Abstract: The invention provides a new sub-class or organic peroxyacids comprising N-alkyl substituted peroxytrimellitimide of formula (I) in which R=hydrogen or linear or branched alkyl, which demonstrates an excellent combination of safe-handling and bleach performance rendering the sub-class particularly suitable for use as bleach and/or disinfectant in various bleach, bleach additive or washing compositions. Effective bleaching peroxyacids include those in which R=n propyl, iso-propyl, n butyl, sec-butyl, n pentyl and n heptyl. The invention also comprises processes for making the peroxyacids, compositions containing them and processes for washing and/or bleaching and/or disinfecting employing the invention peroxyacids or compositions containing them.