Organic Indoor Air Pollutants: Occurrence, Measurement, Evaluation, Second Edition

Organic Indoor Air Pollutants Occurrence, Measurement, Evaluation Edited by Tunga Salthammer and Erik Uhde Second, Completely Revised Edition

Organic Indoor Air Pollutants Edited by Tunga Salthammer and Erik Uhde

Related Titles Parlar, H., Greim, H. (eds.)

The MAK-Collection for Occupational Health and Safety Part III: Air Monitoring Methods, Volume 11 Series: The MAK-Collection for Occupational Health and Safety. Part III: Air Monitoring Methods (DFG) (Volume 11) 2009 ISBN: 978-3-527-31959-6

Parlar, H., Greim, H. (eds.)

The MAK-Collection for Occupational Health and Safety Part III: Air Monitoring Methods, Volume 10 Series: The MAK-Collection for Occupational Health and Safety. Part III: Air Monitoring Methods (DFG) (Volume 10) 2007 ISBN: 978-3-527-31601-4

Bester, K.

Personal Care Compounds in the Environment 2007 ISBN: 978-3-527-31567-3

Organic Indoor Air Pollutants Occurrence, Measurement, Evaluation Edited by Tunga Salthammer and Erik Uhde Second, Completely Revised Edition

The Editors Prof. Dr. Tunga Salthammer Fraunhofer Wilhelm-Klauditz-Institut (WKI) Material Analysis and Indoor Chemistry Bienroder Weg 54 E 38108 Braunschweig Germany

All books published by Wiley-VCH are carefully produced. Nevertheless, authors, editors, and publisher do not warrant the information contained in these books, including this book, to be free of errors. Readers are advised to keep in mind that statements, data, illustrations, procedural details or other items may inadvertently be inaccurate. Library of Congress Card No.:

Dr. Erik Uhde Fraunhofer Wilhelm-Klauditz-Institut (WKI) Material Analysis and Indoor Chemistry Bienroder Weg 54 E 38108 Braunschweig Germany

applied for

British Library Cataloguing-in-Publication Data A catalogue record for this book is available from the British Library. Bibliographic information published by the Deutsche Nationalbibliothek Die Deutsche Nationalbibliothek lists this publication in the Deutsche Nationalbibliografie; detailed bibliographic data are available on the Internet at . © 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim All rights reserved (including those of translation into other languages). No part of this book may be reproduced in any form – by photoprinting, microfilm, or any other means – nor transmitted or translated into a machine language without written permission from the publishers. Registered names, trademarks, etc. used in this book, even when not specifically marked as such, are not to be considered unprotected by law. Composition SNP Best-set Typesetter Ltd., Hong Kong Printing betz-druck GmbH, Darmstadt Bookbinding Litges & Dopf GmbH, Heppenheim Cover Design Adam Design, Weinheim Printed in the Federal Republic of Germany Printed on acid-free paper ISBN:

978-3-527-31267-2

V

Foreword During my lectures on ‘indoor air quality’ with architectural students, I often ask them how much, in their opinion, air weighs. The most common answer I get is that 1 m3 of air must weigh just 1 g or less. They believe that air is very light. However, the weight of 1 m3 of air is 1.2 kg. Our daily breathing rate is 15∼20 m3 of air – approximately 0.3 m3 per 1 kg of body weight. Thus, we inhale and exhale approximately 20 kg of substances every day. The mass of inhaled air is much more than that of drinking water and food. Materials made from organic compounds contribute to improvement of the quality of life; on the other hand, organic chemical pollutants emitted from materials and appliances can adversely affect human health. People in developed countries spend more than 90% of their time indoors. In the light of this fact, the cleanliness of occupied spaces such as buildings, houses, and transportation systems becomes very important. In contemporary society it can be assumed that the quality of building products, houses and equipment is relatively poor. Moreover, people often suffer from pollutants caused by activities like cooking, cleaning and heating. The conservation of energy is strongly recommended from the viewpoint of saving the global environment. An air-conditioning system is often installed to obtain thermal comfort indoors; as a result, there is a marked increase in energy consumption for cooling, heating, and ventilation. With regard to buildings and their environments, the increase in life-cycle CO2 emissions has often been discussed in recent years. Approximately 40% of CO2 is emitted from the building sector, including housing. Therefore, reducing the emission of CO2 from the building sector is imperative to prevent global warming. Air-tightness and insulation are effective measures for energy conservation. Reduction in ventilation in air-conditioned spaces is often considered to be one of the most effective methods to conserve energy. However, as a result of lower air exchange rates, the indoor air concentrations of pollutants, such as volatile organic compounds (VOCs) and semi-volatile organic compounds (SVOCs) emitted from building materials and other sources, increase. This often leads to building-related symptoms if the dwell time in a polluted indoor environment is high. During the 1980s in Europe and North America and the 1990s in Japan, indoor air pollution by formaldehyde was identified and suitable countermeasures were Organic Indoor Air Pollutants. 2nd Edition. Edited by Tunga Salthammer and Erik Uhde Copyright © 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim ISBN: 978-3-527-31267-2

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Foreword

taken. Formaldehyde is a single chemical compound, and since we are already aware of the sources of emission, it is comparatively easy to control it. However, since VOCs and SVOCs consist of many substances, it is difficult to control their emissions effectively. VOCs and SVOCs are also emitted from natural materials. Moreover, a proper health risk assessment of VOC mixtures has not yet been established. Indoor air quality is an important determinant of health and well-being. To maintain better indoor air quality, we have to understand the mechanism of indoor air pollution. For this purpose, the measurement of indoor air concentration and use of chemical analysis methods are essential. To estimate indoor air concentration, we have to know the emission and ventilation rates. Emission takes place not only from building products but also from automobile parts, electric appliances, office equipment such as printers, household consumer products, and even printed materials like newspapers. This book serves as a useful guide for chemists, architects, mechanical engineers, constructors, and manufacturers of electronic products. It emphasizes a holistic and multidisciplinary approach toward the indoor environment. This book reminds us that a healthy indoor environment is essential, and provides scientific evidence and countermeasures for the future. Department of Architecture, Waseda University, Tokyo, Japan

Shin-ichi Tanabe, Prof., Ph.D.

VII

Contents Foreword V Preface to the Second Edition XVII List of Contributors XIX List of Symbols and Abbreviations XXIII Part One 1

1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 1.8.1 1.8.2 1.8.3 1.9 2 2.1 2.2 2.2.1 2.2.2 2.2.3 2.3 2.4 2.4.1

Measuring Organic Indoor Pollutants

Application of Solid Sorbents for the Sampling of Volatile Organic Compounds in Indoor Air 3 Erik Uhde Introduction 3 Solid Sorbents – A Brief Overview 4 Active or Passive Sampling 7 Thermal Desorption or Solvent Extraction 8 Sampler Design 8 Breakthrough Volumes 11 Safe Sampling Volume 11 Artifacts and Interferences 12 Water Affinity – A Chromatographic Problem 12 Sorbent Degradation Products and Sorbent Background 13 Target Compound Degradation and Artifact Formation 15 Conclusions 16 Sampling and Analysis of SVOCs and POMs in Indoor Air 19 Per Axel Clausen, Vivi Kofoed-Sørensen Introduction 19 Definitions and Properties of SVOCs and POMs 19 Gas/Particle Partitioning in Indoor Air 20 Surface Adsorption 21 Health Related Properties 22 Compounds and Matrices in the Indoor Environment 22 Sampling, Transport and Storage of SVOC/POM Samples 23 Preparation of Sampling and Analysis Equipment 23

Organic Indoor Air Pollutants. 2nd Edition. Edited by Tunga Salthammer and Erik Uhde Copyright © 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim ISBN: 978-3-527-31267-2

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Contents

2.4.1.1 2.4.1.2 2.4.1.3 2.4.1.4 2.4.2 2.4.2.1 2.4.2.2 2.4.2.3 2.4.2.4 2.4.3 2.4.3.1 2.4.3.2 2.4.4 2.4.4.1 2.4.4.2 2.5 2.5.1 2.5.1.1 2.5.2 2.6 2.6.1 2.6.1.1 2.6.1.2 2.6.1.3 2.6.1.4 2.6.1.5 2.6.1.6 2.6.2 2.6.2.1 2.6.2.2 2.6.3 2.7 2.7.1 2.7.1.1 2.7.1.2 2.7.2 2.7.3

Background Contamination and Loss of Target Compounds 23 Cleaning of Filters 24 Cleaning of Sorbents 24 Cleaning of Glassware and Other Equipment 24 Sampling SVOCs/POMs in Air 25 Filter/Sorbent Sampling 25 Determination of the Gas/Particle Partitioning: Denuder Sampling 26 Artifact Formation Caused by Reactive Gases in Indoor Air 26 Air Sampling Pumps 27 SVOCs/POMs in Surface Dust 27 Filter Sampling with Vacuum Cleaner 27 Specially Designed Dust Sampler 28 SVOCs/POMs in Building Materials and Consumer Products 28 Indoor Material Samples Containing SVOCs/POMs 28 Testing Emission of SVOCs from Indoor Materials in Chambers 28 Preparation of SVOC/POM Samples for Analysis 30 Extraction of SVOCs/POMs from Samples 30 Cleaning of Extraction Equipment 31 Concentrating Extracts of SVOC/POM Samples 32 Analysis of SVOCs/POMs 32 Gas Chromatography (GC) 32 On-Column Injection (OC) 34 Large Volume Injection (LVI) 34 Thermal Desorption (TD) 34 ‘Cold Spots’ and Other Adsorption Problems 35 Flame Ionization Detection (FID) 35 Mass Spectrometric Detection (MS) 35 High Performance Liquid Chromatography (HPLC) 36 HPLC with Fluorescence Detection (HPLC-FD) 36 HPLC with Mass Spectrometric Detection (LC-MS) 36 Analysis Sequences 36 Quality Assurance and Control 37 Method Validation 37 Calibration Curves 39 Limit of Detection (LD) and Limit of Quantification (LQ) 39 Controls and Control Charts 41 Documentation 41 References 42

