Question

A laser is emitting at a power of 10mW and exposes a surface of 0.1 cm2 on the skin. Assume that the laser is pulsed at 1ms. For the above-mentioned laser, SEL = 250 mJ/cm2 and OEL = 15 uJ/cm2. Which of the following statement is correct based on what is known about the laser? The density of energy for the laser is 100uJ/cm2. It is hazardous on the eye, but not on skin. The density of energy for the laser is 100mJ/cm2. It is hazardous on the eye, but not on skin. The density of energy for the laser is 100J/cm2. It is hazardous on both the eye

Answer 1

the density of energy for laser =

  

10mW x 1ms 0.1cm2 100w/cm2

this is class2 laser which is not hazardous.

radiance of laser exposure factor = log10 exposure limit

100w/cm2 exposure factor = log10 15uJ/cm2

exposure factor = 0.82

it is less than 1.5.

hence it is non hazardous for eye and skin.