The janitor was being treated for chest pains and trouble breathing Tuesday afternoon. The incident took place about 7:30 a.m., the St. Paul (Minn.) Pioneer-Press reported.
About 30 firefighters entered the building at 340 Cedar St., in St. Paul, which houses the 340 Hotel and the St. Paul Athletic Club, the Minneapolis Star Tribune reported.
No other injuries were reported, though a fire captain said it would "take a while" for a hazmat team to remove the chemicals and ventilate the area where the chemicals were mixed.
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