Being a common consumer item, we must recycle glass. While glass, in general, is recyclable, there are exceptions. Learn more in this glass recycling guide.
The first glass was made in 3500 BC, and it reigned supreme until plastic became king. Nowadays, glass is starting to reclaim its popularity as Americans’ desire for sustainability and recycling grows.
Not only is glass infinitely recyclable, but it has multiple benefits — it saves energy, lowers the use of raw materials, extends the life of recycling equipment, and lowers emissions.
It’s estimated that Americans get rid of 10 million metric tons of glass annually. Only one-third of it gets recycled!
Did you ever wonder what happens with the glass you get rid of?
How is it recycled?
And, most importantly, what happens to the glass that isn’t recycled?
Today, I’ll answer all of these and explain everything there’s to know about glass recycling.
Yes, glass is 100% recyclable. It can be recycled endlessly, and it won’t lose quality. To be recycled, glass should be separated from other recyclables, which helps stop the recycling stream contamination.
Glass recycling conserves resources, and it can create new consumer items, such as bottles and jars, or industrial materials, such as insulation, faux turf, countertops, and more.
Glass is extremely recyclable because it’s made of domestic materials, such as sand, limestone, soda ash, and cullet. Cullet is crushed glass that can be remelted, and it’s widely used. In fact, the only material used more than the cullet is sand.
The more the glass is recycled and used, the greater the energy decrease. Recycling glass is profitable long-term and lowers the cost for glass container manufacturers.
Moreover, recycling glass is environmentally-friendly. It lowers the need for raw materials, as 1 kg of cullet can replace 1.2 kg of raw materials.
Also, according to the EPA, making glass from cullet needs 30% less energy than using virgin materials.
However, one thing to note is what kind of glass can be recycled together.
Still, they can’t be mixed with other types of glass. Glass, such as windows, crystal, ovenware, Pyrex, and more, is manufactured differently compared to glass containers and bottles. If these kinds of glass are recycled together, it can cause production problems and defective glass items.
Finally, it’s easier for consumers to recycle glass compared to plastic. Where plastic has seven numbered chasing arrow symbols, which are confusing for most users, glass has only 3 symbols. Each of them refers to a specific type of glass:
All of these are 100% recyclable, and it’s easy to distinguish between them.
Certain kinds of glass can’t be recycled. These are:
Many glass products can be recycled endlessly in the same stream. However, the US infrastructure is currently set in such a way that contamination levels are between 50% to 60%. Here’s how is glass recycled properly:
The glass recycling process starts with the collection.
Glass is collected from multi and single-stream recycling bins and community drop-off points.
Residential properties in shared waste management zones usually have curbside glass pick up, while businesses usually have private waste collection programs.
The same can be said about taking help from any private recycling service.
Once the glass is picked up, it’s transported to glass recycling centers.
Once the glass has been picked up and transported to the glass recycling facility, the facility checks for contaminants using an optical sorting process.
The recyclables are loaded onto an accelerator or a high-speed conveyor belt to thin out the material layer in the optical sorting process. The material moves under bright light. Some of the light is absorbed, while some light waves are reflected. Several camera lenses record the light waves that bounce off the glass.
Each material on the conveyor belt has a light signature that’s read with a spectrometer. This helps identify the kind of glass and whether it can be recycled or not.
The process also helps find the contaminants, which are separated from the rest of the glass.
Also, the glass is sorted by color. Glass is colored with additives, which can create issues when recycling, as different additives shouldn’t be mixed.
Glass manufacturers limit the amount of mixed-color cullets used to produce new containers. When recycled glass is separated by color, it helps the industry make sure the new containers match the color standards that container customers require. This is why the glass has to be color sorted as well.
After the glass is sorted, it has to be broken into smaller pieces. This is done with a machine that has about 24 hammers that pulverize the glass. The hammers spin in an axle and break the glass.
Sometimes, water mist can be added to prevent glass particles from being airborne.
After the glass is broken, it goes through rotary or trommel screens. These screens separate broken glass according to size — usually 3/8” and 3/4”.
At this stage, a fan is also used to separate paper labels that don’t come off during the breaking.
In case there are other items that can’t be broken down or don’t fit through the screens, they are removed to be recycled through their own processes.
The broken pieces are then put through a drier that's about 4’’ in size.