3

Application of Diffusive Samplers 47 Derrick Crump Introduction 47 Principles of Diffusive Sampling 48 Selection of Appropriate Methods 50 Performance of Diffusive Samplers for the Measurement of VOCs in Indoor Air 50

3.1 3.2 3.3 3.4

Contents

53

3.5 3.6 3.7

Studies of VOCs in Indoor Air Using Diffusive Samplers Other Applications of Diffusive Samplers 59 Conclusion 59 References 60

4

Real-Time Monitoring of Indoor Organic Compounds 65 Yinping Zhang, Jinhan Mo Introduction 65 Proton Transfer Reaction – Mass Spectrometer (PTR–MS) 66 Detection Principles 66 Measuring Method 68 Accuracy, Linearity, Limits of Detection and Precision 69 Applications of PTR–MS 72 Photo-acoustic Spectroscopy 73 Detection Principles 73 Measuring System and Method 74 Discrete Sampling: Nondispersive PAS 74 Discrete Sampling: FTIR/PAS 76 Continuous Flow-PAS 76 Selectivity, Sensitivity and Accuracy 77 Applications of PAS 78 Flame Ionization Detection 78 Detection Principle 79 Measuring System and Method 79 Selectivity and Sensitivity 80 Applications of FID 80 Photo-ionization Detection 80 Detection Principles 81 Selectivity and Sensitivity 81 Applications of PID 82 Metal Oxide Sensors 83 Measuring Principle 83 Selectivity and Sensitivity 86 Air Sampling and Data Recording 87 Examples of Investigations Using Real-Time Monitoring 87 Laboratory Investigations of VOC Emissions from Building Materials 87 Experimental Principle 88 Experimental System 88 Organic Compounds in Outdoor Air 90 The Effect of Photocatalytic Oxidation on VOC Removal 91 Detection of Harmful By-Product During the Removal of Toluene by PCO 92 Evaluating the Formaldehyde Removal Performance of PCO Reactors 94

4.1 4.2 4.2.1 4.2.2 4.2.3 4.2.4 4.3 4.3.1 4.3.2 4.3.2.1 4.3.2.2 4.3.2.3 4.3.3 4.3.4 4.4 4.4.1 4.4.2 4.4.3 4.4.4 4.5 4.5.1 4.5.2 4.5.3 4.6 4.6.1 4.6.2 4.7 4.8 4.8.1 4.8.1.1 4.8.1.2 4.8.2 4.8.3 4.8.3.1 4.8.3.2

IX

X

Contents

4.8.4 4.9

5 5.1 5.2 5.3 5.4 5.5 5.6 5.7

Products of Ozone-Initiated Chemistry in a Simulated Aircraft Environment 94 Concluding Remarks 96 Acknowledgments 97 References 97 Environmental Test Chambers and Cells 101 Tunga Salthammer Introduction 101 Characteristics of Chambers and Cells 102 Sink Effects 105 Calculation of Emission Rates 106 Kinetics and Mass Transfer 108 Application of Test Chambers and Cells 109 Final Remarks 112 References 113 Part Two

6

6.1 6.2 6.2.1 6.2.2 6.2.3 6.2.4 6.3 6.4 6.4.1 6.4.2 6.5 6.6 6.6.1 6.6.2 6.6.2.1

Investigation Concepts and Quality Guidelines

Standardized Methods for Testing Emissions of Organic Vapors from Building Products to Indoor Air 119 Elizabeth Woolfenden Introduction: The Need for Standardization 119 Materials Emissions Testing: A Challenge for Method Standardization 120 The Range of Products and Materials Requiring Emissions Testing 121 The Range of Potential Target Compounds 121 Method Variability or Uncertainty 130 Nonuniformity of Test Methods 130 Regulations, Standard Methods and Test/Certification Protocols 131 Emissions Test Methods for VOCs: An Overview of Basic Principles 133 Standard test Methods for Formal Evaluation and Certification of Emissions 133 Secondary or ‘Screening’ Methods for Materials Emissions 134 The Total-VOC Debate 137 Standard Methods and Protocols for Emissions Testing: Current Status 138 Typical Conditions for Emissions Testing Using Chambers/Cells 138 Standard Methods: What Can Go Wrong? 139 Effect of the Emission Mechanism 139

Contents

6.6.2.2 6.6.2.3

6.6.2.4 6.6.2.5 6.6.2.6 6.7 6.8

7

7.1 7.2 7.3 7.3.1 7.3.2 7.3.3 7.3.4 7.3.5 7.4 7.5 7.6

8 8.1 8.2 8.2.1 8.2.2 8.2.3 8.3 8.3.1 8.3.1.1 8.3.1.2 8.3.1.3 8.3.2 8.3.2.1 8.3.2.2 8.3.2.3

Collection and Transport of Samples Plus Homogeneity Issues 140 Potential Variables Associated with Testing Materials Using Emissions Chambers/Cells: Edge Effects, Sample Orientation and Sample Storage Between Tests 140 Sink Effects 141 Target Analytes and System Calibration 141 Chromatographic Integration and Summation Limit Levels 142 Confidence Limits for Emissions Test Data for Individual VOCs 143 Concluding Remarks 143 Acknowledgments 144 References 144 Standard Test Methods for the Determination of VOCs and SVOCs in Automobile Interiors 147 Michael Wensing Introduction 147 Conditioning of the Automobile Interior 149 Measurement Procedure 151 Quantitative Determination 152 Semi-Quantitative Determination of VOCs (TVOC) 154 Qualitative Determination of VOCs (Identification) 154 Identification of SVOCs (Fogging Precipitate) 155 Measurement of the Sum of Organic Substances (ΣVOC) 155 Quantitative and Qualitative Results from Brand New Cars 156 Emissions of Organophosphate Esters inside Automobiles 159 Conclusion 161 References 161 Material and Indoor Odors and Odorants 165 Florian Mayer, Klaus Breuer, Klaus Sedlbauer Introduction 165 Odor Evaluation 167 Indoor Environments 167 Materials 168 Panels and Scales 168 Odor Analysis – Odorant Identification 172 Methods 172 Sampling of Volatiles and Odorants from Indoor Environments 174 Sampling of Volatiles and Isolation of Odorants from Materials 175 Identification 175 Examples 176 Cleaning Products, Detergents, Air Fresheners 176 Carpets 176 Adhesives 177

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Contents

8.3.2.4 8.3.2.5 8.3.2.6 8.3.2.7 8.3.2.8 8.3.2.9 8.3.2.10 8.3.3 8.3.4

8.4

9

9.1 9.2 9.2.1 9.2.2 9.2.3 9.3 9.3.1 9.3.2 9.4 9.4.1 9.4.1.1 9.4.1.2 9.4.2 9.4.3 9.4.4 9.4.5 9.5 9.5.1 9.5.2 9.6 9.6.1 9.6.2 9.7 9.8

Rubber Materials Used for Sealings, Floorings, Insulations 177 Wood 177 Wood-Based Flooring Materials 178 Linoleum 178 Gypsum-Based Products 179 Plastics 179 Electronic Devices 180 Odorants and Odor Thresholds 180 Application of the Combination of Odor Evaluation and Odor Analysis for Product Optimization 182 Conclusion and Outlook 183 References 184 Evaluation of Indoor Air Contamination by Means of Reference and Guide Values: The German Approach 189 Birger Heinzow, Helmut Sagunski Introduction 189 Definition of Terms 190 Indoor Environment 190 Utilization Cycle 190 Volatile Organic Compounds (VOCs) 191 Values for Evaluating the Indoor Air Quality 191 Toxicologically Based Values 191 Statistically Defined Values 192 Evaluation of Indoor Air Quality with the Aid of Guide Values 192 Requirements Relating to Guide Values for Indoor Air 192 Health Reference 192 Legal Reference 194 Basic Scheme for Deriving Guide Values for Indoor Air 194 Application of the Guide Values in Risk Management 196 Recommendation 197 Guide Values by the Ad-hoc WG Not Based on RW I and RW II 197 Health Evaluation with the Aid of the TVOC Concept 198 Recommendation Relating to the Application of TVOC Values 198 Time Curve of Higher TVOC Concentrations 203 Evaluation of Indoor Air Quality with the Aid of Reference Values 203 The Current State of Indoor Air Reference Values 204 Recommendations 204 Application of Measured Values in Order to Evaluate Indoor Air Quality 206 Evaluation of Substances Without Reference Values From the IRK/ AOLG Ad-hoc Working Group 207 Acknowledgment 208 References 209

Contents

Part Three 10 10.1 10.1.1 10.2 10.2.1 10.2.2 10.2.3 10.3 10.3.1 10.3.2 10.4 10.5 10.5.1 10.5.2 10.5.3 10.6

11

Field Studies

Effect of Ventilation on VOCs in Indoor Air 215 Kwok Wai Tham, S. Chandra Sekhar, Mohamed Sultan Zuraimi Introduction 215 Building and Ventilation Characteristics of Office Buildings in a Tropical Climate 216 VOC Concentration Levels in Eight Singapore Buildings 216 Concentrations 217 Health Effects Caused by VOCs in Singapore Buildings 221 Possible Sources 221 Apportionment of VOCs Source Strengths in Five Buildings 221 Area-Specific Emission Rates of VOCs 221 Source Apportionment of VOC Sources 225 Effects of Typical Ventilation Operations on TVOC Levels 227 Effect of Purging on Indoor TVOC Levels 230 Purging System 230 Building Characteristics 231 Purging Measurements 233 Summary 236 References 237

