China is tightening rules for infant formula makers to improve food safety. China's Food and Drug Administration, or CFDA, released Wednesday the latest production regulations.

The new rules raise the entry barrier for producers and impose stricter supervision. Formula makers need to apply for new permits by the end of next May.

The CFDA said they will closely watch each step of the formula making process, from the milk source to the final quality inspection. Meanwhile, the CFDA requests complete tracking of every link in the chain of formula production.

China's infant formula market is estimated at nearly 12.4 billion U.S. dollars.