2.1 Until recently, Australia has maintained strict quarantine barriers against the importation of chicken meat and chicken meat products, permitting only canned products to enter. Currently, cooked meat from New Zealand is permitted, as that country's disease status is similar to that of Australia.

2.2 Since the mid 1980s, the governments of Thailand, Denmark and the United States of America have made a number of requests to import both fresh frozen and cooked products into Australia.

2.3 As a member of the World Trade Organisation (WTO) and signatory to international trading agreements intended to free up world trade, Australia is obliged to objectively assess such applications. Quarantine barriers to products can only be maintained if there is scientific justification for doing so.

2.4 The Australian Quarantine and Inspection Service (AQIS) is responsible for assessing applications to import products. It commenced its consideration of the proposal to import chicken meat in 1990 and issued a series of discussion and position papers in 1990, 1991 and 1994. As a result of comments made in response to the 1991 risk assessment discussion paper, AQIS decided to defer consideration of the applications to import uncooked chicken meat and finalise the assessment of cooked meat first.

2.5 This process culminated in a "in-principle" decision by AQIS, in mid-1995, to admit cooked chicken meat that had been processed in accordance with specified time and temperature parameters, the details of which were subject to final confirmation.

Responsibility for decisions

2.6 During the public hearings, the Committee recognised that there is an element of confusion in the community about the decision on cooked chicken meat, responsibility for the decision and Australia's obligations in this regard.

2.7 Under the Quarantine Act 1908, ultimate responsibility for quarantine decisions relating to the importation of cooked chicken meat and other food products rests with the Director of Quarantine; that is, the Secretary of the Department of Primary Industries and Energy or his delegate.

2.8 The Minister for Primary Industries and Energy does not have responsibility for individual decisions about whether a product should or should not be permitted to enter the country. However, the Minister is responsible for the administration and operation of the Quarantine Act and the conduct of his Department.

2.9 Mr Paul Hickey, Executive Director, AQIS, informed the Committee that in keeping with these responsibilities, AQIS has responsibility to advise the Minister of the processes that have been carried out during consideration of a request to import a product. Mr Hickey emphasised that:

...whilst they are decisions for AQIS, the point that has always been recognised, the fundamental point of government administration, is that the Minister has the authority to ask to be satisfied that the decision AQIS is going to take is consistent with Government policy and that there has been a proper process of consideration of all relevant issues in the lead up to that decision being taken.(1)

2.10 The Committee considers that the current method of finalising major quarantine decisions is unsatisfactory. The Minister and the Government are ultimately accountable to the electorate for decisions and their consequences. Further, the Committee considers that, in view of the probable impact of future quarantine decisions relating to imported food, such decisions require the implementation of a whole of government approach.

2.11 The Committee recommends that the Government amend the Quarantine Act and place final responsibility for quarantine decisions in the hands of the Minister and/or Government. The Committee recognises that Ministerial or Government decisions must be consistent with the provisions of the Agreement on the Application of Sanitary and Phytosanitary measures. Accordingly, the Minister and Government will inevitably need to rely on appropriate advice from the Director of Quarantine and the Minister for Foreign Affairs and Trade in this regard.

International obligations

2.12 When AQIS receives an application to import a product, it is obliged to assess the quarantine issues associated with importation of that product. Mr Hickey advised the Committee that these obligations arise from Commonwealth legislation and Australia's commitment to the Sanitary and Phytosanitary (SPS) agreement of the World Trade Organisation. These obligations are as follows:

Quarantine decisions must have a sound scientific and technical basis;
Quarantine decisions must flow from a proper process of risk assessment;
AQIS must adopt a consistent approach to risk management, that is, not arbitrarily adjust the acceptable level of risk from case to case;
access decisions must be designed to achieve the determined level of risk in the least trade restrictive way; and
the decision making process must be transparent and open.(2)

2.13 Mr Digby Gascoine, Director, Development and Evaluation Division, AQIS, explained how the standards imposed by the importing country must be consistent, based on sound science and minimise trade restrictions:

We are not allowed to treat the product of other countries more harshly than we treat our own. But where there are relevant international standards, we are entitled to apply more stringent measures, if we wish, subject to our ability to demonstrate, if we are challenged, that our more stringent standards are based on sound science risk assessment, a consistent approach to risk management, and that they reflect the least trade restrictive approach necessary to achieve our acceptable level of protection.(3)

2.14 Mr Hickey submitted that although the SPS agreement imposed formal obligations, the effect of the provisions are in Australia's interests:

...it is clearly in our interests, as a large net exporter of agricultural products, to apply the principles of openness, transparency and fairness.(4)

2.15 The Committee sought information from officers of the Department of Foreign Affairs and Trade (DFAT) about the provisions of the SPS agreement. Mr Iain Dickie, Director, Agricultural Trade Policy Section, advised that the SPS agreement is one of the agreements concluded at the GATT Uruguay round.

