By SIMON COLLINS

Don't look too carefully at your toast this morning. American regulators have decided that it can safely contain one rodent hair for every 50g of the flour that goes into it.

Your cup of coffee can contain 14 allegedly rodent-sourced carcinogens.

And the canned tomatoes that you might have with your bacon are allowed up to either two maggots or 10 fly eggs in every 500g can.

AgResearch food safety scientist Guill Le Roux told New Zealand's annual food safety summit in Takapuna yesterday that people who objected to genetically modified food did not seem to realise that all food involved risks.

"You can't have zero risks," he said. "Some degree of contamination of all foods is inevitable and regulations allow certain levels which, fortunately for the general public, is not well known."

New Zealand laws ban any food that is "unfit for human consumption or contaminated". The Food Safety Authority said the law did not define allowable levels of contamination.

But Mr Le Roux said the US Food and Drug Administration defined "levels of natural or unavoidable defects in foods that present no health hazards for humans".

The list on its website is disarmingly explicit.

Maggots, for example, present "no health hazard" as long as they average less than one maggot in every 250ml of orange juice, two in every 100g of tomato juice or 20 in every 100g of mushrooms.

Rodent hairs are allowed at the rate of up to one in every 100g of peanut butter, one in every 450g of popcorn or 4.5 hairs in every 225g of macaroni or noodles.

Wheat can contain up to 9mg of rodent droppings in every 450g of grain.

"Rats get into grain silos and get processed during milling, and rat droppings get into the grain. You just can't prevent it," Mr Le Roux said.

"Any vegetables and fruit have a certain level of maggots, and if you reduce the pesticides you'll have an increased level of foreign bugs."

He said people who tried to protect their children from bugs by making their houses into completely sterile environments might actually increase their children's chances of developing allergies such as asthma, because they had built up no natural immunity.


Mr Le Roux blamed the media for "distorting" the dangers by giving huge attention to GM and toxic substances in food. Toxins accounted for 32 per cent of news stories about food safety in the US, but caused only 3 per cent of deaths.