Numbers On The Bottom Of Plastic Bottles Can Tell You A Lot

No, your water bottle isn’t going to kill you. But knowledge is power and when it comes to the materials used to store our food and drink, it pays to be powerful. When you look on the bottom of a bottle of water, a plastic food container, or many other plastic-packaged products you buy at the store, you will find a small number encircled in a triangle.

That number is known as a resin identification code, and can tell you generally what type of plastic that container is made of. Before we get started on that, let’s talk a bit about plastic. Plastic seems to be a little misunderstood, as the woman in this video clearly demonstrates. Plastic refers to any number of long, organic (yes, organic) molecules that possess a very high degree of plasticity. That is, they can deform without breaking. Plastics exist in nature and our use of them dates back thousands of years. Lacquer is a great example of an early use of a natural plastic. Do you love your cast iron pans? Do you take good care of them by seasoning them with oil? You’re actually creating a plastic coating over the metal when you do that.

But what do the numbers mean? Well, #3 is code for PVC, or polyvinyl chloride, is not used for food or beverage containers. It is however very common in non-food items like children’s toys, and can leach lead if your child puts said toy in your mouth. Very often these products are not labeled and so you should do your research.

As far as #6 plastic? Well, that’s polystyrene, an incredibly common plastic that is used for food storage and service. Styrofoam is the most well-known form of this plastic but it shows up in microwaveable dinner packaging and all sorts of other places. It’s actually generally considered safe but there’s a big debate about whether food should be microwaved in a polystyrene container.

Now #7? That’s a whole different story. It doesn’t refer to a specific type of plastic but any plastic that isn’t covered by the other numbers. Many are completely harmless. You would have to research the specific product on your own for this one.

Read more: