We're faced with the potential for similar incidents, quite often. The region is covered with "Marcellus Shale Gas Exploration", they use hydraulic fracturing to drill, which includes use of caustic, toxic and radioactive chemicals. And.. with the popularity of METH labs, we've done quite a few clean up stand-by's. When these at home labs were just starting to pop up, the only clean up crew in Penna., was in Pittsburgh. So our stand by lasted anywhere from six to fourteen hours. One of the big materials used to make this toxic brew, is Anhydrous Ammonia, something many of the farms around here have on hand. People were stealing this shit, and transporting it in their car, to the lab. So there would be MVA's, where we'd find propane cylinders in the trunk, leaking this AA. You just have to be prepared for anything, anywhere; if there's a vapor, stage out, SCBA up.. walk in behind a fog line. AA may not be flammable itself, but the vapor can explode at high temps.