Evaluation of corrosivity of indoor museum atmospheres using lead specimens

The corrosivity of indoor atmospheres is usually evaluated according to the ISO 11844-1 standard, utilizing specimens of different metals. However, the sensitivity of this setup is not sufficient to the presence of specific organic pollutants, such as acetic and formic acid or formaldehyde. In this study, lead metal specimens were added as complementary specimens in the series of exposures including various museums and cultural sites. Temperature and relative humidity were monitored and adsorbent tubes were deployed for estimation of the content of the organic compound. For comparison and verification, lead specimens were exposed in laboratory conditions with controlled levels of acetic acid, which is supposed to be the main cause of the increase in lead corrosion rates. The results show that the use of lead specimens can provide valuable data about the corrosivity of the atmosphere due to its sensitivity to the presence of the carboxylic acids. This can be particularly important information for indoor storage conditions in museums and depositories. However, a proper method to evaluate the lead corrosion rates is necessary.