Agricultural chemicals

The use of chemicals is integral to agricultural production systems. Farm or rural chemicals cover agricultural chemicals or pesticides as well as veterinary medicines.

In 1986, it was estimated that $75 million worth of chemicals were sold annually in South Australia resulting in increased production in the order of $300 to $600 m. Moreover, chemicals provide employment to many people in rural areas, including retailers, sprayers, crop protection consultants, veterinarians etc.

The Department of Agriculture prepared a more detailed analysis of the role chemicals in South Australian agriculture in 1992: Agriculture and Veterinary Chemicals, 1992 (PDF 20.5 MB).

Chemicals were introduced into South Australian agriculture soon after the establishment of the colony. The Sheep scab mite Psoroptes communis ovis was detected in sheep from NSW and Tasmania in about 1840, and it was not until 1867 that it was totally eliminated.

Treatments favoured included a tobacco wash comprising 10 lb tobacco (a source of nicotine) boiled in 15 gallons of water; add ½ pint each of spirits of tar and spirits of turpentine per gallon of wash before use. Another option promoted was an ointment of equal parts of lard and mercury - to each lb add 3 lbs of lard, ¼ lb of flour of sulphur, ½ pint of spirits of turpentine well rubbed together and applied with the fingers to the sheep’s back (with little regard to the farmer’s safety). Arsenic was added to other mixtures.

There were strong controls over the movement of infected sheep, but little evidence of control over the assortment of chemicals in use. A butcher observed “it was better to kill for slaughter a slightly infected scabbing sheep than one recently cured with mercury, corrosive sublimate and a farrago of other poisons”. (Use of these mixtures has long since been discontinued.)

For more details, see Eradication Programs.

Fertilisers

In the 1880s Professors Custance and Lowrie at Roseworthy Agricultural College showed that the key plant nutrient missing from infertile soils after years of cropping was phosphorus. The general decline in yields at the time was halted when superphosphate was applied to the soil.

Although it took nearly 30 years before all cereal growers and high rainfall graziers were all using superphosphate, the importance of this as a chemical was recognised from 1894 with the passage of legislation to regulate the sale of agricultural fertilisers. The initial legislation required purchasers to be provided with an invoice stating whether the fertiliser was artificially compounded, and to provide specific details of the percentage of nitrogen, potash, phosphoric acid in soluble form and insoluble phosphoric acid. In effect, this was to represent a warranty for the product being sold.

A government analyst was available to undertake checking of products being traded. Within two years, there was further clarification that guano (from which superphosphate is manufactured) was covered by the legislation, but farmyard and stable manure or “crude night soil” and later “crude offal” and seaweed were not encompassed. Packaging requirements were defined. Invoices were required for any packages exceeding 1 cwt. Other fertilisers included basic slag, kainit (a potassium mineral also including magnesium, sodium and sulphur), bone meal and nitrate of soda.

Government Fertiliser Inspectors were introduced and “Local Fertiliser Inspectors” could be appointed by local government. The use of a “three sample system was required of inspectors (one for analysis, one left with the purveyor and one retained by the Inspector for comparative purposes if required). Analytical results could be published in the Journal of Agriculture.

New legislation in 1918 replaced earlier Fertiliser Acts, definitions being expressed in current chemical nomenclature. Manufacturers and importers were required to pay a licence fee of £2-2-0 for each and every fertiliser bearing a distinctive brand. They had to provide details of nitrogen, nitrates as nitrates, potash as total phosphate, water soluble phosphate and citrate soluble phosphate and acid soluble phosphate and lime with minimum calcium contact expressed as calcium oxide or expressed as calcium sulphate if gypsum. Invoices and packages were to be so marked.

Superphosphate for many years was purchased by farmers in jute bags weighing 187lb (85kg). Composition of water soluble, citrate soluble, acid soluble and total phosphorus was shown on the bag. Bags were lumped manually on the back, with sack trucks and in later years could be lifted with “G-Well” hoists which ran off a truck’s exhaust or small motor driven elevators. Bags had to be washed after use to prevent acidity breaking down the jute before returning the bags for refilling.

