These include photocopying machines, many construction materials, paint fumes, cardboard, carpets, and janitorial supplies. Metal cabinets, such as powder-coated steel cabinets, are preferred over wood as wood often generates harmful peroxides. Finally, keep photographs in archival-quality enclosures. Enclosures keep dirt off objects and may help decrease the effects of pollutants. Enclosures containing activated charcoals and molecular traps have recently become available and appear to be effective in this regard.
Light damage is cumulative and usually irreversible.
However, all forms of light are damaging and should be moderated. Do not place valuable photographs on permanent display. Avoid hanging photographs where they will be exposed to daylight, especially direct sunlight, or to unfiltered fluorescent lights. Both of these light sources generally give off high amounts of damaging ultraviolet light. Also, low UV-emitting bulbs are now available.