China is working to unify different sets of bottled water quality standards, said a major food safety agency on Friday, in the wake of a public outcry for supervision of the industry.

The National Health and Family Planning Commission is clearing up four state quality standards related to bottled water as well as a number of local and industrial standards and will finish the work by the end of this year, said the China National Center for Food Safety Risk Assessment, a state agency in charge of monitoring and assessing food safety risks.

A new unified national standard will come out by the end of 2015, according to a statement from the agency.

Since April, several media reports including the latest one in Friday's Beijing News have argued that various standards are being implemented by the bottled water industry, under inefficient supervision.

The agency rebutted public concern that the quality standard of bottled water is lower than that of tap water.

The current food safety law and state standards clearly regulate that producers should bottle water that meets the same quality standards as tap water, the statement said.

The agency welcomes the public to visit its website and put forward proposals, it added. Endi