• The agrochemical industry has been developing since the 1950’s and has now reached maturity.
• The major players have become very competitive and must maximize 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 amongst 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.
• 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.
• 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 has led to a reduction in herbicide and insecticide usage, notably in North America. This technology is forecast to become much more important over the next decade.

All of these factors and their effects on the development of pesticide formulation technology over the last few years will be discussed in later chapters.

The last 20 years or so have seen rapid development in pesticides 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.

In the scientific area, 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 technology is now seen as an “enabling technology” which can provide safe and effective products which are convenient to use. It 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 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, or by introducing a new formulation of an existing active ingredient.

1.2 Scope of report

Why are pesticide formulations sometimes thought to be complex? The Pesticide Manual 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 components. 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.

• Optimize biological activity
• Improve handling and application
• Maximize 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, and packaging of pesticide formulations, product regulation by governments and international quality standards. Reviews are also included of 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.

The formulation and use of biopesticides are contrasted with conventional chemical pesticides.

Likely future trends in all of the areas of formulation, additives, packaging technology 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.

Pesticide markets and company profiles have been surveyed.

Over the last decade or more the major agrochemical companies have been reviewing their product/pack strategies, and government regulatory authorities have introduced stricter controls and legislation which have lead to the introduction of reduced risk active ingredients, and safer and more environmentally friendly formulations in more convenient packaging.

The cost of the successful development of new products is becoming increasingly high and it is estimated that it can cost up to US$200 million to develop one new active ingredient with a development time scale of up to 10 years from initial discovery to first registered commercial sales of the product. This has caused the industry to consolidate by mergers of companies or research joint ventures between companies. The long development time scale 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 research and development effort in the discovery of new molecules.

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

1.3 Formulation types and codes

A search of the Pesticide Manual shows that many different types of formulations have been developed depending largely on the physico-chemical 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 pesticide because they are applied directly to the seed. They, therefore, have the potential to reduce significantly the total environmental impact.

• sub-standard ingredients
• incorrect quantities used
• incorrect ingredients used
• processing errors
• contaminated equipment
• sub-standard packaging
• incorrect labelling

QC is the process of ensuring that all products leaving the plant conform with defined specifications. A comprehensive QC system for a pesticide formulation and packing plant must ensure that:

• the quality of ingredients and packaging materials received in the plant complies with purchasing specifications
• the correct ingredients and quantities are used during formulation
• reliable and repeatable formulation procedures are defined and maintained
• the conformation of product quality to specification is controlled by validated sampling and analytical procedures
• reliable and repeatable packing procedures are defined, maintained and checked
• despatch details are correct

Official methods of analysis for active ingredient content and physicochemical properties are given in AOAC Methods of Analysis, ASTM methods, and in CIPAC Handbooks. For full information on test methods, visit the following websites:

www.aoac.org
www.astm.org
www.cipac.org

All the latest methods for physicochemical properties are given in CIPAC Handbook F, 1995 and Handbook K, 2003. Product specification guidelines are given in FAO Specifications for Plant Protection Products, First Edition 2002, www.fao.org.

Full CIPAC methods have been investigated in accordance with internationally accepted rules and have given results falling within the accepted ranges for repeatability and reproducibility. Provisional methods are either candidate CIPAC methods, which may become full methods after a trial period, or methods with minor imperfections, which are nonetheless the best available. Tentative methods usually have not been tested in a full-scale study but are still accepted because there is a need for them.

In the USA the main source of test methods is ASTM (American Society for Testing and Materials). Since the Eighth IUPAC International Congress of Pesticide Chemistry, held in Washington D.C., USA in 1994, there has been some initiative between CIPAC and ASTM to harmonize test methodologies.

Storage stability testing of pesticide products is carried out to check the chemical and physical stability of formulations at various temperatures and time periods. For provisional registration, it is necessary to provide short term accelerated storage test data under at least one of the following conditions:

• 14 days at 54oC (FAO standard)
• 4 weeks at 50oC
• 8 weeks at 40oC
• 12 weeks at 35oC
• 18 weeks at 30oC

Tests should be carried out in sealed glass bottles or material similar to sales pack. For low melting materials or for suspension concentrates, temperatures below 40oC may be used.

Full registration of products usually requires two year testing in sales packs at ambient temperature, and cold temperature tests, especially for liquid formulations which may be subjected to temperatures below their crystallizing point or freezing point during storage and use. Further details on specifying the shelf life of plant protection products is given on CropLife’s website in Technical Monograph No.17, May 1993, www.croplife.org

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