The drier has a vibration that moves the glass across the drier bed and makes hot air go through the glass.
This is done to burn off sugar and bacteria and loosen any remaining glue.
If there are any contaminants left, they are removed with a vacuum.
Next up is the primary screening, where recycling stations screen the glass. This is done to separate the glass into different sizes.
Different screens can be used here, and it’s important to separate different glass particles, as, for example, fiberglass shouldn’t be more than 12 mesh in size.
When the glass has gone through primary screening, it’s time for pulverizing.
All glass particles that couldn’t fit into the rotary screen go to the pulverizer, where they are further broken down.
The pulverizer has around 36 hammers that work in an enclosed area to reduce glass particle size.
Once the glass is broken down, it’s taken back to the rotary screen (primary screening), where it’s separated with a net.
This is repeated until all glass particles can fit into the screen.
Once again, glass particles go through screens to be separated into four sizes:
This is done because different uses require different sizes, so each size will be used in a specific manufacturing sector.
The cullet is the final step of the glass recycling process. Glass has been turned into cullet, and it’s used to produce new products. Cullets can range from fine sand, powder to pebbles in size.
Cullet is now used to produce new containers, fiberglass, ceramics, abrasives, and other glass materials.
Even though glass is a highly recyclable material, the US glass recycling data is not encouraging.
In 2018, only 31 million tons of glass were recycled, and nearly 62% went to landfill. It’s estimated that 28 billion glass bottles are buried in landfills every year, where they take between 4,000 to 1 million years to decompose.
Here’s how the US compares to European nations according to the Glass Packaging Institute, only 33% of all glass gets recycled in the US, compared to the 70% that’s recycled in Europe.
The main reason for the low numbers of glass recycling in the US is that recyclers are refusing glass recycling jobs.
There’s a lot of processing that has to be done to get the cullet in furnace-ready form. One of the main issues is that recycling in the US is done by single-stream collection. This means residents use recycling bins for different materials — aluminum, steel, plastic, different paper products, and more.
Also, people throw many things that shouldn’t go in the bins. This contaminates the glass in the recyclable bin, and the recycling facilities have to sort through all of these, which requires time and resources.
It can also happen that a facility can’t separate the glass from other materials or other glass colors, which results in contaminated products that they can’t find a market for.
Recycling facilities are refusing glass recycling jobs because of the difficulties with producing satisfactory cullet.
Apart from the glass being the contaminant or being contaminated by other materials, several other factors make it difficult to recycle, such as:
Several things can boost glass recycling.
One of those is legislation. Data from the Container Recycling Institute shows that states with container deposit legislation have a recycling rate of over 63%, while states that don’t have this legislation have a recycling rate of 24%.
Another solution is multi-stream recycling, which is common in Europe. Only 40% of glass from single-stream is recycled, compared to 90% from multi-stream systems. Multi-stream programs ask consumers to separate glass from other recyclables and deposit them in glass-only bins.
This route would require consumer education and is more expensive than single-stream, but is cleaner, especially when it comes to the final recycling product. Another positive side of multistream is that it doesn't have to go through recovery facilities but straight to cullet processors.
Yes, glass negatively impacts the environment. Most glass waste ends up in landfills in the US, where it takes 4,000 years upwards to decompose.
75% of all glass ends up in landfills, which is the equivalent of 110,000 glass bottles going into landfills daily.
Recycle Across America says that 28 billion glass bottles and jars are sent to landfills yearly.
Why does this happen?
I’ve talked about single-stream waste and how the glass recycling process works. The problem is that only a small portion of the glass is able to be recycled this way. The majority of glass items can’t be optically sorted, usually due to breakage, and are sent to the landfill.
So, what happens to all this glass at the landfill?
It outlives generations of people while lying in a landfill, and it negatively impacts the environment. Glass in landfills can kill wildlife and impact air and water pollution.
Items made from glass can contain lead, cadmium, and mercury, which are hazardous for people and animals. For example, enameled drinking glasses can have 1000 times the limit level of lead and 100 times the limit level of cadmium.
Broken glass in a landfill is also a hazard to wildlife, especially if it’s contaminated with toxic chemicals or other infectious substances. These can enter the bloodstream through a cut or a puncture.
