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 xiii xv 1 Introduction 1 D. A. KNOWLES References 7 2 Review of major agrochemical classes and uses 8 L. G. COPPING 2.1 Introduction 8 2.2 Future needs 9 2.3 World markets, 1996 9 2.4 Sales by category, 1995 10 2.5 Sales by crop, 1995 12 2.6 Sales by region, 1995 13 2.7 Herbicides 13 2.7.1 Photosynthesis 15 2.7.2 Amino acid biosynthesis 17 2.7.3 Lipid biosynthesis 17 2.7.4 Interference with plant hormones 18 2.7.5 Cell division 19 2.7.6 Cellulose biosynthesis 19 2.7.7 Respiratory uncouplers 19 2.8 Insecticides 20 2.8.1 Organophosphorus insecticides (OPs) 21 2.8.2 Carbamate insecticides 22 2.8.3 Insecticides that interact with neurotransmitter ligand recognition sites 22 2.8.4 Insecticides that interlbre r with ion channels 23 2.8.5 Inhibition of oxidative phbspitorylation 24 2.8.6 Insect growth and regulation 25 2.8.7 Compounds^ wkh-'uifcertjiin.modes.of action 26 2.9 Fungicides.. 27 2.9.1 Protectant fungicides. ^ \r -,, 27 2.9.2 Protein biosynthesis... " ' 28 2.9.3 Nucleic acid metabolism 28 2.9.4 Cell division 28 2.9.5 Sterol biosynthesis 28 2.9.6 Triglyceride biosynthesis 29 2.9.7 Chitin biosynthesis 29 2.9.8 Respiration 29 2.9.9 Indirectly acting fungicides 30 2.10 Plant growth regulators 30 2.11 Biological screening: discovery and development of a new agrochemical 30 2.11.1 Chemical synthesis 31 2.11.2 Biological evaluation 35 References 38
VI CHEMISTRY AND TECHNOLOGY OF AGROCHEMICAL FORMULATIONS 3 Formulation of agrochemicals 41 D. A. KNOWLES 3.1 3.2 3.3 3.4 3.5 References 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) New-generation formulations 3.3.1 3.3.2 3.3.3 3.3.4 3.3.5 3.3.6 3.3.7 General trends Oil-in-water emulsions (EW) Suspoemulsions (SE) Microemulsions (ME) Controlled-release formulations Water-dispersible granules (WG) Formulations using a built-in wetter Surfactants for agrochemicals 3.4.1 3.4.2 3.4.3 3.4.4 3.4.5 3.4.6 3.4.7 3.4.8 3.4.9 3.4.10 3.4.11 3.4.12 3.4.13 Other 3.5.1 3.5.2 3.5.3 3.5.4 3.5.5 3.5.6 3.5.7 3.5.8 General characteristics Adsorption and surface tension Micellization Krafft temperature and cloud point Wetting and contact angle Particle and droplet stabilization Wetting agents Dispersion Emulsification Solubilization Bioenhancement Conventional surfactants Recent surfactant developments formulation additives Carriers and diluents Solvents Anti-settling agents Water-soluble polymers Preservatives Anti-freeze agents Anti-foam agents Anti-caking agents 41 43 43 44 45 46 47 49 50 50 51 52 53 53 55 56 57 57 59 61 61 61 62 63 64 65 66 67 67 70 71 71 71 73 74 75 78 78 78 79 Water-dispersible granules 80 G. A. BELL 4.1 Introduction 80 4.2 Manufacturing methods 83 4.3 Physical properties 87 4.3.1 Granule size and shape 88 4.3.2 Particle assemblies and structures 91 4.3.3 Quantity and type of binders 98 4.4 Design: modern methods 112 References 114
CONTENTS Vll Recent developments on safer formulations of agrochemicals 121 P. J. MULQUEEN 5.1 Introduction 122 5.2 Liquid formulations 125 5.2.1 Emulsifiable concentrates (EC) 125 5.2.2 Concentrated emulsions (CE) 126 5.2.3 Suspension emulsions (or suspoemulsions) 130 5.2.4 Microemulsions 131 5.2.5 Multiple emulsions 131 5.2.6 Suspension concentrates 132 5.3 Controlled-release formulations 132 5.3.1 Methods of encapsulation 134 5.3.2 Advantages of microencapsulation 142 5.3.3 Microencapsulated products 146 5.3.4 Future trends in microencapsulation 147 5.4 Water-soluble packaging 147 5.5 Dry products (water-dispersible granules) 148 5.6 Adjuvants 148 5.7 Other formulation types 149 5.7.1 Seed treatment formulations 149 5.7.2 Biotechnological improvements 149 5.8 Summary and future possibilities 152 References 154 Agrochemical formulations using natural lignin