Ultraviolet Germicidal Irradiation Handbook (eBook)

Kowalski consults on air cleaning construction and retrofit projects through Immune Building Systems, Inc. (IBSI) of New York, and speaks at international conferences on issues related to disease control and biodefense. He is currently chairman of the Air Treatment Group of the International Ultraviolet Association (IUVA) with whom he is developing a series of standards and guidelines for air treatment systems in collaboration with ASHRAE, ARI, and other professional societies.

Preface 6
Acknowledgements 7
Contents 8
1 Introduction 15
1.1 Ultraviolet Germicidal Irradiation (UVGI) 15
1.2 Brief History of Ultraviolet Disinfection 16
1.3 Units and Terminology 20
1.4 Air vs. Water Disinfection 22
1.5 Surface Disinfection 23
1.6 Air Disinfection 23
1.7 Air Disinfection Field Studies 24
1.8 Pathogens and Allergens 25
1.9 Current Research 26
1.10 UVGI and the Future of Disease Control 26
References 27
2 UVGI Disinfection Theory 31
2.1 Introduction 31
2.2 UV Inactivation 31
2.3 UV Absorption Spectra 38
2.4 UV Photoprotection 42
2.5 Covalent Bonding and Photon Interaction 45
2.6 UV Photoproducts 46
2.7 DNA Conformation 47
2.8 Photon Density and Single-Hit Concepts 49
2.9 Photochemistry of RNA Viruses 52
2.10 Photochemistry of DNA Viruses 53
2.11 Photochemistry of Bacteria 53
2.12 Photoreactivation 54
2.13 UV Scattering 56
References 61
3 Mathematical Modeling of UV Disinfection 65
3.1 Introduction 65
3.2 UV Disinfection Modeling 65
3.3 UV Exposure Dose (Fluence) 66
3.4 Single Stage Decay 67
3.5 Two Stage Decay 67
3.6 Shoulder Curves 69
3.7 Two Stage Shoulder Curves 72
3.8 Relative Humidity Effects 73
3.8.1 RH Effects on Viruses 74
3.8.2 RH Effects on Bacteria 76
3.8.3 RH Effects on Bacterial and Fungal Spores 81
3.9 Modeling Photoreactivation 82
3.10 Air Temperature Effects 84
References 84
4 UV Rate Constants 87
4.1 Introduction 87
4.2 Rate Constants and Survival Curves 87
4.3 UV Rate Constant Database 88
4.3.1 Bacteria Rate Constants 89
4.3.2 Virus Rate Constants 90
4.3.3 Fungi Rate Constants 95
4.4 Surface UV Rate Constants 95
4.5 Water Rate Constants 97
4.6 Airborne Rate Constants 100
4.7 Narrow Band UVC vs. Broadband UVB/UVC 101
4.8 Relative Humidity Effects 102
4.9 Rate Constant Determinants 104
4.10 UV Scattering in Water 108
4.11 Prediction of UV Susceptibility 109
References 119
5 UVGI Lamps and Fixtures 132
5.1 Introduction 132
5.2 Types and Characteristics of UV Lamps 133
5.3 Lamp Power, Size, and Nomenclature 136
5.4 Lamp Ballasts 137
5.4.1 Magnetic Ballasts 138
5.4.2 Electronic Ballasts 139
5.5 Microwave UV Lamps 139
5.6 UV LEDs 140
5.7 Pulsed UV Lamps 141
5.8 Lamp Ratings 142
5.9 Lamp Shapes 142
5.10 Lamp Fixtures 142
5.11 Upper Room Lamp Fixtures 144
5.12 Lamp Cooling Effects 145
5.13 Ozone Generation 148
5.14 Lamp Maintenance 148
References 149
6 Systems and Equipment 151
6.1 Introduction 151
6.2 Air Disinfection Systems 151
6.2.1 In-Duct Air Disinfection 152
6.2.2 Recirculation Units 154
6.2.3 Upper Room Systems 155
6.2.4 UV Barrier Systems 156
