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ANSI Safe Use of Lasers and Laser Safety
Introduction
The American National Standards Institute (ANSI) through the Z136 series has a number of laser safety standards, all geared toward users. Starting out with Z136.1 Safe Use of Lasers first issued in 1973 (at the request of the federal government), a number of additional Z136 application standards have been developed and issued. These include medical use of lasers and outdoor use. The ANSI standard Z136.8 entitled Safe Use of Lasers in Research, Development, or Testing is the most significant application standard for any facility where laser and product development is taking place.
The two most important items to remember are the following: first, these standards are suggested user guidance and all call on the individual laser safety officer (LSO) to apply their controls as needed and modify per use application. Second, the majority of regulatory bodies have adopted them as gospel. These two applications are not always compatible.
Any text that tries to explain all the ANSI controls will date itself as new standards and modifications of the existing standards come about. Technology is always advancing. Control measures that once stood tall for the argon ion laser fall short for the diode array. This is why the standard puts so much on the LSO to evaluate the setup and select and approve the proper controls. All of this supports Chapter 3 on hazard evaluations.
The laser user and laser safety community owes a great debt to those who worked on and developed the early ANSI standards and editions, particularly when one considers all this has been accomplished on a volunteer basis. Over time, the ANSI standards and international rules for safe use of laser may/will meld together. No matter when that may happen, the LSO will always serve a critical function.
I have been active on several ANSI standard and technical committees, and I can easily say I have met some of the finest people in the laser field working to make things better for all of us on those committees.
ANSI Z136.8 Safe Use of Lasers in Research, Development, or Testing, as mentioned in Chapter 1, is a great improvement in guidance to laser users and management. Some of the additions to laser safety guidance are given in this chapter.
IS Z136.8 Acceptable To Regulatory Authorities?
Z136.1 allows guidance from specialized/application standards, such as Z136.8, to take precedence within the scope of that standard. “Other special application standards within Z136 series may deviate from the requirements of this standard. Each deviation is valid only for applications within the scope of the standard in which it appears.”
Therefore, guidance from Z136.8 can be used for research and development (R&D)-specific applications that may not have been fully addressed or may be in conflict with Z136.1. It is up to the discretion of the LSO to determine which specialized standards apply to their particular environment, just as an outdoor range officer will look toward Z136.6 the outdoor laser standard rather than Z136.1. Remember Z136.1 is a horizontal standard and was designed to encompass a wide range of laser applications, but it always expected the generation of vertical/application standards to provide more specific and germane guidance. The following sections are some highlights from Z136.8.
Hazard Evaluation
Since the first laser, ANSI standard laser hazard evaluation has been broken down into three factors: the capability of the laser to injure people; the environment in which the laser is used; and, finally, the personnel who may be exposed to laser radiation. These three factors have served the laser user community well for 40 years. Today, advances in lasers and their application in R&D have called for an expansion of the hazard evaluation parameters. Therefore, Z136.8 added the beam path and process interaction. Today’s beam path can be complex and made up of many elements. It can be in fiber, with nonlinear optics wavelengths can change, with tunable laser techniques and chirped pulse amplification the pulse duration and peak owner can be manipulated over a wide range. Because of these and other beam path options, the standard committee felt it was important to call out the beam path of hazard evaluation. As to process interaction, the use of laser beams to generate high harmonics, and ionizing radiation made it clear that this element needed to be called out to the LSO and user for evaluation.
Laser Alignment Eyewear
The use of alignment eyewear has been ongoing in the laser use community in one form or another, which includes looking over full protection. The goal is to provide visibility of beams during alignment and still provide some eye protection to the user. This is preferable to one removing their eyewear to see the beam and having no protection. The challenge for the LSO is what optical density to suggest that allows visibility and reduces the transited beam to a Class 3R level or less. Section 4.5.2.10, Alignment Eyewear, of Z136.8 addresses the issues with suggestions for both continuous-wave and pulse lasers.
Laser Use Locations
Defining the following laser use locations assists the LSO in applying their professional judgment and aiding in justification validation:
Unrestricted location—unlimited access (hallway in a public building)
Restricted location—access granted to authorized people and limited for the general public (a research laboratory)
Controlled location—access, occupancy, and activities subject to strict control (R&D area with positive access control and video surveillance)
Exclusion location—occupancy possible but denied during the operation of the laser (free electron laser machine room or beam path)
Inaccessible location—occupancy not possible due to dimensions (enclosed beam path on an optical table)
Additional Topics
Use of noncertified lasers and the appropriate administrative, procedural, and engineering controls are discussed.
