Environmental Health & Safety

Ultra-Violet Radiation

Ultraviolet (UV) radiation is the portion of the electromagnetic spectrum which has a wavelength of between 220 and 400 nanometers (nm). UV radiation is considered non-ionizing which means that the radiation is not sufficiently energetic to remove electrons from an atom. UV radiation can, however, cause some tissue damage depending upon the duration and energy level of the exposure. The lower the wavelength of light, the higher the energy. Of particular interest to research is the UV wavelengths between 220 and 290 nm known as UVC.

UVC is used in many applications because of its bactericidal qualities. This type of light is used in biosafety cabinets throughout the college and can be harmful to skin and eyes. The symptoms of UVC exposure are generally not felt until a few hours after exposure. It is very important to use the proper shielding at all times when the UV light is on. Eye protection should consist of safety goggles which meet ANSI Z87.1-1989 and C.S.A. standard CAN/CSA - Z94.3-M88. In addition, face and skin coverings should be worn. The glass sash of the biosafety hood should fully shield any UVC if it is closed completely. In addition to shielding, the power output of these lights drops off dramatically with distance, therefore, it is prudent to maintain the greatest distance from any unshielded light.

To keep the light in the optimum working order, it is advised that the bulb be washed with an ethanol wipe each week and replaced after one year of service. Before working on the UV lamp make sure that the light is off. It is a good idea to disconnect the unit to assure that lamp will not turn on during installation. Most work with UV light is safe and easy and the simple precautions mentioned above will ensure that the risk of exposure is minimized. If you have any questions or want to learn more about UV radiation, please call the Environmental Health and Safety Department at x4152.

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