Distinguishing wastes from non-wastes under Australia's Hazardous Waste Act

Table A is a list of disposal operations which do not lead to the possibility of resource recovery, recycling, reclamation, direct re-use or alternative uses;

Table B is a list of disposal operations which may lead to resource recovery, recycling, reclamation, direct re-use or alternative uses; and

Table C is a list of 16 reasons why materials are intended for disposal. These reasons are only relevant to material intended for an operation listed in Table A or Table B.

Example 1. Blood and urine samples

Representative samples comprising 2-3 ml of blood and urine may be imported into Australia for pathological testing that is not available in the country of origin. After testing any residues are incinerated with other waste from the laboratory. One view could be that a final disposal operation follows so closely after the testing that the samples must be considered to be wastes destined for final disposal.

However, these samples were taken intentionally from a material that was not a waste and they do not fit within any category listed in Table C. The samples are being imported for continued and lawful use for their originally intended purpose and no part of them is destined for a disposal operation until after that purpose has been accomplished. They are not considered to be wastes.

Note that although the transboundary movement of these samples is not controlled under the Hazardous Waste Act, the requirements of other legislation such as the Quarantine Act 1908 and Proclamation 1998 must be met. For human serum, blood and urine no permit is required unless the material is knowingly infected, but IATA safe handling packaging requirements must be observed. Samples of animal serum and urine always require a permit in addition to the IATA requirements. On completion of work all imported materials and the direct or indirect derivatives thereof shall be disposed of by incineration, autoclaving or other methods approved by the Director of Animal/Plant Quarantine.

Example 2. Spent potlinings

An aluminium smelter wishes to send a representative sample comprising 150 tonnes of spent potlinings to the country of manufacture to determine why the material had failed earlier than normally expected. After testing the residues of testing are to be disposed of in a secure landfill.

This material may be assigned to Q7 in Table C, substances which no longer perform satisfactorily. In this instance Australia took the view that the sample was taken from a waste and, since it was destined for final disposal, after testing, it required a permit. The proposed country of import took the contrary view, that the material was not destined for a Basel Convention disposal operation and consequently did not require a permit.

Example 3. Smelting of zinc residues

A company proposes to import zinc residues containing 10% lead to an Imperial Smelting Furnace (ISF). The zinc residues arose in a copper smelter from a washing of gas process from the electric furnaces and may be assigned to category Q9 in Table C, residues from pollution abatement processes. In the ISF they are treated in the same way as concentrates. Concentrates, residues and oxides are proportioned and blended with recycled sinter fines. As this mix slowly passes through the sinter machine it is burnt, resulting in the release of sulphur dioxide and the partial melting of the mix into "sinter". The sinter is crushed and screened to provide rock-hard, low sulphur, lump feed which is then smelted in the ISF blast furnace. Sinter fines are returned to the sinter process.

In this instance, the residues are subjected to recovery operation R4, recycling/reclamation of metals and metal compounds, in a facility which, although not primarily a waste management operation, utilises certain waste materials as feedstocks. The zinc residues are considered to be a waste which is recovered in a facility which operates under applicable domestic law of the State of New South Wales.

Example 4. Use of waste solvents in cement kilns

Waste solvents can be used as an alternative fuel source in cement kilns. The solvents are assigned to Q7 in Table C, substances which no longer perform satisfactorily and are destined for recovery operation R1, use as a fuel (other than in direct incineration) or other means to generate energy. The acceptability of this practice depends upon the specific emission controls in place and the suitability of the furnace to accept the material and the resulting composition of the cement. It is not considered to be an environmentally sound outcome when cement is produced which would have limited application because it is contaminated rendering the material hazardous.

In this instance the cement kiln is not primarily a waste management operation, but is able to utilise certain waste materials as fuel subject to the waste material complying with the specifications for fuel used in the kiln. The waste solvents are clearly wastes in this context.

(a) Is the material produced intentionally?

(b) Is the material made in response to market demand?

(c) Is the overall economic value of the material positive?

(d) Is the material part of the normal commercial cycle or chain of utility?

