TGA participates in international workshare agreement

One of the most significant problems facing the chemical industry is the burgeoning cost of developing, registering and marketing pesticide products. During the past decade, the OECD has worked at increasing international harmonisation of pesticide registration, so as to reduce the complexity, duplication, time and cost involved. This has covered most aspects of registration, including data requirements and test guidelines, format of registration submissions, and government agency data assessment.

Last year, TGA participated in a groundbreaking international workshare agreement on assessment of a new herbicide, whose manufacturer was seeking simultaneous registration in Australia, the USA, Canada and the EU. Possibly seeing it as a perfect opportunity to test the effectiveness of the recent OECD "Guidance notes for Analysis and Evaluation of Repeat-dose Toxicity Studies", the company contacted the Chemicals Review and International Harmonisation Section of the Chemicals and Non-prescription Drugs Branch and proposed that the work be divided among the responsible agencies of the four nations. CRIH referred the inquiry to Australia's National Registration Authority for Agricultural and Veterinary Chemicals. Similar approaches were made to the US EPA, Health Canada, and the Pesticide Control Service of Ireland, the rapporteur member state for the EU. Australia's participation was jointly agreed by the NRA and TGA.

The work was allocated as follows: Australia - shortterm, subchronic and chronic mouse studies; USA - genotoxicity studies; Canada - short-term, subchronic and chronic rat studies; and EU - acute and reproductive toxicity studies. The balance of the data set was not workshared but evaluated independently by all agencies. Shortly after the application was lodged with the NRA, the toxicity data package was referred to the Chemical Products Assessment Section for assessment. Following internal peer review, Australia's assessment of the mouse studies was transmitted to the other agencies via the Internet. Overseas contributions were received the same way, peer reviewed, modified to suit CPAS's assessment format and incorporated electronically into the TGA evaluation report, completed in mid-December, 1997. This is a notable achievement considering that the submission had been lodged with the NRA only 7 months earlier.

Agencies and industry discussed the workshare at the Joint OECD/EU Workshop on Harmonisation of Dossiers and Monographs, held in Dublin in September, 1997. All parties expressed strong support. Australia's evaluation was judged to be at international benchmark level, and sufficiently comprehensive for use by Canada and the US. Canada estimated that worksharing might yield efficiencies of up to 80%, compared with undertaking the entire effort in house. Australia was favourably impressed with the contributions from Canada and the USA. However, the EU conceded that other participants were using a more advanced level of reporting and that it would have to achieve the OECD standard in future.

Several benefits for Australia arise from this exercise. First, TGA has enhanced its international reputation for performing toxicological assessments of pesticides to a high standard and within a limited timeframe. This is of crucial importance, for unless Australia can make an equivalent contribution, it cannot expect to gain from assessment exchanges or to influence their development or use. Second, TGA now has a better understanding of the working methods used by overseas agencies to make regulatory decisions. Experience gained in this limited "ad hoc" workshare will greatly assist in the organisation of future projects and may increase the efficiency of risk assessment processes in Australia and other nations.

The following TGA personnel participated in the project:

• Brian Priestly (Scientific Director, CNPDB)
• Gladwin Roberts (Head, CPAS-peer review of assessments)
• Mark Jenner (Principal Toxicologist, CPAS-data assessment)
• Les Davies (Head, CRIH-coordination with NRA and overseas agencies)
• Drew Wagner (Principal Toxicologist, CRIH-delegate to OECD Workshop)

At the NRA:

• Greg Hooper (Executive Manager, Policy & Public Affairs)
• Jeanine Crowther (International & Development Projects) and
• Julie Taylor (Agricultural Chemicals Evaluation).

The Chemicals Unit

The Chemicals Unit has been a part of the Chemicals and Non-Prescription Drugs Branch since mid 1996. It currently comprises two Sections, the Chemical Products Assessment Section (CPAS) and the Chemical Review and International Harmonisation Section (CRIHS). The unit was established in 1992 to ensure expert consideration of potential human health effects arising from the use of a variety of chemical types and environmental contaminants.

The major activity of the Unit is to determine the public health implications of the use of agricultural and veterinary chemicals. Both new and existing chemicals and products are reviewed under different programs of the Agricultural and Veterinary Chemicals Code Act (1994). The CPAS is responsible for the assessment of new chemicals and formulated products containing them whilst the CRIHS is responsible for the review of older chemicals under Australia's Existing Chemicals Review Program. The tasks are accomplished through the evaluation of toxicological data and hazard identification, followed by the establishment of a number of public health standards which serve to minimise the risk to users of the product and the public.

The public health standards established for agricultural and veterinary chemicals are as follows

• Acceptable Daily Intakes (ADI)
• Poisons Schedule Classification (which is the responsibility of the NDPSC)
• First Aid Instructions (FAI)
• Safety Directions (SD)
• Warning Statements (WS)

These public health standards, published in various documents, are recommended to the National Registration Authority for Agricultural and Veterinary Chemicals (NRA) and they form an important component of its decisions on product registration. Future articles in the TGA News will expand on the mechanisms for establishing these standards.

The Chemicals Unit plays a leading role in forums aimed at harmonisation of assessment methodology and report formats. Unit officers contribute to a number of international organisations such as the OECD Pesticide Forum, and serve as expert advisers on several international committees and work groups involved in chemicals assessment activities such as those conducted under the auspices of the International Programme on Chemical Safety.

The unit is a major focus for regulatory toxicology in Australia and has input into national and international policies for the management of chemical risks. Further, it participates in a number of activities to promote the science of toxicology and puts scientific issues before the public. Over half the unit staff are scientific professionals such as toxicologists, pharmacologists, veterinarians, biochemists, geneticists, chemists, pharmacists and regulatory/registration scientists.

Relevant documents

ADI List. Acceptable Daily Intakes for Agricultural and Veterinary Chemicals. TGA (1997). Australian Government Publishing Service, Canberra. Available from AGPS.

Standard for the Uniform Scheduling of Drugs and Poisons <http://www.tga.gov.au/ndpsc/susdp.htm> (SUSDP). AHMAC (1997). Australian Government Publishing Service, Canberra. Available from AGPS.

Handbook of First Aid Instructions and Safety Directions for Agricultural and Veterinary Chemicals. TGA(1996). Australian Government Publishing Service, Canberra. Available from AGPS.