Use of Lasers in Educational Institutions Addresses laser safety concerns in educational settings. ANSI Z136.6 – Safe Use of Lasers Outdoors Provides guidance for the safe use of lasers in an outdoor environment, e.g., construction, displays/laser lightshows, scientific/astronomical research, and military. ANSI Z136.7 – Testing and Labeling of Laser Protective Equipment Provides reasonable and adequate guidance on the test methods and protocols used to provide eye protection from lasers and laser systems. ANSI Z136.8 – Safe Use of Lasers in Research, Development, or Testing Provides guidance for the safe use of lasers and laser systems found in research, development, or testing environments, where safety controls common for commercial lasers may either be missing or disabled. ANSI Z136.9 – Safe Use of Lasers in Manufacturing Environments Intended to protect individuals with the potential for laser exposure when lasers are used in manufacturing environments, this standard includes policies and procedures to ensure laser safety in both public and private industries as well as product development along with testing. Through 21 CFR 1040, the US Food and Drug Administration (FDA) regulates laser products entering commerce and requires all class IIIb and class IV lasers offered in commerce in the US to have five standard safety features: a key switch, a safety interlock dongle, a power indicator, an aperture shutter, and an emission delay (normally two to three seconds). OEM lasers, designed to be parts of other components (such as DVD burners), are exempt from this requirement. Some non-portable lasers may not have a safety dongle or an emission delay, but have an emergency stop button and/or a remote switch. Classification Lasers have been classified by wavelength and power into four classes and a few subclasses since the early 1970s. The classifications categorize lasers according to their ability to produce damage in exposed people, from class 1 (no hazard during normal use) to class 4 (severe hazard for eyes and skin). There are two classification systems, the "old system" used before 2002, and the "revised system" being phased in since 2002. The latter reflects the greater knowledge of lasers that has been accumulated since the original classification system was devised, and permits certain types of lasers to be recognized as having a lower hazard than was implied by their placement in the original classification system. The revised system is part of the revised IEC 60825 standard. From 2007, the revised system is also incorporated