2.16 This agreement restricts WTO members, including Australia, in their use and application of quarantine measures. Mr Dickie confirmed that the SPS agreement reaffirms the right of all WTO members to apply such measures as they consider necessary to protect human, plant and animal health and life. However, these measures must be consistent with the terms of the agreement:

It is possible for countries to apply measures that are stricter than international standards if standards exist. If they choose to do so they must be prepared to justify them on a scientific basis. It is specifically included,I think it is in article 3 of the agreement,that you can apply measures that result in a higher level of protection provided there is a scientific justification. Part of that may be that you have carried out an import risk assessment which has concluded that this high level of protection is necessary.(5)

2.17 The provisions of the SPS agreement are binding. If the country that wishes to import a product into another country disagrees with the standards imposed by the destination country, the dispute may be referred to a dispute settlement. In the event that a review panel finds that the quarantine measures of the destination country cannot be justified, the treaty obligations require the country to import the product.(6)

Risk assessment of imported chicken meat

2.18 Consistent with its obligations, AQIS has conducted a lengthy risk assessment process. The Committee has previously examined quarantine issues including risk assessment in considerable detail. In its recent report on AQIS the Committee devoted several chapters to risk analysis and risk management, matters that are central to this inquiry. The relevant sections of that report, including a detailed description of the principles underlying risk assessment, are attached at Appendix 3.

2.19 AQIS's risk assessment of the importation of chicken meat commenced in 1990, when AQIS circulated a memorandum to the relevant Commonwealth and State Departments, the Australian Veterinary Association and industry. This memorandum notified AQIS's intention to conduct a full quarantine risk assessment and public consultation in accordance with Government policy and sought industry submissions on the proposal.

2.20 In April 1991, AQIS circulated a risk assessment discussion paper and again sought comments. This paper addressed the importation of both fresh frozen and cooked chicken meat and products.

2.21 Following comments made in response to the 1991 paper, AQIS decided to finalise the assessment of cooked meat first and deferred consideration of the "more complex" analysis of the proposal to import fresh frozen product until after it had finalised the cooked meat proposal.

2.22 AQIS's risk assessment of cooked chicken meat identified nine diseases of possible concern. It concluded that all but two of these diseases were of negligible quarantine significance. The two diseases considered to be significant were:

Newcastle disease (ND); and
Infectious bursal disease (IBD).

2.23 These diseases pose a threat both to Australian poultry producers and to the Australian native bird population. The Committee received advice that native birds in this country are "immunologically naive", that is, the bird population has no history of exposure and consequently, no natural immunity to disease. Consequently, they may be highly susceptible.

Newcastle disease (ND)

2.24 Newcastle disease is a highly contagious viral disease of poultry and other susceptible bird species. There are several strains of the virus ranging from relatively harmless varieties to highly virulent strains that produce mortality rates of up to 100 per cent.

2.25 The United States Department of Agriculture considers the most virulent form of the disease, viscerotropic velogenic Newcastle disease (VVND) to exist in all countries of the world except Australia, Canada, New Zealand, Denmark, Fiji, Finland, Great Britain (England, Scotland, Wales and the Isle of Man), Iceland, New Zealand, Northern Ireland, Norway, Republic of Ireland and Sweden.(7)

2.26 The Committee understands that this assessment may be somewhat out of date. A letter written by Dr Dennis Alexander to Mr Robert Baldwin, MP indicated that Denmark reported 14 outbreaks of ND 1995 and 2 in 1996, all in backyard flocks. Similarly, Canada reported infections in cormorants in 1992.(8)

2.27 A lentogenic strain (that is, a strain that produces mild, predominantly respiratory disease or subclinical infection)(9)of ND is widespread in Australia. However, Australia is free of the virulent strains and there has not been an outbreak since 1932.(10)

2.28 AQIS advised that VVND is present in Thailand and the United States. In Thailand, the disease is endemic and poultry flocks are routinely vaccinated. In the United States, poultry flocks remained free of VVND between 1972 and 1992, when there was an outbreak on a turkey farm. Poultry flocks are routinely vaccinated there also. AQIS advises that Denmark is currently free of the disease and vaccination of poultry is not permitted. However outbreaks have been reported in backyard flocks - see paragraph 2.27 above.(11)

2.29 Therefore, all three countries seeking to import cooked chicken meat into Australia have reported cases of ND in recent years.

