In its simplest form, vulcanization is brought about by heating natural rubber with some form of sulfur. The process is widely used in tire manufacturing where temperatures of about 140°–180° C are employed. During the heating process, the sulfur mixed into the rubber oxidizes to produce sulfur dioxide. Sulfur dioxide concentrations are highest in the mixing, extruding, and curing processes. When studies using corrosion coupons are conducted, the results show that silver is more reactive to sulfur dioxide, typically forming silver sulfide Ag2S. The formation of silver sulfide can be particularly damaging to newer, commercial grade electronics that use silver immersion soldering and are not hardened for industrial atmospheres.
Typical areas of concern are MCCs, stand-alone control panels, onsite datacenters, telecom rooms, router hubs, and computer rooms.