“Most of them are working like headless chickens, having no clue what are the major food-borne diseases that need to be addressed or what are the major contaminants in the food process,” said Dr. Peter Ben Embarek, a food safety expert with the World Health Organization’s Beijing office.

In recent weeks, China’s news media have reported sales of pork adulterated with the drug clenbuterol, which can cause heart palpitations; pork sold as beef after it was soaked in borax, a detergent additive; rice contaminated with cadmium, a heavy metal discharged by smelters; arsenic-laced soy sauce; popcorn and mushrooms treated with fluorescent bleach; bean sprouts tainted with an animal antibiotic; and wine diluted with sugared water and chemicals.

Even eggs, seemingly sacrosanct in their shells, have turned out not to be eggs at all but man-made concoctions of chemicals, gelatin and paraffin. Instructions can be purchased online, the Chinese media reported.

Scandals are proliferating, in part, because producers operate in a cutthroat environment in which illegal additives are everywhere and cost-effective. Manufacturers calculate correctly that the odds of profiting from unsafe practices far exceed the odds of getting caught, experts say. China’s explosive growth has spawned nearly half a million food producers, the authorities say, and four-fifths of them employ 10 or fewer workers, making oversight difficult.

China’s iron political controls ensure that no powerful consumer lobby exists to agitate for reform, press lawsuits that punish wayward producers or lobby the government to pay as much attention to consumer safety as it does to controlling threats to its own power. Instead, like Alice after falling through the rabbit hole, consumers must guess what their food and drink contain.