Vinyl Chloride - Texas Commission on Environmental Quality

<strong>Vinyl</strong> chloride
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TABLE OF CONTENTS
CHAPTER 1 SUMMARY TABLES..........................................................................................................................4
CHAPTER 2 MAJOR USES OR SOURCES ...........................................................................................................5
CHAPTER 3 ACUTE EVALUATION......................................................................................................................6
3.1 HEALTH-BASED ACUTE REV AND ESL ...............................................................................................................6
3.1.1 Physical/Chemical Properties and Key Studies ..........................................................................................6
3.1.1.1 Physical/Chemical Properties................................................................................................................................6
3.1.1.2 Essential Data and Key Studies............................................................................................................................. 6
3.1.1.2.1 Human Studies.............................................................................................................................................. 6
3.1.1.2.2 Animal Studies.............................................................................................................................................. 7
3.1.2 Mode-of-Action (MOA) Analysis and Dose Metric .....................................................................................7
3.1.3 Point of Departure (POD) for the Key Study ..............................................................................................8
3.1.4 Dosimetric Adjustments ..............................................................................................................................8
3.1.4.1 Default Exposure Duration Adjustments............................................................................................................... 8
3.1.5 Critical Effect and Adjustment of PODHEC..................................................................................................8
3.1.6 Health-Based Acute ReV and acute ESL.........................................................................................................8
3.1.7 Special Considerations................................................................................................................................8
3.2 WELFARE-BASED ACUTE ESLS...........................................................................................................................9
3.2.1 Odor Perception..........................................................................................................................................9
3.2.2 Vegetation Effects .......................................................................................................................................9
3.3 SHORT-TERM ESL AND VALUES FOR AIR MONITORING EVALUATION................................................................9
3.4 COMPARISON OF RESULTS .................................................................................................................................10
CHAPTER 4 CHRONIC EVALUATION...............................................................................................................10
4.1 NONCARCINOGENIC POTENTIAL ........................................................................................................................10
4.1.1 Physical/Chemical Properties and Key Studies ........................................................................................10
4.1.1.1 Human Studies .................................................................................................................................................... 10
4.1.1.2 Animal Studies.................................................................................................................................................... 10
4.1.1.2.1 Key Study ................................................................................................................................................... 10
4.1.1.2.2 Supporting Studies...................................................................................................................................... 11
4.1.2 MOA Analysis and Dose Metric................................................................................................................14
4.1.3 POD for Key and Supporting Studies........................................................................................................15
4.1.4 Dosimetric Adjustments ............................................................................................................................15
4.1.4.1 Exposure Duration Adjustments ......................................................................................................................... 15
4.1.4.2 Default Dosimetry Adjustments from Animal-to-Human Exposure ................................................................... 16
4.1.5 Adjustment of PODHEC and Critical Effect................................................................................................16
4.1.5.1 Critical Effect...................................................................................................................................................... 16
4.1.5.2 Uncertainty Factors ............................................................................................................................................. 16
4.1.6 Health-Based Chronic ReV and chronic ESLnonlinear(nc) ..................................................................................16
4.1.7 Comparison of Results ..............................................................................................................................16
4.2 CARCINOGENIC POTENTIAL ...............................................................................................................................17
4.2.1 Carcinogenic Weight-of-Evidence ............................................................................................................17
4.2.2 MOA Analysis ...........................................................................................................................................18
4.2.3 Key Studies................................................................................................................................................18
4.2.3.1 Human Epidemiologic Studies............................................................................................................................ 18
4.2.3.2 Animal Studies.................................................................................................................................................... 18
4.2.4 Dose-Response Assessment.......................................................................................................................19
4.2.4.1 Dose Metrics and Potency Estimates Based on Human Epidemiological Studies............................................... 19
4.2.4.1.1 USEPA (2000) ............................................................................................................................................ 19
4.2.4.1.2 Clewell et al. (2001).................................................................................................................................... 20
4.2.4.2 Dose Metrics and Potency Estimates Based on Animal Data.............................................................................. 20
4.2.4.2.1 USEPA (2000) ............................................................................................................................................ 20