By 2020, fertilizers were largely industry regulated through a uniform national system whereby a National Code of Practice had been adopted to provide a clear and consistent description and labelling of fertiliser producers to manage food safety and environmental risks. Truth in labelling of the content of fertilizers is managed through the Code and supported in SA by the Agricultural and Veterinary Products (Control of Use) Act 2002 and Regulations 2004.

The Code of Practice was developed by the Fertilizer Working Group and Product Safety and Integrity Committee (PSIC) in 2012 to create a nationally consistent and harmonised approach to fertilizer regulation.

Insecticide and fungicides

Legislation was introduced in 1910 to regulate the use of insecticides and fungicides. The definition of fungicides included products to control parasitic plants and bacteria as well as fungi. Insecticides, as well as providing for the destruction of insects attacking plants, fruit or animals, also encompassed products for the control of vermin, notably rabbits.

Minimum and maximum standards for active ingredients could be set by proclamation in the Government Gazette. The usual provisions for inspectors and labelling were applied. It was found that while standards could be proclaimed for commonly accepted insecticides and fungicides such as arsenate of lead, Bordeaux mixture, lime sulphur and copper sulphate, there arose a trade in specialised named mixtures or potions for which no standards had been set. By the time this could be done, the dealers of such undefined products had disappeared.

Subsequently in 1919, the Insecticides Act was revised to make it similar to fertiliser legislation. It became the responsibility of the dealer to define the active ingredients in the product by labelling packages and invoices. Samples could be taken and analysed and the results could be published in newspapers as well as the Journal of Agriculture.

An important set of developments between 1915 and 1925 were introduction by Mr Alf Hannaford, originally from Riverton. These included seed “pickling” to provide protection of grain crops, primarily wheat, from fungal diseases, by controlling spores of smut and bunt on seeds before sowing.

Initially, equipment was sold to farmers allowing use of a wet pickling process with copper sulphate. By 1925, this was replaced by a dry pickling process initially using copper carbonate incorporating grading of the seed, but more modern fungicides are now used. Equipment for the pickling and grading process was mounted on trucks whose operators took them from farm to farm preparing seed before sowing.

Grasshoppers (Australian plague locusts, a native species Chortoicetes terminifera) had become specific insect problem in the 1930s. The Noxious Insects Act 1934 was introduced, with the primary purpose of giving local government responsibility for control programs.

A mixture of arsenite of soda, bran, molasses, and honey was initially distributed as baits, but the Waite Agricultural Research Institute’s assistance was invoked to pursue further research. It was recognised that collaboration between the states would be required and this subsequently led to the creation of the Australian Plague Locust Commission involving the Commonwealth, New South Wales, Victorian, Queensland and South Australian governments.

Awareness of agriculture chemicals

Increasing community concerns worldwide have driven significant changes to the way chemicals are regulated, used and disposed of. In many cases older and more dangerous chemicals were gradually withdrawn or restricted to certain uses.

In 1939, the Stock Medicines Act was established to regulate the sale of stock medicines with appropriate registration and packaging, giving details of the active principle and intended use, inspection and analytical provisions, overseen by a Stock Medicines Board. The act allowed registered veterinary surgeons to produce their own specific stock medicines outside the compass of the legislation.

The Agricultural Chemicals Act 1955 sought to bring together into a single piece of legislation the intent of earlier acts covering fertilisers, insecticides and fungicides and products used for vermin destruction. Previously, there had been no regulation over trace elements, plant hormones or weedkillers (herbicides), and these were also incorporated. Crop spraying was, by then, being widely adopted. Herbicides such as 2,4-D and 2,4,5-T used on broad-acre crops and strategic weed control programs but were highly volatile and could drift onto other crops such as grapes with deleterious consequences.

Some fertilisers were being applied as foliar sprays with doubts as to whether the older Fertiliser Acts would include them. As previously, certain “natural” products were excluded from the legislation, including farmyard manure, crude night soil, crude offal and seaweed. Truth in labelling was recognised and the use of meaningless chemical expressions was prohibited. During the 1970s, Dr Peter Kloot in the Department of Agriculture was undertaking herbicide tolerance trials to advise industry of the effectiveness of various formulations.

These two Acts were designed to allow companies to market their products once registered but had no provisions for controlling the subsequent use of registered chemicals.

