Chemistry and Technology of
Agrochemical Formulations
Edited by
D. A. Knowles
FORM-AK Formulation Consultancy Services,
Tonbridge, Kent, UK
Kluwer Academic Publishers
Dordrecht / Boston / London
Contents
Preface
List of contributors
1 Introduction
D. A. KNOWLES
References
2 Review of major agrochemical classes and uses
L. G. COPPING
2.1
2.2
2.3
2.4
2.5
2.6
2.7
Introduction
Future needs
World markets, 1996
Sales by category, 1995
Sales by crop, 1995
Sales by region, 1995
Herbicides
2.7.1 Photosynthesis
2.7.2
Amino acid biosynthesis
2.7.3
Lipid biosynthesis
2.7.4
Interference with plant hormones
2.7.5
Cell division
2.7.6
Cellulose biosynthesis
2.7.7
Respiratory uncouplers
2.8
Insecticides
2.8.1
Organophosphorus insecticides (OPs)
2.8.2
Carbamate insecticides
2.8.3
Insecticides that interact with neurotransmitter ligand
recognition sites
2.8.4
Insecticides that interlBrerwith ion channels
2.8.5
Inhibition of oxidative phbspitorylation
2.8.6
Insect growth and regulation
2.8.7
Compounds^ wkh-'uifcertJiin .modes .of action
2.9
Fungicides
..
2.9.1
Protectant fungicides. ^ \r
- ,,
2.9.2
Protein biosynthesis . . . • " '
2.9.3
Nucleic acid metabolism
2.9.4
Cell division
2.9.5
Sterol biosynthesis
2.9.6
Triglyceride biosynthesis
2.9.7
Chitin biosynthesis
2.9.8
Respiration
2.9.9
Indirectly acting fungicides
2.10
Plant growth regulators
2.11
Biological screening: discovery and development of a new agrochemical
2.11.1 Chemical synthesis
2.11.2 Biological evaluation
References
xiii
xv
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38
VI
3
CHEMISTRY AND TECHNOLOGY OF AGROCHEMICAL FORMULATIONS
Formulation of agrochemicals
D. A. KNOWLES
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3.1
3.2
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Introduction
Conventional formulations
3.2.1
Granules (GR)
3.2.2
Solution concentrates (SL)
3.2.3
Emulsifiable concentrates (EC)
3.2.4
Wettable powders (WP)
3.2.5
Suspension concentrates (SC)
3.2.6
Seed treatments (DS, WS, LS, FS)
3.3
New-generation formulations
3.3.1
General trends
3.3.2
Oil-in-water emulsions (EW)
3.3.3
Suspoemulsions (SE)
3.3.4
Microemulsions (ME)
3.3.5
Controlled-release formulations
3.3.6 Water-dispersible granules (WG)
3.3.7
Formulations using a built-in wetter
3.4
Surfactants for agrochemicals
3.4.1
General characteristics
3.4.2
Adsorption and surface tension
3.4.3
Micellization
3.4.4
Krafft temperature and cloud point
3.4.5
Wetting and contact angle
3.4.6
Particle and droplet stabilization
3.4.7
Wetting agents
3.4.8
Dispersion
3.4.9
Emulsification
3.4.10 Solubilization
3.4.11 Bioenhancement
3.4.12 Conventional surfactants
3.4.13 Recent surfactant developments
3.5
Other formulation additives
Carriers and diluents
3.5.1
3.5.2
Solvents
3.5.3
Anti-settling agents
3.5.4
Water-soluble polymers
3.5.5
Preservatives
3.5.6
Anti-freeze agents
3.5.7
Anti-foam agents
3.5.8
Anti-caking agents
References
Water-dispersible granules
G. A. BELL
80
4.1
4.2
4.3
80
83
87
88
91
98
112
114
Introduction
Manufacturing methods
Physical properties
4.3.1
Granule size and shape
4.3.2
Particle assemblies and structures
4.3.3 Quantity and type of binders
4.4
Design: modern methods
References
CONTENTS
Recent developments on safer formulations of agrochemicals
P. J. MULQUEEN
5.1
5.2
Introduction
Liquid formulations
5.2.1
Emulsifiable concentrates (EC)
5.2.2
Concentrated emulsions (CE)
5.2.3
Suspension emulsions (or suspoemulsions)
5.2.4
Microemulsions
5.2.5
Multiple emulsions
5.2.6
Suspension concentrates
5.3
Controlled-release formulations
5.3.1
Methods of encapsulation
5.3.2
Advantages of microencapsulation
5.3.3
Microencapsulated products
5.3.4
Future trends in microencapsulation
5.4
Water-soluble packaging
5.5
Dry products (water-dispersible granules)
5.6
Adjuvants
5.7
Other formulation types
5.7.1
Seed treatment formulations
5.7.2
Biotechnological improvements
5.8
Summary and future possibilities
References
Agrochemical formulations using natural lignin products
S. T. HUMPHREY
6.1
Introduction
6.1.1
Lignosulphonates: some basic information
6.1.2
Lignin modification
6.2
Wettable powders (WP)
6.2.1
Formulation
6.2.2
Production methods
6.3
Water-dispersible granules (WG)
6.3.1
Formulation
6.3.2
Production methods
6.4
Suspension concentrates (SC)
6.4.1 Formulation
6.4.2
Production methods
6.5
Oil-in-water emulsions (EW)
