Alkali metal perchlorate-containing gas generant compositions which, upon combustion, produce or result in an improved effluent and related methods for generating an inflation gas for use in an inflatable restraint system are provided. Such alkali metal perchlorate-containing gas generant compositions include at least one alkali metal perchlorate present with a mean particle size in excess of 100 microns. Such alkali metal perchlorate-containing gas generant compositions also include or contain a suitable non-azide, organic, nitrogen-containing fuel and at least one copper-containing compound selected from the group consisting of basic copper nitrate, cupric oxide, copper diammine dinitrate-ammonium nitrate mixture wherein ammonium nitrate is present in the mixture in a range of about 3 to about 90 weight percent, copper diammine bitetrazole, a copper-nitrate complex resulting from reaction of 5-aminotetrazole with basic copper nitrate and combinations thereof.