The present invention relates to shelf stable and/or less corrosive peroxycarboxylic acid antimicrobial compositions, including ready-to-use compositions. Shelf stable compositions can include defined ratios of hydrogen peroxide to peroxycarboxylic acid and/or hydrogen peroxide to protonated carboxylic acid, but need not include strong acid. Reduced corrosion compositions can include carboxylic acid and corrosion inhibitor at acid pH. Compositions of the invention can have advantageous activity against spores.