Occurrence of Semi-Volatile Organic Compounds in the Indoor Environment 239 Werner Butte 11.1 Introduction 239 11.2 Concentrations of SVOCs in Indoor Air and House Dust 240 11.2.1 Phenols and Their Derivatives (Other than Biocides) 240 11.2.2 Biocides 241 11.2.3 Musk Compounds 242 11.2.4 Organophosphates 243 11.2.5 Organotin Compounds 246 11.2.6 Perfluorinated Compounds 246 11.2.7 Phthalates 248 11.2.8 Polybrominated Diphenyl Ethers 253 11.2.9 Polychlorinated Biphenyls 253 11.2.10 Polychlorinated Dioxins and Furans 256 11.2.11 Polycyclic Aromatic Hydrocarbons 257 11.3 Sources for SVOCs Indoors 260 11.4 The Indoor Environment: A Source for Exposure? 261 11.4.1 Indoor Air and House Dust: Associations to Human Biomonitoring 261 11.4.2 Indoor Biocides: A Reason for Health Impairments? 262 11.4.3 Reference and Guideline Values 263

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Contents

11.5

Summary 264 References 265

12

Indoor Pollutants in the Museum Environment 273 Alexandra Schieweck, Tunga Salthammer, Simon F. Watts The Museum Environment: An Introduction 273 Climatic Conditions 276 Humidity 277 Temperature 278 Inorganic Atmospheric Compounds 278 Formaldehyde, Organic Acids (Formic Acid, Acetic Acid) 281 Volatile Organic Compounds (VOCs) 284 Semi-volatile Organic Compounds (SVOCs) 287 Occurrence of Biocides in the Museum Environment 288 The Role of People 291 Risk Assessment and Preservation Strategies 292 Recommendations and Guidelines 293 Conclusion 293 References 296

12.1 12.2 12.2.1 12.2.2 12.3 12.4 12.5 12.6 12.7 12.8 12.9 12.9.1 12.10

13 13.1 13.2 13.3 13.3.1 13.3.2 13.3.3 13.3.4 13.3.5 13.4 13.4.1 13.4.2 13.4.3 13.5

14 14.1 14.2 14.2.1 14.2.2 14.2.3 14.2.4

Indoor Organic Chemistry 301 Glenn Morrison Introduction 301 Relevance of Chemistry Using Indoor Air Models 302 Homogeneous Chemistry 303 Gas-Phase Organic Oxidation Chemistry: Ozone 303 Gas-Phase Organic Oxidation Chemistry: Hydroxyl Radical 308 Gas-Phase Organic Oxidation Chemistry: Nitrate Radical 309 Condensed-Phase Chemistry: Oxidation 310 Condensed-Phase Chemistry: Hydrolysis 311 Heterogeneous Chemistry 313 Heterogeneous Chemistry: Ozone and Fresh Indoor Surfaces 313 Heterogeneous Chemistry: Ozone and Soiled Surfaces 316 Heterogeneous Chemistry: Acid–Base 318 Concluding Remarks 319 References 320 Human Responses to Organic Air Pollutants 327 Lars Mølhave Introduction 327 VOC Exposures Indoors 329 Health Effects of Indoor Air Pollution 330 Indicators of Indoor Air Quality and Health 332 Classes of Indoor Air Pollutants 334 The TVOC Indicator 336

Contents

14.3 14.3.1 14.3.2 14.4

Summary of Experimental Evidence of Health Effects of VOC Exposure 337 Symptoms Relevant to VOCs 337 Effect of Exposure Types 342 Conclusions 342 References 343 Part Four Emission Studies

15

Volatile Organic Ingredients in Household and Consumer Products 349 Godwin A. Ayoko 15.1 Introduction 349 15.2 Literature Survey 350 15.3 Product Classes 351 15.3.1 Newspaper and Journals 351 15.3.2 Insecticides 356 15.3.3 Air Fresheners and Deodorizers 357 15.3.4 Cleaning Agents 358 15.3.5 Polishes 359 15.3.6 Products for Personal Hygiene and Cosmetics 361 15.3.7 Incenses 363 15.3.8 Perfumes and Fragrances 365 15.3.9 Cooking and Cooking Related Products 366 15.3.10 Miscellaneous Products and Studies 366 15.4 Conclusion 368 References 368 16 16.1 16.2 16.2.1 16.2.2 16.2.3 16.2.4 16.2.5 16.3 16.3.1 16.3.2 16.3.3 16.3.4 16.4 16.4.1

Building Products as Sources of Indoor Organic Pollutants 373 Stephen K. Brown Introduction 373 Organic Pollutants Emitted from Major Building Products 373 Building Products 373 Organic Pollutants 374 VOC Emissions Levels Over Time 375 VOC Emission Limits/Labels 376 TVOC Emissions from Building Materials 377 Interior Paints 377 Water-Based Paints 379 Solvent-Based Coatings 383 ‘Natural’ Paints 386 Low-VOC/VOC-Free Paints 387 Floor Covering Systems 388 Adhesives 388

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Contents

16.4.2 16.4.3 16.5 16.6 16.7 16.8 16.9

Carpets and Underlays 389 Plastic Floorcoverings 392 Concrete and Plaster Products Wood-Based Panels 394 Natural Wood 396 Ovens and Heaters 397 Concluding Remarks 399 References 400

17

Emission of VOCs and SVOCs from Electronic Devices and Office Equipment 405 Tobias Schripp Michael Wensing Introduction 405 Test Procedures 408 VOC and SVOC Emissions from Various Devices 414 Printers and Copiers 414 Personal Computers 419 Television Sets and Computer Monitors 421 Ultra-Fine Particle Emission from Office Devices 425 References 427

17.1 17.2 17.3 17.3.1 17.3.2 17.3.3 17.4

Index

431

393

XVII

Preface to the Second Edition The first edition of this book went to print in 1999, the year that the 8th Conference on Indoor Air Quality and Climate was held in Edinburgh, Scotland. The papers read at this last major indoor air conference of the final years of the 20th century dealt once again with the central concerns of indoor air research in the 1990s, most of which are also found in the various chapters of the first edition. As regards determination of volatile organic compounds (VOCs), the definition of the sum parameter TVOC by an European Union work group and the standardization of emissions test chambers and cells by a CEN committee may be regarded as milestones. With the introduction of the TVOC value, GC/MS thermal desorption also finally established itself as a standard method of analysis. Furthermore, during this period important fundamentals were laid down for the derivation of indoor air guide values and for product labeling. Over the last ten years, indoor air research has experienced a significant transformation and this has made substantial revisions necessary for the 2nd edition of this book. A number of chapters dealing with the topics of solid sorbents, passive sampling, automobile interiors and household products could, after updating, also be included. However, many sampling techniques and analytical methods today form part of the tools routinely used in indoor air research and are for this reason no longer treated in such detail in this new edition. On the other hand, real-time methods, sensory testing and SVOC analysis have gained in importance and have now been given their own chapters. At the present moment probably the highest level of research activity is to be found in the field of indoor chemistry. Although chemical reactions in indoor air were recognized more than 15 years ago as the source of air-polluting substances, systematic investigations have not been possible until relatively recently when the necessary measuring technology became available. A new chapter provides an overview of the state of development in this field. Two contributions are concerned with the effects on health of VOCs and SVOCs as regards exposure and the identification of guide values. Other chapters are devoted to further topics of current interest in the field of indoor air research such as ventilation concepts, museums and archives and also emissions from electronic devices.

Organic Indoor Air Pollutants. 2nd Edition. Edited by Tunga Salthammer and Erik Uhde Copyright © 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim ISBN: 978-3-527-31267-2

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Preface to the Second Edition

Despite all of these changes the book still has the same demand: to provide the reader with a clear introduction to an important area of indoor air research. We should like to express our thanks to all colleagues and friends who as authors submitted state-of-the-art contributions despite their daily workloads and other commitments. We also thank Mrs Lesley Belfit of the WILEY-VCH Verlag for her support and patience and Frau Susanne Beerstecher for organizational work. Braunschweig, May 2009

Tunga Salthammer Erik Uhde

XIX

List of Contributors Godwin A. Ayoko Queensland University of Technology School of Physical and Chemical Sciences International Laboratory for Air Quality and Health GPO Box 2434 Brisbane 4001, QLD Australia Klaus Breuer Fraunhofer Institute for Building Physics (IBP) Fraunhoferstr. 10 83626 Valley Germany Stephen K. Brown CSIRO Sustainable Ecosystems PO Box 56 Highett Victoria 3190 Australia Werner Butte Universität Oldenburg Fakultät V, Institut für reine und angewandte Chemie Carl-von-Ossietzky-Str. 9-11 26129 Oldenburg Germany

Per Axel Clausen National Research Centre for the Working Environment Lersø Parkallé 105 2100 København Ø Denmark Derrick Crump Cranfield University Institute of Environment and Health Cranfield Health Cranfield Beds, MK43 0AL UK Birger Heinzow Landesamt für soziale Dienste Dezernat Umweltbezogener Gesundheitsschutz Brunswikerstr. 4 24105 Kiel Germany University of Notre Dame School of Medicine Sydney Campus Australia Vivi Kofoed-Sørensen National Research Centre for the Working Environment Lersø Parkallé 105 2100 København Ø Denmark

Organic Indoor Air Pollutants. 2nd Edition. Edited by Tunga Salthammer and Erik Uhde Copyright © 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim ISBN: 978-3-527-31267-2