Example 5. Processing of nickel-cobalt ores

Company A has sourced nickel ores from mines in Queensland and also from New Caledonia and Indonesia. The ores contain approximately 1.5% nickel and 0.15% cobalt: nickel and cobalt commonly occur together in ore bodies. The refining process produces nickel metal, nickel sulphide and cobalt sulphide. The metal sulphides are refined to a specification and sold to a company overseas for further processing. If the nickel is regarded as the primary product, the question is whether the cobalt sulphide falls within the scope of Q11 in the Q-list (residues from raw materials processing including mining residues)? In this example the cobalt sulphide is considered to fall outside the scope of the Q-list because:

a) there is clear evidence of an intention to produce both nickel and cobalt. The company's mission statement is "to provide high quality nickel and cobalt products...", and their plant was designed in 1974 to extract both nickel and cobalt from a particular ore body;

b) the cobalt sulphide meets a specification from a customer whose operations form part of a normal commercial cycle; and

c) the company has stated that the commercial viability of its operations has always depended on the sale of both materials. Cobalt sulphide comprises 20% of the company's sales and it supplies a significant fraction, 8%, of the world market.

Based on all these considerations, these materials are considered to be non-wastes.

Example 6. Processing of nickel-cobalt ores

Company B also exports sulphides which are produced in the refining of nickel ores. The nickel and cobalt sulphides are refined to specifications at the facility and exported for further processing. They are blended with other nickel concentrates from mines located around the world, and subjected to an extraction process which involves autoclave pressure leaching and solvent extraction. In this example the initial production process is not economically dependent on the production of the sulphides, but they are not considered to fall within the scope of Q11 in the Q-list because:

a) the sulphides have been subjected to a set of conventional extractive processes, with quality controls to meet a standard required and recognised by market demand;

b) this market demand comes from a normal commercial cycle, not a commercial waste cycle. The sulphides have suffered no loss in value and are in fact acquiring increased value at each step of processing; and

c) in this process, the materials can be used directly as an alternative feedstock in competition with other ores.

Based on all these considerations, these materials are considered to be non-wastes.

Example 7. Brass dross

In the production of brass alloys in electric core-type induction furnaces, oxides form on the surface of the melt. These are poor thermal conductors and inhibit complete melting. This results in considerable amounts of unmelted metal remaining on the surface of the melt, mixed up with the oxide. This is known as dross or brass dross. This dross is considered to fall within the scope of Q8, residues of industrial processes, in the Q-list because:

a) the production of the dross is an unavoidable consequence of choosing the most economical production process;

b) the dross is not produced to quality controls to meet a standard required and recognised by market demand;

c) the process is not economically dependent on the production of the dross, even though the revenue from its sale has been important to the industry;

d) the market demand for the dross comes from a waste recovery industry which separates the higher value metallics from the lower value fines. The metallics have suffered a loss in value by being mixed with the fines; and

e) when recovered, the materials are used as an alternative feedstock but this is subsidised because the dross is subject to lower tariffs than primary metal.

The dross is also destined for recovery operation R4, recycling/reclamation of metals and metal compounds and is considered to be a waste.

(e) Is the production of the material subject to quality control?

(f) Does the material meet well developed nationally and internationally recognised specifications/standards?

(g) Do these standards include environmental considerations, in addition to technical or economic considerations?

(h) Is the use of the material as environmentally sound as that of a primary product?

(i) Does the use of the material in a production process cause any increased risks to human health or the environment greater than the use of the corresponding raw material?

(j) Is further processing required before the material can be directly used in a manufacturing/commercial application?

(k) Is this processing limited to minor repair?

(l) Is the material still suitable for its originally intended purpose?

(m) Can the material be used for another purpose as a substitute material?

(n) Will the material actually be used in a production process?

(o) Does the material have an identified use?

(p) Can the material be used in its present form or in the same way as a raw material without being subjected to a recovery operation?

(q) Can the material only be used after it has been subjected to a recovery operation?

Example 8. Anode slimes

A company sources copper and copper/gold concentrates from different mines and processes them in furnaces and converters before casting the copper into anodes which are sent to another plant for electrolytic refining. The anodes typically contain 99.7 % copper and the remaining 0.3 % comprises gold, silver, nickel and arsenic. The anodes are placed in a liquid electrolyte and the copper ions migrate to be electroplated onto steel cathodes.

