BEIJING, July 22, 2008 -- China has stepped up control of hydroxylimine, a raw material for synthesizing the drug ketamine, to prevent it from being used illegally, said a notice jointly issued by six government departments, including the Ministry of Public Security, on Tuesday.

Starting from Aug. 1, hydroxylimine will be added to the Category I list in the Regulation on Management of Drug-Making Chemicals. It is considered one of the most dangerous precursor chemicals used for making narcotics, the notice said.

According to a 2005 regulation, relevant parties must obtain licenses prior to the production, distribution, purchase, transport and import and export of precursor chemicals.

Precursor chemicals are classified into three categories. Category I includes the major materials that can be used for producing narcotic drugs, while Categories II and III includes chemical agents that can be used for producing drugs.

The list, which is allowed to be adjusted upon approval of the State Council, China's Cabinet, is shown in the annex of the regulation.