An antifoul composition especially for use in vinyl chloride polymerisation comprising a) at least one poly acrylate (co) polymer binder and b) at least one of (i) a cross-linked product formed by reacting formaldehyde and a phenol, (ii) a phenol/formaldehyde condensate, (iii) a condensation product formed by reaction of an effective 1-naphthol and formaldehyde, and (iv) a product based on naphthenic molecules substituted with sulfur compounds at at least one position on the aromatic structure and (v) the composition optionally comprising less than 2wt%, preferably less than lwt% 0.5wt% polyvinyl acetate or partially hydrolysed polyvinyl acetate.