What is number 1 in plastic?

What Is Number 1 Plastic? The Story of PET

When you check the bottom of a plastic water bottle or a food container, you might spot a tiny triangle with the number "1" inside. That symbol means the item is made from Polyethylene Terephthalate, commonly known as PET or PETE. It’s one of the most widely used plastics in the world—and for good reason.

Invented in 1940 by British chemists J. Rex Whinfield and James T. Dickson, PET quickly became a favorite in packaging thanks to its clarity, strength, and ability to form a good barrier against moisture and gases. That makes it ideal for holding beverages, sauces, and even ready-to-eat meals. Its lightweight nature also cuts transportation costs and emissions, adding to its appeal.

But what truly sets PET apart is its recyclability. Most curbside recycling programs accept number 1 plastics, turning used bottles into new ones, carpet fibers, or even clothing. However, despite its recyclable reputation, only a fraction of PET actually gets recycled into new bottles—much of it downcycled into lower-value products or ends up in landfills.

The journey of PET from lab invention to household staple reflects both the ingenuity of modern materials science and the growing challenges of waste management. As demand for sustainable solutions grows, innovations in chemical recycling and biodegradable alternatives are beginning to reshape PET’s future.

So the next time you toss a plastic bottle into the bin, remember: that little "1" stands for more than just a material. It’s a symbol of over 80 years of industrial progress—and a reminder of how much further we have to go in building a truly circular economy.