6.5.1 Formulation
6.5.2
Production methods
6.6
Controlled release
6.6.1
Granules
6.6.2
Tablets
6.6.3
Gels
6.6.4
Microencapsulation
6.7
Ultraviolet protection
6.8
Compatibility agents
6.9
Adjuvants
6.10
Complexing agents
6.11
Environmental and regulatory information
6.11.1 Personnel
6.11.2 Environmental
References
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Vlll
7
CHEMISTRY AND TECHNOLOGY OF AGROCHEMICAL FORMULATIONS
Novel surfactants and adjuvants for agrochemicals
S. REEKMANS
7.1
Polymeric surfactants and stability
7.1.1
Introduction
7.1.2
(De)stabilization of colloidal systems
7.1.3
Colloidal stabilization
7.1.4
Structure of polymeric surfactants for steric stabilization
7.1.5
Polymeric surfactants in agricultural formulations
7.1.6
Conclusion
7.2
Trends towards environmentally safer surfactants
7.2.1
Surfactants and the environment
7.2.2
Toxicity and biodegradation
7.2.3
Hazard labelling of surfactants
7.2.4
Effect of chemical structure
7.2.5
New-generation surfactants
7.2.6
Conclusion
7.3
Enhancing biological activity using adjuvants
7.3.1
Introduction
7.3.2
Relevance of a surfactant's properties
7.3.3
Built-in activators and spray-tank mixtures
7.3.4
Future trends in surfactants and adjuvants
7.3.5
Conclusion
Acknowledgements
References
8
Improving agrochemical performance: possible mechanisms
for adjuvancy
P. J. HOLLOWAY
8.1
8.2
Introduction
Chemical composition of adjuvants
8.2.1
Surfactants
8.2.2
Emulsifiable oils
8.2.3
Polymers
8.2.4
Polymer-forming compounds
8.2.5
Phospholipids
8.2.6
Inorganic salts
8.2.7
Other ingredients
8.3
Mechanistic approaches for investigating adjuvancy
8.3.1
Atomization
8.3.2
Retention
8.3.3
Predicting retention performance
8.3.4
Spreading and coverage
8.3.5
Uptake and translocation
8.3.6
Predicting uptake enhancement performance
8.4
Future; prospects
Acknowledgements
References
Packaging of agrochemicals
P. D. CURLE, C. D. EMMERSON, A. H. GREGORY,
J. HARTMANN and P. NIXON
9.1
Selection of packaging types
9.1.1
Selection of packaging materials for solid
formulations
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CONTENTS
9.1.2
9.1.3
9.1.4
9.1.5
9.1.6
Selection of packaging materials for liquid formulations
Plastics
Metal
Glass
Recommended tests to be carried out on the main types of
containers
9.1.7
Specifications
9.1.8
Packaging instructions
9.2
Closures
9.2.1
Prevention of leakage
9.2.2
Tamper evidence
9.2.3
Closure diameter - liquid products
9.2.4
Dispensing liquid products from packs designed for pouring
9.3
Labelling
9.4
Shelf life
9.5
Pack design with regard to easy rinsing and disposal
9.6
Types of secondary packaging
9.6.1
Unit cartons
9.6.2
Combination with primary pack
9.6.3
Methods for protection of unit loads
9.7
United Nations performance tests
9.8
Rinsing methods
9.9
Closed transfer systems
9.10
Collection of containers after use
9.11
Summary of key design criteria
9.12 Returnable packaging systems
9.12.1 Small-volume returnable containers
9.12.2 SVR design criteria
9.12.3 Stewardship
9.12.4 Closures
9.12.5 Labelling and marking
9.12.6 Handling
9.12.7 Disposal
9.13 ECPA standard SVR interface
9.13.1 Container interface/extractor valve
9.13.2 Coupler
9.13.3 Extractor valve and coupler combined
9.14 Future direction
Glossary of terms and definitions
Bibliography
10 Application techniques for agrochemicals
G. A. MATTHEWS
10.1
10.2
10.3
10.4
10.5
10.6
10.7
10.8
10.9
Hydraulic nozzles
10.1.1 Types of hydraulic nozzle
Portable sprayers
Tractor sprayers
10.3.1 Portable lines
10.3.2 Orchard sprayers
Aerial application
ULV and CDA ground application
Fogs, mists and aerosols
10.6.1 Mists
Electrostatically charged applications
Chemigation
Granule, dust and seed treatments
10.9.1 Seed treatment