Gold and silver materials in the anode do not dissolve in the electrolyte. Along with lead, tin, bismuth, antimony and arsenic, these elements form anode slimes which accumulate in the cells and are removed at intervals. This process increases the concentration of gold: the anode slimes contain about one thousand times more gold than the original concentrate. After removal, the anode slimes are thickened in a holding tank, filtered to about 15 % moisture using a tube press and packed into bulk bags for export to an overseas facility.

The overseas facility separates the remaining copper from the anode slimes in a sulphuric acid leaching process. After the separation of selenium, the anode slimes are smelted in an electric furnace to produce Doré metal (an alloy rich in precious metals) and a slag containing precious metals. The slag is processed in an electric furnace in order to recover the precious metals.

The company does not consider the anode slimes to be a waste for the following reasons. First, the company argued that, the material clearly has economic value and this is high because of the value of the gold. The market value of the anode slimes is typically more than 50 times the unit value of the refined copper metal produced by the company.

Second, the material is produced intentionally. Although the company is primarily in the business of producing copper, it supplements its own concentrate by buying in additional copper-gold feedstock which is deliberately chosen for its gold content. Gold frequently occurs with copper in mineral deposits and earnings from both the gold and copper contained in the mineral concentrates produced by mining are economically important.

The material is made in response to market demand. Not only do markets for anode slimes exist, there is also competition among buyers who are aiming to compete by achieving economies of scale. The production of the material is subject to quality control, beginning with careful blending of the concentrates so that the desired content of gold is achieved in the resultant anode slimes, and ending with spear sampling of every bag produced for analysis of copper, gold, silver, palladium and moisture.

The material meets well-developed specifications laid down by the processor. These specify precise concentrations of twelve metallic elements plus moisture content. The Australian producer has had to adjust the moisture content on occasion to remain within specification but has no experience of being out-of-specification with the metallic elements. The specifications are primarily technical and economic, but there are charges for penalty elements such as selenium and arsenic and these are relevant to environmental considerations.

The material remains part of the normal commercial cycle: there has been no loss of value and the production of the anode slimes has been so arranged that it is used as an effective mechanism for increasing the concentration of gold in the material. The applicant company provided evidence, in the form of documents on the public record, of its intention to produce both copper and gold.

Third, the material does not require a recovery operation before being subjected to the Doré (separation) process. In other words it does not require a processing step which is outside the normal commercial cycle.

It may be concluded, from the following considerations taken together, that this particular material is not a waste:

(a) the anode slimes are not proposed for a final disposal operation in Table A;

(b) the anode slimes are not proposed for an operation which may lead to resource recovery, recycling, reclamation, direct re-use or alternative use, as in the Table B, for the reasons set out in the rest of this list;

(c) the anode slimes have a financial value far greater than that of the primary copper product;

(d) feedstocks are deliberately selected, purchased and blended to achieve a specified concentration of gold in the resultant slimes;

(e) the production of the material is subject to strict quality control and testing;

(f) the material must meet strict specifications set out by the buyer;

(g) the specifications contain penalty causes relating to the presence of environmentally hazardous metals; and

(h) the applicant demonstrated clear evidence of intent to produce both copper and gold.

Example 9. Lead solder residues

A company producing soft solder collects up to 40 tonnes of solder residues per year. Most comes from customers' solder baths (oxides/drosses, spills and splashes). Some is waste solder from car radiator repair shops and scrap dealers and the remainder comprises the internal arisings of oxides from the company's own production processes

A second source of residue generation is from the manufacturer's own recycling operations. Solder residues from various sources are put through a gas-fired reverberatory furnace to recover the maximum possible amount of metallics by melting. About 70 % of the metal can be recovered in this way but about 30 % comprises a residue which is still oxidised and is drummed for export. At the same time a small amount of baghouse dust is produced (600 kg/year).

The company proposes to export 40 t/year of residues, with an overall composition of about 40 % lead, 30 % tin, 4 % zinc, 2 % chloride (from fluxes) and 1 % copper. These comprise arisings from internal recycling operations, other residues which are collected but not recycled, and the 600 kg of baghouse dust. There is no Australian recycling facility but an overseas facility can recover tin and lead values through smelting with coke and fluxes.

