An environmentally friendly decontaminant solution, which may be disposed of after use without posing significant environmental hazards, is formulated without molybdenum-based corrosion inhibitors and preferably is free of all heavy metals. A zeolite-based buffering system optionally replaces phosphate buffers for maintaining the pH of the decontaminant solution at an appropriate pH for effective antimicrobial decontamination. Molybdenum-free decontaminant solutions containing peracetic acid retain their peracetic acid levels, and thus their antimicrobial effectiveness, for longer periods than comparable solutions formulated with a molybdate corrosion inhibitor.