Collateral radiation [1040.10(b)(12)] is generally any optical, electromagnetic, or x radiation that is either necessary for, or occurs as a result of, the operation of a laser. Collateral radiation includes x radiation produced by a high voltage power supply, plasma glow in a discharge tube, excitation lamp light or reradiation from a workpiece. Limits for collateral optical radiation are the same as the Class I limits for laser radiation for 1000 seconds or less; limits for collateral x radiation are 0.5 milliroentgen in an hour averaged over an area of 10 cm2 parallel to the product surface with no dimension greater than 5 cm [1040.10(d)(Table VI)].