In considering whether the solder residues are a waste, the following factors are considered:

(a) the solder residues have economic value because they may be sold, mainly for the value of the tin content.

(b) the solder residues are not produced intentionally. The manufacturer aims to make metal, not dross, and seeks to minimise the quantity of dross produced. The residues are not made in response to market demand: the manufacturer is not seeking to maximise production so that more can be sold. There is some quality control but this is directed mainly at the production of metal and the process seeks to minimise the quantity of metallics in the dross. The use of a gas-fired furnace influences the kind of material that is produced but the furnace was not chosen with a view to producing a particular type of residue.

(c) the solder residues do not meet well developed nationally and internationally recognised specifications/standards but this is not unreasonable because this is a small-volume and highly specialised material. The inputs are tightly controlled and as a result there is little variation between batches. Specifications for the material do not include environmental considerations.

(d) the solder residues are no longer part of the normal commercial cycle or chain of utility. They are proposed for sale to a processor whose company profile describes the company as smelters and refiners of secondary tin-, lead- and antimony-containing raw materials. They buy and process these materials to recycle and recover the metal content as tin-lead solder alloy and antimonial lead alloy. The company's business is buying wastes for recovery and returning this waste to the normal commercial cycle.

(e) a recovery operation is necessary because the material cannot be used in its present form or in the same way as a raw material until it has been processed through a reducing furnace. The material is a waste because it falls within the scope of Q8, residues of industrial processes, in Table C and is destined for recovery operations R4, recycling/reclamation of metals and metal compounds, and R11, uses of residual materials obtained from any of the operations numbered R1-R10. The latter applies to residues already subjected to operation R4 in the gas-fired reverberatory furnace.

Therefore, it may be concluded that the lead solder residues are a waste. It is relevant that:

(a) the production of the residues is an unavoidable consequence of choosing the most economical production process;

(b) there is some quality control in the production of the residues but this is directed mainly at the production of the metal: the residue quality is almost incidental;

(c) the process is not economically dependent on the production of the dross and steps are taken to minimise the amount of dross produced;

(d) the market demand for the residues comes from a secondary metals processor who returns waste to the normal commercial cycle. The metallics have suffered a loss in value by being oxidised and mixed.

Example 10. Export of spent catalysts for regeneration/remanufacture

A company wishes to export spent catalysts for regeneration/remanufacture to maintain catalyst activity. Operation R8 in Table B refers to recovery of components from catalysts. Regeneration does not fall within the scope of R8 but it is necessary to consider whether it could fall within the definition of a recovery operation.

Catalyst life can vary anywhere between 2-6 years: the activity of the catalyst reduces as it becomes coated in coke and other carbon products. Regeneration usually involves simply burning off the coke. This can be an odorous process and so it is preferably carried out off-site. Because the regeneration process can stress the molecular structure of the catalyst, regeneration is usually only possible a limited number of times, usually three. Once the catalyst is considered beyond regeneration it is disposed of by operation R8, recovery of components from catalysts.

The catalyst regeneration process is not considered to fall within the definition of a recovery operation because all that happens is that a film of coke or other material is burned off the catalyst. The life of the catalyst is not determined by the coking itself, but by structural stresses resulting from the regeneration process and by metallic contamination. Catalysts destined for regeneration do not fall within the definition of a recovery operation but catalysts destined for recovery of components (operation R8) do.

Example 11. Export of used computers for continued use

Australia exports used computers for sale and continued use as computers. These often require minor repairs to restore them to working order before sale. Such repairs include replacement of broken parts or mother boards, or upgrading of chips. The computers may be assigned to Q14 in Table C, products for which there is no further use, but the minor repairs are not considered to be R-list operations and the computers are not considered to be wastes. Note, however, that the term minor repair is not considered to encompass reconstruction of single units from multiple units.