Several other Acts administered by other departments had some provisions to cover transport of dangerous chemicals used in agriculture, licencing of aerial applicators, air pollution, environment contamination residues in food etc. On a national scale, there was innumerable pieces of legislation affecting farm chemicals from “cradle to grave”, i.e. from manufacturing to disposal or consumption as residues in foods or livestock feeds.  Prior to registration of chemicals for sale, assessment of safety and efficacy were done nationally through an administrative ‘clearance’ process. This was done from 1967 under the oversight of the Coordinating Committee on Agricultural Chemicals (CCAC).

Export contamination problem

In 1987, US authorities detected residues of organochlorine (OC) chemicals including DDT in beef exported from Australia, that were well above the legal Maximum Residue Limit (MRL) and threatened to close down a billion-dollar market overnight. DDT had been available to farmers from after World War II, during which it had been widely used by fighting forces for control of lice spreading typhus as well as for mosquito control to reduce malaria. It became available from pharmacies to control head lice in children.

The 1987 OC crisis exposed some major deficiencies in the way Australian State and Commonwealth governments had provided oversight in the management of chemicals and became a trigger for reforms over the next 10 to 15 years.

In response to the immediate threat of losing a major export market, the States and Commonwealth immediately banned all uses of OC chemicals except to control termites, and a national program was established to monitoring OC residues in meat. In South Australia, stock from about half of the 12,500 livestock properties were tested and cleared of risks of causing residues. In many cases, the residues in meat came from livestock grazing trash from pesticide treated crops as well as digesting contaminated soils from termite treatments around abandoned houses, sheds and power poles.

An associated national program was the recall and collection of old OC chemicals. In South Australia, this was done by the Department in association with local governments. This program was completed in 1989, and by which time, a total of 57 tonnes of chemicals had been collected.

To achieve a more proactive approach to the chemical debate, the South Australian Cabinet approved the agricultural and veterinary chemicals budget initiative in 1989. This resulted in internal departmental restructuring to establish the Farm Chemicals Branch under the leadership of the Registrar, Dr Mikael Hirsch, to:

• review and manage all relevant State and Commonwealth legislation
• improve internal information systems
• establish an educational program to address public concerns of chemical use.

A Ministerial Advisory Committee on Agricultural Chemicals was established in 1987 to provide a broader input and advice to the Minister and the Department from farming and horticultural industries, including organic farmers. This proved to be very useful, and the Advisory Committee worked closely with the department until 1993.

Other important industry links included the annual Plant Protection Conferences held since 1985 and the Horticultural Chemical Liaison Forum.

National Chemical Registration System

The OC crisis of 1987 heralded a period of significant legislative reforms. At the time, state-by-state legislation on farm chemicals was aimed at the approval and registration of labels on chemical containers offered for sale.

In November 1988 the Commonwealth enacted legislation to bring the clearance process under control of the new Australian Agricultural and Veterinary Chemicals Council (AAVCC), which was a high-level statutory committee with South Australia represented by Dr Barbara Wilson.

Concurrent with the introduction of the Commonwealth legislation, a Senate Select Committee was established in 1988 to review the existing administrative coordination as well as the wider economic, social and environmental impact of farm chemicals and their alternatives. The Committee reported in 1990, and it recognised that the improvement in legislation to establish the AAVCC and bring the clearance process under legislative control was a step forward. However, much more needed to be done to make the overall regulatory system more accountable and transparent to the public, in particular as there were consistent community concerns around continued use of OCs for termite control and aerial spraying.

As part of the “New Federalism” microeconomic reform agenda under the Hawke-Keating government, the Special Premier’s Conference in October that year focussed on identifying areas for harmonisation. The need for ongoing reforms of farm chemicals regulation was singled out as a priority area, and agricultural ministers were tasked to implement a national system for registration of farm chemicals, preferably within 12 months.

The legal and technical complexity was considerable, and the AAVCC established a national steering committee, chaired by Dr Barbara Wilson. It was to develop the new administrative framework in parallel with maintaining the existing coordination and registration systems. As a first step, the National Registration Authority for Agricultural and Veterinary Chemicals (NRA) was established as a Statutory Authority in December 1992. Two years later, the South Australian legislation was changed to embed the national AgVet Code to give effect to the new national registration system.

