Lasers are sources of optical monochromatic and coherent radiation: this equipment has a high degree of technological diversification and many applications that are related on the wavelength used and the power emission; besides lasers emit continuous or pulsed radiation and can propagate in free or guided modality.

There are several kinds of risk from laser radiation: optical, electrical and toxic risk, explosion and fire. The protection measures and exposure limits are based on the classification of lasers which depends on the dangerous effects of the radiation sources (Directive 2006/25/EC transposed by Legislative Decree no. 81/08, Chapter V, Title VIII, all. XXXVII).