You might have a pile of empty plastic ice cream containers that seem perfect for freezing food for later use.

However, consumer advisers suggest not using them as freezer containers, which applies to containers for other food, like yogurt.

Disposable packaging is designed solely for the purpose it is used for, says a German consumer advice center. The danger is that chemicals can migrate from the packaging into the food, especially when you pour hot or greasy food into the container.

Instead, use special container alternatives for the freezer. "Cans or trays made of plastic or heat- and cold-resistant glass are a good choice for freezing," says consumer adviser Caroline Brunnbauer.

When in doubt, look for the snowflake symbol, which designates items suitable for freezing. These items are frost-proof and can go in your freezer.

But no matter what you are using, try not to freeze water-rich foods such as lettuce, radishes, cucumbers, apples and melons, as they lose their consistency and turn mushy when defrosted, said the German Consumer Protection Organization. Likewise, avoid freezing yogurt, sour cream or creme fraiche, again, as the consistency will not be the same later on.