Tainted food outbreaks like the deadly melamine discovered in Chinese infant formula will happen again and there is not much that regulators can do about it, safety experts warned on Monday.
That's because there are so many different ways for a tainted product to enter the food chain and so few inspectors available to guard against either deliberate or accidental contamination.
"I do stay awake at night worrying about what's the next melamine," said Steve Solomon, deputy director of regional operations for the US Food and Drug Administration.
Counterfeiting is a major problem in the global food industry with the level of fraud estimated at around 50 billion dollars a year, said John Spink of Michigan State University's Food Safety Policy Center.
That's just shy of 10 percent of the total estimated trade in counterfeit goods and is likely to increase as food prices rise.
While some of that trade poses little or no health risk -- like falsely labeling food as organic or substituting tilapia for a more expensive type of fish -- adulteration can be deadly.
When protein supplements are watered down, "babies starve to death of malnutrition while their bellies are full of milk," he said.
Another example is when low-grade heating oil taints the grain it is drying and cattle carry the chemicals on to the consumer.
"If you think of about the bad guys, their goal is to make more money," Spink told a meeting of the American Association for the Advancement of Science.
"They're not aware of, or they're not considering the implications of, what they do."
While better regulations and inspection systems are needed in countries like China, recent deaths due to tainted peanuts which a US company knowingly shipped to consumers shows that even the best systems cannot catch every criminal, Spink said.
"Monitoring all food manufacturing is not practical," Spink said.
"The problem and the solution is all about profit."
Crack-downs on counterfeiters will lower the profit incentive, while producers and exporting countries will respond with better standards after seeing their business collapse in the wake of health scares, he said.
But inadvertent contamination is impossible to prevent even in the most responsible companies, warned Joseph Scimeca, director of global regulatory affairs for food giant Cargill.
"Accidents will happen," Scimeca said.
The genetic modification of plants for use in pharmaceuticals and industry also threatens to contaminate the food supply with unapproved substances, he noted.
The problem from a food safety perspective is the sheer scale of modern food production: a single shipment of high fructose corn syrup can go into two million cans of soda, he said.
While the ability to detect harmful substances in food is "getting better by leaps and bounds," Scimeca said food safety "must depend on a preventative system designed to keep hazards out of food not test for them."
Nearly 10 million shipments of imported food enter the United States every year, which represents about 15 percent of the nation's food supply.
Only one percent is inspected and 0.3 percent is sampled or tested.
"We can't inspect everything," said Solomon of the FDA. "We need to focus on the highest risks."
The FDA is developing a system to better diagnose which shipments pose the most risk and has begun sending inspectors out to overseas facilities.
It is also setting up offices in China, India, the Middle East and Europe help establish better standards and develop a global rapid alert system for when the next outbreak hits, Solomon said.