The fourth talk I wanted to highlight is Michelle Sullivan’s “Rigid polysaccharide gels for paper conservation: a residue study” - of particular interest to me as a paper conservator. They ranged from coating/grime removal from a giant sequoia tree cross section, to dirt and varnish removal from Delacroix wall paintings, to removal of repairs from a fragile felt hat from a 18 th century ship wreck, and an experiment comparing residues left behind by various gels on paper. The talks were excellent, and I’ve focused on four that were notable for the wide range of materials treated and challenges faced. In mid-October, over the course of three days, some 41 authors presented research, techniques and ideas on gels in conservation.
UV LIGHT CONVERSE SERIES
This blog post is part of a series of observations about the London “Gels in Conservation” conference co-hosted by the Tate and IAP (International Academic Projects, Ltd). There are no standard guidelines for monitoring UV equipment, but there are commercial UV monitors that detect output or leakage.Gels in Conservation Conference, October 16-18, 2017 Maintenance should be performed according to manufacturer’s instructions electric power should always be turned off to prevent accidental exposure. These should be clearly visible for the operators or maintenance personnel and include the temperature and relative humidity ranges specified by the system design to ensure safe operation. The operating instructions and recommendations for proper use of any UV system should be kept for reference to reduce hazardous exposure. Proper installation, monitoring, education of maintenance personnel, signage and use of safety switches can help to avoid overexposure. Each UVC system should have the option of a viewport so workers can view the lamp assembly without the possibility of over-exposure to UVC.
UV LIGHT CONVERSE PASSWORD
Switch locations should be locked or password protected to ensure that the UVC source is not accidentally turned on. Or placing ON/OFF switches for UVC light sources separate from general room lighting in locations only accessible by authorized persons. For example, safety switches wired in series allow UVC sources to be turned off without exposing workers to UV light. UVC exposure can be reduced through product safety design considerations and controls. Safety Design/Control/Monitoring/Maintenance The same study found the minimum health and safety requirements regarding the exposure of workers to risks arising from artificial optical radiation ( 2006/25/EC) - albeit for all UV bands combined: “Exposure limit value for UV (180-400nm) is 30 J/m 2 (= daily value of 8h)”
UV LIGHT CONVERSE SKIN
However, UVC is likely to cause acute photokeratitis… UVC exposure is unlikely to cause acute or long-term damage to the skin but can cause severe acute damage to the eye and should not be permitted at all from any tanning device.” It is unlikely that UVC from artificial sources presents an acute or long-term hazard to human skin. “In any case, UVC is strongly attenuated by chromophores in the upper epidermis (Young, 1997) and UVC-induced DNA damage in the dividing basal layer of human epidermis is not readily detected (Campbell et al, 1993 Chadwick et al, 1995) which may explain why the dose response curve for UVC erythema in human skin is very much less steep than for UVB (Diffey and Farr, 1991). The EU health agency’s safety guidelines on the use of UVC sources can be found here. Therefore, safety recommendations with UVC LEDs include protecting skin (in particular open wounds) and, most importantly, the eyes from UVC radiation. In rare instances of prolonged direct exposure to UVC light, temporary eye and skin damage has been exhibited, such as cornea injury (sometimes referred to as “welder’s eye”) although this generally heals after a couple of days.
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