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List of Contributors

Florian Mayer Fraunhofer Institute for Building Physics (IBP) Fraunhoferstr. 10 83626 Valley Germany Jinhan Mo Tsinghua University College of Architecture Department of Building Science & Technology Beijing 100084 China Lars Mølhave Aarhus University Department of Environmental and Occupational Medicine Bartholins Allé 2 BLd 1260 8000 Aaarhus Denmark Glenn C. Morrison Missouri University of Science & Technology Civil, Architectural and Environmental Engineering 221 Butler-Carlton Hall 1401 N. Pine St. Rolla, MO 65409 USA Helmut Sagunski Behörde für Soziales, Familie, Gesundheit und Verbraucherschutz Billstraße 80 20539 Hamburg Germany

Tunga Salthammer Fraunhofer Wilhelm-Klauditz-Institute (WKI) Material Analysis and Indoor Chemistry Bienroder Weg 54 E 38108 Braunschweig Germany Alexandra Schieweck Fraunhofer Wilhelm-Klauditz-Institute (WKI) Material Analysis and Indoor Chemistry Bienroder Weg 54 E 38108 Braunschweig Germany Tobias Schripp Fraunhofer Wilhelm-Klauditz-Institute (WKI) Material Analysis and Indoor Chemistry Bienroder Weg 54 E 38108 Braunschweig Germany Klaus Sedlbauer Fraunhofer Institute for Building Physics (IBP) Fraunhofer Straße 10 83626 Valley Germany Chandra Sekhar National University of Singapore School of Design and Environment Department of Building 4 Architecture Drive Singapore 117566 Singapore

List of Contributors

Kwok Wai Tham National University of Singapore School of Design and Environment Department of Building 4 Architecture Drive Singapore 117566 Singapore

Michael Wensing Fraunhofer Wilhelm-Klauditz-Institute (WKI) Material Analysis and Indoor Chemistry Bienroder Weg 54 E 38108 Braunschweig Germany

Erik Uhde Fraunhofer Wilhelm-KlauditzInstitute (WKI) Material Analysis and Indoor Chemistry Bienroder Weg 54 E 38108 Braunschweig Germany

Elizabeth Woolfenden Markes International Ltd. Gwaun Elai Campus Llantrisant RCT CF72 8XL UK

Simon F. Watts Victoria University Wellington Department of Geographical, Earth and Environmental Sciences 2 Kelburn Parade Kelburn Wellington 6012 New Zealand

Yinping Zhang Tsinghua University College of Architecture Department of Building Science & Technology Beijing 100084 China Mohamed Sultan Zuraimi National University of Singapore School of Design and Environment Department of Building 4 Architecture Drive Singapore 117566 Singapore

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XXIII

List of Symbols and Abbreviations A ACH ADI AM APM APS AQG ASHRAE ASTM BaP BHT BREC BRI BRS BTV C or C(t) C0 CS CAPs CEN CFU CIB CMD CPC d δ D Dp DBP DEHP DIBP

sample surface air exchange acceptable daily intake arithmetic mean airborne particulate matter aerodynamic particle sizer air quality guidelines American Society of Heating, Refrigerating and AirConditioning Engineers American Society for Testing and Materials benzo[a]pyrene 2,6-di-tert-butyl-4-methyl-phenol building related environmental complaints building related illness building related symptoms breakthrough volume concentration initial concentration vapor pressure [mg/m3] concentrated air particles European Committee for Standardization colony forming unit National Council for Building Research, Studies and Documentation count median diameter condensation particle counter distance boundary layer thickness molecular diffusity (diffusion coefficient) particle diameter di-n-butylphthalate di-(2-ethylhexyl)phthalate di-isobutylphthalate

Organic Indoor Air Pollutants. 2nd Edition. Edited by Tunga Salthammer and Erik Uhde Copyright © 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim ISBN: 978-3-527-31267-2

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List of Symbols and Abbreviations

DINP DMA DMPS DNPH DOP EC ECA ECD EDS EDXRF ELISA ELPI EM EPA EPXMA ETS FAAS FID FLEC FT-IR GC GFAAS GM GSD h HDM HPLC HVAC IAP IAQ IC ICP-AES ICP-MS INAA ISIAQ ISO I/O k1 i2 ki (i > 2) L LOAEL LOEL LOI LR

di-isononylphthalate differential mobility analyzer differential mobility particle sizer dinitrophenylhydrazine di-octylphthalate electrostatic classifier European Collaborative Action electron capture detector energy dispersive spectrometer energy dispersed X-ray fluorescence enzyme linked immunosorbent assay electrical low pressure impactor electron microscopy Environmental Protection Agency electron probe X-ray microanalysis environmental tobacco smoke flame atomic absorption spectrometry flame ionization detector field and laboratory emission cell Fourier transform infrared spectroscopy gas chromatography graphite furnace atomic absorption spectrometry geometric mean geometric standard deviation height house dust mite high performance liquid chromatography heating ventilating air conditioning system indoor air pollution indoor air quality ion chromatography inductively coupled plasma – atomic emission spectrometry inductively coupled plasma – mass spectrometry instrumental neutron activation analysis International Society of Indoor Air Quality and Climate International Organization for Standardization indoor/outdoor source strength air exchange (modeling) rate constant loading factor [m2/m3] lowest observed adverse effect level lowest observed effect level loss on ignition leak rate (test chamber) [h−1]

List of Symbols and Abbreviations

m M M0 MCS MD MS MVOC N (or n) Np NDIR NOAEL NOEL OEL OPC OSHA OT P PAD PAH PAN PAS PCB PCDD PCDF PCP PCR PID PIXE PM PM2.5 PM10 POM PPN PUF q Q QSAR r RH RI RPM RSD RSP RT SBS

mass mass in source initial mass in source multiple chemical sensitivity median mass spectrometry microbiological originated volatile organic compounds air exchange rate [h−1] particle concentration non-dispersive infrared no observed adverse effect level no observed effect level occupational exposure limit optical particle counter Occupational Safety and Health Administration odor threshold [mg/m3] percentile photo-acoustic detector polycyclic aromatic hydrocarbon peroxyacetyl nitrate photoelectric aerosol sensor (or photoacoustic spectroscopy) polychlorinated biphenyl polychlorinated dibenzo-p-dioxin polychlorinated dibenzofuran pentachlorophenol polymerase chain reaction photo-ionization detector particle induced X-ray emission particulate matter suspended particulate matter (− 80 °C)

Low

>400 °C

Low – medium

Graphitized carbon blacks

12–100

Carbotrap, Carbopack, Carbograph

Thermal

Non-polar VOCs (>60 °C)

Low

>400 °C

Low

Styrene, divinylbenzene or polyvinylpyrrolidone polymers

300–800

Porapak Q/N, Chromosorb 106/102,

Thermal/ solvent

Non-polar and moderately polar VOCs (>40 °C)

Variable

60 °C)

Low

> ks the emission is controlled by the external diffusion process and the thickness of the boundary layer δ is directly related to the air velocity above the surface. This applies to most wet-applied or liquid products during the drying/curing phase. In this case, the air flow conditions in the test facility (i.e., air velocity and turbulence) are important. This means that precise control of the air velocity may be critical in the short term (i.e., 1–14 days) if it is not to influence the emission test result. For kg 80% toluene and n-C12 (chambers)

Used as a check against ‘sink effects’ within the chamber/cell

Target analyte range

Formaldehyde and VOCs (n-hexane to n-hexadecane)

Very volatile and semi-volatile organic compounds also considered

Samplers for vapors in cell/chamber exhaust

DNPH cartridges for formaldehyde Tenax TA or alternative sorbent for VOCs

When using Tenax TA tubes for VOCs, max volume restricted to 5L

Detection limits

2 μg/m3 vapor concentration in exhaust stream from chamber/cell

Analysis technique

Formaldehyde – HPLC of DNPH derivative VOCs – TD-GC-MS/FID

Larger chambers allow larger (more representative) samples to be tested, but need much longer to equilibrate.

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by various regulators and standards organizations. Screening methods have been proposed, for example, by:

• • • •

ECHA for release of chemicals from articles under REACH (ECHA, 2008a); EC mandate M/366 for the CPD; ASTM (ASTM, 2008); various industries (GUT, 2008; VDI, 2008).

Under M/366 and the CPD, one suggestion is that screening or initial test methods could be used to demonstrate that a product or material can be classed as ‘without further testing’ (WFT), allowing manufacturers to short-cut the full certification process. Regulators on both sides of the Atlantic are also keen to provide manufacturers with a cost-effective means of demonstrating that a product continues to conform to emissions limits in between formal certification tests. From industry’s perspective; screening methods would also facilitate in-house checks on batch-to-batch product uniformity/conformity, at-line quality control, confirmation of the results of external certification tests and demonstration of emission profile consistency across a product range (e.g., demonstrating identical emission profiles from different colored versions of the same product, to minimize the requirement for formal certification testing). Practical and quick screening methods would also contribute to the development of low emissions products by allowing manufacturers to test new products during development and by enabling them to compare their own materials against recognized ‘best-in-class’ products. At the current time, few analytical methods have been developed for emissions screening from construction products. Examples of the types of method available include EN ISO 11890-2 for measuring the organic content of paint, VDA 278 for screening car-interior trim components for volatile and semi-volatile (fogging compound) emissions, the GUT screening method for flooring emissions and VDI 2083-17 for screening emissions from products used to construct and furnish clean-room fabrication facilities (see Table 6.1). Screening methods used to date for VOCs have typically involved either direct GC analysis of the ‘volatile’ content of products which are applied as liquids (paints, coatings, etc.) or direct thermal desorption/extraction of small samples of solid or liquid-applied products and materials. The challenge for developing useful screening methods is to find something that meets the criteria of speed, simplicity and cost, but that still produces data which correlates with results from standard emissions testing methods. The issue with organic content testing is that results rarely correlate to emissions from the respective products after they are applied/installed. Manufacturers of paint or paint additives, for example, can design products that contain solvent, but in which that solvent is encapsulated such that it can never escape to the indoor environment. Content testing is also unsuitable as a guide to emissions from most composite products. Significant discrepancies may additionally be observed between data from direct thermal desorption and standard emissions testing methods. In this case, the differences are primarily the result of:

6.5 The Total-VOC Debate

•

The high temperatures used for direct thermal desorption/extraction. Note that emissions testing is conventionally carried out at room temperature (Table 6.2) whereas VDA Method 278 for example requires desorption temperatures of 90 and 120 °C for volatiles and ‘fogging’ compounds respectively.

