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CHAPTER 1 - INTRODUCTION

1.1 Historical background

The first report entitled “Adjuvants and Additives in Crop protection” (DS183) was published by AGROW Reports in 2000. This report was updated in 2003 by a second report (DS235). Since these reports were published, the pace of change in the international agrochemical industry has been accelerating rapidly, and the whole industry has been subject to numerous changes. The effect of these changes and challenges, and their impact on the technology for pesticide formulations, additives and adjuvants, is described in this current update.

One notable result of the changes that have occurred over the last few years has been the consolidation of the global agrochemical business by major international agrochemical companies through mergers and acquisitions. For example, in the 1990’s, there were 12 major agrochemical companies, with generic agrochemical producers and formulators beginning to take a hold of the market. By the time of the millennium in 2000, the number of majors had reduced to eight with an increase in the importance of generic producers and formulators. At the present time in 2006 there are only six major international companies remaining, the so-called “Big 6”, and generic producers are now much more important to the business as a whole.

The “Big 6” companies are carrying out the bulk of the research aimed at discovering new compounds involving chemical synthesis, biological, toxicological and environmental testing. Of the “Big 6” companies only Syngenta continues to do significant research in the UK, while its Headquarters are in Switzerland. The other two European companies, Bayer CropScience and BASF are based in Germany. The remaining three companies, Du Pont, Monsanto and Dow AgroSciences are based in the US. Some other agrochemical companies, along with a few Japanese companies are still doing research to discover new agrochemicals, but in terms of global annual sales these companies are now in a so-called “Second Division”. There is an increasing presence of Asian companies, notably from China and India, producing generic pesticides and formulations. However, a small number of organizations, especially in China, are beginning to do their own discovery research work. The status of all these companies worldwide is discussed fully in later chapters in this report.

The total sales of the global agrochemical business increased annually to a peak of about US$ 32 billion in 1998, and contracted to a value of about US$ 27 billion in 2003, although it recovered to about US$ 33.6 billion in 2005. Forecasts indicate that it will decline again from 2006 onwards. Why have these drastic changes come about in a relatively short time? Many factors have been involved in the consolidation and rationalization of the agrochemical industry, and the most important of these key factors are listed below.

• The agrochemical industry has been developing since the 1950s and has now reached maturity.
• The major players have become very competitive and must maximise their efficiency.
• Regulatory demands for safer and more environmentally friendly pesticide products have made the cost of discovering and registering new pesticide compounds very expensive. This has led to an upsurge in Merger and Acquisition activity among the major companies.
• Many of the leading pesticide active ingredients have come off patent during the 1990’s giving opportunities for generic companies to enter the market with reduced product prices, especially for the world’s biggest single product, glyphosate. In the next few years a number of other important pesticides will come off patent.
• Developing countries in east Europe, South America and Asia have become more self-sufficient and have improved the quality of their pesticide products. This applies particularly to China and India.
• Consumer pressure has forced agricultural food commodity prices downwards, leading to low farm incomes, especially in Europe and North America.
• The rapid development of biotechnology and the introduction of genetically modified crops over the last few years have led to a reduction in herbicide and insecticide usage, notably in North America. This technology is forecasted to become much more important over the next decade.

The last 20 years or so have seen rapid development in pesticide technology, particularly in the discovery of new active ingredients with reduced application rates, low toxicity and with minimum environmental impact. At the same time, there has been a big increase in the number of formulation types to give different technical effects and to satisfy market and regulatory requirements. Much of the development of new formulation technology has been driven by the availability of new technology, equipment and scientific understanding which allows previously impossible or difficult formulations to be prepared and stabilised as finished products. Equipment has been introduced to produce very small particles or droplets of pesticides for suspension or emulsion formulations. Various processing techniques have been developed for producing granular products which will disperse in water before use. Encapsulation methods have been devised to control the rate of release of pesticides at the target site.

