Recycling Mystery: Old Kitchen Glassware

You may have heard the phrase, “glass is infinitely recyclable.” So why isn’t kitchen glassware — drinking glasses, glass dishes, and glass bakeware — accepted by your local recycler?

Various additives are used in the manufacture of kitchen glassware, which makes it much more difficult to recycle than common container glass. In fact, it’s so challenging that you’re unlikely to find a recycler that accepts it. Made from sand, glass is in greater demand than ever, growing at six percent a year, according to the United Nations Environment Programme. Nevertheless amidst a growing sand shortage, glass collected by recycling programs has often been ground into a sand-like material for use as daily cover in landfills, replacing soil instead of being melted down for new products and packaging.

Different Types of Glass

In your home, you have primarily two types of glass, soda-lime glass and borosilicate glass.

• Soda-lime glass is used in everything from jars to windows. It’s the most common type of glass produced.
• Borosilicate glass is a type of glass that is able to heat and cool rapidly without breaking. It has many applications, but for home use you’re probably most familiar with it as bakeware, such as the old Pyrex baking dish your mom used to use.

When it comes to recycling glass, most U.S. recycling programs accept soda-lime glass — within limits. They typically accept what’s called container glass, such as glass soda and beer bottles, wine bottles, and other glass food containers you see at the grocery store.

And while we’re talking about types of glass, colored glass is also a consideration. Recyclers will often accept several different colors of glass, but not all the colors you may buy. Glass manufacturers use a number of materials to create colored glass. If different colors of glass get recycled together, it diminishes the quality of the recycled product and loses its market value. So, separating the differently colored glass prior to recycling is an extra, expensive step for recyclers.

Reuse Before Recycle

Before we jump to recycling, it’s important to note that if your glassware is in perfect condition, please don’t recycle it or throw it away. Give it to someone who could use it. Most donation centers accept clean, unbroken glass cups and dishes. If you have a complete set of cups or bakeware, you may even be able to sell it on Craigslist or at a local consignment store.

Can You Recycle Glass Cups or Bakeware?

The short answer to this question: Not likely. Check with your local recycling program to find out if they have a program in place for kitchen glassware. Add your ZIP Code to this Earth911 Recycling Search for help finding glassware recyclers in your area.

While your glass cups and wine glasses are likely made from soda-lime glass, they aren’t recyclable in most places. This is because manufacturers use additives to adjust the glass for its intended purpose. You’ve probably noticed that wine glasses break more easily than a soda bottle or a pickle jar. This is because the composition of the glass is slightly different. Additives change the melting point of the glass. Container glass, as well as glass used in food jars and beverage bottles, share a common melting point, making it easy to recycle together. This is why recycling programs commonly accept only container glass.

Glass bakeware is manufactured to have a higher melting point. Although older glass bakeware used to be made of borosilicate glass — and much European bakeware still is — most U.S.-manufactured glass bakeware is now made of tempered soda-lime-silica glass. But no matter what your glass bakeware is made of, if it’s mixed in with container glass, it will contaminate the entire recycling batch since it won’t melt at the same temperature.

For this reason, glass bakeware can’t be recycled with container glass. Because the lifespan of most glass dishes is so long and the volume of bakeware made from this type of glass is so low, it isn’t possible for companies to make money recycling it, so there aren’t really recycling programs out there.

How to Dispose of Broken Glassware

Even if it’s recyclable container-type glass, don’t put any broken glass in your recycling bin. Broken glass is a hazard to workers who collect and sort your recyclables. So, the only option is to throw it away. Since it’s also a hazard to trash collectors, here’s the best way to handle it:

1. Wrap up the broken glass in newspaper or cloth and place it inside a small cardboard box. Pour any other small broken glass inside the box.
2. Stuff any additional newspaper into the box so the glass can’t bounce around as easily.
3. Tape the box closed securely and write “Broken Glass” on the outside.
4. Throw the box into the trash bin.

One last thing, while this article focuses on kitchen glassware, please note that windows and glass doors typically cannot be recycled in your city recycling bin either. Because most windows contain plastic layers between sheets of glass, they are often not accepted for recycling. If they are still in working condition, the Habitat for Humanity ReStore may accept them, but do call first to confirm. If you can’t find anyone interested in reusing them, please dispose of them carefully in the trash.

Editor’s Note: This article was originally published on February 20, 2019, and was updated in May 2024.