Hong Kong (CNN)Almost half of Chinese food-processing plants fail to meet internationally acceptable standards, new figures suggest.
Quality control specialist AsiaInspection said 48% of the "several thousand" inspections, audits and tests it conducted in China last year failed to meet the requirements stipulated by some of its clients -- Western food trading companies and retailers.
"There are horror stories, obviously," Mathieu Labasse, AsiaInspection's vice president told CNN by phone. "We find factories that just have no basic idea about hygiene standards. People that handle the food, they have no gloves, nothing."
Labasse said there was a host of reasons for the failings. In some cases, laboratory tests found abnormal levels of pesticides, antibiotics, heavy metals, bacteria or viruses that could put consumers at risk.
Other transgressions included mislabeling packaging, abnormal coloring and odors, bruising and, in the case of seafood, adding water to make the fish appear to weigh more than it does.
China has experienced a string of stomach-churning food scandals in recent years.
The most high-profile recent case involved a U.S.-owned meat factory operating in China that was accused of selling out-of-date and tainted meat to clients including McDonald's, Starbucks, KFC and Pizza Hut chains.
"We see awareness growing but we don't see on the ground a concrete improvement yet -- it will come," Labasse said.
Labasse said the extremely fragmented nature of China's food chain -- the country has 500,000 food production and processing companies, 70% of which have fewer than 10 employees -- made it very difficult for authorities to control and foreign buyers to understand.
"Companies like McDonald's or KFC are dealing with their suppliers at arm's length. So they know well the people they communicate with on a daily basis but they don't know what's going on behind the scenes," said Labasse.
"The buyers are focusing their efforts on the people they signed a contract with but they should take the extra step and take control of the full supply chain and going as far as the third or fourth level of suppliers. "