The steel base plates were treated with automotive paint and since it is known that the paint cure process releases VOCs, such as formic acid and formaldehyde and that such compounds are harmful towards several materials,3,5,13-16 it was decided to investigate the effect of the paint used in the showcases. Both formic acid and formaldehyde react at the metal surface generating formates with composition largely dependent on the VOC concentration, RH and environmental CO2 concentration.3
Another possible formaldehyde source to be considered is the glass cleaning product. The use of formaldehyde in household products was banned in Brazil only recently, in 2008,19 but it is frequently found in street marketed products which are not under the government control and, although formaldehyde use is now prohibited, it was largely employed for decades in sanitizing products.
Thus, this work aims the identification of the corrosion products formed on the polychrome sculptures from the collection of the Oratory Museum and the investigation on the sources and nature of the harmful agents.