It’s a particularly unsettling notion: that the lunchboxes we use to send our kids packing off to school with a healthy noontime meal may be tainting their midday repast with a side order of unhappy surprise. Yet that’s the conclusion of a new report from the Center for Environmental Health, which examined a variety of popular lunchboxes and found that 25% of those tested contained a heaping helping of hazardous lead.

At issue are lunchboxes made from soft vinyl, an increasingly popular choice with manufacturers because of their ability to insulate foods and absorb all kinds of punishment on those rugged journeys to and from school.

Researchers testing the surfaces of over 100 lunchboxes found that 27 contained lead. Further analysis of the offending containers at an independent laboratory revealed that 17 had lead levels that exceeded federal safety standards. One lunchbox featuring the character Angela Anaconda had more that 90 times the legal limit for lead in paint used on children’s products. Tests on the other lunchboxes containing lead, which included those featuring Superman, Tweety Bird, and the popular Powerpuff Girls, found levels between two and twenty-five times the legal limit.

According to the Center for Environmental Health, researchers found that the lead contaminating the lunchboxes was not bound up in the vinyl material itself, but rather was simply resting on its surface where it could easily transfer to hands or food that touched it. Even more disturbing, in most cases the highest levels of lead detected were found not on the outside of the lunchboxes, but on the inner lining, the surface with which food is much more likely to have contact. Researchers believe the lead is added to the vinyl either as a stabilizer or as part of its pigment.

The ability of even the smallest amounts of lead to cause neurological, behavioral, and developmental problems is well documented. While the levels of lead found in the guilty lunchboxes are not capable of causing acute lead poisoning in and of themselves, parents are obviously advised to do whatever they can to protect their children from any and all lead exposures no matter how minor because lead is a cumulative hazard.

• Test all your household’s soft plastic lunchboxes for lead. A simple inexpensive lead test kit such as those found at hardware stores will do the trick. Just rub the test swab on the surface of the lunchbox and see if it changes color to indicate the presence of lead. (Follow all manufacturer’s instructions for accurate results.) Remember to conduct two tests: one on the outside of the lunchboxes and another on the inside.

• Until you can test your soft vinyl lunchboxes, don’t take chances. Pack your children’s lunches in old-fashioned metal lunchboxes, brown paper bags, or reusable cloth lunch bags until you know their plastic boxes are okay.

• If your lead tests come up positive, don’t try to simply wash the lead off the tested lunchbox. It won’t work! Instead, discard the lunchbox immediately and use one of the above options.

• When shopping for lunchboxes, and indeed any product, avoid soft vinyl as a matter of principle. The manufacture of polyvinyl chloride (PVC) is one of the world’s most toxic industrial processes, one responsible for large amounts of deadly pollution and toxic waste.

• If you find lead in your lunchboxes, call the Center for Environmental Health at (800) 652-0827. They’re collecting toxic products as evidence as part of their ongoing work to protect children’s health and could use your help.

• Share this information with teachers, administrators, and other parents at your child’s school.

For more information about the Center for Environmental Health study, visit http://www.cehca.org/lunchboxes.htm.