products 158 S. T. HUMPHREY 6.1 Introduction 158 6.1.1 Lignosulphonates: some basic information 158 6.1.2 Lignin modification 159 6.2 Wettable powders (WP) 160 6.2.1 Formulation 160 6.2.2 Production methods 162 6.3 Water-dispersible granules (WG) 163 6.3.1 Formulation 164 6.3.2 Production methods 166 6.4 Suspension concentrates (SC) 167 6.4.1 Formulation 167 6.4.2 Production methods 170 6.5 Oil-in-water emulsions (EW) 172 6.5.1 Formulation 172 6.5.2 Production methods 172 6.6 Controlled release 172 6.6.1 Granules 173 6.6.2 Tablets 173 6.6.3 Gels 173 6.6.4 Microencapsulation 174 6.7 Ultraviolet protection 175 6.8 Compatibility agents 176 6.9 Adjuvants 176 6.10 Complexing agents 177 6.11 Environmental and regulatory information 177 6.11.1 Personnel 177 6.11.2 Environmental 177 References 178
Vlll CHEMISTRY AND TECHNOLOGY OF AGROCHEMICAL FORMULATIONS 7 Novel surfactants and adjuvants for agrochemicals 179 S. REEKMANS 7.1 Polymeric surfactants and stability 179 7.1.1 Introduction 179 7.1.2 (De)stabilization of colloidal systems 179 7.1.3 Colloidal stabilization 180 7.1.4 Structure of polymeric surfactants for steric stabilization 183 7.1.5 Polymeric surfactants in agricultural formulations 187 7.1.6 Conclusion 195 7.2 Trends towards environmentally safer surfactants 196 7.2.1 Surfactants and the environment 196 7.2.2 Toxicity and biodegradation 197 7.2.3 Hazard labelling of surfactants 204 7.2.4 Effect of chemical structure 204 7.2.5 New-generation surfactants 209 7.2.6 Conclusion 211 7.3 Enhancing biological activity using adjuvants 212 7.3.1 Introduction 212 7.3.2 Relevance of a surfactant's properties 213 7.3.3 Built-in activators and spray-tank mixtures 220 7.3.4 Future trends in surfactants and adjuvants 221 7.3.5 Conclusion 226 Acknowledgements 226 References 226 8 Improving agrochemical performance: possible mechanisms for adjuvancy 232 P. J. HOLLOWAY 8.1 8.2 8.3 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 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 Future; prospects 8.4 Acknowledgements References 232 233 233 237 239 240 240 241 241 241 241 244 246 250 252 253 257 259 260 Packaging of agrochemicals 264 P. D. CURLE, C. D. EMMERSON, A. H. GREGORY, J. HARTMANN and P. NIXON 9.1 Selection of packaging types 264 9.1.1 Selection of packaging materials for solid formulations 264
CONTENTS IX 9.1.2 Selection of packaging materials for liquid formulations 267 9.1.3 Plastics 267 9.1.4 Metal 269 9.1.5 Glass 269 9.1.6 Recommended tests to be carried out on the main types of containers 269 9.1.7 Specifications 271 9.1.8 Packaging instructions 271 9.2 Closures 272 9.2.1 Prevention of leakage 272 9.2.2 Tamper evidence 273 9.2.3 Closure diameter - liquid products 274 9.2.4 Dispensing liquid products from packs designed for pouring 275 9.3 Labelling 277 9.4 Shelf life 278 9.5 Pack design with regard to easy rinsing and disposal 279 9.6 Types of secondary packaging 279 9.6.1 Unit cartons 281 9.6.2 Combination with primary pack 281 9.6.3 Methods for protection of unit loads 281 9.7 United Nations performance tests 281 9.8 Rinsing methods 283 9.9 Closed transfer systems 285 9.10 Collection of containers after use 287 9.11 Summary of key design criteria 289 9.12 Returnable packaging systems 289 9.12.1 Small-volume returnable containers 289 9.12.2 SVR design criteria 290 9.12.3 Stewardship 290 9.12.4 Closures 291 9.12.5 Labelling and marking 291 9.12.6 Handling 291 9.12.7 Disposal 291 9.13 ECPA standard SVR interface 291 9.13.1 Container interface/extractor valve 291 9.13.2 Coupler 292 9.13.3 Extractor valve and coupler combined 293 9.14 Future direction 295 Glossary of terms and definitions 295 Bibliography 299 10 Application techniques for agrochemicals 302 G. A. MATTHEWS 10.1 Hydraulic nozzles 302 10.1.1 Types of hydraulic nozzle 308 10.2 Portable sprayers 312 10.3 Tractor sprayers 315 10.3.1 Portable lines 320 10.3.2 Orchard sprayers 320 10.4 Aerial application 321 10.5 ULV and CDA ground application 324 10.6 Fogs, mists and aerosols 327 10.6.1 Mists 328 10.7 Electrostatically charged applications 329 10.8 Chemigation 330 10.9 Granule, dust and seed treatments 331 10.9.1 Seed treatment 332
X CHEMISTRY AND TECHNOLOGY OF AGROCHEMICAL FORMULATIONS 10.10 Miscellaneous 332 10.10.1 Weed wiper 332 10.10.2 Lure and kill 332 10.10.3 Tree injection 332 10.11 Standards 333 References 333 11 Regulatory requirements in the European Union 337 W. K. DE RAAT,I. A. VAN DE GEVEL, G. F. HOUBEN and B. C. HAKKERT 11.1 Introduction 337 11.2 Some basic features of 91/414/EEC 339 11.2.1 Which plant protection products? 339 11.2.2 Authorization of active substances and plant protection products 339 11.2.3 Existing and new active substances 340 11.2.4 Harmonization of methods and procedures 341 11.2.5 Quality standard 341 11.2.6 Mutual recognition 342 11.2.7 Data protection 342 11.2.8 Exemptions from the 'standard' authorization procedures 343 11.3 Overview of authorizations 344 11.4 Data requirements 345 11.5 Dossier preparation 348 11.6 Inclusion of active substances in Annex I of 91/414/EEC 353 11.6.1 Introduction 353 11.6.2 Initial evaluation 355 11.6.3 Detailed evaluation and the preparation of the monograph 356 11.6.4 Procedure 361 11.7 Authorization of plant protection products 361 11.7.1 General requirements 361 11.7.2 The Uniform Principles 362 11.7.3 Evaluation 363 11.7.4 Authorization criteria 366 11.8 Transitional measures and the review programme 370 11.8.1 Transitional authorizations 370 11.8.2 Review programme 371 11.9 Adjuvants 374 Acknowledgements 374 Appendix 11.A An overview of European Community general legislation associated with plant protection products 375 12 Regulatory requirements in the USA 377 J. M. WAGNER 12.1 Introduction 377 12.2 Federal pesticide laws 377 12.2.1 Federal Insecticide, Fungicide, and Rodenticide Act 378 12.2.2 Federal Food, Drug, and Cosmetic Act 379 12.2.3 Food Quality Protection Act, 1996 379 12.3 EPA Office of Pesticide Programs 383 12.3.1 Organization 384 12.3.2 Operating objectives 385 12.4 Product registration: obtaining a license to sell 386 12.4.1 Experimental Use Permit 386 12.4.2 Registration 387 12.4.3 Tolerances and exemptions from tolerances 393
CONTENTS XI 12.5 Registration and tolerance data requirements 397 12.6 Data evaluation 397 12.6.1 EPA risk assessment process 402 12.6.2 Industry interaction with EPA: practical advice 403 12.7 Data protection and compensation 404 12.8 Reregistration and product defense 405 12.8.1 Data Call-in and industry task force groups 406 12.8.2 Special review process and cancellation of registrations 406 12.9 Product labeling 407 12.10 State registration requirements 409 12.11 Conclusions 411 Acknowledgements 412 Appendix 12.A Index of EPA study guidelines 412 Appendix 12.B Sources of registration information 412 Appendix 12.C Office of Pesticide Programs: senior EPA contacts 415 References 416 13 Waste management and disposal of agrochemicals 418 K. S. JOHNSON 13.1 13.2 13.3 13.4 13.5 13.6 13.7 13.8 References 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 Waste types 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 Documentation and records 13.6.1 Waste producer (originator) 13.6.2 Identification 13.6.3 Consignment Waste disposal 13.7.1 Waste disposal options 13.7.2 Waste disposal contractors 13.7.3 Waste transfer stations 13.7.4 Transport 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 418 418 419 419 420 421 422 422 422 423 423 423 423 427 429 429 429 429 Index 435 430 430 430 431 431 434 434 434