"I am wondering what's in this flour. Are there additives, and are they toxic or safe?" asked housewife Wang Jinghua as she shopped in an outlet of Walmart in southwest Beijing.

Wang told a Xinhua reporter she was worried about benzoyl peroxide, an additive widely used in flour, biscuits and other food. "A friend told me even a slight amount of this chemical is harmful, but I'm not sure what to do," Wang said.

Her confusion is understandable. No single agency or ministry in China is solely responsible for food safety, and it's often difficult for the shopper to know what's allowed, what's banned, and what's safe. Labels sometimes contain correct but obscure chemical descriptions, which are confusing to the ordinary consumer. Packaging isn't always safe, either.

Pesticides, industrial chemicals, excessive or banned additives and suspected carcinogens show up in many food products.

The safety of Chinese food isn't just a domestic issue. With food exports of US$31 billion from January to November 2008, up 13.8 from the same period in 2007, Chinese produce, fish and dairy items, among other foods, are rapidly becoming part of the global food chain.

Supervising the industry is a huge undertaking. Statistics show that as of 2008, China had an estimated 500,000 "large-scale", 350,000 small- and medium-sized food processing enterprises, and more than 20 million privately owned businesses that producing and selling food products.

Last year, authorities investigated an average of 200 fake food cases a day, which were mostly involved in small enterprises and businesses.

In response to these concerns and problems, China has stepped up its efforts to ensure food safety and quality, with new labeling laws and a Food Safety Law that will take effect June 1. The new law, among other provisions, calls for the State Council to establish a food safety commission but does not give a deadline for that.

Pretty, but is it safe?

"Chinese people traditionally favor 'good-looking food' and a substance like benzoyl peroxide makes flour-based products look white and tasty, as it bleaches wheat's natural yellow color," said Chen Junshi, a member of the Chinese Academy of Engineering.

"It is simply called 'wheat bleaching' in Chinese, but this is a misunderstanding," he said. "Benzoyl peroxide is not only used to make the flour appear white. It also plays an antiseptic role."

Under Chinese food additive regulations, the maximum volume of benzoyl peroxide is 0.06 grams per kilogram. Regulations vary elsewhere. Canadian rules limit the content to 0.15 gm, but the European Union banned its use in food several years ago.

Benzyol peroxide has non-food uses, too: according to the UN Food and Agricultural Organization (FAO), it is also used in the manufacture of plastics, a curing agent for silicone rubber, and a component of treatments for skin disorders.

Also according to the FAO, there are possible side effects of benzoyl peroxide in foods: the formation of harmful degradation products, the destruction of essential nutrients and the production of toxic substances from the food components.

Benzoyl peroxide is one of the around 1,700 additives that China allows to be used in food products.

Consumers wonder, worry

Surveys reflect the concern of the Chinese public over food safety. In 2006, the State Administration of Grain held an online survey, and about 87 percent of those responding said they didn't want to buy food with bleached wheat.

Other, later polls from a variety of sources indicate continued, broad concern over food safety:

-- A 2007 survey by US-based consulting company ATKearney found more than 95 percent of 1,500 Chinese questioned ranked food safety as "very important" in 2007.

-- In March 2008, China's Ministry of Commerce said another survey found that 97.2 percent of urban residents ranked food safety as a major concern. Even among rural residents, who tend to have lower incomes and fewer sources of information, 86.1 percent responded that they put food safety among their major concerns when shopping.

-- In December 2008, a telephone survey of 300 Chinese consumers by U.S.-based IBM found that "over the last two years in China, distrust with food retailers and manufacturers has grown even more" than in the United States and Britain. IBM said 84 percent of respondents claimed they had become more concerned about food safety over the previous two years.

"It's just difficult for me to believe that food with [benzoyl peroxide] is 100-percent safe. Instead, I would rather be more cautious," Wang said: "The problem is I can not tell whether the food ingredients listed on the label are believable."

What's in a name?

Although the Ministry of Health maintains a list of food additives on its website, many Chinese consumers, like Wang, complain it's hard to know whether their food contains additives or other harmful substances, as the labels are often "confusing".

Zhang Jun, who does chemical research at a Beijing-based institution, said he always pays attention to labels, but most of his friends find it hard to know what the labels mean.

Some companies, he said, list additives by their chemical equation or scientific name, which puzzle consumers.

"I often tell my friends that potassium sorbate is an antiseptic and people should avoid eating it," he said. Potassium sorbate is used to prevent spoilage. "But, the question comes: who can assure us there is no antiseptic in the product if the company did not put it on the label?"

China adopted a food-labeling regulation in last September, which requires producers to specify names and amounts of additives in food. Those who violate this regulation face fines of 5,000 yuan to 10,000 yuan.

"Moreover, there is no effective way for consumers to know which additive is safe and which is toxic," Zhang said

Zhang also criticized the widespread practice of having film and music celebrities endorse food and medicines in advertising.

"People are always prone to trust stars and will not doubt their word. But some famous people take advantage of consumers' trust," he said.

Qiu Baochang of the Beijing Lawyers' Association told Xinhua:" The government should call a halt to the practice of celebrity endorsements of food, to protect the rights of consumers and the stars' reputations."

Beijing Consumers Association Secretary-General Zhang Ming agreed, saying: "These stars actually seldom try the products they endorse."

Loopholes everywhere

The major problem was the use of banned substances, such as melamine (an industrial chemical used in plastics) and Sudan red (a dye used in oils, waxes, gasoline and shoe polish).

At the Sixth China Food Safety Annual Meeting held last August, China National Food Industry Association Chairman Wang Wenzhe said that the county's food quality had improved greatly in recent years. But he also acknowledged that food quality was far below consumer expectations, with many cases of excessive pesticide residue and banned food additives.

Ma Yong, a senior official with the National Food Industry Association, told a food-quality seminar in Beijing on March 13 that problems can occur at every step, including production, raw materials, animal feed, planting, slaughtering, processing, transportation, packaging and sales.

There have been many cases of banned and dangerous substances turning up in a wide variety of food.

In 2005, Sudan red was found in salted duck eggs in some provinces and cities. It turned out that poultry farmers were giving hens and ducks the chemical to make the yolks of their eggs red, which commands higher prices.

A year later, several fish farms in eastern Shandong Province that were raising turbot, a popular type of flatfish, were fined and ordered to halt sales after traces of carcinogens including malachite green were detected in samples. Malachite green is an anti-fungal agent for aquarium fish, but it's not supposed to be used for fish intended for human consumption.

Packaging can be a particular problem if it doesn't protect the food or contains harmful substances.

"In some developed countries such as the European Union and the United States, producers can face severe punishment if there are problems with the packaging, but China has no strictly enforced packaging requirements," Zhu Tiancheng, a lawyer with Beijing Jindong Law Firm told Xinhua.

Liu Yonghao, the board chairman of farming company New Hope Group, told Beijing Sci-Tech Report earlier this month that food companies should reduce safety risks by better monitoring of the whole production and distribution process, from raw material to sales.

"Although it requires a huge investment to establish an entire monitoring chain, it is good for a company in the long run," he said.