Saturday afternoon Chief 2-13 (Mulhollan) came across an unusual odor while driving through the Borough of Lemoyne.  He recognized the smell and called for the Comany to be dispatched along with the Hazmat team to Kesslers on Hummel Avenue.  Crews initially entered the building with normal conditions however during their investigation they encountered the room with the source of the leak.  The Hazardous Materials Team had equipment that measured the gas to be over 400 parts-per-million in the room with the leaking gas.  Crews contained the leak by isolating a bad valve.  Units were on the scene for about 2 hours.  Thanks to Co. 14 (Camp Hill) and Co. 10 (New Cumberland) for providing extra manpower.