Two formulas for chlorine-containing disinfectant developed for use at low temperatures by the Chinese Center for Disease Control and Prevention have been evaluated as effective, the center said.

Lab and onsite assessment showed that the new disinfectants are effective at low temperatures and can solve the problem of disinfection in China's northern frigid regions and disinfection of the outer packaging of frozen goods. They are also easy to produce and cheap in terms of raw material costs.

The disinfectants were put into emergency use in Suifenhe, Northeast China's Heilongjiang province, and Qingdao, East China's Shandong province, in January.

One disinfectant can be used at temperatures down to -18 C and the other to -40 C. The main ingredients are sodium dichloroisocyanurate, calcium chloride and ethanol.

There are three ways to use them -- spraying, immersion and wiping. The contact time is 10 minutes.