The Special Considerations section discusses visitors and spectators, laser user facilities, and export controls, as well as useful information on fiber optics and laser robotics.
Education and Training is expanded to include the importance of on-the-job training (OJT) for users in the dynamic environment of R&D.
Updates information on standard operating procedure requirements.
Discusses the management of multiple types of laser use areas, including indoor Class 3 and 4 lasers, laser exclusion areas, and airspace (includes references to related Federal Aviation Administration and ANSI sources).
Information on non-beam hazards has been condensed to R&D-relevant information. Z136.8 includes full-color signage and diagrams.
Included in the figures section is current ANSI Z136.1 and Z535.2 compliant signage for
Class 2 and 2M lasers
Class 3R, 3B, and 4 lasers
Temporary laser-controlled areas
Unattended laser operations
Warning signal word
There are diagrams and explanations for exterior entryway controls, multiple entry point controls, and Class 4 entryway controls for laboratories with and without entryway interlocks.
Introduction of New Appendixes
The Z136.8 standard includes three new appendixes as well as all R&D-relevant appendixes from Z136.1. New appendixes contain useful information not addressed in the main standard, whereas appendixes pulled from Z136.1 are modified to focus on information that is relevant to the R&D.
Appendix B: Sample Forms
Two sample laboratory audit forms
Sample laser program self-evaluation form
Appendix C: Frequently Reported Incidents
Discusses the most common causes of accidental eye and skin exposures to laser radiation and accidents related to non-beam hazards.
Appendix H: Laser Product Safety Rules
New engineering controls: many engineering controls present in Z136.1 are not found in this standard. To maintain proper emphasis on their importance, “CDRH Sec. 1040.10 Laser Products” is included as guidance for Appendix A: Supplement to Section 1:
LSO requirements and responsibilities
Guidance on laser safety committees
Personnel responsibilities (supervisors and employees)
Appendix D: Education and Training
Class 1M, 2, 2M, and 3R awareness training
OJT
Laser pointer awareness
Certifying laser products
Going back to Z136.1, the following are some of the critical items.
Section 1: Establishment Of The Laser Safety Officer
The laser safety program established by the employer shall include provisions for the following:
Designation of an individual as the LSO with the authority and responsibility to effect the knowledgeable evaluation and control of laser hazards and the implementation of appropriate control measures, as well as to monitor and enforce compliance with required standards. The specific duties and responsibilities of the LSO are designated in the Normative Appendix A. Throughout the body of this standard, it shall be understood that wherever duties or responsibilities of the LSO are specified the LSO either performs the stated task or assures that the task is performed by qualified individual(s).
Education of authorized personnel (LSOs, operators, service personnel, and others) in the safe use of lasers and laser systems and, as applicable, the assessment and control of laser hazards. This may be accomplished through training programs. Employers should consider the benefits of initiating awareness training for employees working with and around lasers and laser systems greater than Class 1. If training is warranted for embedded lasers, it shall extend to those routinely around the systems, who will be present when service and maintenance occurs.
Application of adequate protective measures for the control of laser hazards as required in Section 4 of the standard.
Incident investigation, including reporting of alleged accidents to the LSO, and preparation of action plans for the prevention of future accidents following a known or suspected incident.
Formation of a laser safety committee when the number, hazards, complexity, and/or diversity of laser activities warrant it.
Section 4: Control Measures
Establishing Control Measures
Control measures shall be devised to reduce the possibility of exposure of the eye and skin to hazardous levels of laser radiation and other hazards associated with laser devices during operation and maintenance.
The LSO shall have the authority to monitor and enforce the control of laser hazards and effect the knowledgeable evaluation and control of laser hazards and conduct surveillance of appropriate control measures. The LSO may, at times, delegate specific responsibilities to a deputy LSO or some other responsible person.
Applicability of Control Measures
The purpose of control measures is to reduce the possibility of human exposure to hazardous laser radiation and to associated hazards.
“In some cases, more than one control measure may be specified. In such cases, more than one control measure that accomplishes the same purpose shall not be required.”
Substitution of Alternate Control Measures (Class 3B or Class 4)
The engineering control measures recommended for Class 3b and Class 4 lasers or laser systems, upon review and approval by the LSO, may be replaced by procedural, administrative, or other alternate engineering controls, which provide equivalent protection. This situation could occur, for example, in medical or R&D environments. Accordingly, if alternate control measures are instituted, then those personnel directly affected by the measures shall be provided the appropriate laser safety and operational training.
These empower and allow the LSO to do the job at hand. Working safely is compatible with high-quality work and innovative work.