A man was injured Monday afternoon in an acid spill in a Boston University laboratory, the Boston Fire Department said. Emergency crews responded just after 4 p.m. to 24 Cummington St., BU’s Life Sciences & Engineering Building, the Fire Department said in an official tweet. The building was evacuated. Trichloroacetic acid had spilled on a research assistant in an eighth-floor lab. The man had already self-decontaminated using a “lab deluge shower,” the Fire Department said. The man was taken to a hospital for further evaluation.