of the free beam).
The requirements on the environment where the LASER is used depend on the ratio between the NOHD value and the size of the environment.
Dmin is the distance between the typical position of the LASER and the nearest aperture to the exterior of the LASER environment (door, window, end of the wall); Dmax is the distance between the typical position of the LASER and the farthest aperture to the exterior of the LASER environment (door, window, end of the wall);
Which of the following situations is observed:
The NOHD value indicated by the manufacturer is lower than 20 cm
The NOHD value indicated by the manufacturer is higher than the above defined Dmax