A propane gas-utilizing system includes a housing having propane gas and a propane leakage prevention material having a catalyst, scavenger, and/or oxidizer of the propane gas arranged in the housing and including at least one of (a) an oxide material having at least one composition of formula (I): Ru.sub.1-xM.sub.xO.sub.2 (I), where 0<x0.1 and M is Ag, K, Pt, Rh, or Ir, or (b) an oxide material having at least one composition of formula (II): Co.sub.3-xM.sub.xO.sub.4 (II), where 0<x0.3, and M is Pd, Cu, or Sr, or (c) an oxide material having at least one composition of formula (III): MM.sub.xO.sub.y (III), where x is a stoichiometric ratio of M to M, 0x1.5, y is a stoichiometric ratio of O to M, 1y3, M is an alkali metal, and M (if x>0) is Y, Ce, Nb, Ta, La, Nd, Mn, Ag, Au, or Cr.