•

Direct thermal desorption is usually carried out on bulk samples, that is, with emissions from multiple surfaces rather than just one exposed surface.

•

Direct thermal desorption is normally limited to relatively small sample sizes ($100 000 (∼€8500 to >€85 000), this is, in most cases, prohibitively expensive. Samples are thus often removed from the test chamber in between tests (for example between tests at 3 and 28 days) and only replaced in the chamber or cell 72- or 24-hours respectively before a measurement needs to be made. Control of the sample storage conditions during this period is critical. Temperature, humidity and levels of atmospheric contaminants in the storage containers must be maintained at, or as near as possible to, the conditions specified for the emission test itself. Storage containers must also be well ventilated and care must be taken to prevent cross-sample/ product contamination. 6.6.2.4 Sink Effects Emission test chambers/cells and associated air supply and ventilation/air mixing equipment must be nonemitting/-absorbing and designed to minimize still air volumes and risk of ‘sink effects’ within the chamber/cell, that is; the apparatus must be designed to prevent condensation of organic vapors on the inner surfaces of the chamber or cell. Tests for higher boiling organic emissions are particularly prone to sink effects which cause emission rates to be underestimated and may also increase risk of background contamination in subsequent tests of other samples with the same apparatus. Most well recognized emissions test methods/ protocols require assessment of sink effects in the apparatus by introduction of pure standards of toluene, n-C12 and key compounds of interest (especially if they include polar compounds or analytes less volatile than n-C12). Such checks are an essential part of analytical quality assurance for material emissions testing methods. 6.6.2.5 Target Analytes and System Calibration Extensive lists of target analytes, if associated with stringent calibration requirements (e.g., requiring authentic standards for every identified compound) can sometimes increase test costs without necessarily reducing analytical uncertainty. In fact, difficulties in sourcing and preparing large numbers (>50) of authentic compounds in mixed standards and the time taken for subsequent multilevel calibration of the analytical system with all these standards, can even add to measurement uncertainty in extreme cases. For example, if the time taken for multilevel calibration extends over several days, it is possible for the system response to have drifted significantly over the period reducing confidence in the subsequent data. Other difficult to characterize contributions to variability can also creep in, for example, analyte interactions and the general stability of mixed standards. While there is an understandable demand from regulators and consumers to quantify as many emitted compounds as possible, as accurately as possible, there needs to be a balance between the desire to use authentic standards in each case and the need to ensure that the calibration process is practicable to carry out over a reasonable time period. Calibrating with fewer compounds, for example a mix

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containing ∼10 compounds, including components which are broadly representative of the range of chemical compounds of interest, can be achieved more reproducibly, quickly (and affordably) and thus lead to a higher degree of confidence in subsequent analytical data. Care must certainly be taken to ensure that any and all compounds, specified as target analytes in emissions test standards/protocols, are compatible with the analytical methodology used. For example; many standard emission test methods have evolved to focus on GC-compatible VOC components, ranging in volatility from n-hexane to n-hexadecane (n-C6 to n-C16). The rationale for this is that more volatile or reactive emissions should disappear so quickly after product installation that they are unlikely to affect the health or quality of life of building occupants. However, this takes no account of multilayer products where VVOC emissions may be slowed by a coating, or the potential for very volatile organics to continue to be produced by chemical processes within a material (e.g., degradation of an additive) long after installation. Similarly, SVOC emissions are traditionally considered to present a lower risk because their vapor-phase concentration in ambient air is, by definition, very low. These considerations have led to most standard emissions test methods and protocols focusing on Tenax TA sorbent for trapping/sampling vapor-phase organics from the exhaust stream of chambers/cells. Tenax is a relatively weak sorbent, offering only 6 l retention volume for n-hexane in a standard tube at 20 °C. However, it has other useful properties such as low artifact levels, efficient desorption/ release characteristics and excellent hydrophobicity (water passes through almost unretained provided the sorbent trap/tube is not cooler than the sampled air/gas). Provided the volume of vapor pumped onto the sorbent tube is kept below 5 l, most GC-compatible organics within the n-C6 to n-C16 volatility range will be quantitatively retained by the Tenax during vapor sampling and will be efficiently desorbed during subsequent analysis. However, restricting the vapor trapping/sampling medium to Tenax means that more volatile compounds – n-pentane, vinylchloride, propanol, methyl chloride, etc. – cannot be included among lists of target analytes. It also means that vapor sampling volumes must be restricted to 5 l or less. More information on the potential toxicity of some common semi-volatile additives such as phthalates (Larson et al., 2008; ECHA, 2008b), has also caused a recent increase in demand for the accurate measurement of much higher boiling compounds, species that cannot be completely recovered from Tenax TA. These developments have led to increased focus on additional sorbents, which can be used in conjunction with Tenax TA (i.e., in the same sorbent tube) in order to increase the target analyte volatility range without increasing measurement costs. (ISO DIS 16000-6, 2008; CEN TC 351 WG 2, 2008) 6.6.2.6 Chromatographic Integration and Summation Limit Levels Potential concerns with TVOC (and total SVOC [TSVOC]) have been discussed above. For TVOC or TSVOC data to be of any value, even for the intercomparison of different batches of the same product, care must be taken to ensure that exactly the same procedure is used for each TVOC or TSVOC measurement.

6.8 Concluding Remarks

Other potential causes of discrepancy include variable integration results (Oppl, 2008) resulting from components which are not adequately chromatographically resolved. This can be particularly significant when trace target compounds are required to be measured at levels that are close to system or method detection limits. New enhanced software data-processing tools are becoming available to address this (Rosser et al., 2008), but if such data is interpreted by unskilled analysts without access to appropriate advanced data processing tools, the potential for error remains.

6.7 Confidence Limits for Emissions Test Data for Individual VOCs

As has been described, conventional material emissions testing is a multistep process involving sample selection, transport and storage, emissions testing using chambers/cells, vapor sampling and, finally, TD–GC–MS–FID analysis. Each stage of this process introduces some level of uncertainty. By way of comparison it is worth noting that even the most rigorous air monitoring methods for individual vapor-phase VOCs, for example EN 14662-1 (2005) for ambient benzene, quote confidence limits in the order of 15%. This methodology involves pumped sampling of ppb-level vapor onto sorbent tubes with subsequent TD–GC(–MS) analysis and is analogous to the latter stages of material emissions testing except that only one compound is involved. A reasonable estimate of the confidence that could be expected for pumped tube sampling and TD–GC–MS–FID analysis of multiple ppb-level VOCs (for example using EN/ISO 16017-1 or ASTM D 6196) is 25–30%. If the additional variables of sample selection, transport and preparation and chamber/cell emissions testing are taken into account, overall uncertainty for emissions testing methods is likely to be in the range 30–50%, even with best practice. Pass/fail criteria in associated test protocols and product standards, must take this into account.

6.8 Concluding Remarks

Recent regulatory developments at state, national and international level suggest that certification of products, according to their emissions, is expected to become mandatory across much of the developed world for building materials and related products. This will affect both manufacturers and importers. Harmonization, simplification and validation of relevant standard test methods/ protocols are all essential steps if emissions testing is to become as widespread as regulators and consumers desire, without burdening industry with unjustified extra cost. Failure to achieve this could reduce confidence in materials emissions testing generally and thus undermine the overall objective. It could also jeopardize

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the survival of smaller specialist producers and those from the developing world as well as having an adverse impact on product diversity, none of which is socially desirable. Parallel development of broadly-applicable and meaningful emissions screening methods will be another important factor in facilitating the development of improved ‘low-emission’ materials and in allowing emissions testing to become an accepted part of routine in-house quality control during product manufacture. Similar attention needs to be paid to broadening the base of competent and accredited emissions test laboratories to ensure competitive rates for certification testing. Perhaps the greatest challenge will be to achieve consensus on harmonization of standard methods/protocols. National standard methods, or those adopted by one specific industry group or labeling scheme, are often defended vigorously by the proponents of each individual scheme, unwilling to modify a procedure in which they, and their user-base, will have made significant investment. However, failure to address this issue head-on and as soon as possible could lead to the promulgation of more and more independent emission test methods/schemes which will ultimately increase the burden on manufacturers wanting to supply into more than one geographical or market sector. Current international efforts in this area, for example the program of work on horizontal emissions standards for construction products planned by CEN TC 351 in response to EC Mandate M/366, should be warmly welcomed and further liaison with other geographies and industry groups encouraged. Material emissions testing is also beginning to move out from the construction products sector and into furnishings, furniture and other equipment. Given the recent adoption of REACH in Europe and the Green Chemical act in California and the associated focus on chemical emissions from consumer goods in general, this trend is set to continue. If the construction products industry and associated test laboratories have already ‘blazed a trail’ in terms of developing reliable and cost-effective test methods, it is likely that these methods will be extrapolated, where appropriate, to products and materials in other sectors.

