The surface of ebonite (vulcanite or hard rubber) undergoes severe decomposition through the action of light, air, and moisture. The surface acid formed by this process can be wiped away, but in extreme cases neutralization may be necessary. This can be done by rinsing with a dilute solution of sodium bicarbonate, and quick drying in industrial methylated spirit. For storage and display, light levels should be reduced to a minimum and ultraviolet eliminated. Relative humidity must be kept low. If possible, oxygen should be eliminated; this can be achieved by keeping the objects in special containers.