2.30 A characteristic of ND is that vaccination can mask the presence of the virulent forms of the disease and otherwise healthy birds can be potential sources of infection. AQIS noted that vaccinated chickens exposed to the virus have been demonstrated to excrete the virus for up to four months.(12)

2.31 The virus can be spread readily. AQIS officers advised that the most common method of spreading the virus is by contact with infected birds. However, methods of spread may also include the following:

transport of clinically normal but virus shedding birds;
infected poultry products and by-products;
people wearing virus contaminated clothing or footwear;
equipment;
litter;
manure; and
feed containing uncooked poultry offal meal.(13)

2.32 The disease can be transmitted by wild birds if infected. Some species, particularly parrots, ducks and geese can become carriers for a long periods. Rats and flies have also been implicated as carriers. The disease may also be spread by wind.(14)

Infectious Bursal Disease

2.33 Infectious bursal disease (IBD), like ND, is also caused by a virus and is highly contagious. The disease does not produce the same high mortality rates as ND, causing losses of between zero and thirty per cent. Affected birds may die either from the clinical effects of the disease or from suppression of the immune system which also has a greater longer term economic impact.(15)

2.34 There are many strains of the disease, including a relatively mild strain found in all Australian States. The strain found in this country does not cause clinical disease, although researchers have observed bursal(16)damage and depression of the immune system. Highly virulent strains found in other countries have not been observed here.(17)

2.35 The virus is regarded as resistant to both heat and disinfectant. It is spread by contact between birds, mechanically, for example on boots, clothing, vehicles or packagings and in contaminated water and feed. AQIS's risk assessment paper notes that cross contamination of carcasses during processing is possible and expresses concern that contaminated carcases may act as vehicles for spreading the virus.(18)

2.36 AQIS advised that highly virulent strains of IBD are endemic in Thailand and the United States. Poultry is routinely vaccinated with live vaccines in both countries. In Denmark, IDB is endemic but like Australia, there have been no reports of the highly virulent strains. Vaccination is widely practiced in both Australia and Denmark against this disease.(19)

Heat treatment of chicken meat

2.37 In its 1991 paper, AQIS examined heat treatment as a method for inactivating viruses of concern and identified a range of studies on ND, IBD and other diseases.

2.38 While it considered a range of studies, AQIS adopted a 1988 study of IBD conducted by a scientist in the United Kingdom, Dr Dennis Alexander, as "the basis for the determination of definitive time/temperature parameters for the inactivation of the virus in cooked chicken meat"(20). Alexander's study was also extensively quoted in the position paper published in 1994.

Alexander's study of inactivation of Infectious Bursal Disease virus

2.39 Dr Alexander's study of IBD virus was commissioned by General Foods Poultry, New Zealand. In his experiment, Alexander extracted the bursa of fabricius, a lymphoid organ in birds, from chickens that had been infected with IBD. High concentrations of virus are present in this organ in infected chickens. The bursae were homogenised then heated in a water bath at 70C, 75C and 80C for times ranging from 1 to 60 minutes.

2.40 Alexander then inoculated susceptible chickens with prepared solutions of the resulting samples. These birds were subsequently killed and tested to see if they had become infected. Using these results, Alexander determined the probability that IBD virus would remain infective after heating. He published results for heat treatment at 70C and 80C.

2.41 For samples heated at 70C , Alexander calculated that the probability that a sample remained infective was 1 in 10 after heating for 50 minutes and 1 in 1000 at 90 minutes.

