Everything that is used to make up a showcase may give off gases that will react with the objects to cause deterioration. We can test all the materials such as paint, fabric, backboards and floorboards. We take a sample of the material and place it inside a sealed jar with coupons of copper, silver and lead.
The jar has a small amount of water in the base and it is heated in an oven for a month to accelerate the ageing of the material. By looking at how the metal coupons change we can determine the extent of damage the material may cause. Comparing the coupons to the control shows just how much damage can be caused by the material being tested.
In this case both materials caused darkening to the copper coupon (left hand coupon). The most drastic change is the effect of the fire resistant MDF on the lead coupon (right hand coupon). This coupon is almost unrecognisable from the control lead coupon (centre) as it has corroded completely.
This would be unacceptable to happen to one of our objects and the test alerts us to this potential problem. We would therefore avoid using this material in an enclosed space with an object.