BUNTINGFORD, U.K. -- The increased use of potentially dangerous optical power sources as fibre optic media becomes more prevalent in the LAN environment has prompted the Fibreoptic Industry Association to publish its latest Technical Support Document, 2000-5-1, Optical Power Safety Levels. The 850nm, 1300/1310nm and 1550nm wavelengths commonly used to power optical networks are all in the infra-red part of the electromagnetic spectrum; they are invisible to the naked eye, so consequently there is no blink reaction, even to high powered emissions. Exposure to such light sources can cause severe eye damage, including total loss of sight. The guide describes the classification of sources into Classes 1, the safest, to Class 4; it defines unrestricted, restricted and controlled access areas and details the restrictions applicable to the use of different source Classes in each area, the precautions to be taken and the type of warning labels required. The responsibilities are quite specific: for example, it is the original installer’s duty to designate access areas and correctly to label them; however, if the layout is subsequently modified by the user, the responsibility and liability then pass on to the user. The TSD is an interpretation of the relevant BS Standard, BS EN 60825, and is intended to be read in conjunction with the published BS Specification. The guide is available by download from the FIA website, www.fibroptic.org.uk, on CD or as hard copy. It is free to FIA members; it costs £75 to non-members who can order online or by contacting the Secretariat on 01763 273039 or by email [email protected].Fibreoptic Industry Association (FIA)