A great deal of work has been done on understanding the role of surfactants, adjuvants and other formulation additives in the development of improved formulations, especially in terms of dispersion and emulsion stability, long-term shelf life, dispersibility of granules into water, and biological availability. Fundamental research in colloid and surface chemistry has led to a better understanding of the various properties and functions of surfactants in pesticide formulations and, indeed, it is possible to “tailor-make” surfactants for different functions in formulations. The rheology and flow properties of liquids can now be measured accurately so that problems of particle separation and sedimentation on storage can be overcome. Improved anti-settling polymeric systems have also been essential in providing good long-term storage stability. Many new formulation additives and adjuvants have been developed to meet the requirements of companies and regulators for safer products to the user and to the environment. Pesticides can now be designed to be target specific at low dose rates, and with low toxicity to mammals and other non-target species.

Formulation and adjuvant technologies are now seen as “enabling technologies” which can provide safe and effective products which are convenient to use. They can also modify the toxicity of active ingredients and improve their ability to target a specific pest. Formulation is seen as an essential part of the total “delivery” system, which can also include the packaging and application equipment. At a time when the discovery of new pesticide compounds is more difficult and certainly a high risk and expensive operation, formulation and adjuvant technology can extend the useful patent life of an active ingredient. It can also provide a competitive edge by improving product quality of existing formulations, by introducing a new formulation of an existing active ingredient, and by enhancing the activity of formulations. Adjuvants can be added to the formulation in some cases, or added as tank mix adjuvants to improve biological activity by after spray application.

1.2 Scope of report

The Pesticide Manual (BCPC 13th Edition, 2003/04) describes about 800 different active ingredients, of which about 300 are of major commercial importance. There are about 80 known formulation types, of which about 20 are commercially significant. Some of these formulations may contain as many as 10-12 different formulation additives. The Pesticide Manual lists some 2,000 formulated products, most of them containing a single active ingredient. These days it is becoming popular to produce mixed formulations containing two or more active ingredients in order to achieve a broad spectrum of activity or to overcome pest resistance problems.

The main objectives of formulation technology are listed below.

• Optimise biological activity
• Improve handling and application
• Maximise long-term stability
• Modify persistence on target
• Safety in manufacture and use
• Convenience for user
• Reduce dose of active ingredient applied
• Reduce waste and effluent of all kinds
• Extend patent life of active ingredient
• Provide a competitive edge for products

The main factors governing the choice of formulation type are shown below:

• Physico-chemical properties of active ingredient
• Mode of action of active ingredient
• Method of application of product
• Toxicity and environmental considerations
• Registration requirements of individual authorities
• Economic considerations of individual companies
• Competitive situation in agrochemical market

This report includes reviews of all the major formulation types, additives and adjuvants for formulations and tank mixes, and regulation requirements by government organizations.

Reviews are included on dispersing and emulsifying agents and surfactant and oil-based adjuvants, some of which can be tailor-made to improve the long-term stability of formulations, as well as to enhance the biological activity of the active ingredients. The additives and adjuvants themselves must have low toxicity and environmental impact, and the end result can often be a reduction in the dose rate of active ingredient per hectare.

Likely future trends in all of the areas of formulation, additives, adjuvants and regulation are discussed with a view to producing low-risk products for the sustainable development of crop protection and public health throughout the world. Moves towards international product quality and regulatory harmonization are also covered.

The report includes views and comments from three experts in adjuvant technology who are also Executive Committee Members of the ISAA (International Symposium on Adjuvants for Agrochemicals).

Pesticide global markets and company profiles of major additive and adjuvant suppliers have been surveyed.

The cost of the successful development of new products is becoming increasingly high and it is estimated that it can cost more than US$150 million to develop one new active ingredient with a development timescale of up to ten years from initial discovery to first registered commercial sales of the product. This has caused the industry to consolidate through mergers or form research joint ventures between companies. The long development timescale significantly reduces the available patent life for commercialization of new products and allows generic manufacturers to produce off-patent products without the high cost of the R&D effort in the discovery of new molecules.

Major companies tend to concentrate their R&D on the important world crops and pests. Patenting of new active ingredients, formulations and adjuvants is essential to protect intellectual property rights in commercial markets where patents are protected.

