American National Standards Institute - Z136.2
Safe Use of Optical Fiber Communication Systems Utilizing Laser Diode and LED Sources
This standard addresses the hazards of, and provides guidance for the safe use, maintenance, service and installation (manufacture) of optical communication systems (OCS) utilizing laser diodes or light emitting diodes (LED) operating at wavelengths between 0.6 µm and 1 mm, and not intended for visual communications.
For purposes of this standard, OCS includes end-to-end optical fiber based links (optical fiber communications systems (OFCS), fixed terrestrial point-to-point free-space links (free space optical communication systems (FSOCS) or a combination of both.
The Z136.2 standard provides specific requirements for the safe use, service, operation, maintenance and installation of OCS, including OFCS and FSOCS. It is intended to be used by those who assemble the end-to-end system (installation) and by service, maintenance and other personnel who may be exposed to such systems where access is in uncontrolled, controlled and restricted locations. It provides detailed safety information for systems where optical energy may be accessible and where source parameters are uncertain or not under the control of the user.
In previous editions of the Z136.2 standard, the hazard level of an OFCS, which is based on the hazard class, i.e., Class 1, 1M, 2, 2M, 3R, etc., was called Service Group since most inadvertent exposures would be expected to occur during installation and service. In order to address exposures not related to service, e.g., a fiber break in an accessible location, and to harmonize with international standards such as IEC 60825-2, the term Service Group has been replaced with Hazard Level.