Meg Geiss-Mooney writes: >You must also be concerned on how these UV light fixtures are oriented in relation to the viewers. UV light is very damaging to eyes. When we conservators are using them to examine artifacts (the lamps are pointed at the object briefly), we were protective goggles.> in reply to: >>Hello all, We have a group of people that would like to donate some UV light fixtures to illuminate some extremely large paintings that will floresce (no idea how to spell that) when lit. I am concerned about prolonged exposure to UV light, even if the paintings were "meant" to be displayed in that light.>> It is important that you determine whether the UV light fixtures emit short-wave or long-wave ultraviolet radiation. Go to http://www.uvminerals.org/spectrum.htm to read about short-wave and long-wave UV. Some materials absorb UV radiation, which excites electrons, making them unstable. This absorbed energy can cause chemical bonds to break, is converted to heat, or is converted to light as phosphoresence or fluorescence. The time interval between absorption and fluorescence is measured in millionths of a second. Visible fluorescence can be seen by humans; ultraviolet radiation cannot. Short-wave UV is used in many natural history collections -- behind glass -- to excite fluorescence of mineral specimens, but should never be used to illuminate works of art or in public spaces because exposure can cause (sometimes irreversible) damage to organic materials like paint, paper, textiles, zoological and plant specimens, skin, eyes, etc. (see http://www.ftc.gov/bcp/conline/pubs/health/indootan.htm). Long-wave UV is used by conservators to examine and photograph visible fluorescence of coatings, pigments, and other materials comprising works of art. (Long-wave UV also is used to illuminate black-light posters in novelty shops and teenagers' bedrooms.) Some organic materials are vulnerable to long-wave UV, so prolonged exposure to long-wave UV radiation could cause discernable and sometimes irreversible damage. For this reason, conservators often recommend that exterior windows and fluorescent lights should be covered with UV absorbing film or sleeves, respectively. Long-wave UV radiation can cause eye discomfort for museum visitors, especially when works are viewed in a darkened room because pupils dilate to take in more light, or, as Meg pointed out, when visitors can look directly at lamps. The potential for damage to the paintings in question (and architectural materials such as wall paint and carpet) would depend on the materials comprising the paintings (and architectural materials), the wavelengths and intensity of UV radiation emitted by the fixtures, proximity to the fixtures, and exposure time. Before ruling out the installation, consider that works of art are vulnerable to many environmental variables (temperature, moisture, air quality), housing and framing, vandalism, and inherent vice of component materials. With careful planning and testing it may be possible to design an installation that balances short-term exhibition objectives against long-term conservation goals and visitor comfort. James Martin Conservation Scientist Orion Analytical, LLC www.orionanalytical.com 413-458-0233 ========================================================= Important Subscriber Information: The Museum-L FAQ file is located at http://www.finalchapter.com/museum-l-faq/ . You may obtain detailed information about the listserv commands by sending a one line e-mail message to [log in to unmask] . The body of the message should read "help" (without the quotes). If you decide to leave Museum-L, please send a one line e-mail message to [log in to unmask] . The body of the message should read "Signoff Museum-L" (without the quotes).