More than 10,000 products manufactured by 605 Chinese companies have been certified as energy-efficient products, according to the China Standard Certification Center (CSC) of the General Administration of Quality Supervision, Inspection and Quarantine.

Products in 55 categories from almost 350 companies were submitted for certification in the first half, said Cui Hua, director of the CSC integration department.

The program started with residential refrigerators in 1998, and about 20 products were certified in the first year. However, since 2004, certifications have accelerated a yearly growth rate of about 50 percent.

"The acceleration mainly resulted from the gradual establishment of the certification system and the government's promotion of energy efficiency," Cui said.

Only 20 to 30 percent of the total products would be labeled "energy efficient", she said. The standard would be constantly upgraded to catch up with new energy conservation technology.

Some products, such as consumer electronics and office equipment, were also recognized by the United States and Australia, as CSC has reached consensus with the US Environmental Protection Agency and Australian Greenhouse Office on exports of such products.

The government requires products with energy conservation certificates be clearly labeled for consumers. A CSC survey showed more than 20 percent of consumers in China's major cities recognized such labels.

Energy efficiency was the third most important factor for consumers in purchasing after quality and brand name, though such products tended to be more expensive than ordinary products, said the survey.

"I definitely consider energy efficiency, though it's not decisive," said a lady in her 30s surnamed Li, who was shopping for a new air-conditioner at a local supermarket.

The Ministry of Finance and the National Development and Reform Commission required government departments to give preference to products with such certificates in procurement.