Example 12. Export of used computers for disassembly

In addition to the circumstances in Example 13, Australia has also exported used computers for disassembly followed by re-use, recycling and recovery of their components. The computers are assigned to Q14 in Table C and are classified as a waste (although not necessarily a hazardous waste) destined for R3, R4 and R5, recycling/reclamation of organic substances, metals and other inorganic materials. If the computers to be exported for disassembly contain hazardous components or constituents, recognised as hazardous under the Basel Convention, to the extent that they possess any of the hazardous characteristics listed in Annex III, then the computers themselves would be regarded as hazardous and regulated as hazardous wastes under the Convention. Nickel-cadmium batteries, mercury switches, glass from cathode-ray tubes and lead and cadmium in printed circuit boards are examples of hazardous constituents which may be present in hazardous concentrations.

Example 13. Draining of used lead-acid batteries

Used lead-acid batteries are in demand within the commercial waste cycle, but fall outside the normal commercial cycle for the production of refined lead. The batteries may be prepared for transport by draining off the acid; this could be described as minor processing, but merely draining the battery does not return the material to a normal commercial cycle (that is, its intended use), This could only be achieved if the battery was then refilled and it operated in the normal way. The drained battery remains within the commercial waste cycle because a recovery or recycling operation is still required before a material (lead metal) is obtained which is of direct use in a manufacturing/production process.

Example 14. Dewatered and demineralised oils

An oil recycling company produces either a dewatered oil by allowing the oil to stand and draining off the water, or a demineralised oil by operating a counter current partuition process that heats, demineralises and dewaters the oil. The dewatered oil can be used in cement kilns as a fuel. The demineralised oil has been processed to meet the specifications for use as diesel fuel and can be safely used as a substitute for diesel oil.

The dewatered oil would still be classified as a Basel waste because it is fit and intended only for an operation in the Table B (R1, use as a fuel other than by direct incineration). The demineralised oil, on the other hand, has been processed to the point where it meets the specifications for, and can be safely used as a substitute for, diesel oil: it is not a waste.

Example 15. Export of used tyres

Used tyres are not classified as hazardous wastes under Article 1.1(a) of the Basel Convention and may be commercially traded and exported from one country to another country for continued use. The tyres are exported because they no longer meet the legal requirements in the country of export. However, the legal requirements in the importing country are different (i.e. less stringent) and the used tyres are considered to be fit for their original intended purpose. The tyres may be assigned to Q13, any materials, substances or products whose use has been banned by law in the country of exportation. In the absence of national legislation to the contrary, they are not considered to be wastes because they are not destined for an operation in Table A or Table B.

"R14 Recovery or regeneration of a substance or use or re-use of a hazardous waste, other than by any operation set out in R1 to R10"

Example 16. Smelting of lead dross

An Australian company proposes to export lead dross containing 60-80% lead to a non-ferrous smelter in another country. The lead dross originates during the refining process of lead, with the purpose of separating and concentrating other non-ferrous metals, after drossing (decoppering). It may be assigned to category Q8 of Table C, residues of industrial processes. The dross cannot be processed in Australia because of the high arsenic and silver content.

In this instance, the residues are subjected to recovery operation R4, recycling/ reclamation of metals and metal compounds. The competent authority of the State of import has certified that the refining process is a production process, not comparable with a waste disposal process, with the purpose of recovering the remaining metals. Nevertheless, the competent authority is still of the opinion that this material is to be considered as a waste because, among other things, of its origin and composition (presence of heavy metals higher than 1,000 mg per kg dry weight arsenic).

The competent authority of the State of import has also certified that the particular smelter is recognised as a preauthorised facility for the environmentally sound recovery of non-ferrous metals classified as residues, solid wastes or hazardous wastes, including lead dross. The plant is duly authorised by an integrated permit limiting emissions to air, water and soil, and is submitted to permanent monitoring and regular inspections

The competent authority of the State of import first judged that the legal regimen of the international transfer of waste did not apply in this case because the waste is directly transported from the place of origin to the place of recovery. There it will be used completely and without any pretreatment as a raw material in a production process that is not comparable with a waste disposal process. The State of import therefore declared that if the competent authority in the State of origin agreed with the non-application of the regulations, international movements may take place accompanied only by copies of the relevant declarations.

