[49Stude63]

If it were yellowish I would say it is cadmium oxidation, or I always called it cadmium pollen since in GA in the spring you have layers of yellow pollen all over your car. Cadmium is a heavy metal and was used to coat electronic parts so you don't want to ingest it in any way. You can use a dust mask and some rubber gloves and some people will use naval jelly to clean chassis of crud and corrosion. So if you see this just be careful if there are any doubts, since heavy metals are fairly dangerous and were used extensively for electronic parts for rust prevention.