Department of the Environment

About us | Contact us | Publications

Settlements Header ImageSettlements Header ImageSettlements Header Image

Publications archive - Waste and recycling


Key departmental publications, e.g. annual reports, budget papers and program guidelines are available in our online archive.

Much of the material listed on these archived web pages has been superseded, or served a particular purpose at a particular time. It may contain references to activities or policies that have no current application. Many archived documents may link to web pages that have moved or no longer exist, or may refer to other documents that are no longer available.

Environmental Impact of End-of-Life Vehicles: An Information Paper

Environment Australia
ISBN 0642547513

ELV Waste - Shredder Flock


While the metals in ELVs are generally recovered and recycled, the remainder of the ELV is not. This shredder residue, which constitutes approximately 25%-35% of the weight of the vehicle, and up to 60% of ELV volume (27, p.3), is sent to landfill.

Shredder flock is a key area of potential environmental concern in relation to ELVs. The areas of possible impacts are:

A couple of points should be noted at the outset. Firstly, shredder flock is dependent on the feeder materials entering the shredder - a large proportion of which is not ELV-related such as white goods, waste building materials etc.

Secondly, in relation to ELVs, the shredding process does not of itself create any new hazardous materials - the shredder flock from ELVs is entirely comprised of materials which were present in the vehicle. Accordingly, it would also be wrong to interpret anything in this report as suggesting that the burden of any new measures for ELV processing should fall largely or entirely on the metal shredding industry. This may well be inequitable and counter productive.

As discussed in Chapters 9 and 10, responsibility for the vehicle waste stream could potentially rest with some or all of the following: manufacturers/importers; vehicle dealers; the original purchaser; subsequent owners; the last owner; governments and public instrumentalities; auto dismantlers and metal recyclers. Placing an undue financial burden upon metal recyclers would also threaten the current high levels of ELV recycling.

In short, the fact that metal recyclers generally constitute the "last stop" for ELVs ought not to be confused with the issue of responsibility for ELV waste.

Composition of Shredder Flock

The chart illustrates the materials found in shredder flock, which are resources lost to landfill.

Composition of Shredder Flock

(source: Ref. 4, p.29)

Note: indicative only - based on international data. There maybe slight variations in Australia given differences in the average type and age of shredded ELVs, and differences in the shredding processes. For instance, evidence provided during the review indicated that the wire harnesses are sometimes separated and sent overseas for recycling of the copper content.


In addition to plastics, rubber (primarily from tyres) and glass (windscreen and other windows) account for the bulk of ELV waste.

Recycling these materials is more difficult than metals for technical and economic reasons. Issues associated with these wasted materials are discussed below.

Volume of ELV Waste

As discussed earlier, the non-metal portion of ELVs is estimated at between 25% and 35% of ELV weight.

The amount of shredder flock that can be attributed to ELVs has not been able to be established through available empirical data during the project, and this is an area that might warrant further investigation.

If it is assumed that about 500,000 ELVs are processed annually by metal shredders, and the average weight of an ELV is estimated at 1,300 kg, then:

This is a rough estimate that needs to be tested further and should be treated cautiously. For instance, it is considerably greater than the total ELV-related flock output of less than 70,000 tonnes which has been estimated by one industry stakeholder. However, as discussed in Chapters 3 and 5, ABS vehicle "attrition" estimates and estimates of ELVs being processed by the auto recycling industry appear to be sound and broadly consistent. The reason for this discrepancy is thus not immediately apparent.

In the United States, it is estimated that shredder flock accounts for almost 2% of all landfilled material (5, p.9). In the United Kingdom, shredder flock is estimated to contribute 0.3% of total UK waste (1,p.11). It is unclear why there should be such a significant variation between these countries, and probably reflects the difficulties in obtaining accurate statistics of ELV-related shredder flock (as opposed to other products shredded in the same machines) and total landfill volumes.

There were no comparable figures found for Australia. While no firm statistics on annual landfill volumes in Australia were found (although this may warrant further investigation), various environmental protection agencies suggested around 1 tonne per person (or 20 million tonnes in total). On the basis of the rough estimate given above, shredder flock would account for 1% of total waste.

