Perhaps the most exotic thing at Area 51? Not aliens. Rather, it's the secret, radar-absorbent stealth paint used to make the planes virtually invisible. Burning this shadowy stuff -- a messy way of keeping top-secret material secret -- however, made countless Area 51 workers very ill. From the Telegraph:
Among the most sensitive of the secrets was the coating that was applied to the aircraft. The exact make-up of this radar-absorbent paint has still not been made public, even though the aircraft has been retired from active service, and pieces of one of them are on display in a museum in Serbia, where it was shot down in 1999. What is known is that it was considered toxic enough that safety instructions drawn up for first-responders – firemen and other emergency services who may have to attend a crash site – called for breathing apparatus to be used if an F-117A caught fire. While a lot of waste material put into the pits was generated on-site, there were also the contents of those trucks that hauled up every week from California. Inside the locked and sealed containers there might be classified paperwork, sometimes shredded – and often there’d be 55-gallon chemical drums, containing remnants of the secret stealth paint. Every time a new part of the aircraft’s skin had to be manufactured, the coating would be applied, and if a whole barrel wasn’t used quickly, the rest of it was rendered useless and had to be disposed of.