Editor’s note: This is the first installment of a two-part series on why glass is a greener choice. Please click here for part two.

Glass is possibly the easiest material to recycle: After you finish your pickles, jam or spaghetti sauce, or down those final swigs of iced tea or beer, simply place the empty jar or bottle into your recycling bin. That’s it! No need to remove labels, separate by color or check the bottom for a number inside that triangle of chasing arrows. 

All colors of glass bottles and jars can be recycled in Evanston. Credit: Ian Mitchell

You’ll want to pour out liquids, rinse away messy food residue and throw away the lids or caps (which are often too small and made of mixed materials that cannot be recycled). Peel off any shrink wrap; you can recycle it as plastic film along with your plastic grocery and produce bags. 

Once your recyclable glass is picked up, sorted at a material recovery facility (in Evanston’s case, that’s Groot), crushed and sold to a glass processor, it can be melted down, made into new jars and bottles and be back on grocery store shelves within a month. What an easy way to reduce landfill waste and help the environment, right?

Yet only 30% of all recyclable glass across the U.S. lands in recycling bins. (By comparison, the European Union recycles 75% of its glass.) The rest ends up in the trash and is hauled to landfills, where it may break into smaller pieces over many thousands of years but will never truly decompose. Instead of languishing eternally in a garbage dump, that discarded glass could be used to create more glass. 

Old glass helps make new glass

“Recycled glass is a key component of making new bottles, and there is recycled glass in virtually all glass that’s made,” said Scott DeFife, president of the Glass Packaging Institute, a trade association representing the North American glass industry. 

Adding post-consumer glass (our food jars and beverage bottles) to the glassmaking process conserves raw materials, DeFife said. It’s also more energy-efficient: Recycled glass melts at lower temperatures than the raw materials on their own. 

“The more recycled content we use, the lower the temperature of the furnace, the lower the energy usage and the lower the carbon footprint,” DeFife said, “so it’s good to use recycled glass.”

Every 2 pounds of crushed post-consumer glass that is used in the glass manufacturing process saves 2.6 pounds of raw materials, according to RoadRunner Recycling, a waste management company based in Pittsburgh. And the Glass Packaging Institute asserts that every six tons of recycled container glass used to make new glass reduces carbon dioxide emissions by one ton.

A brief history of glass

Glass is not strictly a human invention: The intense heat from volcanoes, lightning strikes and meteor impacts can melt silica sand, which results in glassy formations such as obsidian stone, fulgurites, tektites and Libyan Desert glass. 

Soda-lime glass production goes back at least 4,000 years, according to the Museum of Glass in upstate New York. Early glass pieces found in Egypt and Mesopotamia were often cast or molded pendants, decorative art pieces and pots formed around mud cores. 

As glassmaking spread westward so did techniques such as glassblowing, which made the creation of glass vessels for wine, water, oils and other types of food storage easier and more widely available. Pressed glass, a U.S. invention from the early 19th century, enabled the mass production of tableware as well as glass bottles and jars, which improved home canning and preserving.

A literal endless cycle

Glass can be melted and reused repeatedly without breaking down, making it endlessly recyclable. Keep putting those empty jam jars and iced tea bottles into the recycling bin, and eventually they will come back as a shiny new jam jars and iced tea bottles.

The circular economy of glass. Credit: Courtesy of Strategic Materials Inc.

“Unlike some materials, like plastic, glass is 100% recyclable forever,” said Laura Hennemann, senior vice president of sustainability and corporate affairs at Strategic Materials, a glass recycler with locations throughout North America.

Most plastics fully degrade after being recycled five to seven times, Hennemann said, whereas glass maintains its integrity no matter how often it is melted down and made into new glass containers.

Glass is kind to the environment in other ways, Hennemann said. Most of the glass packaging we use is manufactured and recycled domestically, eliminating the energy impacts of international transportation. Glass doesn’t leach chemicals into food or waterways, and wildlife don’t ingest glass or become entangled in it, as can happen with plastic waste.

Meg Evans

Meg Evans has written science stories for the Evanston RoundTable since 2015, covering topics ranging from local crayfish, coyotes and cicadas to gravitational waves, medical cannabis, invasive garden...

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  1. Hi Jean, that little nugget is kind of hidden in the story: “… throw away the lids or caps (which are often too small and made of mixed materials that cannot be recycled).” If you leave the cap on, the glass itself will still be recycled because eventually it is crushed and separated from the cap, but the cap itself is very likely not recyclable and will end up as trash, so you’re better off throwing it away before putting the glass into your recycling bin. I hope that helps!

  2. Great information. So, take lids off? Are lids recyclable?

    If lid is on, does glass still get recycled?