Laser safety measures

ANSI ZI36.4, Recommended Practice for Laser Safety Measurements... 

ANSIZ136.4—RecommendedPractice for Laser Safety Measurements for Hazard Evaluation... 

Safety Standards. Protection from laser beams involves not allowing laser radiation at a level higher than a maximum permissible exposure level to strike the human body. Maximum permissible exposure levels for both eyes and skin have been defined (55—57). One of the most common safety measures is the use of protective eyewear. Manufacturers of laser safety eyewear commonly specify the attenuation at various laser wavelengths. Under some conditions safety eyewear has been known to shatter or to be burned through (58), and it is not adequate to protect a wearer staring directly into the beam. 

Eor evaluation of a particular laser installation, the standard should be consulted to determine the classification of the laser and appropriate safety measures. The maximum permissible exposure for the particular laser also should be determined in order to select the appropriate protective eyewear. 

Laser safety officer—Person with authority to monitor and enforce measures to control laser hazards and effect the knowledgeable evaluation and control of laser hazards. 

The most important safety measure that you must remember for all lasers is never stare directly into the beam. You must always avoid eye exposure to lasers. Eye injuries, including permanent eye damage, are the most common serious result from laser exposure. If you are working with Class 3B or Class 4 lasers, you must make a conscious effort to wear eye protection. All persons working in this area should also be wearing laser eye protection. 

Many larger institutions have a Laser Safety Officer (LSO) who has been assigned the duty of reviewing the safety measures for using lasers in that institution. If your institution has an LSO, you should establish a working relationship with this person and learn as much as possible about safety measures. The LSO can assist you in the proper selection of laser safety glasses or goggles. 

Lasers are widely used in the workplace for a variety of purposes ranging from cutting and welding to materials analysis and measurement. The t5q)es of laser used including their output powers vary depending on the application. The current standard for laser safety provides appropriate advice to both the manufacturer and the user of laser products. 

This standard provides information on how to classify lasers for safety, laser safety calculations and measurements, and laser hazard control measures. The standard also addresses requirements for laser safety officers (LSOs) and laser safety committees. The standard specifies that design of signs and labels be in accordance with ANSI Z535 series of standards for accident-preventing signs. 

This standard provides guidance for optical measurements associated with laser safety requirements. The information contained in this document will help users who conduct hazard evaluations and ensure the use of appropriate control measures. It contains clearly written definitions, examples, and other practical information for manufacturers, LSOs, technicians, and other trained laser users. 

The lowest value for optical radiation power capable of igniting a gas-air mixture has been measured for CS2-air mixtures with 50 mW (Nd YAG-Laser, X = 1064 nm). Including a margin of safety of Xl.5, the optical radiation power shall not exceed 35 mW. 

Fig. 8.2.1. Low angle laser light scattering photometer (Chromatix KMX-6) simplified optical diagram. 1 Flelium-neon laser 2 prism system 3,4,5 measuring attenuators 6 calibrating/ shutter attenuator 7 condensing lens 8 sample compartment 9 annuli 10 safety attenuator 11 relay lens 12 field stops 13 interference filter 14 analyzing polarizer 15 microscope objective 16 photomultiplier...

---