Another negative impact of sending glass to landfills is wasted resources. A new study by the University of Southampton showed that glass might be even worse than plastic. Researchers compared beverage containers to determine their harm to the environment.
This is because glass is mined from rare materials and uses a lot of fossil fuels to produce and ship. When glass ends up in landfills, a huge amount of resources is wasted.
Did you ever wonder: How to find glass recycling near me? Luckily, it’s never been easier to find recyclers who accept glass.
The best way of finding where you can recycle your glass is to use GreenCitizen’s Green Directory.
By using Green Directory, you’ll be able to find a place to recycle your glass in seconds. All you need to do is input the material you want to recycle, your location, and if you want services to be provided near your address. You can even choose how far the recycler should be located (5, 10, 25, 50, 100 miles).
Here’s how to use the Green Directory:
The Green Directory will list all the glass recyclers close to you in seconds.
Here’s an example:
Step 1: Search for: Clear glass containers
Step 2: Add Location/Zip Code: Valencia Street, SF
Step 3: Search Radius: 25 miles
Step 4: Enjoy Results!
After clicking “search,” scroll down, and you’ll see all the places that accept clear glass containers for recycling in a 25 miles radius.
Pro Tip: This is a great way to find recycling places not only for your glass items but for friends and family as well. Help your parents and grandparents find glass recyclers, especially if they aren’t tech-savvy.
Glass recycling has several benefits:
However, glass recycling is becoming more difficult to perform, as recyclers are starting to refuse these jobs.
In this case, you should reuse glass. Reusing glass uses even fewer resources than glass recycling.
Here are some of my favorite ways to reuse glass.
Imagine having a Jack Daniels soap dispenser in your bathroom!
It’s easier than you think. Simply buy a liquid pump, put it in the glass bottle, pour some soap, and you’re done.
This is also an original gift idea.
This is a great idea to reuse your old wine bottle and feed some birds.
Start by choosing the bottle. It should be an interesting shape or have an eye-catching label or color to draw the birds.
When you construct a bird feeder, make sure it’s tall enough for the bottle to fit and leave out a few walls. Attach the bottle with wire rope to hold it in place, and secure it with washers and screws to the inner wall of the feeder.
Carve at L hook against the back of the feeder base, and place the bottle, so its lips rest on it. Finally, fill the bottle with a funnel, turn it upside down, and the seed will slowly come out.
One final idea on how to dispose of glass is to reuse glass jars. Instead of throwing it out, fill the jar with something else.
Glass jars can be used as storage for:
Need more inspiration?
Check out some more recycling and upcycling ideas.
Yes, glass can be recycled. Glass is 100% recyclable, it can be recycled endlessly, and it won’t lose quality or purity.
Yes, glass recycling is profitable. Data from 2014 shows that the glass recycling industry employs more than 1.1 million people and has $236 billion in gross revenue. However, because a lot of manufacturers are stepping away from glass bottle production, municipalities are removing glass recycling programs due to the lack of demand.
Glass waste can be reused in an infinite number of ways. Glass bottles can be used as vases, soap dispensers, in a bird feeder, and more. Drinking can be turned into floral displays, and jars can be used for storage.
A glass bottle can be reused indefinitely. You’ll know it’s time to recycle a glass bottle once it cracks or chips.
A glass bottle takes 4,000 to a billion years to decompose in a landfill.
When glass decomposes, the surface of the glass absorbs moisture, which results in devitrification — the outer layer crystalizes and flakes off, which results in an iridescent appearance. Because glass is made with a very stable formula, glass in landfills only goes through a slight devitrification.
Yes, glass is eco-friendly. It’s made of natural ingredients, so it doesn’t release harmful chemicals into the soil when it breaks down.
Both glass recycling and reusing are eco-friendly options. While there’s a lot of room for improvement in the US recycling system, we should take advantage of it as much as we can.
Whenever you wonder, “Where can I recycle glass,” use the Green Directory to find where you can recycle glass close to you.
Finally, if you’re out of options for glass recycling, you can always reuse your glass waste. Check Youtube, Pinterest, and the ideas I’ve mentioned above to get some inspiration.
Glass is one of the most eco-friendly materials out there, so let’s also dispose of it consciously.
If you have other ideas of how to dispose of glass responsibly, let me know in the comments below.