Glass recycling information sheet

 

Why bother?	What you can do
How's, what's and where's of recycling glass	Sources of Further Information
What the law says

 

As early as 4000 BC glass was used in the Middle East as a glaze to decorate beads. By 1550 BC, coloured glass vessels were widespread and used for cooking and drinking. The earliest known clear glass is a vase found in Nineveh in Assyria, dating from around 800 BC, which is now in the British Museum in London.

Until the 18th and 19th centuries glass was very expensive and was used for limited applications, such as stained glass windows for churches. Large-scale glass manufacture began with the industrial revolution with the mass production of glass containers beginning at the onset of the 20th century and glass light bulb production automated in 1926.

Nowadays glass is much less expensive and is taken for granted as a packaging material in addition to its use in windows and other applications. New glass is made from a mixture of four main ingredients: sand, soda ash, limestone and other additives. These additives include iron for colour (brown or green), chromium and cobalt for colour (green and blue respectively, lead to alter the refractive index, alumina for durability and boron to improve the thermal options.

Annually, total glass use in the UK is estimated at around 3.6 million tonnes.

Why bother?

top of page

Using present technology the UK glass industry has the capacity to recycle over one million tonnes of glass each year and this coupled with the materials unique ability to be infinitely recycled without compromising its quality creates a compelling case for the recycling of glass. Despite this, glass makes up around 7% of the average household dustbin and in 2001 over 2.5 million tonnes of this material was landfilled.

Source: Analysis of household waste composition and factors driving waste increases - Dr. J. Parfitt, WRAP, December 2002

The manufacture of glass uses energy in the extraction and transportation of the raw materials, and during processing as materials have to be heated together to a very high temperature. Large amounts of fuel are used and the combustion of these fossil fuels produces carbon dioxide - a greenhouse gas. In 2002 the glass industry consumed a total of 8611,000,000 kWh of energy including electricity and carbon dioxide emissions totalled 1.8 million tonnes from the fossil fuels burnt in the factories. An efficient furnace will require 4 GJ of energy for each tonne of glass melted.

Glass can be recycled indefinitely as part of a simple but hugely beneficial process, as its structure does not deteriorate when reprocessed. In the case of bottles and jars, up to 80% of the total mixture can be made from reclaimed scrap glass, called "cullet". Cullet from a factory has a known composition and is recognised as domestic cullet. From bottle banks it is known as foreign and its actual properties will not be known.

If recycled glass is used to make new bottles and jars, the energy needed in the furnace is greatly reduced. After accounting for the transport and processing needed, 315kg of CO₂ is saved per tonne of glass melted.

In addition:

• Recycling reduces the demand for raw materials.  There is no shortage of the materials used, but they do have to be quarried from our landscape, so from this point of view, there are environmental advantages to recovering and recycling glass. For every tonne of recycled glass used, 1.2 tonnes of raw materials are preserved.
• Recycling reduces the amount of waste glass which needs to be landfilled.  Although glass is inert and is not directly hazardous to the environment, it will remain there indefinitely.
• Taking part in recycling the waste we produce makes us think about the effect we are having on our environment and enables us to contribute towards a greater level of sustainability

 

How's, what's and where's of recycling glass

top of page

Types of glass

Glass that we are familiar with is divided into different streams based on its particular composition and use.

Container glass

Container glass is largely bottles and jars and represents around 80% of the recycled glass market. Total container glass flow is estimated at 2.23 million tonnes of which around 629,000 tonnes may be imported

Reuse

Returning bottles to the retailer and receiving the deposit in return used to be common practice. However as manufacturing plants became larger and decreased in number, bottles had to be carried further for refilling. This removed much of the financial and environmental advantages associated with returnable bottles. In addition to this, consumer preference turned to the convenience of non-returnable bottles. Milk bottles are one of the few types of glass packaging still reused (an average of 12 times). Despite the extra weight required to withstand wear and tear and the costs of cleaning, returning bottles can still be the best option when they are recovered and refilled locally. There is also the option of reusing bottles and jars as storage containers for home made wine, beer or jam.

Recycling

Many people set aside glass for recycling and either participate in kerbside collection schemes or take them to a bottle bank. The first bottle banks appeared in 1977, and there are now roughly 50,000 on some 20,000 sites around the country, usually located at civic amenity sites and supermarkets. To find your nearest bottle bank you can use the recycle bank locator at http://www.recycle-more.com.

Glass can also be recovered from businesses, such as pubs and restaurants, and from companies, schools or organisations which are able to have a bottle bank on site. 600,000 tonnes of glass bottles are thrown out from pubs, clubs, hotels, restaurants and cafes every year (a quarter of the UK's waste glass containers). Up to 75% of this is currently being sent to landfill sites.

The UK has a current municipal recycling rate of 34% for container glass. This is poor when considering that Switzerland and Finland recycle more than 90% of their container waste and recycling figures of more than 50% are the norm.

 

 

Destinations of UK container glass %

Bottle banks are emptied by glass collection companies, or by the reprocessors, and the local authority or other party operating the bank is then paid by the tonne for the 'cullet'. When glass cullet reaches the plant it is monitored for purity, contaminants are removed and it is crushed and added to the raw material mix in the melting furnace.  It is then moulded or mechanically blown into new bottles or jars. For more information contact the organisations and websites at the end of this data sheet.

Colour imbalance The main barrier to recycling glass is the shortage of clear cullet collected in the UK. The UK predominantly produces clear and amber glass but because the UK exports a lot of clear glass, in the form of spirit bottles, and because consumers are also reluctant to deposit jars in bottle banks, little clear cullet is produced. The UK imports twice as much green glass as is manufactured, mainly in the form of wine bottles. In the past this has lead to a surplus of green cullet. The industry has worked hard to increase the amount of green glass recycled and currently all the green bottles we make in the UK contain at least 85 per cent recycled green glass.