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CHEMISTRY AND TECHNOLOGY OF AGROCHEMICAL FORMULATIONS
10.10 Miscellaneous
10.10.1 Weed wiper
10.10.2 Lure and kill
10.10.3 Tree injection
10.11 Standards
References
11 Regulatory requirements in the European Union
W. K. DE RAAT, I. A. VAN DE GEVEL,
G. F. HOUBEN and B. C. HAKKERT
11.1
11.2
Introduction
Some basic features of 91/414/EEC
11.2.1 Which plant protection products?
11.2.2 Authorization of active substances and plant protection products
11.2.3 Existing and new active substances
11.2.4 Harmonization of methods and procedures
11.2.5 Quality standard
11.2.6 Mutual recognition
11.2.7 Data protection
11.2.8 Exemptions from the 'standard' authorization procedures
11.3 Overview of authorizations
11.4 Data requirements
11.5 Dossier preparation
11.6 Inclusion of active substances in Annex I of 91/414/EEC
11.6.1 Introduction
11.6.2 Initial evaluation
11.6.3 Detailed evaluation and the preparation of the monograph
11.6.4 Procedure
11.7 Authorization of plant protection products
11.7.1 General requirements
11.7.2 The Uniform Principles
11.7.3 Evaluation
11.7.4 Authorization criteria
11.8 Transitional measures and the review programme
11.8.1 Transitional authorizations
11.8.2 Review programme
11.9 Adjuvants
Acknowledgements
Appendix 11.A An overview of European Community general legislation
associated with plant protection products
12 Regulatory requirements in the USA
J. M. WAGNER
12.1
12.2
12.3
12.4
Introduction
Federal pesticide laws
12.2.1 Federal Insecticide, Fungicide, and Rodenticide Act
12.2.2 Federal Food, Drug, and Cosmetic Act
12.2.3 Food Quality Protection Act, 1996
EPA Office of Pesticide Programs
12.3.1 Organization
12.3.2 Operating objectives
Product registration: obtaining a license to sell
12.4.1 Experimental Use Permit
12.4.2 Registration
12.4.3 Tolerances and exemptions from tolerances
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CONTENTS
12.5
12.6
Registration and tolerance data requirements
Data evaluation
12.6.1 EPA risk assessment process
12.6.2 Industry interaction with EPA: practical advice
12.7
Data protection and compensation
12.8 Reregistration and product defense
12.8.1 Data Call-in and industry task force groups
12.8.2 Special review process and cancellation of registrations
12.9 Product labeling
12.10 State registration requirements
12.11 Conclusions
Acknowledgements
Appendix 12.A Index of EPA study guidelines
Appendix 12.B Sources of registration information
Appendix 12.C Office of Pesticide Programs: senior E P A contacts
References
13 Waste management and disposal of agrochemicals
K. S. JOHNSON
13.1
13.2
13.3
Introduction
Site management responsibilities
Waste minimization
13.3.1 General principles and definitions
13.3.2 Examples of source reduction options
13.3.3 Example of recycling, use and reuse of waste and reclamation
13.4 Waste types
13.5 Waste handling
13.5.1 Operator safety
13.5.2 Workplace designated waste collection areas
13.5.3 Site waste collection
13.5.4 Secure waste storage
13.5.5 Waste preparation prior to disposal
13.5.6 Detoxification of containers
13.5.7 Toxic wastes
13.6 Documentation and records
13.6.1 Waste producer (originator)
13.6.2 Identification
13.6.3 Consignment
13.7 Waste disposal
13.7.1 Waste disposal options
13.7.2 Waste disposal contractors
13.7.3 Waste transfer stations
13.7.4 Transport
13.8 Treatment and disposal of aqueous effluents arising from formulation
and packaging of agrochemical products
13.8.1 Introduction
13.8.2 Treatment process
13.8.3 Plant details and layout
13.8.4 Final effluent quality
13.8.5 Effluent disposal
13.8.6 Sludge disposal
References
Index
XI
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