A prefectural public health center was to file a criminal complaint Friday afternoon against Kyowa Perfumery & Chemical Co. for using five unauthorized substances in flavoring agents, prefectural officials said.

The five substances — acetaldehyde, propionaldehyde, castor oil, dimethylbutylaldehyde and isopropanol — have been used in violation of the Food Sanitation Law for more than 30 years at the Tokyo-based company's plant in Juo, Ibaraki Prefecture.

The flavoring agents containing these substances were shipped to some 600 clients, including several major food makers, provoking a large-scale food product recall nationwide.

"It is unforgivable that the company has been using the banned substances for more than 30 years," an official said.