Potential for human exposure to mercury and mercury compounds from hat collections

Mercury salts have been detected in a significant number of felted hats within the collection of the Victoria and Albert (V&A) museum. The most likely source of this mercury is as the sulfate product of the salts used in the preparation of the animal hair to enhance their felting properties. Two potential groups of user—the conservator and the curator/public—have been identified as being at risk. Qualitative analysis by energy dispersive X-ray fluorescence spectroscopy (EDXRF) has identified a wide date of manufacture of felted hats containing these salts and new quantitative analysis has shown that one hat contained 1% w/w mercury. At this level, it is necessary to label the hats with appropriate hazardous chemical warning stickers and to minimise handling. Care should be exercised when transporting or disposing of such hats.