2.42 For samples heated at 80C, Alexander calculated that the probability that a sample remained infective was 1 in 10 after heating for 8.8 minutes and 1 in 1000 at 14.4 minutes.(21)

Bureau of Resource Sciences' review of thermal heat treatment of chicken meat

2.43 AQIS commissioned the Bureau of Resource Sciences (BRS) to advise on the thermal heat treatment of chicken meat. The terms of reference for the BRS review were as follows:

1. Review published data on the heat stability of various strains of IBD and its thermal stability in chicken meat as distinct from culture broth;

2. Review published data on virus levels in chicken meat resulting from natural infection of chickens with the IBD virus;

3. Review published data on the infective oral dose of IBD in susceptible birds; and

4. Advise whether sufficient information is available to determine a thermal processing standard to remove any quarantine risk associated with importation of chicken meat and, if so, the thermal process that is appropriate.(22)

2.44 The BRS report noted that the literature contains little of the direct information sought by AQIS concluded that:

There is no evidence that IBD strains vary significantly with regard to thermostability;
The literature does not contain any data on the thermal stability of IBD virus in chicken meat as distinct from other suspension or dilution media. The buffering components in skeletal muscle cells would protect virus during heating, and virus would be more thermostable in chicken meat than in low protein, unbuffered solutions;
The literature does not contain any quantitative data on the infective oral dose of IBD virus for susceptible birds. This would be expected to be low, and chicken meat, at peak periods of viraemia, could be expected to be infectious if fed to chickens;
The decimal reduction times of IBD virus (D values) obtained by Alexander (1988) could be accepted as representative of the thermoinactivation of field strains of IBD virus in contaminated chicken meat at 70C and 80C. D values at other temperatures, using realistic IBD virus suspensions, will need to be obtained if other processing temperatures are contemplated; and
The time/temperature standards suggested in the AQIS discussion paper, 70C for 90 minutes or 80C for 14.4 minutes, should be adequate to remove any IBD quarantine risk with imported chicken meat.(23)

Application of IBD data to Newcastle disease virus

2.45 Dr Sarah Khan, Assistant Director, Animal Quarantine Policy Branch, AQIS advised the Committee that IBD is recognised as a very heat resistant virus and that a heat treatment sufficient to inactivate this virus would also inactivate ND virus, which is considerably more susceptible to heat treatment than IBD. She explained:

We looked at infectious bursal disease virus and tried to identify a treatment that would be adequate, even for that very heat resistant virus. We had confidence that that virus would be inactivated by the cooking and we had a many times higher degree of confidence in relation to Newcastle disease virus, because that is a much less resistant virus. So if you like we had a much higher level of confidence again that Newcastle disease virus would not survive the cooking.(24)

AQIS's conclusion on heat inactivation

2.46 In its 1994 position paper, AQIS recommended that importation of cooked chicken meat processed in accordance with specified time and temperature requirements proceed, subject to prescribed quarantine conditions.

2.47 AQIS recommended that the chicken meat should be cooked at specified minimum core temperatures. The cooking temperature chosen determines the length of the cooking process. AQIS's specified time/temperature protocol is listed in the draft protocol and at paragraph 2.51 of this chapter.

2.48 This recommendation was followed, in mid-1995, by a formal decision to admit cooked chicken meat that met the specified time and temperature parameters. Mr Hickey emphasised that this decision related to "the scientific and technical view that the time and temperature parameters would be sufficient to inactivate the viruses of concern".

2.49 He explained that a final set of conditions before importation could occur remained to be resolved. The conditions requiring resolution are that AQIS could reasonably be satisfied that:

the time and temperature parameters were applied;
there was no processing contamination; and
human health issues were addressed.(26)

Importation protocol

2.50 On 7 June 1996, AQIS published a draft protocol that sets out the conditions under which cooked chicken meat may be imported. AQIS set a deadline of 28 June 1996 for comments on the draft protocol.

2.51 The draft protocol sets out detailed requirements that must be observed for the importation of cooked chicken meat to proceed. These are as follows:

Each consignment must be accompanied by certification endorsed by an official veterinarian in accordance with the current "Quarantine requirements for the importation of cooked chicken meat" and will require on arrival a "Quarantine entry";
Only de-boned cooked chicken meat is permitted for importation;
the chickens from which the cooked meat or meat products are produced must originate from the country of export;
The chickens must be slaughtered and the meat processed in establishments currently approved by the Director of Quarantine. The standard of construction and facilities of slaughter and processing establishments should be equivalent to standards that apply to comparable establishments in Australia. Product should be processed and handled in a hygienic manner and in accordance with good manufacturing practices as applied in Australia. AQIS may take into account existing approvals granted by competent veterinary authorities of foreign countries.
Officials of the veterinary authority of the country of export must be present in plants at all times when slaughtering chickens and processing cooked chicken meat for export to Australia;
Chicken meat must be processed and stored separately from other meat products;
Processing equipment shall be equipped with an AQIS approved system for recording time and temperature of cooking. Time and temperature records of processing for all consignments for export to Australia shall be maintained and made available to AQIS on request;
While preparing product for Australia, establishments must conduct slaughter and processing operations in accordance with quality assurance principles such as the HACCP approach;
Any ingredient of animal or plant origin present in the product for export to Australia must comply with AQIS quarantine and other requirements.