It also needs to be borne in mind that not all ELV waste is derived from shredder flock. ELVs that are not processed by shredders, and components that are removed from ELVs prior to shredding, are also likely to contribute to waste levels, although no statistics on this waste source were found.


Environmental Impact of ELV Waste Volumes

The volume of waste is considered a much greater problem in Europe and Japan, which is reflected in tipping fees which may be 10 times higher than in Australia

As in the United States, Australia's low landfilling charges reflect the lower population density and greater availability of land.

Recently in Australia, governments have taken a greater interest in waste volumes and the requirement for landfilling sites. The availability of landfill space in metropolitan areas, and social and environmental concerns, have led some States and Territories to release policies to reduce waste volume, or even aim to eliminate waste totally (see, eg. Ref. 56 and 57).

Concurrently, however, many states have privatised landfill sites - from discussions with some State EPAs this has the potential to create tensions between waste reduction objectives and the commercial viability of the privatised landfill sites.

The ACT indicated a particular concern with waste volumes, which is not surprising given its landfill constraints. This is reflected in a policy of "zero waste by 2010".

However, the overall conclusion drawn from consultations with the States and Territories was that land contamination and resource loss issues, rather than landfill volumes per se, were likely to be of greater interest.

Potentially hazardous materials in shredder flock

Several international jurisdictions see the contamination of the environment through the landfilling of waste as an important environmental issue associated with ELVs. This was one factor leading to the recent European Union directive on ELVs (Ref. 8). As noted above, the materials present in flock are not derived from the shredding process per se but from the materials already present in ELVs. As noted previously above, shredder flock also comes from a variety of products other than ELVs.

The composition of shredder flock will also vary considerably from batch to batch and shredder to shredder - due to the different mixes of raw materials being processed; and the differing levels of pre-processing and inspection by shredder operators.

It should also be noted that shredder flock is likely to vary significantly between shredders due to varying requirements under State and Territory licensing conditions, and the changes in those conditions over time. By way of example, amongst the conditions attached to a recent land and environment court approval for a scrap metal shredding operation were:

  1. a requirement to install a fully roofed decommissioning pit for motor vehicles, fitted with environmental safeguards and stormwater controls
  2. a requirement to remove, store and dispose of petrol, oil and all other fuels, fluids and substances from all raw materials entering the site;
  3. no crushed cars can be received on the site for processing except those vehicles inspected, treated and crushed by the shredder operator themselves;
  4. all petrol tanks to be drained of fuel and triple rinsed with water;
  5. the site is to be fully concreted with extensive stormwater cleaning devices installed; and
  6. all batteries are to be removed from ELVs prior to shredding.

Notwithstanding the variations in feedstock and pre-treatment procedures, shredder flock may contain a variety of materials including heavy metals used in vehicle manufacture:

When the metal substrates are separated, the heavy elements listed above which are used as coatings tend to go with the substrate, leaving only small quantities in the shredder flock (ie. in the unseparated metal).

These heavy metals may cause environmental degradation as toxic leachate seeping through landfill, and may be bio-accumulative, persistent toxins. In the absence of independent scientific test data on ELV related shredder flock, no firm conclusions can be drawn on the extent of these heavy metals in Australian flock, nor the propensity for leaching, other than noting overseas experience (eg. refs: 1, 5, 22 etc).

In cases where fluids are not removed from the ELVs prior to shredding, other potential environmental contaminants may include:

Some of these fluids are recognised as being of significant environmental concern - "one litre of motor oil alone has the potential to contaminate up to one million litres of water" (Ref. 22, p.9).

Overseas literature has also expressed environmental concern in relation to:

The source or extent of PCBs in ELVs is, however, unclear as discussions with manufacturers did not lead to identification of a source of PCBs in Australian vehicles (although it may come from non-ELV sources).

The presence of these substances in shredder flock has been reported extensively in the literature surveyed during this review and is acknowledged by many of the manufacturers themselves and by the reactions of governments. For example, Japan and European governments require reduction or elimination of lead in motor vehicles.

