Safety laser

Preview This section discusses the basics of lasers and safety practices and procedures and other safeguards when using lasers in the laboratory. 

Hokey religions and ancient weapons are no match for a good blaster at your side, kid. 

An undergraduate student was working with an experienced researcher using two different kinds of Class IV lasers. One laser was a particle-generating laser that produced suspended particles in a chamber, and the other laser was an LIBS (laser-induced breakdown spectroscopy) laser that vaporized suspended particles. The student bent down to look at the suspended particles and experienced a flash. A red-brown substance was seen in her eye and later medical evaluation confirmed that the student had a retinal traumatic hole burned in her eye due to a pulsed laser. Neither the researcher nor the student wore eye protection. No one immediately reported the incident. 

INCIDENT 73.3.2 SHOCK FROM LASER POWER SUPPLY  

A researcher was working on a laser with a 17,000-volt power supply when he noticed some condensation on one of the contacts of the power supply. He decided to wipe the moisture away with a tissue but touched the anode and received a sudden shock. He staggered into the hall and collapsed into the arms of a passerby after uttering I ve been shocked . His heart had stopped and cardiopulmonary resuscitation (CPR) was started. Emergency personnel arrived and used a defibrillator to restore his normal heartbeat. He was able to explain what happened. Safety interlocks had been bypassed allowing him to be exposed to this high voltage. 

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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. 

One of the most significant laser safety standards is that developed by the Z-136 committee of the American National Standards Institute (ANSI) (55). Although it is voluntary, many organi2ations use the ANSI standard. It contains a number of items including a recommendation for maximum permissible levels of exposure to laser radiation for various wavelengths, exposure durations, and different parts of the body separation of lasers into four different classes according to the level of ha2ard they present and recommendation of safety practices for lasers in each of the classes. 

R. J. Rockwell, Jr. and J. Parkinson, State and local government laser safety requirements, J. Laser Appl., 11,... 

American National Standards Institute (ANSI), American national standard for safe use of lasers, in Z136 Laser safety standards series. Z136.1 (2007). 

If a Fourier transform infrared spectrometer is being used, do not attempt to adjust the laser. Safety glasses must be worn in the laboratory at all times. Appropriate safety gloves and other personal protection equipment should be used when handling chemicals. 

Health and safety requirements Mechanical safety for robotic movement, radiation safety for systems that involve the use of radioactive sources, and laser safety for systems that use high-power lasers. 

Rockwell, R.J., Jr Parkinson, J. State and Local Government Laser Safety Requirements /. Laser Appl. 1999, 11, 225-231. 

ANSI. Z136 Laser Safety Standards Series Z136.1-2000 American National Standard for Safe Use of Lasers. 2000. 

OSHA Guidelines for Laser Safety and Hazard Assessment (Std 01-05-001-Pub 8-1.7). 1991 http //www.osha.gov/pls/oshaweb/owadisp.show document p table=DIRECTIVES p id—1705. 

A laser power of 5 mW or less is sufficient for this experiment. At this power level, such sources are relatively harmless but of course the beam should never be viewed directly. Further discussion of laser safety practices is given in Appendix C. A safety shield should be used in any spin coating operations. 

D. C. Winburn, Practical Laser Safely, 2d ed., Dekker, New York (1990). Contains ANSI Z136.1 classification scheme and a critique of this from the standpoint of a laser safety officer with much experience. 

Asrani S, D Anna S, Alkan-Onyuksel H, Wang W, Goodman D, Zeimer R. Systemic toxicology and laser safety of laser targeted angiography with heat sensitive liposomes. J Ocul Pharmacol Ther 1995 11 575-584. 

Provided that the pulse generator already exists, this is certainly the eheapest pi-eoseeond light source ever used. Of course, operating a laser diode this way is most likely not in eompliance with any laser safety regulations. In addition, RF emission can be a problem if the diode and the driving generator are not properly shielded. 

Please note that the suggested laser diode calibrator is legally a laser deviee . Although it is not potentially dangerous, its operation is subject to laser safety regulations. 

Absorption coefficients of water and a typical human tissue (aorta) as a function of wavelength. The suitable region for optical excitation is between 650 and 1000 nm. This figure is drawn using data from the Handbook on Industrial Laser Safety, http //info.tuwien.ac.at/iflt/safety/index.htm. 

Laser safety standards for the United States are given for all laser uses and types in the American National Standard (ANSI) Z136.1-1993, Safe Use of Lasers. 

Safety personnel can help lab safety by providing training, resources, and consultation for a variety of laboratory safety issues, including chemical safety, biological safety, electrical safety, laser safety, radiation safety, and other topics. They can also review the chanical hygiene plan, help develop and maintain laboratory safety manuals, conduct exposure monitoring, inspect fume hoods, and perform safety audits. 

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. 

Laser Safety Guide—Laser Institute of America, 4th ed. Cincinnati, OH, 1977. 

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