The Pesticide Manual shows that many different types of formulations have been developed depending largely on the physicochemical properties of the active ingredients. The early conventional formulations were simple solutions in water, emulsifiable concentrates in a non-aqueous solvent or dusts and wettable powders. The current trends are to replace petroleum-based solvents as much as possible with water to give water-based suspensions and emulsion formulations. There is also a move away from dusty powders towards water-dispersible granules, which are free flowing and essentially dust-free.

Controlled-release formulations are being developed to improve safe handing of some toxic active ingredients, or to extend the persistence of activity on the crop. Seed treatments are a special case, which enable better control and placement of the active ingredient. Flowable seed treatment formulations can be supplied in bulk containers, and are safe to the operator and less wasteful of the pesticide product because they are applied directly to the seed. They, therefore, have the potential to reduce significantly the total environmental impact. Other types of formulations are now becoming available such as microemulsions (ME) and gels for special markets. For a complete listing of pesticide formulation codes, visit the CropLife International website www.croplife.org

1.3 Formulation additives and adjuvants

The wide variety of agrochemical formulations available requires a range of different formulation additives to produce safe and usable products. Probably the most important of the formulation additives are surface active agents (surfactants). Synthetic surfactants, which have been specially synthesised in order to obtain surface-active effects, represent a relatively modern development with the introduction of amphiphilic molecules with anionic and cationic properties for specific applications. Later, nonionic surfactants became available in which the hydrophilic part of the molecule was based on condensed chains of ethylene oxide. A wide range of surfactant properties can be achieved by varying the ethylene oxide chain length, which affects the fundamental functional properties of wetting, dispersion, emulsification and solubilisation in the formulation and application of pesticides. Consequently, surfactant suppliers often produce "tailor-made" surfactants to suit particular formulations. More recently, polymeric surfactants have been introduced to provide better long-term formulation stability.

Surfactants, either alone or mixed with oils, are essential components of adjuvants which can enhance the biological activity of the spray mixture by affecting spray droplet size, retention and spreading on leaf surfaces or by assisting uptake and translocation of the active ingredient into the crop.

Many other additives are used in formulations for specific purposes, such as antisettling, antifreeze and antifoam agents for water-based formulations, and fillers and disintegrants for powders and water-dispersible granules. Preservatives are also used to prevent biodegredation during preparation and storage, particularly for formulations containing water and polysaccharide thickeners. Preservatives are also used where the products are exposed to the atmosphere after application, eg, baits and pellets.

The toxicity of additives and adjuvants is now becoming an important topic and suppliers are developing surfactants and adjuvants based on natural materials such as vegetable oils and sugars. These products will become more popular in future as a means of increasing product safety and enabling quicker product registrations.

1.4 Delivery systems for pesticide formulations

Agrochemical companies are now paying increasing attention to the packaging of pesticides as part of the total “delivery system” for convenient use and user safety. Rinsing and safe disposal of plastic bottles is becoming very important. In some cases, this can be overcome by using bulk or mini-bulk containers, or small volume returnable containers, all of which are returned to the manufacturers for cleaning and refilling. The move from liquids to granules allows the use of simple bags or cartons for ease of disposal. However, there is currently a debate about whether such packaging can be regarded as contaminated or not. If packaging is classed as contaminated with pesticide, it must be disposed of in a suitable and safe manner, such as landfill, at approved sites, or incineration. Powders and granules can also be supplied in water-soluble bags to eliminate operator contact entirely. In this case, the outer wrapper would normally be regarded as uncontaminated by pesticide.

Despite the extensive R&D which goes into the introduction of a new product, when the product is diluted and sprayed onto crops in the field it is likely that less than 10% of the pesticide actually reaches the target pest. This can be caused by many factors, such as poor spraying conditions causing spray drift, or spray droplets missing the crop and hitting the soil, and droplets bouncing off or running off the crop leaves. There is, therefore, a great deal of scope for improving the efficiency of the whole spray application process, and also understanding the effect that formulations and adjuvants can have on it. This is an area where all the technologies of formulation, packaging and spray applications can work together to produce safer and more efficient total “delivery systems”. There is also an opportunity to improve biological activity by understanding the mode of action of adjuvants on leaf surfaces and how they can affect the uptake and translocation of pesticides within plants.

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