Upon responding to a 2:00 a.m. domestic transportation mishap, your hazmat team determines that a liquefied compressed gas is leaking from a 5lb (2.3 kg) steel cylinder. The chemical commodity is described on the relevant shipping paper as follows: 5 lb RQ, Compressed gas, flammable, toxic, n.o.s. (POISON - Inhalation Hazard, Zone B). How would you identify, and what is, the radius of the initial isolation zone and the magnitude of the each side of the protective-action zone associated with the release of this substance? How would you handle the response, and how would you determine the proper type of PPE to be used in this incident? What type of PPE would you recommend?