1.1

Z136.5 Safe Use of Lasers in Educational Settings

This standard was first published in 2000 and updated in 2009. The scope of the standard is described in section 1.1 which reads: This standard addresses laser safety concerns and situations characteristic of the education environment. This standard is not a substitute for ANSI Z136.1-2007, which is required for a full understanding of laser safety officer duties and laser hazard evaluation. Environments characteristic of educational institutions wherein lasers may be found include teaching laboratories, classrooms, lecture halls, science fairs, museums, and student projects on and off campus. This standard is intended for faculty and students using lasers at primary, secondary, and college levels of education excluding graduate level research laboratories. The wavelength range of interest includes the ultraviolet, visible, and infrared regions of the electromagnetic spectrum, specifically the wavelength from 0.18 micrometer to 1 millimeter.

As in all the laser safety standards for Class 3B and Class 4 laser use, the standard calls for the designation of a Laser Safety Officer (LSO). This person is to administer and manage the laser use at the facility. They need to be knowledgeable of laser hazards and controls. For laser or laser systems with lower class lasers (lower output) an LSO is not required (this not completely true). Institutions need to be aware that some equipment that is completely safe during normal operation may contain a Class 3B or Class 4 laser and access to this level of laser radiation may be present during service or maintenance. In the educational arena, such devices are usually found at the college level or laser technician training schools.

Laser hazards fall into three groups: real injuries, perception of injury and potential injuries. Real injuries are a rather simple concept. One has received sufficient energy to cause biological damage. Depending on the wavelength and irradiance (note not just power of the beam), the effect of the exposure may be immediate (400-1400nm) to delayed (180-400nm, .1400 to 1 mm). Institutions need to have a plan in place, for example, as most schools do for items above first aid to, address a possible laser eye injury. In the case of eye injuries, knowing an eye clinic or retinologist is an example of good planning.

Perception of injury involves could be exposure to a low power beam or one seeing laser beams reflected on an optic, giving the impression one has been exposed to laser radiation (light). Experimental laser set ups should be designed to contain this type of issue. Beams should be contained to inside the classroom or demonstration enclosure or device.

Potential injuries, is the role of safety planning, taking steps to mitigate a potentially hazardous situation. Following is a key element of this standard that is complementary to standard teaching practices. The standard calls for review of all lesson plans that involve laser use. The guidance can be found in section 4.1.1 Standard Operating Procedures (SOPs), Laser Lesson Plans and Controls. This can be performed by the LSO or delegated to a faculty member or outside resource. Once the lesson plan with controls has been approved, the process does not have to be repeated as long as the plan is followed each time.

Section 4.2 Controls by Grade Level, breaks down guidance to the following groups: Grades K-6, Grades 7-8, Grades 9-12, Vocational School, College and University Students, Classroom Demonstrations and Lecture Halls. While section 4.3 covers multi-use laser settings.

Section 5 covers “Laser Safety Programs and Student Training”. The subsections have the titles, 5.1 General, 5.2 Educational Laser Safety Committee, 5.3 Student Laser Safety Training, 5.4 Faculty and Staff Laser Safety Training.

The standard recognizes the fact that many primary and secondary schools will not have a designated LSO, and still might have class projects that involve lasers. Therefore, it recommends having a teacher who has had some laser safety training; this does not have to be at the same level of an LSO. It reminds faculty and staff of the responsibility they have when they introduce students to an environment that contains laser radiation. At each grade level the maturity of students needs to be considered as one decides on the level of controls that need to be put in place and yet still get the class lesson across.

1.2

Z136.8 Safe Use of Lasers in Research, Development or Testing

This standard, after a 5 year development effort, was first published in late 2012. The next edition is aiming for 2016-17. The standard addresses a number of items not found in Z136.1-2007 Safe Use of Laser or the other Z136 laser safety series standards.

The standards scope is rather simple, and really just repeats the title. It is in section 1.2 Application where its philosophy is made clear. “The objective of this standard is to provide reasonable and adequate guidance for the safe use of lasers and laser systems in research, development, and testing environment, where safety controls common for commercial laser may be either missing (nonexistent) or disabled.”

At this level of educational facilities, laser safety falls most commonly, not to the instructor or senior scientist, but to the laser safety officer. The day to day laser safety is under the supervision of a Post Doc or senior graduate student. The safety culture of such a group is established by either the expectations of the institution or lead scientist. At this level, the laser safety officer needs all the assistance and tools they can acquire to monitor and set the safety tone. Here is where Z136.8 can be extremely helpful.

First, it recognizes that institutional laser safety training is only an awareness step and that real laser safety comes from mentorship, also known as on the job training (OJT). It provides guidance on the topic, emphasizing that there is no set time period to accomplish OJT as well as the importance of documenting such activities. Second, that lasers used in research are not always commercial products and the exclusion of some commercial laser safety controls are acceptable by authorized and trained users as compared to general laser operators and the public.

Some of the topics the standard covers for the first time are, On the Job Training, User Facilities, Export Control, Beam path evaluation, Process interaction, Using laser use locations to vary control measures, use of Alignment eyewear and its selection, safety qualification of service personnel and noncommunication fiber optics, among other topics.

Z136.8 provides needed guidance to the laser safety officer, who is responsible for laser safety in the University setting. In addition, it helps explain to an institutions management the real world of laser use and safety at this level and how laser safety will interact with students.

1.3

Definitions that will help the reading of this paper:

Class 3B laser: Lasers may produce visible or invisible emissions. The Continuous Wave output power ranges from 5mW to 500mWatts. Class 3B lasers may cause injury from direct and specular exposure.

Class 4 Laser: This laser can be visible or invisible emitting radiation greater than the 3B range, with the capability of causing eye or skin injury from direct, specular or diffuse exposure.

Classroom environment: A classroom or closed room in which most, if not all, students are seated and one or more instructors are present to provide supervision.

Irradiance: Radiant power incident per unit area upon a surface, expressed in watts-per-centimeter squared.

Laser Safety Officer (LSO): One who has authority and responsibility to monitor and enforce the controls of laser hazards and effect the knowledgeable evaluation and control of laser hazards. This individual has the training and experience to administer a laser safety program.

Standard Operating Procedure: Formal written description of the safety and administrative procedures to be followed in performing a specific task.