The Issue
Co-mingling Report
Questions & Answers about Glass Recycling in New Zealand
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The ongoing development of policies by Local Governments to increase the recovery of recyclable materials and their resulting diversion from landfill has lead to the development of new collection programmes, which are in the main, automated with the benefit of improved health and safety. One aspect, however which is not beneficial is the cessation of the traditional separation at source, the outcome of which is deterioration in the quality of glass offered for recycling and remanufacture. The challenge is to minimise the effects of the reduction of quality while enjoying the benefits of increased collection tonnages. An additional option is the establishment of alternative uses for those collections, which do not meet the standard required for the manufacturer of new containers. With the construction of an additional furnace and extra glass making capacity the Forum has two prime objectives:
This second objective requires not only the identifying of the alternative uses but also the establishment of them as acceptable. | ||||||||
Changes in the way Local Authorities collect household recyclables have had an adverse effect on the quality of glass available for recycling. This is a direct result of all recyclables being transported as a combined load for subsequent separation. Overseas experience has raised concerns that, notwithstanding increased volumes being collected, there is a reduction in the amount available for recycling and an increase in the volumes which need to be landfilled.
Below is independent report addressing the subject
Co-mingling report (PDF 333KB)
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If you have kerbside recycling, you can put out your glass containers for recycling. There are also some landfills and transfer stations that have bins for recycling glass.
Remember, you can only recycle food and beverage containers, for example:
Clear glass jars and bottles
Brown glass (beer bottles)
Green glass (wine bottles)
The above types of glass can be fully recycled WITHOUT loss of purity when making a new bottle

You can't recycle light bulbs and fluorescent tubes, pyrex dishes and ovenware, china and crockery - cups, saucers, plates, decorated drinking glasses, window glass, opal glass, glass bricks, medical and laboratory glass containers, TV tubes and computer screens.
Why? Because if the recycled glass is being used to make new glass it must be pure and this means you can only use glass and beverage containers. Other types of glass can have a damaging or harmful affect on the quality of the new glass.

O-I New Zealand, New Zealand's only glass manufacturer, makes bottles and jars in seven colours. These are flint or clear glass, amber glass, blue glass and four varieties of green. The reason for sorting the glass is to maintain the green, brown and clear colours which consumers want and which are an important part of a product's branding and also to ensure that the glass furnaces can be run as energy efficiently as possible.
When the raw materials are mixed in the furnace, other minor ingredients are added (some of which will determine the colour of the glass).
When recycled glass (cullet) is added to the mix, it already contains these minor ingredients and can have an impact on the colour of the glass made.
It is really important that the bottles and jars are consistent in their colour, so they only add clear to clear glass in the furnace and green to green and so on.

If it is not going to make new glass it is not so important to have it colour separated but it still needs to be separated from other packaging.
Currently if glass is being collected with other packaging in large wheelie bins, this has to be sorted by a combination of magnets and hand picking. However if glass is mixed in by colour and compacted with other cans, plastic and paper on the collection truck, this does reduce the amount of glass which can be recycled into new glass.
In 2009 a new state of the art Materials Recovery Facility (MRF) opened at Visy's recovery facility at Onehunga servicing both Auckland and Manukau cities and is expected to increase recycling rates by an additional 15-20%. When fully operational it is expected that the new plant will separate glass by colour and separate materials by type.
However an independent report by Palmerston North City Council1 is concerned that based on overseas experience of co-mingled collections; glass should be kept separate from other materials at point of collection. This is because although more recyclables are collected, less good recycled glass is available to make new glass containers due to glass breaking into very fine pieces in transit. However glass collected in this way can still be used for other things such as aggregate for roads, concrete etc.
1 The Glass Packaging Forum has funded this research following a request for funding from Palmerston North City Council. As a result the Palmerston North City Council and a number of other Local Authorities are further considering the need for glass to be kept separate at the time of collections.

It is really important to remove bottle tops and jar lids and other metals from your recycled glass, before it goes in the recycling bin. Metal can contaminate the glass recycling process. Of particular concern are the aluminium ring tabs and neck rings.


97% of New Zealanders have access to facilities to household recycling facilities, either at kerbside or at drop-off centres.
77% of New Zealand councils offer households a kerbside recycling service.
Check with your local council to find your nearest recycling facilities.

When commercial glass recycling first started, glass from all over the country was returned to Auckland to make new glass at the glass furnace. However in 2006 New Zealanders recycled nearly 110,000 tonnes of glass which is more than is needed to make new glass so councils and recycling operators are having to consider what else they can do with the glass.
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For that glass not of furnace quality we need to find alternative uses. It can be crushed and made into:
Click here for further information on ALTERNATIVE USES FOR GLASS

- Because recycled material uses less energy and a certain volume is required for optimum production there are savings. With commingling affecting local supplies there are at the current costs, (e.g.NZ dollar value etc for imported raw material ) benefits in using glass from the south of the South Island.
- 85,000 tonnes of recycled glass are used to make new glass containers each year. However when the new furnace is operational in October 2010 a further 70,000 tonnes will be required for optimum production i.e. 155,000 tonnes. The current recycled content of over 60% recycled in new glass is amongst the best in the world
- Using recycled glass requires less energy to melt than using virgin materials (silica sand, soda ash etc)
- Less raw material is needed when recycled glass is used in a batch of new glass.

- Diverts glass from going into landfills
- Using glass as an aggregate for roads or concrete reduces quarrying


Product Stewardship Scheme Accredited |
| 19 May 2010
Minister for the Environment, the Hon. Dr Nick Smith congratulates the Glass Packaging Forum as the first packaging sector to achieve accreditation status for their
Glass Product Stewardship Programme
more »
Press Release Press Release Photo - Chairman of GPF receives accreditation from Minister, the Hon Dr Nick Smith. August 2010 - A formal function to celebrate the Scheme’s
accreditation will be held on the |
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| Wednesday, August 11 5-6:00pm Ellerslie Event Centre Greenlane - Auckland |
Product Stewardship Definition |
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Product stewardship moves responsibility for waste to those involved in the production and supply of the product (and its packaging) and indirectly to the consumer by ensuring the costs of its disposal are reflected in the purchase price. It involves those who know the most about the product - the businesses who make and sell it- in designing the solution. Ministry for the Environment's |