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Glass and sustainability

Glass is a useful material that has been around for thousands of years.

In this article you can learn:

  • How glass is made
  • What glass is used for
  • What its environmental impact is

This resource is suitable for sustainability topics for primary school learners.

Video - Glass and sustainability

In this video, you can learn how glass is made and how sustainable it is.

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How is glass made?

A glass furnace
Image caption,
It takes a lot of energy to melt the materials needed for glass. (Traimak Ivan / Alamy Stock Photo)

Glass is made from sand, limestone and soda ash.

The materials are heated until they melt, then shaped and cooled.

The heating process uses a lot of heat energy. Most of this is from burning gas. This causes carbon emissions that contribute to global heating and climate change.

Making glass by recycling old glass uses less emissions than making it from raw materials. This means that each time we recycle glass instead of making new glass, we are reducing our impact on the environment.

In fact, every tonne of glass re-melted saves 246kg of carbon dioxide emissions compared to production of new glass. It's even better to reuse glass when you can. That saves a lot of energy.

A glass furnace
Image caption,
It takes a lot of energy to melt the materials needed for glass. (Traimak Ivan / Alamy Stock Photo)

What is glass used for?

There are many uses for glass. Here are some examples:

Image gallerySkip image gallerySlide 1 of 7, A glass jar containing raw pasta, Food storage Glass can be sterilised and sealed to preserve food and drink so it is safe to eat or drink. (Danny Smythe / Alamy Stock Photo)
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Is glass environmentally friendly?

It's a little complicated.

As mentioned above, a lot of heat energy is needed to make glass. Most of this comes from burning fossil fuels. the materials used to make glass can damage the environment and cause pollution.

Glass bottles and jars are also heavier and bulkier than plastic, cardboard or metal containers. This means transporting products in glass containers can use more fuel.

Glass does not biodegrade over time either. This means that without recycling, it won’t break down naturally and will be with us forever.

However, unless it cracks or breaks, glass can be used over and over again without wearing down or needing to be thrown away.

Most glass can be recycled over and over again (apart from certain things like lightbulbs and mirrors). The recycling process uses less energy so is better for the environment. In the UK, about 70% of household glass is recycled from glass bottle banks and bin collections.

It is really important to recycle glass separately from other materials. It can be recycled at a glass bottle bank or your local council should have glass collection recycling two or three times per month.

Remember

Image gallerySkip image gallerySlide 1 of 3, , Glass litter can injure wildlife and people It is important to recycle or bin glass carefully. (EyeEm / Alamy Stock Photo)
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The advantages and disadvantages of glass

Advantages

  • Glass is 100% recyclable and can be reused over and over again, without losing its quality.

  • Most types of glass can be recycled. It doesn’t matter what shape, colour or size, all types of glass bottles and jars can be recycled.

  • Very little waste is generated in the glass recycling and manufacturing process. Recycled glass can be used to remake the same products as well as new products like insulation.

  • Every tonne of glass re-melted saves 246kg of carbon dioxide compared to making a tonne of new glass.

  • Glass can be so it is good for preserving food, drink, medicines and cosmetics.

Disadvantages

  • Glass does not decompose and therefore puts a great strain on landfill, which is not good for the environment.

  • New glass is made from four main ingredients: sand, soda, ash, and limestone. While there is no shortage of these raw materials yet, they have all been quarried, which can damage the landscape, affect the environment and use more energy.

  • Glass containers are heavier and bulkier than other materials, so it takes more fuel to transport them.

  • Not all types of glass products can be recycled. Items such as mirrors, drinking glasses and lightbulbs cannot be recycled and need to be disposed of carefully.

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Key words about glass and sustainability

- To break down and disappear over time.

- To remove or destroy bacteria and other living microorganisms.

- Doing something that will cause little or no damage to the environment and will be able to continue for a long period of time.

- This is the release of carbon into the earth’s atmosphere which contributes to climate change.

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Test your knowledge

Quiz

Challenge

Challenge

Design a poster to encourage people to recycle their used glass

You will need to include important facts and information that will help them understand the importance of recycling glass and why they should do it.

Recycling glass is good but reusing is even better!

Find ways to reuse your old glass jars and bottles as storage jars or up-cycle and decorate them for something else!

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