One of the first initiatives by the NRA was to remove the last remaining use of OCs for termite controls. The NRA was later renamed into the Agricultural Pesticides and Veterinary Medicines Authority (APVMA).

Control of agricultural chemical use

Early in the process of moving from a States-based registration system to developing the national chemical registration system, the States and Commonwealth agreed that the States should continue to exercise control over agricultural use. There were significant differences in approaches between the various jurisdictions.

The state-based registration systems were focussed on assessment of claims to control number of crop pests and weeds as stated on the approved label. The system assured that when chemicals were used in accordance with the label, including observance of the withholding period before harvest, the remaining chemical residues in the produce would be below the Maximum Residue Limit (MRL).

This was approved by the National Health and Medical Research Council (NH&MRC) and the food regulatory system. The NH&MRC dated from 1937, as the successor to the Australian Health Council established in 1926, comprised the Commonwealth and States Directors of Health.

Once chemicals were registered and allowed to be sold, they were also used in other situations against other pests and in other crops; so-called ‘off-label’ uses. In some States, off-label uses were considered illegal unless approved, but outside the chemical industry, there were no groups or organisation to take responsibility to seek such approval. Other States, including South Australia, had a more relaxed approach and considered off-label uses as a relative minor issue in the scheme of things.

Immediately following the beef crisis in 1987, the South Australian Agricultural Chemicals Act was amended to require ‘authorisation’ before certain agricultural chemicals were allowed to be used strictly in accordance with the registered label. The initial list of chemical uses requiring authorisation only covered the remaining uses of organochlorines, but the intent was to expand it to all uses of pesticides in agriculture.

However, the extent of off-label use in South Australia was not well documented, and as a first step, Peter Carr and Hadyn Hanna assembled a database of off-label uses that research and extension staff deemed necessary according to general practice.

The initial database had approximately 4700 entries of chemical uses beyond those stated on the label that would require authorisation under the South Australian Act. Many of those were in minor crops where the chemical industry had insufficient data on residues and efficacy to register label claims. These were often off-patent chemical products where the industry would have little incentive to recover costs of new residue trials.

The Farm Chemicals Branch worked closely with industry and departmental field staff to assess each entry on their residue status against the needs of producers, and some 3200 genuine off-label uses were confirmed, of which only 1000 were covered by MRLs. In 1989, the Department submitted 480 applications to the NH&MRC for setting MRLs for minor uses considered to be critical to producers. There was limited scope to fund new residue studies in minor crops, and it was therefore proposed to extend MRLs for similar use patterns in related crops.

The assessment by the Commonwealth progressed slowly as the development of the national registration system took priority. Developing a national approach to the associated minor use policy proved to be complex but ultimately the APVMA’s permit system to control use beyond registration was introduced in 1995.

The review of the South Australian legislation in regard to controlling use of chemicals in agriculture was finally completed by the Agricultural and Veterinary Chemicals (Control of Use) Act in 2002.

Progress on other farm chemical issues

During the period of developing and implementing the national registration system for farm chemicals there were other significant developments that affected the way chemicals were used in South Australian agriculture.

For many years, chemical spray drift had been the cause of conflict between producers and the public. For more detail, see separate article – Herbicide spray drift.

This was particularly in the urban/rural interface, but without legislative control over use, issues were often resolved by informal arbitration. In South Australia, 105 chemical complaints were investigated from 1978 to 1989, a major proportion of these complaints related to spray drift.

The need for better controls over aerial spraying was also brought to the attention of the 1988-90 Commonwealth Senate Select Committee, which called for better controls of aerial spraying, alternatively suggested if not sufficiently reformed, the practice should be banned or phased out.

The South Australian Department of Environment and Planning then considered amending the Clean Air Act to classify chemical aerosols as pollutants, but this could have significant impact on broad acre farming. Instead, it was agreed in 1991 to have a joint review of spray drift in South Australia by the two departments, managed by the Farm Chemicals Branch. Around 600 submissions were received indicating strong community interest to improve systems to deal with complaints, better regulatory oversight and training of spray operators.

Then followed a national review in 1992-93 by CCAC and chaired by South Australia recommending a national approach, which ultimately resulted in the National Code of Practice for Aerial Spraying as well as national guidelines for the management of spray drift that was published in 2002. The AVPMA subsequently assumed responsibility for spray drift and issued management principles in 2008, since upgraded. As a result of concerns about the impact of drifting chemicals on the natural environment, it has since terminated use approvals for some chemicals.

