CONTENTS
Foreword .................................................................. iii
Abstract ................................................................... iv
Abbreviations ............................................................... vii
Glossary ................................................................... ix
Acknowledgments ........................................................... xi
1. INTRODUCTION ................................................... 1
2. BACKGROUND .................................................... 2
2.1 Composition and Uses of Asphalt ................................ 2
2.2 Manufacture of Asphalt Roofing Products . ........................ 2
2.3 Manufacture of Roofing Asphalts ................................ 2
2.4 Asphalt Roofing Products and Systems . . . ........................ 4
2.4.1 Asphalt Shingles and Roll Roofing .................... 4
2.4.2 BUR Systems ..................................... 4
2.4.3 Modified Bitumen Roofing Systems ................... 5
3. MANUFACTURE OF ASPHALT ROOFING PRODUCTS ................ 6
3.1 Primary Manufacturing Processes .............................. 6
3.1.1 Air-Blowing ...................................... 6
3.1.2 Supporting Operations .............................. 6
3.2 Manufacturing Line ......................................... 9
3.2.1 Saturant Asphalt Felt ............................... 9
3.2.2 Asphalt Shingles and Roll Goods ..................... 9
3.2.3 Modified Bitumen Products . . ....................... 13
4. OCCUPATIONAL EXPOSURE TO ASPHALT FUMES ................. 16
4.1 Occupational Exposure Limits ................................ 16
4.2 Potential for Exposure ...................................... 16
4.3 Operations and Jobs with Potential for Asphalt Fume Exposure ..... 22
5. GUIDELINES FOR PROTECTING WORKERS ........................ 23
5.1 Delivery, Handling, and Storage .............................. 23
5.1.1 Engineering Controls .............................. 23
5.1.2 Work Practices ................................... 24
vi
5.2 Saturators ................................................ 24
5.2.1 Engineering Controls .............................. 24
5.2.2 Work Practices ................................... 24
5.2.3 Equipment Substitution ............................ 26
5.3 Modified Bitumen Impregnation Vats .......................... 26
5.4 Coaters .................................................. 26
5.4.1 Full Enclosure ................................... 26
5.4.2 Canopy Hood .................................... 27
5.5 Surfacing and Subsequent Processes ........................... 28
5.6 Work Practices and PPE .................................... 28
6. RESEARCH NEEDS .............................................. 30
REFERENCES ............................................................. 31
APPENDIX—Respirators ..................................................... 35