It was determined that DBDS
was found in certain transformer oils
which were in transformers that had
failed due to corrosive sulfur attack.
Experiments showed that DBDS easily
degraded into sulfur species that
were highly reactive to copper and
attacked the copper forming copper
sulfide films. Theories were put forward
indicating that at least one of the
DBDS breakdown products is benzyl
mercaptan and testing of this compound
directly showed that it is highly
corrosive. Chemical reactions showing