A number of international jurisdictions (including in north America and Europe) have, or are moving towards, classifying shredder flock as hazardous waste, with separate (and significantly more expensive) disposal arrangements.

No published information was found to suggest that widespread independent tests of shredder flock contamination have been undertaken in Australia. One shredder operator did provide test results for one batch of NSW shredder flock which appeared to show low levels of heavy metals - apparently this data is required in relation to some State waste transport regulations.

State Environmental Protection Agencies, local councils and waste boards contacted during the review were also unable to provide any information on the extent of heavy metals and other contaminants in shredder flock.

The one jurisdiction that did have some information in this regard was the ACT. While the ACT does not have a metal shredder facility, interstate flock had been brought to ACT landfill sites since 1996. While initial testing of the shredder flock proved satisfactory, subsequent testing showed unacceptable concentrations of lead, PCBs and other contaminants. It should be noted that the validity of the testing methodology and results were not assessed as part of this report.

Extract from press article, Canberra Times, 9 October 1999

…The ACT Government closed the Belconnen tip and ordered health tests for workers yesterday afternoon over lead contamination fears.

Tests revealed that 2000 tonnes of metal waste or "flock" from interstate, which has been the subject of union bans, had lead levels up to 10 times the acceptable standard for landfill.

"I am advising workers at the plant that they may have been exposed for up to one year and as a result may require testing and treatment … We are yet to find out what lead levels are in the air" Dr Bowen (ACT Chief Health Officer) told ABC Radio.

The Construction, Forestry, Mining and Energy union imposed a ban on moving the metal flock … The union was alerted to the contamination by workers complaining of sore throats.

They said about five trucks from Sydney or Wollongong arrived at the tip each day to dump the flock in the three months before union intervention…

Shredder flock is no longer accepted at ACT landfill sites.

It would seem reasonable to conclude from the ACT experience (and international research) that the concentrations of heavy metals and other contaminants may vary significantly from batch to batch, and that at least some shredder flock may be unacceptable for landfilling for environmental (and health and safety) reasons.

State environment agencies consulted during the review appeared to have limited if any data available on the constitution of shredder flock, nor the extent of any environmental contamination resulting from its disposal in landfill.

A related issue is that some States (Queensland and Western Australia) indicated that there are several unattended landfill sites in regional and remote areas of the State. The potential exists for contaminated shredder waste that may not be accepted at other landfills to be dumped at these sites. While this possibility was raised during discussions, it should be stressed that it was beyond the scope of this review to assess whether this was occurring in practice.

The extent of environmental contamination resulting from hazardous fluids not being removed prior to shredding was also unable to be accurately quantified. Overseas efforts to quantify the extent of the oil content "has proved difficult to quantity by analytical techniques, and remains contentious … The true figure for operating fluid contamination of shredder residue is … unlikely to exceed 3% by mass" (Ref: 67 p.4).

Industry stakeholders agreed during discussions that the removal of fluids may be a concern. Although it was stated that the fluids are at least sometimes removed, one industry player argued that fluids should be removed before they arrive at the shredder facilities:

Any measures to enhance the removal of fluids, batteries, petrol tanks, air-conditioning gases and other contaminants should recognise the importance of not undermining the commercial viability of current recycling levels.

Key Findings

Shredder flock - resource loss

Resource loss through landfilling the non-metal materials in ELVs constitutes the third main area of ELV environmental impact.

For technical and commercial reasons, the non-metal balance of ELVs (flock) has little if any current economic value and is dumped to landfill sites. The fact that this waste (primarily plastics, seat foam, rubber, glass, and carpet) is not recycled represents an environmental cost through not conserving raw materials and other resources.

Recycling of plastics for instance, the main component of shredder flock, produces energy savings of more than 80% over the production of new plastics from virgin materials, with substantially less emissions (Ref: 6, p.2).

7.5% of world plastic production is used in car manufacturing, using 4% of total annual world oil output. Not maximising the potential for recycling automobile plastics represents a significant environmental cost. The issues are discussed further in the next chapter.