The Farm Chemicals Users Training Course was developed by the National Farmers Federation and the Rural Training Council in the early 1990s. It was initially a voluntary program, and a pilot course was conducted in 1992, and vigorously promoted throughout the State. Later in 1999, the training program became the basis for ChemCert, the industry-led training and accreditation program for primary producers.

The need for better access to chemical label information was recognised as an early priority as part of the Department’s Farm Chemicals initiative in 1989. At that stage, labels were only kept in hard copy format in extensive manual filing systems in the Department, but the Initiative included resources to computerise the label information.

This proved to be a technological challenge until the advent of the Internet and more widespread use of personal computers. As an interim, the Department established a resource centre and a telephone hotline to meet community expectations on better access to information around chemicals. Ultimately, the Department developed the InFINDer chemical database that provided online access to the registration status of chemicals, product label images and material safety data sheets.

The 1987 OC crisis had brought attention on the need for better training of chemical resellers as well as collection and disposal of unwanted chemicals and their containers. The national industry association of farm chemical manufacturers, National Association for Crop Protection and Animal Health (AVCARE, now Croplife Australia), took leadership and gained approval under the Trades Practices Act in 1994 to collect levies from chemical sales. This resulted in the accreditation system of resellers, as well as the drumMUSTER program in 1999 for the collection and destruction of unwanted pesticide containers and the ChemClear program to collect and dispose unwanted registered chemicals.

Implants of Hormonal Growth Promotants (HGPs) have been used in beef cattle since the 1970s to improve feed conversion efficiency. Repeated studies indicated that when used according to registered practice, the low dose would not pose a threat to human safety. Nevertheless, the European Commission banned the use in imported beef in 1989, resulting in the potential loss of a $100 m export market from Australia.

The Department introduced a system to segregate HGP-free beef cattle to Europe by requiring all producers to use pink tailtags and issue vendor declarations. The system proved sufficient to maintain the market, and the national program was further strengthened in 1984 by introducing audit and traceback provisions.

Mouse plagues had been a periodic problem for southern Australia, most notably at the time of World War I. For more detail, see:

• Weevil in wheat and storage of grain in bags (PDF 10.7 MB)
• Weevil in wheat photo (JPG 710.4 KB).

In July 1993, South Australia was seriously affected by a mouse plague. An estimated loss of production reached $36 m with the prospect of losing a further $60 m if no action were taken, but there were no registered chemicals available to combat the plague.

Even through the NRA was in place, South Australia had retained the right to take special measures in case of emergency, and the Cabinet subsequently approved a program for the importation and use of strychnine for use in bait. Eventually 300 t of bait was applied by licenced applicators. This was followed up by a program to monitor wildlife impacts as well as residue analysis to satisfy consumer safety.

2000-2020 AgVet Chemical Use

PIRSA’s role in the regulation of agricultural and veterinary chemicals saw the Rural Chemicals Operations team moved to the new Biosecurity SA Division of PIRSA in the early 2000s after a structural review and physically relocating to the Glenside offices in 2012.

The team of staff has reduced from just over 10 in 2000 to a core group of four Operational staff and one policy support staff in 2020 resulting in the need to streamline Agvet regulatory activities.

The focus of PIRSA’s Rural Chemicals Operations Unit has been to manage misuse incidents, respond to emergency incidents, provide education/extension on high priority issues and provide ongoing policy advice and reform where appropriate. This has seen a continued focus on being the lead SA government agency for:

• recording and managing chemical trespass incidents (particularly summer herbicide spray drift on grapevines)
• responding to National Residue Survey (NRS) residue detections to maintain key export and domestic markets (Grain, Livestock and Aquaculture)
• auditing and investigating vertebrate pesticide use incidents (1080 use and dog poisonings)
• responding to mouse plagues, locust plagues and other new biosecurity pest incursions requiring chemical control.

PIRSA continued to work closely with the APVMA on registration and permit issues, with a focus on education to industry for high-risk issues, such as spray drift. PIRSA moved away from direct responsibility for chemical use training, which moved to Registered Training Organisations.

