Coffee beans are allowed to contain insect fragments and rodent hair. (bigstockphoto)

Maggots in your canned tomatoes? Harmful chemicals in your water bottle? Pork rinds dressed up as health food? You might be shocked, or at least surprised, by what can be found in your food or your food’s packaging and by the labeling tricks manufacturers use to imply that their foods are more healthful than they really are. Not all of these surprises are necessarily dangerous. But a better understanding of what’s in the items you toss into your supermarket cart can help you make better choices. Here are three unsettling food issues to be aware of, along with suggestions for what to do about them:

Bugs in your food

Like it or not, you can find things with legs in many widely consumed foods. The Food and Drug Administration sets acceptable levels for what it calls “naturally occurring defects.” For example, a 24-ounce container of cornmeal can have up to 13 (mostly tiny) insects, 745 insect fragments and 27 rodent hairs.

Other foods allowed to harbor bugs include chocolate, coffee beans, dried beans, grains, nuts, pasta and peanut butter. And, yes, maggots can be found in canned tomatoes. Sure, it’s not appetite-stoking, but could it be harmful?

“Generally, these defects, including rodent filth, insects or mold, are not hazardous to health at low levels,” says Robert Gravani, a professor of food science at Cornell University. And the FDA says that, on average, the actual quantities of defects are far less than the legal maximum.

What to do: If you find something in your newly purchased food that shouldn’t be there, return it to the store or contact the manufacturer for a refund. If you’ve had the food item for a while, even if it’s unopened, it’s possible that the pests originated in your home. If your cupboard becomes infested with pests, empty it and vacuum the shelves thoroughly, paying close attention to crevices. Discard heavily infested food and the contents of your vacuum bag outdoors. If you’re unsure whether a particular item is infested (say, flour), freezing it for four days or heating it in an oven for an hour at 140 degrees can kill insects and their eggs.

Containers that could make you sick

News about bisphenol A (BPA), the potentially harmful chemical that can leach from containers into food, seems to be everywhere lately. And a recent survey by the Centers for Disease Control and Prevention found that most Americans have measurable amounts of the substance in their urine.

The likely source is food-can linings and plastic bottles and other food containers made of polycarbonate, a type of plastic. In 2010, the FDA said it had “some concern about the potential effects of BPA on the brain, behavior and prostate gland in fetuses, infants and young children.”

What to do: When possible, buy fresh food and use alternatives to canned food and to hard, clear polycarbonate plastic food containers (which are sometimes marked with recycling code 7). Use glass containers when heating food in a microwave. Plastics marked with number 2, 4, or 5 are unlikely to contain BPA.

Misleading labels

The ubiquitous claim “natural” has no standard definition, and products “made with” a healthful ingredient might contain only a tiny amount of it. Food labels can claim that a product is free of trans fat if it has less than 0.5 grams per serving. So you could get more if you ate multiple servings.

Official-looking stamps that proclaim a food “heart-healthy” or “cholesterol-free” (such as the banner on Mazola corn oil) can be meaningless and could mislead consumers. All vegetable oils are cholesterol-free, and there’s little evidence that corn oil is good for the heart.

What to do: The FDA is working on a labeling system that will make selecting food quick and simple. And the food industry has rolled out a “Nutrition Keys” labeling program that highlights such important items as calories, saturated fat and sodium on the front of many products. But if you want a fuller account of what’s in your food, you’ll probably have to do a bit more work by scanning the Nutrition Facts box and paying close attention to serving sizes.

Copyright 2011. Consumers Union of United States Inc.