2.52 The draft protocol also requires imported chicken meat to comply with the Imported Food Control Act 1992 and the Australian Food Standards Code under the National Food Authority Act 1991.

2.53 This legislation enables AQIS to inspect, sample, hold and test imported chicken meat for microbial agents or residues of public health concern. The legislation also requires importers to comply with labelling, packaging and food composition standards.

2.54 The draft protocol also specifies in detail the certification requirements that AQIS requires the official veterinarian of the exporting country to provide with each consignment of cooked chicken meat. This certification is in relation to satisfaction of the requirements described in the preceding paragraphs. The Official veterinarian must certify that:

the cooked chicken meat /meat product was de-boned and derived from chickens originating in the country of export and which passed ante-mortem and post mortem inspection under official veterinary supervision;
establishment(s) where the chickens were slaughtered and the meat was processed and stored meet AQIS requirements for facilities and hygienic operation;
the chicken meat/meat product was heated at one of the following minimum core temperatures for the corresponding period of time:

70C for 95 minutes or

72C for 65 minutes or

74C for 44 minutes or

76C for 30 minutes or

78C for 21 minutes or

80C for 15 minutes.

The temperature/time parameter used must be specified.

the temperature recording equipment was checked during manufacture and was found to be in good order. Records confirm that the time/temperature parameters specified were achieved;
the cooked chicken meat complies with relevant national standards of the exporting country for control of residues and microbial agents of public health concern in food;
The cooked chicken/meat product was processed and stored separately from all other products;
Date of processing and packaging
The cooked chicken/meat product was packed in clean, new packaging in a manner which prevented contamination;
The identification number(s) of the processing and packing establishments must be readily visible on the package or wrapping containing the cooked chicken/meat product in such a way that the numbers cannot be readily removed without damaging package or wrapping;
the cooked chicken meat is to be shipped in a clean container, the seals of which are intact at the time of export and the identifying number(s) are in accordance with the import permit. This container does not contain any meat which is not eligible for export to Australia.

2.55 The final section of the draft import protocol specifies the procedures that AQIS will use to verify that the exporting country has satisfied the requirements specified in the protocol. The protocol specifies that AQIS will maintain appropriate systems to verify these requirements have been met on an ongoing basis. Elements of this system will include:

An authorised quarantine officer will conduct a visual inspection of the product and documentation on arrival in Australia;
Inspection and detention of consignments and sampling/analysis of samples may be performed under the Imported Food Inspection Program (IFIP);
At the discretion of the Director (of Quarantine), premises producing cooked chicken meat/meat product for export to Australia may be inspected/audited as to all aspects of compliance with these requirements.(27)

Technical working group

2.56 On 5 June 1996, the Minister for Primary Industries and Energy met with representatives of the chicken industry and established two joint working groups. The technical working group, which is comprised of representatives of AQIS and industry is intended to resolve proposed conditions under which importation should proceed.

2.57 Dr Sarah Kahn advised that the purpose of the consultations within the technical working group is to determine the details of the conditions or protocol to be applied to cooked chicken imports. Dr Kahn noted the issues under consideration by the working group include the detail of what would appear on the health certificate and the types of systems that should be in place in the processing plants in the exporting country. She explained that work was proceeding on the details of the conditions foreshadowed in AQIS's 1994 position paper:

...we are now working out the finer detail of how we would expect to see those systems applied in practice, how AQIS would carry out inspections and have verification processes, and how we would satisfy ourselves for each consignment of cooked meat coming into Australia that the required time temperature and other conditions have been met.(28)

2.58 Mr Hickey advised the Committee that the working group met on 24 June. The group held a further meeting on 29 August.(29)The Committee has not been advised of the outcome of these meetings.

Reaction to AQIS's risk assessment

2.59 Industry and other organisations including the State Veterinary authorities registered a range of concerns about the importation proposal following the release of the 1991 discussion paper. Many respondents opposed the proposal to import uncooked meat on quarantine grounds, although several expressed qualified support for the entry of cooked products. AQIS tabulated the responses to this paper in its 1994 position paper.

