Guide to Plastic Safety: What You Need to Know About Plastic Resin Codes

The truth about plastic resin codes

Many of us have seen those plastic resin codes beneath plastic containers—you know, those little numbers within triangles? In fact, there are a handful of myths surrounding what those codes are supposed to be. One myth claims that they’re supposed to tell you if a certain plastic is microwaveable. Another myth claims that the numbers tell you for how many years you can use the container.

To set things straight, those codes don't really indicate such things. Plastic containers are marked with these resin codes just so that recyclers would know what type of plastic a particular bottle or vessel is made of. It makes the task of segregating plastics faster for recycling.

What’s so bad about plastic?

As a parent, it’s important for you to know that checking the resin code is also a good way to determine which plastic containers are safer for your family, especially your children. This is because some of the plastic containers produced for household use actually contain harmful substances. For instance, dangerous plasticizers are often added to plastics to improve their “plasticity.”

Phthalates are among the most common plasticizers added to plastics because they increase the final material’s flexibility and durability. However, recent studies have shown that phthalates are dangerous endocrine disruptors. Endocrine disruptors are chemicals that act like natural hormones; but by imitating hormones, they disrupt the body’s endocrine system and cause problems like birth defects as well as physical and mental developmental disorders.

There are many other chemicals added to plastics that act as endocrine disruptors or cause other serious illnesses like cancers. It is therefore important that you familiarize yourself with the dos and don’ts of plastic use before buying and using plastic dinnerware for your family or plastic lunchboxes and water bottles for your kids.

Click here to learn more about plastic resin codes and what numbers to avoid.