In this example the lead dross is subject to the regulations of all States involved, despite the conditional exemption granted by the State of import. This is because the laws of the State of origin, Australia, make no provision for non-application of the regulations, and because there are two States of transit which require the full notification and consent procedure to be applied, including payment of financial guarantees. It is important to note that wastes may only be exempted from the regulations applying to transboundary movement when every State involved in a movement has agreed to the exemption.

(a) Can the material be used for another purpose as a substitute material?

(b) Is the use of the material as environmentally sound as that of a primary product?

(c) Will the material actually be used in a production process?

(d) Does the material have an identified use?

(e) Does the use of the material in a production process cause any increased risks to human health or the environment greater than the use of the corresponding raw material?

Example 17. Production of lead sulphate

A proposed export of lead sulphate was produced as a result of treating fumes from a copper smelter. The fumes were produced as a direct result of copper smelting and all gas from the smelting processes was finally cleaned in a baghouse. The trapped fumes were high in lead content and at this stage were assigned to Q9 in Table C, residues from pollution abatement processes.

The fumes are classified as a waste because they are then subjected to pre-treatment and hydrometallurgical leaching to remove contaminants such as zinc, copper and cadmium which can cause problems in lead smelting. On completion of this recovery operation, the recovered material is known as lead sulphate and is dried and packed to customer requirements. The grade of this material is such that it replaces lead concentrate feed to a smelter. At this stage the material has been treated to meet market demand, the contaminants have been removed as a waste stream, and the lead sulphate has re-entered the normal commercial cycle as a feedstock that may be used in the same way as a material of non-waste origin.

Example 18. Fly ash

A company wishes to know whether flyash destined for use as a cementitious material in concrete and mortar would be considered a hazardous waste. Although most Australian flyash falls below concentration cut-off levels for Annex I constituents, this particular flyash is hazardous because in a TCLP test it generates 30 mg/L antimony in the leachate, or 100 times the concentration cut-off set under the Hazardous Waste Act.

Fly ash is produced by burning pulverised coal in power stations. It is removed from the furnace exit gases, either by electrostatic precipitators or bag filters, and is usually sluiced to ash disposal dams. Although at this stage flyash is a waste, it is also finding increasing application as a low-cost substitute for Portland cement.

Flyash destined for cement manufacture is processed to a degree because the fine fraction (less than 45 microns) is preferred. When collected by electrostatic precipitators the coarser fractions are mostly precipitated in the first stage and the finer grades in the second and third stages. There are also ways of emptying baghouses that separate in part the finer fractions from the coarser fractions. In addition, cyclonic centrifuges may be used to achieve further separation.

Before flyash can be accepted as a cement substitute in Australia it must be tested for conformity with Australian Standard 3582 Part 1. This includes specified minimum requirements for the percentage that passes a 45 micron sieve and maximum requirements for loss on ignition, moisture content and sulfuric anhydride content. The standard also sets out reportable properties for which a purchaser may demand the most recent test results: these include available alkali content, relative density, water requirement and strength, and chloride ion content.

Flyash typically replaces 25 percent of the cement, but may be used at up to 70 percent in some instances. Concrete incorporating flyash has approximately the same strength as concrete made entirely from Portland cement, but the presence of flyash enhances sulfate and chloride resistance and this can be beneficial in marine or industrial environments.

This use of flyash appears to fall within the scope of Table B, not as an operation on the R-list but as "Alternative uses". That is, use of a reclaimed portion of the waste stream without physical and/or chemical transformation as a substitute for other virgin materials. The question that arises is when does the flyash cease to be a waste? Is it after it has been collected and tested in accordance with Australian Standard 3582 Part 1, or is it after it has been made into concrete and mortar?

The reclaimed portion of the flyash will require no further processing by a Table B operation when it has been used as a substitute for Portland cement. After blending with Portland cement the material will no longer be a waste because the threat posed to the environment by the original waste will be sufficiently diminished and the material will be of sufficient beneficial use (see paragraph 45).

Example 19. Upgraded copper flue dust

A flue dust was produced in a copper roaster and subjected to hydrometallurgical treatment to reduce the arsenic content. After treatment it still contained relatively high concentrations of arsenic (3.7%) and antimony (2.0%) and a relatively low copper content (16.7%). Smelters often combine such poor-quality feedstock with other materials with compensatory levels of the same elements. The question was whether the treated material was still a waste.