2.60 AQIS acknowledged that there is no final agreement concerning some risk management aspects of the importation protocol. However, AQIS maintained that there is now widespread agreement concerning the technical aspects of the protocol. Dr Kahn advised the Committee that:

...there is very broad agreement in the scientific community and even on the part of industry that the fundamental scientific work underpinning this quarantine protocol is agreed.(30)

2.61 Representatives of the Australian poultry industry confirmed that the industry had not substantially challenged AQIS's conclusions about the temperaturetime combinations necessary to inactivate viruses of concern in the product. However, they emphasised that the industry nonetheless questioned some of the scientific assumptions made. Industry representatives also expressed substantial concerns about whether the risk management protocols that AQIS had proposed will in practice provide an adequate level of protection from disease.

2.62 Mr Timothy Luckhurst, Executive Officer, Australian Chicken Growers Council, outlined the scope of the industry's concerns. He told the Committee that AQIS had restricted its risk assessment to the "strict biological science" of using heat treatment to inactivate viruses of concern. He argued that this approach underestimated the risks associated with using commercial cooking processes to achieve quarantine objectives.

2.63 Mr Luckhurst contended that AQIS had not made any objective or scientific assessment about the overall risks associated with importing cooked chicken meat:

We would maintain that no risk assessment has been conducted on the totality of the processes involved. That is, not just the cooking parameters, but also the protocols and procedures required to ensure that all batches and all parts of all batches receive the required thermo inactivation, and that no subsequent recontamination occurs.

The assumption is made that the protocols, when these have been finally determined,and that has not even yet occurred,will be adequate. Surely, that is risk assumption rather than risk assessment.(31)

Scope of the Committee's inquiries

2.64 During the course of the inquiry, the Committee asked officers from AQIS and other agencies to elaborate on a number of issues that the Committee considered relevant to its examination of AQIS's assessment of and response to the requests to import cooked chicken meat. The agencies from whom the Committee sought information included:

Australian Quarantine and Inspection Service;
Departments of Primary Industries and Energy;
Department of Foreign Affairs and Trade;
Australia New Zealand Food Authority; and
Australian Nature Conservation Agency.

2.65 Quarantine issues examined by the Committee fall into the following broad categories and are examined in turn in the following chapters:

Scientific basis for the protocol;
Application of the protocol;
Food safety and use of chemicals in poultry production; and
Potential impact of avian disease on Australian native birds.

Chapter 3

Endnotes

Evidence, 30th September 1996, p. 249.
Evidence, 28th August 1996, p. 4.
Evidence, 28th August 1996, p. 35.
Evidence, 28th August 1996, p. 4.
Evidence, 28th August 1996, p. 80.
Evidence, 28th August 1996, p. 87; see also Chapter 7..
AQIS position paper, "The importation of fresh frozen and cooked chicken meat and products from USA, Denmark, Thailand and New Zealand", 1994, Appendix F.
Evidence, 13th September 1996, pp 170-173.
AUSVETPLAN Edition 2.0, 1996, p. 3.
Ibid, p. 2.
AQIS position paper, op. cit., pp 3-4.
Ibid, p. 5.
AUSVETPLAN, op. cit, p. 11.
Ibid, p. 11.
AQIS position paper, op. cit., p. 11.
Bursa of fabricius - "a lymphoid organ in birds having a similar role in immunity to that of the thymus in mammals", Blacks Veterinary Dictionary, 14th edition.
AQIS position paper, op.cit., p. 16.
Ibid, p. 11.
Ibid, p. 15.
Ibid, p. 22.
Ibid, Appendix J
G. Gard, Advice on thermal treatment of cooked chicken meat: A report for the Australian Quarantine and Inspection Service, Animal and Plant Health Branch, Bureau of Resource Sciences, January 1994.
Ibid, p. 14.
Rural and Regional Affairs and Transport Legislation Committee, Inquiry into AQIS, Evidence, 17th November 1995, p. 2050.
Evidence, 28th August 1996, p. 13.
Evidence, 28th August 1996, p. 4.
Evidence, 28th August 1996, pp 40 - 49.
Evidence, 28th August 1996, p. 14.
Evidence, 28th August 1996, p. 5.
Evidence, 28th August 1996, p. 21.
Evidence, 13 September 1996, p. 122.