Misuse of agricultural chemicals

Misuse of chemicals can still occur, and PIRSA has provision for reporting such incidents. Recording chemical misuse information helps understand the problem and informs policy and guidelines. Chemical misuse can include:

• chemical residue violations
• spray drift to other crops, native vegetation, waterways and populated areas
• off-target poisoning of animals
• contamination of native vegetation or waterways

Global trade, evolving community expectations and national consistency have continued to drive changes to chemical regulation policy in the 21^st century and are likely to continue to drive change to chemical use regulatory systems. Various combinations of State and Government regulator committees involving PIRSA have continued to progress, improving and harmonising chemical use regulations through forums such as Product Safety Integrity Committee (PSIC) and then the Harmonised Agvet Chemicals Control of Use Task Group (HACCUT).

The significant issues of record keeping and training, off-label use, veterinary control of use and produce monitoring (horticulture residues not monitored by the NRS) have continued to drive chemical regulatory change at the national level. Within SA, the drivers have continued to be off label use/access to:

• chemicals (particularly for minor crops and emerging industries like aquaculture)
• chemical residues (antibiotics, organochlorines, heavy metals and other chemicals in livestock and various insecticides and herbicides in grains)
• emergency pest incidents (locust plagues, mouse plagues, new insect and weed biosecurity pest incursions)
• off-target issues from spray drift (grapevine damage) and vertebrate pest products (off-target dog poisonings from 1080).

In the 2017–18 financial year, Australia's total market for agvet chemicals was about $4.09 billion in annual sales, with $3.03 billion from crop protection products and $1.06 billion from veterinary medicine products (APVMA 2019). Australia's market is small compared with its trade competitors (typically only 2 to 4% of the global market).

There is only a limited manufacturing industry in Australia for agvet chemicals and imports currently account for 59% of the Australian market for agricultural chemicals—up from 33% a decade ago (IBIS World Australia 2018). With the growth in imports, it is likely to result in Australia becoming largely a price-taker for the cost of agvet chemicals.

Since 2000, the number of registered crop protection products in Australia has risen by over 50% (3,091 versus 7,584); whereas growth in registered veterinary medicine products has remained steady, increasing from 3,144 to 3,223.

Farm survey data for 2017, estimates total Australian broadacre farm expenditure on agricultural chemicals at $1.8 billion. Annual farm expenditure on agricultural chemicals has increased by around 45% (in real terms) since the early 2000s and has risen faster than other farm costs. In 2017, expenditure on crop and pasture chemicals accounted for approximately 9% of non-capital on-farm costs for broadacre farms, up from around 6% in the early 2000s (ABARES 2020).

Australia's veterinary medicines industry is also of significant importance to Australia's livestock industries. ACIL Allen (2018) reported the industry contributed 9,900 FTE jobs and $2.7 billion to the Australian economy. Broadacre farm expenditure on veterinary medicines in 2017 was $438 million, however this figure can fluctuate significantly year to year due to changing livestock numbers. Veterinary medicine sales in Australia are dominated by parasiticides which account for 33% of livestock related sales value, followed by animal vaccines at 29%.

In September 2019, a comprehensive first principles review of the regulatory framework for agricultural and veterinary (agvet) chemicals was initiated. Such a review had not been conducted since Commonwealth agvet chemical oversight began in the mid 1990s. The review was being conducted by an independent panel of experts in regulation, agricultural production, veterinary medicines and public health.

The review was driven by the need for chemical use regulation to continue to evolve and manage changes. The new considerations for the current chemical use regulators and chemical use industry are now about technology around:

• labelling (electronic labelling)
• evolving application technology (remotely piloted aircraft systems (drones)
• access to new chemistry (acceptance of global registration data)
• changing social attitude on issue such as animal welfare and social licence (glyphosate and antimicrobial resistance).

Australia’s chemical use framework will continue to evolve to manage change, due to the economic significance of agvet chemicals and their critical role in agricultural production, human and animal safety, and environmental management. Chemical input costs have been rising faster than other farm input costs.

Australia needs an internationally competitive regulatory system enabling speedy and minimum-cost access to chemicals, whilst also meeting the community's expectations of protecting the environment and human and animal health and welfare.

Mikael Hirsch, John Radcliffe and Michael McManus
Prepared: November 2020