The present invention relates generally to peroxyformic acid forming compositions, methods for forming peroxyformic acid, preferably in situ, using the peroxyformic acid forming compositions. The present invention also relates to the peroxyformic acid formed by the above compositions and methods. The present invention further relates to the uses of the peroxyformic acid, preferably in situ, for treating a surface or a target. The present invention further relates to methods for treating a biofilm using peroxyformic acid, including peroxyformic acid generated in situ.