BEIJING - Some food safety experts have expressed doubts about the use of additives in rice, although officials said they are free from potential safety hazards.

Related readings:  Additives blamed for rising lymphoma cases  Additives feeding growing number with lymphoma  Fight against illegal food additives gains steam  Packets should list all additives: ministry

In response to media reports questioning the revised National Standard for Food Additives, the Ministry of Health issued a statement on Saturday, saying two additives - sodium diacetate and chitosan - were permissible for rice, and that a thickening agent - sodium starch phosphate - can be used in some rice products, such as rice noodles.

In the statement, Wang Zhutian, deputy director of the Fortified Food Office (FFO) under the Chinese Center for Disease Control and Prevention, said sodium diacetate is a widely used preservative in grain, rice and pastry, and chitosan is a coating agent used in rice. Both can help retain freshness and prevent mildew.

The revised regulation, issued early this month, comes into force on June 20.

"The two additives were allowed in rice before 2007, and they passed the safety assessment," Chen Junshi, director of the office, told China Daily on Sunday.

However, some food experts warned that using additives in rice might put food safety at risk, Beijing News reported on Friday.

One expert who wished to remain anonymous was less convinced.

"Rice is a staple food in China as well as a major ingredient for other food products. We must treat the use of rice additives with great caution," the expert was quoted by the newspaper as saying.

Other experts also questioned the need for additives in rice.

"According to the standards for using additives, a substance is used when it is technically indispensable. If rice is rot-resistant without additives, they should not be added," said Sang Liwei, a food-safety lawyer and the China representative of the NGO Global Food Safety Forum.

"I have worked in the grain industry for many years, but never heard of the practice of adding additives to rice during processing. There is no need," a technical veteran with the Food Research Institute of Guangdong province, surnamed Guo, was quoted on Saturday by Guangzhou-based Information Times as saying. According to Guo, there are two ways of packaging grain products in China to keep the rice fresh: vacuum packaging and aerating nitrogen into the packaging bags.

"It is easy, safe and inexpensive to retain the freshness of rice," Guo told the paper.

The revised national standard sought opinions from July to September last year, but officials said they did not receive any objections, so the additives were included on the final list.

"According to the procedure, if someone files an objection, the health department will examine and decide whether to exclude the additive," Chen said.

The standards can also be changed at any time if there are objections from the industry.

"If any rice manufacturer objected to the use of the additives, the health authority will take advice from other businesses and the industry, and make changes in the standard accordingly," Chen said.