Cost of Shredder Flock disposal

Although the metal recycling industry expressed concern about any increases to shredder flock disposal costs, Australia currently has amongst the lowest landfill fees of any developed country:

The usefulness of waste levies as an incentive to increase recycling is problematic. In the absence of a commercially viable market or infrastructure for recycled shredder flock or its constituent ingredients, the current levels of ELV recycling may be jeopardised. These issues are discussed further in the next chapter. However, higher disposal costs may lead to alternative disposal options being pursued such as "thermal recycling" through incineration. This is discussed further in Chapter 11.

Whether the burden for waste disposal should fall entirely on the shredder operators is another important issue. Most international jurisdictions which have acted to implement ELV disposal regulations have decreed that the burden should not fall to the last owner of the vehicle, with the burden instead falling on manufacturers, governments and/or consumers.

In theory, waste levies should reflect the true economic cost of any environmental harm resulting from the dumping of shredder flock. However, the issue of waste disposal costs should not be considered in isolation from an overall strategy for managing the ELV waste stream that reflects the shared responsibility of the many stakeholders. Simply increasing the financial burden on shredder operators may lead to a decrease in current levels of ELV recycling.

Trends in the Use of Plastics

Given the contribution of plastics to ELV waste, it is prudent to consider the trends in the use of plastics in automobiles. As discussed above, plastics (including urethane) may already constitute some 50% of ELV waste, thereby potentially contributing some 95,000 tonnes of waste to landfill annually.

In the mid 1970s, plastics may have constituted only 4-5% of a car's weight, increasing to about 6-7% by the end of the 1980s, and now constituting 9-10% of total vehicle weight (eg. 27, p.2).

The trend towards the increased use of plastics in vehicle manufacture will continue to increase:

Manufacturers have replaced many metal components with plastic ones to ensure lighter weight, more economical vehicles - including bumpers, interior components, splash guards, hoses etc. Increasingly, manufacturers are evaluating plastics for broader applications, including body panels.

As a raw material, plastics are significantly more expensive than steel, which only costs around $2 per kilogram. However, working with steel is generally far more expensive than plastics, due to the very expensive stamping presses and tooling needed to form the metal body panels. The use of composite resin panels offers the potential to replace dozens of individual, welded metal components with a single complex shape, thereby greatly reducing welding, assembly and other manufacturing costs.

As well as simpler and thus much cheaper manufacturing techniques, the use of plastic body panels offers manufacturers substantial weight savings. Reducing the weight of a vehicle in turn allows the use of smaller, lighter and cheaper engines, brakes, wheels, tyres, suspension and steering components to match the performance levels of equivalent steel bodied cars. As a result, the higher cost of plastics can potentially be offset to produce a price-competitive car. Furthermore, all things being equal, a lighter, more fuel-efficient car will produce significantly fewer emissions during its operational life.

There has been some limited use of plastics for car body panels by a number of manufacturers since the 1950s, in the form of glass fibre reinforced resins, primarily to produce lightweight performance cars. More recently a number of vehicles have been developed with thermoplastic body panels, primarily for the European and Japanese markets. The most notable is the Smart Car (now a division of Chrysler-Benz corporation), which may be released in Australia in 2002. Other plastic bodied vehicles include Chrysler's City Cabrio, released in Europe this year, General Motors' Saturn model along with a recent Honda model in Japan. Ford, amongst others, is evaluating prototype models such as the electric powered Think.

A number of other vehicles now contain some plastic body panels, such as the Landrover Freelander and Nissan X-Trail models recently released in Australia.


ELVs appear to be a reasonably significant contributor to waste volumes and hence resource loss. Furthermore, the substances contained within shredder flock may cause environmental degradation, although the extent of contamination is hampered by the lack of data. Issues associated with reducing these environmental impacts by lessening the amount of flock and reducing hazardous materials contained therein are discussed in following chapters.

Any improvements made to new vehicles are likely to have long lead time in redressing the environmental impact of ELVs - changes to vehicle design and materials, for instance, will not affect the 12 million future ELVs currently on the road.

Key Findings