(RNS) Christian Broadcasting Network staffers were evacuated from their Virginia Beach, Va., office Wednesday (July 1) after mailroom employees opened a piece of mail containing a powdery substance.

Three employees and a postal investigator were exposed to the substance, which turned out to be harmless, said CBN spokesman Chris Roslan.

“Several of the people said they developed minor rashes but the authorities don’t believe those are related to whatever the powdery substance was,” he said Thursday. “They were placed under a voluntary medical watch yesterday and nothing developed and the power turned out to be not a harmful substance.”

The substance was determined to be whey powder, a protein that is used to aid bodybuilding.

The CBN building was closed Wednesday after the incident but reopened on Thursday, Roslan said.

“We took all necessary precautions and followed the authorities’ advice and then it turned out to be a hoax,” he said.