6.2.5 Overhead Tank Disinfection 157
6.3 Surface Disinfection Systems 157
6.3.1 Equipment and Packaging Disinfection 158
6.3.2 Cooling Coil Disinfection 159
6.3.3 Lower Room Disinfection 160
6.3.4 Overhead Surgical Site Disinfection 161
6.3.5 Area/Room Disinfection 162
6.3.6 Food Surface Disinfection 163
6.3.7 Mold Remediation Systems 164
6.3.8 UV Hand Wands 164
6.4 UV Reflective Materials 164
6.5 UV Light Baffles 165
6.6 UV-Transmittant Materials 167
6.7 UV Absorbers 167
6.8 Flow Straighteners 168
6.9 PCO Systems 168
6.10 Controls and Integral Sensors 169
References 169
7 UVGI System Modeling 171
7.1 Introduction 171
7.2 UV Lamp Modeling 171
7.3 UV Reflectivity Modeling 175
7.3.1 Modeling Specular Enclosures 175
7.3.2 Modeling Diffuse Enclosures 178
7.3.3 Combined Specular and Diffusive Reflectivity 182
7.4 Air Mixing Effects 183
7.5 UV System Optimization 185
References 187
8 Airstream Disinfection 189
8.1 Introduction 189
8.2 UV Air Disinfection Performance 189
8.3 Filtration Performance 197
8.4 Combined Performance of Filtration and UVGI 198
8.5 In-duct Air Disinfection Systems 202
8.6 EPA Test Results 203
8.7 Unitary UV Systems 207
8.8 Barrier Systems 208
8.9 Zonal Modeling 210
8.9.1 Steady State Single Zone Model 210
8.9.2 Transient Modeling 212
8.9.3 Multizone Modeling 215
8.10 Zonal Protection Factors 215
8.11 UV Air Disinfection Field Trials 218
References 219
9 Upper Room UV Systems 222
9.1 Introduction 222
9.2 Types and Design of Fixtures 223
9.3 Upper Room System Sizing 227
9.4 Air Mixing Effects 231
9.5 Room Design 234
9.6 Performance 235
9.7 Testing 238
9.8 Upper Room UV Safety 240
References 241
10 UV Surface Disinfection 244
10.1 Introduction 244
10.2 Microbial Growth Control 244
10.3 Modeling Surface Disinfection 245
10.4 UV Cabinets 247
10.5 Area Disinfection Systems 248
10.6 Cooling Coil Irradiation 250
10.7 Overhead Surgical Site Systems 257
10.8 Lower Room Systems 260
10.9 Food and Packaging Irradiation 260
10.10 Summary 263
References 263
11 UVGI Guidelines and Standards 266
11.1 Introduction 266
11.2 UVGI Electrical Guidelines 267
11.3 Testing Guidelines and Standards 269
11.4 UVGI Application Guidelines 273
11.5 UVGI Safety Guidelines 288
References 294
12 UVGI Safety 298
12.1 Introduction 298
12.2 The Germicidal UV Spectrum 298
12.3 Biological Effects of UV Exposure 299
12.3.1 UV Effects on Eyes 300
12.3.2 UV Effects on Skin 302
12.4 UV Exposure Limits 304
12.5 UV Measurement 309
12.6 UV Protection and Control Measures 311
12.6.1 In-duct UVGI System Safety 311
12.6.2 Unitary UVGI System Safety 312
12.6.3 Upper Room UVGI Safety 312
12.6.4 Lower Room UVGI Safety 313
12.6.5 Cooling Coil UVGI Safety 314
12.6.6 Equipment Disinfection UVGI Safety 314
12.6.7 Overhead Surgical Site System Safety 315
12.6.8 Area Decontamination UVGI Safety 315
12.7 Personal Protective Equipment (PPE) 316
12.8 Labeling 317
12.9 Ozone Generation Hazards 318
12.10 Lamp Breakage and Mercury Risks 319
References 320
13 Ultraviolet Radiometry 323
13.1 Introduction 323
13.2 Lamp Electrical Characteristics 323