Glass cullet can also be used for aggregate in the construction industry, and the new road laying material glasphalt. Glasphalt comprises around 30% recycled glass and it has been estimated around 14 million crushed bottles were used in this way during construction in the M6 motorway project. These materials can use mixed coloured and contaminated glass, and may be a good market for green glass.   

Inequalities in Glass production and consumption

 

Uses of recycled glass

Glass cullet can be used in the production of new glass bottles. The rise in recycling means that in 2003 the average jar or bottle made in the UK contained 38 per cent recycled glass, four per cent up on 2002. Recycling glass into new containers has four main environmental benefits - energy saving, lower emissions, reduced landfill and a reduction in quarrying.

Flat glass sector

This is the second largest sector of glass manufacture. As opposed to container glass, flat glass tends to be used in long term applications. This longevity lessens the environmental impact of waste glass but waste flat glass is arising as windows and car windscreens are replaced and cars are scrapped.

Taking into account imports and exports this stream accounts for around 886 thousand tonnes annually. The chart below shows the different outputs for flat glass by percentage.

Outputs of flat glass %

Fibre glass sector

Fibre glass can be manufactured using a number of methods to produce either continuous or short fibres. Continuous fibres are commonly used in the production of glass reinforced plastics and cements. Short fibres may be used in the production of blanket fibre material such as that used for insulation. In the UK 220,000 tonnes per annum of fibre glass is made per annum and approximately 11,000 tonnes of glass waste. Because of the difficulties in reusing and recycling this type of glass there is currently little recycling.

Domestic glass sector & Special glass sector

Domestic glass includes domestic houseware such as glasses and ornaments. The special glass sector includes cathode ray tubes as used in televisions, medical and other specialist equipment.

Nearly all cathode ray tubes disposed of from domestic households end up in landfill. The re-use of domestic TV's and computer monitors is negligible. WRAP has a project to assist the diversion of CRT glass from landfill and enable the UK to meet the WEEE Directive's recycling/recovery targets for equipment containing CRTs in the most cost-effective manner. It will identify and develop high value applications, research and report on the necessary technical criteria and quality standards. For further details please see the Wasteline Electrical and Electronics recycling information sheet.

What the law says

top of page

The Producer Responsibility Obligations (Packaging Waste) Regulations 1997, which makes businesses that deal with over 2 tonnes of packaging partly responsible for recovery and recycling, is intended to increase the level of glass recycling and help to establish a more stable market for the 'cullet'. UK businesses are obliged by law to recover at least 65% of glass in the packaging waste stream in 2006.

Glass recycling has also been affected by the WEEE legislation and the ELV legislation.

What you can do

top of page

• If a bottle is returnable it is usually preferable to return it, rather than to recycle it.
• Rinse the bottles or jars - ideally in washing-up water you have in the bowl anyway.
• Wherever possible, remove metal or plastic tops, corks and rings from bottles or jars. Any tops which remain will be removed by magnets, vibratory screens or other methods, but they can cause damage to furnaces if any get through.
• Recycle all glass containers, not just drinks bottles. Containers which hold food, pharmaceutical and household items which are made of glass are all recyclable.
• Never deposit light bulbs or cookware such as 'Pyrex' or 'Visionware'. These have different properties to the glass used to make bottles and can contaminate a load, resulting in a sub-standard finished product. Flat glass, such as window glass, whole or broken, should not be put in bottle banks either - see below.
• Make sure that you put the bottles in the correct bank - clear, green or brown. Most importantly, ensure clear glass is not contaminated with colours as this will considerably reduce the value as a higher price is paid for uncontaminated clear glass. Bottles made from blue glass can be put in the green glass bank.  Bottles with a coloured coating can be recycled as any finishes added later will burn off in the furnace.  To find the original glass colour check the top of the bottle where the cap was and put the bottle in the appropriate bank.
• Try to plan your trip to bottle banks along with other essential activities such as going shopping or to school. This way the environmental impact of the journey is kept to a minimum.
• Do not leave any boxes or bags at the bank that you have used to bring your glass in, there is normally a bin provided for these.
• Try to use bottle banks during the day, to avoid disturbing the local community at night.

 

Sources Of Further Information

top of page

British Glass 9 Churchill Way Chapeltown, Sheffield South Yorks  S35 2PY t 0114 290 1850 f 0114 290 1851 Info@britglass.co.uk http://www.britglass.co.uk British Glass maintains a bottle bank directory and provides information and advice on glass recycling.	Glasspac http://www.glasspac.com Information on glass as a packaging material.
Independent Glass Recyclers Association - The Berrymans 49 Lidgate Crescent Lengthweight Industrial Estate South Kirkby West Yorkshire  WF9 3NR t  01977 608020 Call for general information on glass recycling	letsrecycle.com http://www.letsrecycle.com For information on glass collectors, recyclers and processors.
Recycle More Glass Lidgate Crescent, Langthwaite Grange Industrial Estate South Kirkby, West Yorkshire, WF9 3NR t  01977 608020 f 01977 644021 www.berryman-uk.co.uk For information on the recycle-more-glass scheme, and free glass collection to licensed premises and local authorities, and a bottle bank location indicator.	Recyclingglass.co.uk http://www.recyclingglass.co.uk Educational site with facts about recycling.  They also produce a free educational CD rom for key stages 1 and 2.
WRAP, The Old Academy, 21 Horse Fair, Banbury, Oxon. OX16 0AH t 0808 100 2040 f  01295 819911 helpline@wrap.org.uk http://www.wrap.org.uk

 

 

Updated: February 06

 

top of page