After smelting the antimony would be disposed of in a slag produced from the process but the high arsenic levels could potentially pose a problem when disposed of through the gas handling system. The key issue in determining the material's status was whether the levels of copper, antimony and arsenic remaining after its upgrading were comparable to levels in materials commonly traded for use as a feedstock in smelters. Advice was obtained that the treated flue dust in terms of arsenic and antimony was well outside the range of commonly traded concentrates, which traded in the range 0.5% to 1% with exceptions up to 2%. Copper concentrates generally traded in the copper concentration range of 28% to 32% with lower quality concentrates around 25%. The 16.7% copper in the flue dust material was exceptionally low."

The material was proposed for smelting in a facility which treated annually 50,000 tonnes of copper concentrates, comprising 30,000 tonnes of Type A and 20,000 tonnes of Type B. Type A contained 20-22.5% copper, 0.15-0.25% arsenic and 0.15-0.25% antimony. Type B contained 24-25% copper, 2-4% arsenic and 0.7-0.9% antimony. It was intended that the flue dust material be blended with one or both of these. In Type A, copper was reasonably high and arsenic and antimony were both low. In Type B, arsenic was high but this was compensated by high copper and low antimony.

The flue dust material combined a low copper concentration (16.7%) with high concentrations of arsenic (3.7%) and antimony (2.0%). Normally when purchasing feedstock one would accept one or two disadvantages because something else would compensate for them. For example, in concentrate Type B referred to above, high copper and low antimony compensated for high arsenic. In the flue dust material, however, there were three disadvantages and no compensations and this suggested the material was still a waste.

Because of these disadvantages it would be necessary to feed the material in at a low ratio of about 40:1. This would have to be spread over the greater part of a year and suggested bleeding in of a waste rather than blending in of a non-waste material. Feedstock were typically blended at ratios of 60:40 or 70:30.

Therefore, the processing of the flue dust had not reduced the hazard sufficiently for the flue dust to cease to be a waste. No examples had been found of similar materials sold in commercial quantities of 20,000 to 30,000 tonnes, neither had it been demonstrate that other facilities were interested in taking the material. The material was still a hazardous waste.

Example 20. Use of zinc slag for abrasive blast cleaning

Zinc slag containing 0.7% lead and 0.1% arsenic is taken from a smelter. At this point it is classified both as a Basel waste (A1080, waste zinc residues etc) and an OECD waste (AA020, zinc wastes including, ash, residue, slag etc). It may be assigned to entry Q8, residues of industrial processes, in Table C. The slag is crushed, dried and sized and the material is sold for abrasive blast cleaning of metal surfaces.

In Australia and New Zealand, health regulations and Codes require that abrasive blasting take place under controlled conditions with specified ventilation and personal protection. Use of this material in uncontrolled abrasive blasting produces a dust which, if inhaled, leads to elevated blood levels of lead. If swallowed, it leads to elevated blood levels of lead and arsenic.

The used abrasive material in most instances has to be disposed of in a secure landfill. At this point the material is an OECD amber list waste (AB130, used blasting grit) and is a Basel waste under A1080. The specifications for disposal vary between States.

An evaluation of this material yields the following conclusions:

a) the material can be used for another purpose as a substitute material;

b) the use of the material for that purpose is not as environmentally sound as that of a primary product. The processes of crushing, drying and sizing have not rendered the original slag less hazardous, and have very likely increased the availability of its hazardous constituents. It is not environmentally sound to use a hazardous waste in a process that would not, in itself, inevitably generate a hazardous waste;

c) the material will not actually be used in a production process;

d) the material has an identified use; and

e) the use of this material in abrasive blast cleaning causes an increased risk to human health and the environment greater than the use of the corresponding raw material. There are alternatives available on the market which are not inherently hazardous.

This hazardous waste has not been subjected to a recovery operation or other process that eliminates or sufficiently diminishes the threat posed to the environment by the original material. It remains a waste intended for disposal, regardless of whether it is used for abrasive blast cleaning before that disposal.

It is concluded, therefore, that transboundary movement of hazardous slags for abrasive blast cleaning is subject to control under the Act.