Acknowledgments

I would like to acknowledge the contribution of Dr Derrick Crump, BRE, UK and Prof Tanabe, Waseda University, Tokyo, Japan in preparation of this text.

References Afshari, A., Lundgren, B. and Ekberg, L.E. (2003) Comparison of threee small chamber test methods for VOC emission rates from paint. Indoor Air, 13, 156–65. AFSSET (2004) Protocol 2004/011. Relatif a une procedure d’evaluation des risques

sanitaires concernant les composes organiques volatils (COV) et le formaldehyde emis par les produits de construction. AgBB/DIBt (2001) (last updated 2008) Health-related evaluation procedure for volatile organic compound emissions from

References building products, DIBt-Mitteilungen 1/2001, 3-12, http://www. umweltbundesamt.de/building-products/ agbb.htm (accessed 20 April 2009). Akutsu, T., Kumagai, K., Uchiyama, S. and Tanabe, S. (2000) Development of a measurement device (ADSEC) for aldehyde emissions rates using a diffusive sampler. Proceedings of Healthy Buildings, Helsinki, Finland, Vol. 4, pp. 477–83. ASTM (2008) WK22044 Proposed draft Standard Practice for: Micro-scale test chambers for screening vapor-phase organic emissions from materials/ products. CEN (2008) TC351 WG2. WI 351009 Working Draft Umbrella Standard for Testing Emissions from Construction Products To Indoor Air Under M/366 and the CPD. Collaborative for High Performance Schools(2004) Reference Specifications for Energy and Resource Efficiency, Section 01350, Special Environmental Requirements, http://www.chps.net/ manual/documents/Sec_01350.doc (accessed 20 April 2009). Daumling, C., Brenske, K.-R. and Crump, D. (2008) Harmonisation of material emission labelling schemes in the EU. Paper ID: 1074, Proceedings of Indoor Air ’08, 17–22 August 2008, Copenhagen, Denmark. ECA (2005) IAQ Report 24: Harmonisation of existing indoor material emissions labelling systems in the EU: inventory of existing schemes. ECHA (2008a) Guidance on requirements for substances in articles, European Chemicals Agency ECHA-08-GF-03-EN, http://echa.europa.eu/reach_en.asp (accessed May 2008). ECHA (2008b) Press Release /PR/08/34, ECHA member state committee agrees on the identification of 14 substances of very high concern, European Chemicals Agency, Helsinki, Finland. EC Mandate (2005) M/366EN Development of Horizontal Standardised Assessment Methods for Harmonised Approaches Relating to Dangers Substances under the Construction Products Directive, European Commission Enterprise and Industry DG. EN (2005) 14662-1. Ambient Air Quality – Standard Method for the

Measurement of Benzene Concentrations. Part 1: Pumped Sampling Followed by Thermal Desorption and Gas Chromatography Method, CEN. Finnish M1 Label for Finishing Materials, (2009) http://www.rts.fi/M1classified.htm (updated 2009). Fox, M. (2007) The Danish Indoor Climate Label (DICL) – An Introduction to the Danish/Norwegian concept. Proceedings Construction Products and Indoor Air Quality, Conference, Berlin, Germany. GEV EMICODE® (2001) Labelling Scheme for Flooring Installation Products including flooring adhesives, primers and levelling compounds http://www.emicode.com/ gev-uk/gev.htm GUT (2008) ECO-label for carpet: test method for screening VOC-emissions from textile floor coverings, http://193.201.162.104/ (accessed Dec 2008). Hansen, V., Larsen, A. and Wolkoff, P. (2000) Nordic round-robin emission testing of a lacquer: consequences of product inhomogeneity. Proceedings of Healthy Buildings, Helsinki, Finland, Vol. 4, pp. 99–104. HEMICPD (2009) HEMICPD Project, VITO, Belgium, Final report publication expected March 2009, http://www.wtcb.be\go\ hemicpd (accessed Jan 2009). Howard-Reed, C., Nabinger, S. and Persilly, A. (2008) Assessing the uncertainty associated with product emission measurements. Proceedings of Indoor Air ’08, Copenhagen, Denmark. ISO (2008) DIS16000-6. Indoor Air – Part 6: Determination of VOCs in Indoor and Test Chamber Air by Active Sampling on Tenax TA Sorbent, Thermal Desorption and Gas Chromatography Using MS/FID, International Organization for Standardization, Geneva, Switzerland. Jann, O., Wilke, O. and Brödner, D. (1999) Entwicklung eines Prüfverfahrens zur Ermittlung der Emission flüchtiger organischer Verbindungen aus beschichteten Holzwerkstoffen und Möbeln, Texte 74/99, Umweltbundesamt, Berlin, Germany. Larson, M., Sundell, J., Kolarik, B., HagerhedEngman, L. and Bornehag, C.-G. (2008) The use of PVC flooring material and the

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6 Testing Emissions of Organic Vapors from Building Products to Indoor Air development of airway symptoms among young children in Sweden. Proceedings of Indoor Air ’08, Copenhagen, Denmark, Paper 862. Oppl, R. (2008) Reliability of VOC emission chamber testing – progress and remaining challenges. Gefahrstoffe Reinhaltung der Luft, 68 (3), 83–6. Ries, F. (2005) (Rapporteur) Report on the European Environment and Health Action Plan 2004–2010. Dutch and Luxembourg Presidency Conferences in December 2004 and June 2005 (Final A6-0008/2005). Roache, N., Guo, Z. and Tichenor, B.A. (1996) Comparing the FLEC with traditional emissions chambers, in Characterising Sources of Indoor Air Pollution and Related Sink Effects (ed. B. Tichenor), ASTM STP 1287, Philadelphia, PA, USA, pp. 98–111. Rosser, D., Roberts, G. and Woolfenden, E. (2008) Enhancing GC-MS analysis of trace compounds using a dynamic approach to

reducing background interference, LC-GC The Column, July ’08, www.thecolumn.eu. com (accessed August 2008). Schripp, T., Nachtwey, B., Toelke, J., Salthammer, T., Uhde, E., Wensing, M. and Bahadir, M. (2007) A micro-scale device for testing emissions from materials for indoor use. Analytical and Bioanalytical Chemistry, 387, (5) 1907–19. VDI (2008) 2083-17. Cleanroom Technology – Compatibility with Required Clean Lines Class and Surface Clean Lines, Verein Deutscher Ingenieure, Düsseldorf, Germany. WHO (2006) Development of WHO guidelines for indoor air quality, Report on a working group meeting: Bonn, De 23–34 Oct, 2006, Regional Office for Europe, Copenhagen, Denmark. Wolkoff, P., Salthammer, T. and Woolfenden, E.A. (2005) Emission cells and comparison to small chambers for materials emissions testing. Gefahrstoffe – Reinhaltung der Luft, 65 (3), 93–8.

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7 Standard Test Methods for the Determination of VOCs and SVOCs in Automobile Interiors Michael Wensing

7.1 Introduction

Inside air in automobiles is influenced by a large number of different factors. Air pollutants from various sources inside and outside the automobile can effect the inside air composition, see Figure 7.1. It is important to take into consideration the possible exposure of vehicle occupants since automobile drivers can spend a considerable part of the day in the vehicle, as results of relevant studies in the USA have shown. One study, for example, states that most people spend one to four hours per day in the automobile (Weisel, Lawrik and Lioy, 1992). According to another source (Park et al., 1996) adults spend on average around 7% of their day (approx. 1.7 h) in a motor vehicle. One important type of air pollutant is organochemical compounds. Their occurrence is linked to the interior components, such as seats, dashboard, headliner and carpeting, which are made of a wide range of different materials. These materials vary in their composition as well as in their internal chemical structure. To obtain their necessary and desirable characteristics and to facilitate their production a large variety of organochemical substances needs to be used, such as plasticizers, flame retardants and other additives (Wensing, Uhde and Salthammer, 2005). After completion of the production process, these materials emit chemical compounds with a wide range of volatilities into the air inside the car: these substances may be roughly divided into volatile organic compounds (VOCs) and semi-volatile organic compounds (SVOCs). High temperatures encourage those emissions which can cause undesirable effects in the car’s interior. On the one hand these can cause car users to complain of annoying odors or even to experience health problems, while on the other hand the semi-volatile part of the compounds has been observed to condense as a ‘fogging’ film on the inner side of the windscreen. Together with soot and dust particles, this film impairs the transparency of the windscreen. The driver’s view is further impaired if the screen has a small inclination (Eisele, 1987; Möhler and Schönherr, 1992; Munz et al., 1994). To reduce these disadvantageous effects and to eliminate them as far as possible, comprehensive and reliable information about the types

Organic Indoor Air Pollutants. 2nd Edition. Edited by Tunga Salthammer and Erik Uhde Copyright © 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim ISBN: 978-3-527-31267-2

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7 Standard Test Methods for the Determination of VOCs and SVOCs in Automobile Interiors

Figure 7.1 Air pollutants from different sources indoors and outdoors affect automobile inside air composition.

of organic compounds in the inside air of automobiles and also their concentrations, time behavior and origin is required. In the meantime a large number of studies concerning the measurement of organochemical compounds inside the automobile have been published (e.g., Fine, Reisch and Rounbehler, 1980; Smith and Baines, 1982; Zweidinger et al., 1982; Dropkin, 1985; Ullrich, Seifert and Nagel, 1992; Fromme et al., 1998a, 1998b; Fedoruk and Kerger, 2003; Brown and Cheng, 2003; Zhang et al., 2006; Yoshida and Matsunage, 2006; Yoshida et al., 2006a, 2006b; Meininghaus et al., 2007; Chien, 2007). These measurements were carried out under various conditions: outdoors or indoors, as well as in motion. In some cases the temperature inside the car was increased using a heater. Air samples were simply taken directly from the car’s interior or through a covered-up window-opening by means of an adsorption tube and a small pump. The samples were analyzed by GC with various detectors. The procedure for examining VOCs followed a similar procedure to that for the semivolatile ‘fogging’ substances (SVOCs). The vehicles were either in use or parked outdoors with their windows closed and exposed to the sun. As a rule the fogging film which developed on the inside of the screen was scraped off with a clean razor blade and then examined by GC and IR spectroscopy (Carter, Jensen and McCallum, 1987; Nranian, McCallum and Kelly, 1987; Munz et al., 1994). On the basis of the results from such studies many car manufacturers are today embarking on a strategy of avoiding unwanted emissions right from the very start of the development and production of new automobiles. many test methods exist for the selection of low-emitting materials and interior components (VDA, 1992, 1994, 1995, 2002, 2005; Meyer et al., 1994; Toyota, 2003; Hoshino et al., 2005; Schripp et al., 2007). To measure VOCs and SVOCs inside complete cars under standardized conditions at TÜV NORD in Hamburg a special test stand has been developed during the course of a 5-year research and development project (Bauhof, 1994; TÜV NORD, 1996; Bauhof et al., 1996) and has also been used frequently (Wensing and

7.2 Conditioning of the Automobile Interior

Schwampe, 1989–2002; Lüssmann-Geiger and Schmidt, 1995; Schmidt and Lüssmann-Geiger, 1996). The test stand investigations described below are very useful to automobile manufacturers within the framework of development projects for new automobiles or as part of the production quality assurance: They can then obtain valid data regarding possible emission sources in the vehicle interior and their emission potential. However, results from such studies on a test stand will not be automatically suitable for exposure evaluations in every case. For healthrelated aspects only those measured values should be used which have been obtained under conditions similar to the actual use of an automobile under a realistic exposure scenario. For the interpretation of test stand results it is very important to be aware that the air temperature and the air exchange rate in the vehicle interior can be fundamentally different in test stand investigations and during the driving situation. Depending on the ventilation system setting, the air exchange rate in the traveling vehicle is up to approx. 240 per hour (Schmidt and Lüssmann-Geiger, 1996) and is therefore higher than the air exchange of a stationary vehicle by a multiple (approx. 0.5–1 per hour), or that of other indoor spaces. In other words test stand investigations can be subdivided on the basis of two fundamentally different goals; the principle focus of the test stand methods described below and the corresponding test protocol is to determine materialspecific emission data with the aid of vehicle-specific emission rates (ER). If exposure is to be considered insofar as it affects health the boundary conditions of the investigations (air exchange, temperature) would need to be modified to correspond to a realistic exposure scenario. In principle investigations of this kind are also possible once the test conditions have been correspondingly adapted.

7.2 Conditioning of the Automobile Interior

The concentration of VOCs and SVOCs in the automobile interior during the test stand procedure is essentially influenced by the following factors:

• •

age of the automobile; the strength of the emissions from numerous individual sources in the interior fittings and also from the hollow spaces with a connection to the interior of the car;

•

decomposition reactions in the form of adsorption and absorption on the surface of materials, including chemical conversions (e.g., formation of salt from base and acid combinations, oxidation of aldehydes, and so on);

•

gas exchanges between the passenger compartment and the atmosphere outside the car;

•

contamination by external sources close to the car, from extraneous disturbing emissions from building materials and furnishings in the test bay, and from the outside atmosphere.

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For a representative analysis of the emissions, these measurements should only be taken when the condition of the interior atmosphere is stable. This will be the case if certain effects that increase or decrease the concentration of emissions are balanced and are not subjected to any further change. This is why the precise conditioning of the car’s interior is of utmost importance in adjusting and retaining a defined state of equilibrium. These requirements are met by standardizing the experiment’s set-up and procedure. All vehicles are tested on a test stand and always in the same location. Only a standardized interface consisting of an aluminum sheet is used for inserting probes into the car’s interior for air sampling. The sheet is fitted into the car’s open window and sealed. All connections leading into the interior are airtight. As a rule the set-up includes the following: several sensors to register the temperature at different places inside the interior and to measure the humidity, a mechanical system for air circulation, a glass probe to extract several samples of air simultaneously (analysis of VOCs), a device to take samples of phthalates directly, and a device to enrich the fogging precipitate (SVOCs). The test protocol logged for the experiments usually depends on the particular question which has been asked. The essential conditions for the surroundings, however, are as follows:

•

The temperature of the inside air has to be adjusted to 23 °C (ambient air temperature), 45 °C and 65 °C which are defined as standard temperatures for the inside air.

•

The air has to be kept in constant circulation by mechanical means and thus homogenized.

• •

The heating of the interior is effected from outside the car by radiators. If large samples of air are taken from the interior of the car, ultra-pure gas must be added to balance the draw-off. Figure 7.2 is a diagram of the test stand showing:

• •

provision of ultra-pure gas (A) of defined humidity;

• •

a vehicle (B) to carry probes, with an arm and a standardized interface;

• •

a system for taking air samples;

semi-automatic heating-up device with its controller (H), provision of electricity (G) and the four radiator fields (F) which are attached to a support above the front and the rear windows, the roof and the right-hand side window;

various measuring instruments and data-recording equipment (C) for the continuous recording of measured signals (e.g., for eleven spots for temperature measurement, three spots for humidity measurements, one FID signal and also signals from other measuring instruments);

a gate (K) for entry into and exit from the test car.

7.3 Measurement Procedure

Figure 7.2 Arrangement of the main components of the test stand.

Figure 7.3 shows partial views of the test stand for inside air measurements in automobiles. Detailed information about the test stand may be found in TÜV NORD (1996). Figure 7.4a shows a long-term standard test cycle with measurements taken at room air temperature and at 45 °C and 65 °C and including artificial ageing periods. This cycle was used for the measurement of new automobiles during a 5-year research and development program at TÜV NORD (1996). For routine measurements a modified short-term test protocol is in use with measurements at room temperature and at 65 °C without ageing (see Figure 7.4b). More than 150 different automobiles have now been tested on the basis of this short-term test protocol.

7.3 Measurement Procedure

In the interior of a modern automobile, the presence of a large variety of individual VOCs and SVOCs can be demonstrated. They can roughly be categorized as follows:

•

VOCs responsible for the smell of brand new cars: alkanes, aromatic hydrocarbons, carbonyl compounds, residual monomers, alcohols, esters, ethers, halogenated hydrocarbons, terpenes, nitrogen and sulfur compounds;

•

SVOCs responsible for the ‘fogging’ effect: paraffins, higher fatty acids and esters, phthalates, phosphoric acid esters, organosilicon compounds, halogenated hydrocarbons, oxygen, nitrogen and sulfur compounds.

The concentrations range from a few hundred μg/m3 to less than 1 μg/m3 of inside air. High standards of sensitivity and selectivity are required for the analytical methods. The analysis is complicated by water vapor which is released from water stored in the textile surfaces when the vehicle heats up. This can have a

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7 Standard Test Methods for the Determination of VOCs and SVOCs in Automobile Interiors

Figure 7.3 Different partial views of the test stand for inside air measurements of automobiles.

disturbing effect on sampling and analysis. It is therefore essential that for the analysis of the air inside cars procedures are employed which have been specially validated and also tested in practice. 7.3.1 Quantitative Determination

The standard procedures for the determination of important substance classes can be summarized: Aromatic hydrocarbons • Sampling: charcoal tubes, type NIOSH • Sample preparation: desorption with carbon disulfide • Analysis: GC−MS, SIM-Mode; column: DB5, 60 m × 0.25 mm × 0.25 μm

7.3 Measurement Procedure

Figure 7.4 (a) Long-term standard test cycle. (b) Short-term standard test cycle.

Glycol ethers • Sampling: charcoal tubes, type NIOSH • Sample preparation: desorption with dichloromethane / methanol • Analysis: GC−MS, SIM mode; column: DB-WAX, 60 m × 0.25 mm × 0.25 μm Aldehydes / ketones Sampling: derivatization with DNPH in acetonitrile Analysis: HPLC with ODS-Hypersil/RP8e and LiChrospher 100RP-8e UV detection at 360 nm

• • •

Phthalic acid esters • Sampling: glass fiber filter with Florisil tubes • Sample preparation: desorption with acetonitrile • Analysis: HPLC, ODS-Hypersil • UV detection at 234 nm

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7 Standard Test Methods for the Determination of VOCs and SVOCs in Automobile Interiors

Amines • Sampling: silica gel tubes • Sample preparation: derivatization (FMOC-CL) • Analysis: HPLC, ODS Hypersil • UV detection at 263 nm

with

9-fluorenylmethylchloroformate

Nitrosamines • Sampling: Thermosorb N tubes • Sample preparation: desorption with dichloromethane/methanol • Analysis: GC−MS, SIM mode, PCI • Column: DB-WAX, 60 m × 0.25 mm × 0.25 μm The results of the quantitative measurements are given as concentrations of substances, expressed in mass per unit volume (e.g., μg/m3, standardized for gas under the following conditions: temperature 20 °C, pressure 1013 hPa, dry). As a rule these measured values relate only to the time span of the sampling and the condition of the car’s interior at that time. If the potential emission of a substance i is to be determined, the emission rate ER must be calculated on the basis of the measured concentration: ER = Q totC i ( μg h )

(7.1)

Qtot (m3/h) is the volume flow at which the interior atmosphere is exchanged while measuring the concentration. It is determined experimentally by tracer gas methods (e.g., TÜV NORD, 1996). 7.3.2 Semi-Quantitative Determination of VOCs (TVOC)

