For many Chinese consumers, McDonald's Corp's latest policy on the use of antibiotics in its food products is an example of double standard in food safety.

The multinational fast food chain announced last week that in the United States it had switched to using chickens raised without antibiotics, fulfilling a pledge it made in March 2015, many months ahead of schedule.

Yet it has refrained from promising that it would do the same in its more than 2,000 restaurants in China, its third-largest market after the US and Japan, and one of the fastest-growing in the world.