China's food safety watchdog is still open to proposals from the public and research organizations at home and abroad on gutter oil testing and identification, said a senior official.

Yan Weixing, secretary-general of the safety committee under the China National Center for Food Safety Risk Assessment, made the remarks after the Ministry of Health announced it was looking at four types of equipment and three quick on-site testing methods for the illegally processed oil.

But they still need further assessment and improvement, according to the ministry, which oversees China's food safety.