Many of the organic materials commonly used in the construction and finishing of museum display cases are known to emit small amounts of vapors corrosive to metals. A range of these materials - including paints, adhesives, wood, fabrics, papers and foams - was tested to determine their corrosivity to metals in enclosed spaces. Elevated temperature and relative humidity conditions were created to accelerate the chemical reactions involved. Experimental procedure, observations and conclusions are presented. Recommendations are made for safe display of metal objects in cases.