13.3 UV Irradiance and UV Dose 324
13.4 Measurement Equipment 325
13.5 UV Lamp Ratings 328
13.6 Lamp Irradiance Measurements 328
13.7 Lamp Cooling and Heating Effects 332
13.8 UV Reflectivity 333
13.9 UV Transmittance 334
13.10 UV Absorptance 335
13.11 Reflective Lamp Fixtures and Enclosures 336
13.12 UV Dose Measurement 337
13.13 Spherical Actinometry 337
13.14 Testing Applications 338
13.14.1 Laboratory Testing of Equipment 339
13.14.2 In-duct UVGI System Testing 339
13.14.3 Cooling Coil Systems 340
13.14.4 Overhead Surgical Site Systems 341
13.14.5 Upper Room Systems 342
13.14.6 Lower Room Systems 343
13.14.7 Area Disinfection Systems 343
References 344
14 Microbiological Testing 346
14.1 Introduction 346
14.2 Microbiological Testing 346
14.3 Biodosimetry 347
14.4 Test Microbes 347
14.5 Test Materials and Equipment 348
14.6 Surface Sampling 350
14.7 Test Protocol for Surface Sampling 350
14.7 Air Sampling 354
14.8 Test Protocol for Settle Plate Sampling 354
14.8 Sampling Applications 357
14.8.1 UV Rate Constants 357
14.8.2 Cooling Coil Disinfection Systems 360
14.8.3 In-duct Air Disinfection Systems 361
14.8.4 Upper Room Systems 362
14.8.5 Lower Room Systems 362
14.8.6 Overhead Surgical Site Systems 363
14.8.7 Area Disinfection Systems 364
14.9 Evaluating Sampling Results 364
14.10 Virus Sampling 366
References 366
15 UV Effects on Materials 369
15.1 Introduction 369
15.2 UV Effects on Materials 369
15.3 Activation Spectra 373
15.4 Solarization of Glass 374
15.5 Photodiscoloration 375
15.6 Photodegradation 376
15.7 Damage to Houseplants 379
15.8 Ozone Production 380
15.9 Protective Coatings 381
15.10 UV Absorbers 383
15.11 Photodegradation Testing 385
References 386
16 Pulsed UV Systems 390
16.1 Introduction 390
16.2 Pulsed UV Disinfection 390
16.3 The PUV Spectrum and Germicidal Effectiveness 392
16.4 Modeling PUV Dose 394
16.5 Modeling PUV Decay Curves 396
16.6 A General Model for PUV Disinfection 401
16.7 Pulsed Light Disintegration 402
References 404
17 Health Care Facilities 406
17.1 Introduction 406
17.2 Nosocomial Infections 406
17.3 Operating Rooms and ICUs 408
17.4 Isolation Rooms 413
17.5 General Areas 415
17.6 Hallways and Storage Areas 417
17.7 Dental Offices 419
17.8 AIDS Clinics 419
17.9 Hospital Laboratories 420
17.10 Animal Laboratories and Veterinary Facilities 421
References 425
18 Commercial Buildings 429
18.1 Introduction 429
18.2 Office Buildings 429
18.3 Industrial Facilities 431
18.4 Food Industries 432
18.5 Educational Facilities 437
18.6 Museums and Libraries 438
18.7 Agricultural and Animal Facilities 441
18.8 Malls, Airports, and Places of Assembly 447
18.9 Aircraft and Transportation 447
18.10 Sewage and Waste Facilities 449
References 450
19 Residential Applications 454
19.1 Introduction 454
19.2 Residential Homes 454
19.3 Apartments 457
19.4 Hotels and Dormitories 458
References 459
20 Bioterrorism Defense 461
20.1 Introduction 461
20.2 Bioweapons 461
20.3 Biodefense of Buildings 465
20.4 UV Systems for Biodefense 468
20.5 UV Bioremediation 471
References 472
Appendices 474
Index 496