The yellow 55-gallon plastic drum came ashore near the M.B. Miller County Pier Thursday afternoon.
The barrel had Spanish writing on it, but no other distinguishing labels.
Several people, who handled the container, complained of irritation on their hands and legs. Beach Police evacuated a quarter-mile area around the drum.
A Department of Environmental Protection team now has the barrel in Pensacola and a state lab where they’ll try to determine what substance it contains.