The VOCs in the inside air are enriched by means of active sampling on Tenax TA tubes, which are thermodesorbed. After internal standards have been added, analysis is carried out by capillary GC−MS. The hundred compounds on the chromatogram which have the most intense signals are identified by retention index and mass spectrum (Wensing, Schulze and Salthammer, 2002), and are then semi-quantitatively evaluated with toluene as the reference substance. The toluene equivalents are summed, and this result serves as a semi-quantitative estimation of the total VOC concentration (TVOC). 7.3.3 Qualitative Determination of VOCs (Identification)

Although samples are taken and prepared in the same way here as in the semiquantitative analysis, in the evaluation of the complex spectra of the substances, the multi-dimensional GC technique (GCGC−MS) is employed. This consists of two series-connected GCs combined with an MS detector. As a rule, the process

7.3 Measurement Procedure

Figure 7.5 Apparatus for the collection of SVOCs.

is adjusted in such a way that polar compounds containing heteroatoms are extracted from the non-polar hydrocarbon matrix (which is of no interest) and identified. The laborious work of identification is facilitated by a special powerful database program that works on the principle of standardized retention time indices (Wensing et al., 2002). 7.3.4 Identification of SVOCs (Fogging Precipitate)

The samples are taken from the surface of the two cooled glass plates of a special apparatus (Figure 7.5) which is exposed to the air inside the car at the standardized interface. The glass plates (P) are mounted on both sides of the cooling body (K). The body is hollow inside with a coolant running through it. The temperature of the cooling body is registered by a rod-shaped measuring sensor which is introduced into the drilled hole (F) and reaches right into the center of the plate. While the samples are being taken, the vehicle is heated to increase emissions and thus to speed up the collection of substances. Conceptually, the procedure leans on the sample-taking technique of DIN 75201 (1992). After the sample is taken, the film which built up on the glass plates is washed off with organic solvent. The solution is then concentrated and analyzed by GC−MS. 7.3.5 Measurement of the Sum of Organic Substances (ΣVOC)

For each experiment on a vehicle at the test stand, a FID is used for the sum determination of total organically fixed carbon in the inside air. In this way it is possible to follow the relative dependence of the total concentration of VOCs on various influences, and at the same time the state of the inside air can be continuously documented.

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7 Standard Test Methods for the Determination of VOCs and SVOCs in Automobile Interiors

Figure 7.6 Decrease in the sum of VOCs for six brand new cars during artificial ageing at 65 °C.

7.4 Quantitative and Qualitative Results from Brand New Cars

In an experiment lasting several years, six brand new cars were tested at the test stand for 40 days. For 8 hours each day the inside air was heated up to 65 °C (artificial ageing). At the beginning and after 20 and 40 days the air was characterized by means of the standardized measurement procedures described above (TÜV NORD, 1996). As the sum of VOCs results (FID) in Figure 7.6 show, the measured values for concentrations and calculated ER decrease rapidly over time. The shape of the curve follows a simple exponential function. The calculated emission rate is directly linked to the source strength of the various interior components. The resulting concentration is also influenced by the air tightness of the car cabin. In accordance with the FID measurements, the decrease in the intensities of the individual signals and the clear change in their pattern can be seen in the VOC gas chromatogram (Figure 7.7). Calculation of the measured values of TVOC (toluene equivalents, TE) from the gas chromatogram of the six vehicles results in the following ranges:

7.4 Quantitative and Qualitative Results from Brand New Cars

Figure 7.7 Changes in the VOC gas chromatogram for brand new cars during artificial ageing.

• • •

new condition: 7000–24 000 μgTE/m3; after 20 days of ageing: 2500–10 000 μgTE/m3; after 40 days of ageing: 1000–4500 μgTE/m3.

Measured values of ER are given for a selection of VOCs in Table 7.1. Generally, emission decreases from high measured values at the beginning to lower ones subsequently. Because of these effects, the conclusion can be drawn that the processes are controlled by evaporation. Substances at the surface or in

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7 Standard Test Methods for the Determination of VOCs and SVOCs in Automobile Interiors Table 7.1 Emission rates of selected VOCs: arithmetical mean of six different new cars (TÜV NORD, 1996).

Substance

Benzene Toluene Ethylbenzene m/p-Xylene o-Xylene Styrene 2-Methoxyethanol 2-Ethoxyethanol 2-Butoxyethanol 2-Ethoxyethyl acetate 2-Butoxyethyl acetate 1-Methoxypropyl acetate Formaldehyde Acetaldehyde Propanal n/iso- Butyraldehyde Pentanal Hexanal Benzaldehyde Acetone Methylethyl ketone Methylisobutyl ketone Di-n-butyl phthalate Dimethylamine Diethylamine Di-n-butylamine N-nitrosodimethylamine

New vehicle

24 275 434 965 272 369 3.4 2.6 68 4.4 25 104 40 44 15 19 29 42 10 361 85 755 0.7 9.0 9.6 54 0.20

ER (μg/h) After 20 days of ageing

After 40 days of ageing

22 78 38 95 37 88 0.7 0.7 12 1.4 8.6 24 52 30 9.5 7.2 14 25 34 143 13 78 0.8 3.1 8.1 14 0.12

27 73 18 46 20 68 0.8 0.7 5.6 1.3 9.5 6.8 43 29 13 7.2 16 13 11 116 7.5 47 2.0 2.5 5.7 59 0.07

layers near the surface of the materials of the interior furnishings are desorbed rapidly. However, there are exceptions to these reactions, such as the aldehydes. Here, diffusion-controlled emissions can be assumed. In a slow and steady process, diffusions from the inside of the material take place which fade away only after a longer period of time. In both cases, textiles and textile (laminated) compound materials play an essential part as storage media and as a reversible interim store for chemical substances due to their strong sorption ability (Ehrler, Schreiber and Haller, 1994). The apparatus described in Figure 7.5 was used for the accumulation of SVOCs. The accumulation capacity during the experiments amounted to 10 μg of film mass per glass plate per hour at a constant inside air temperature of 65 °C. Examples of SVOCs found in fogging films are listed below:

7.5 Emissions of Organophosphate Esters inside Automobiles

Hydrocarbons: alkanes, n-alkanes (CI3-C32); branched alkanes Alcohols: 2-ethylhexanol, octadecanol. Amines: 1,4-diazabicyclo-2,2,2-octane; dicyclohexylamine, methyldicyclohexylamine; dis-dimethylaminodiethyl ether; N,N-dimethylpentadecylamine. Amides: tridecylcycloacetamide; pentadecylcycloacetamide. Aromatic carbonic acid esters: dibutyl, dioctyl, di-(2-ethylhexyl) phthalate; dioctyladipate, dioctylsebacate, trihexyltrimellitate. Fatty acids: lauric acid; stearic acid. Fatty acid esters: palmitic acid butyl ester; palmitic acid 2-ethylhexyl ester; stearic acid 2-ethyhexyl ester; dibutyl adipate. Phenols: 2-(1,1-dimethylethyl)-phenol; 2,6-di-tert-butyl-4-methylphenol (BHT); 2,6- di-tert-butyl-4-ethylphenol; 2,6- di-tert-buyyl-4-methoxymethylphenol. Phosphates: tris-(2-chloroethyl) phosphate; tris-(1-chloro-iso-propyl) phosphate; tris-(1,3-dichloro-iso-propyl) phosphate. Other compounds: benzoic acid; 2-ethylhexaneacid; erucic acid amide; siloxanes.

7.5 Emissions of Organophosphate Esters inside Automobiles

In a special exposure study (Wensing, Pardemann and Schwampe, 2003) concerning SVOCs, the passenger compartments of eight new automobiles were tested on the automobile test stand for the emission of organophosphate esters both at room air temperature (RT; approx. 20 °C) and in a heated-up state at 65 °C. The collecting phase used for sampling the organophosphate esters was an XAD-2 (500 mg) specially cleaned with upstream glass wool using various solvents (acetone, methanol, dichloromethane). A quantitative assessment (VDI 4301-5, 2009) of the organophosphates was carried out using solvent desorption (dichloromethane) and GC−MS evaluation (DB 1701, HP 5890/HP 5989A) using original standard solutions (Aldrich) and applying the internal standard method (13C12DDE) in SIM mode (VDI 4301-5, 2009). Table 7.2 shows the concentration ranges of the organophosphate esters that were measured under test stand conditions at RT and 65 °C in the inside air of the eight different new vehicles from different manufacturers. The influence of the temperature on the release of the organophosphate esters used as flame retardants and/or plasticizers can be clearly seen here. Whereas at RT the individual compounds could either not be detected or were clearly below 1 μg/m3, at 65 °C comparably higher concentrations were measured. For this reason the present study also carried out measurements with one car (vehicle V-X) under traveling conditions with regard to an exposure evaluation of organophosphate esters immediately subsequent to the test stand investigations. For results see Table 7.3. In the test stand measurements at 65 °C individual cases of concentration values were obtained. As expected, however, the present measurements under traveling conditions have clearly revealed that after a few minutes no

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7 Standard Test Methods for the Determination of VOCs and SVOCs in Automobile Interiors Table 7.2 Organophosphate esters, chemical names, synonyms and concentration ranges (μg/m3) for RT and 65 °C (Wensing, Pardemann and Schwampe, 2003).

Chemical name

Synonym

Concentration, RT (μg/m3)

Concentration, 65 °C (μg/m3)

Tributyl phosphate Tris(2-butoxyethyl) phosphate Tris(2-ethylhexyl) phosphate Triphenyl phosphate Tricresyl phosphate Tris(2-chloroethyl) phosphate Tris(chloropropyl) phosphate Tris(2,3-dichloro-1-propyl)phosphate

TBP TBEP TEHP TPP TCP TCEP TCPP TDCPP