You already know that a home-cooked meal is likely to be healthier for you than anything you pick up at a fast-food joint. But nutrients aside, there’s another danger lurking in restaurant food, and it extends all the way up to fancy sitdown establishments—exposure to the harmful chemicals known as phthalates.

You may already be aware of these chemicals  found in everything from building materials to your shampoo (savvy manufacturers are labeling more and more personal care products “phthalate-free,” so look for those). They’re also used to make plastics and vinyls softer and more flexible. But how could they wind up in your dinner order? It’s contamination from packaging and equipment used to prepare and/or wrap up your food. Yes, those very gloves that food workers wear to keep your food safe from bacteria may actually be transferring phthalates! And so is much of the packaging that restaurants receive ingredients in…flexible parts of the equipment they use to prep food…and the plastic and plastic-coated wraps a restaurant uses for your take-out orders and doggie bags.

Exposure to phthalates has been linked to a variety of medical problems from harming a baby’s development in the womb to male reproductive issues because they disrupt hormone levels. Researchers are also looking at phthalates’ possible connection to cancer. That’s why it’s so important to reduce your exposure wherever you can.

How widespread is the problem of restaurants feeding you phthalates? A study published in Environment International has found that people who dined out in the previous 24 hours had levels of phthalates that were, on average, nearly 35% higher than those in people who ate their meals cooked at home. And this increase was seen whether the restaurant meal was from a fast food joint, a cafeteria or a sit-down place.

WHAT YOU CAN DO

The obvious answer is to limit eating out, but that’s not always possible or even desirable if you’re a foodie. But you can choose restaurants that focus on serving meals made from fresh, whole ingredients made at the restaurant—because the less your food is processed and packaged, the less it is likely to come into contact with phthalates. Ask if your takeout or leftovers can be wrapped in foil. That seems like something many restaurants could do to help you avoid at least one link in the phthalate chain.

Keep in mind that you can be exposed to phthalates through drinks, too. The inner coating of those paper cups used for tea and coffee for take-out often includes phthalates. If a beverage is stored in plastic, it can absorb chemicals from the container. This is especially true of fatty drinks, such as café au lait. (There’s also concern with cold drink cups and plastic jugs containing BPA (bisphenol A), another hormone disruptor and one that is found in hard plastic bottles and the linings of soda cans.)

And, to keep your exposure level to a minimum at home, store leftovers and drinks in glass or stainless steel…and never microwave food in plastic containers.

Ready to do more cooking at home? Check out these 8 “Forever” Foods Every Healthy Kitchen Needs.

For more about phthalates, see the National Institutes of Health’s Tox Town website.