PEER REVIEW DRAFT - DO NOT CITE OR QUOTE United States Office of Chemical Safety and Environmental Protection Agency Pollution Prevention Draft Risk Evaluation for Carbon Tetrachloride Supplemental File: Occupational Exposure Assessment CASRN: 56-23-5 January 2020 PEER REVIEW DRAFT -DO NOT CITE OR QUOTE TABLE OF CONTENTS/ ABBREVIATIONS ....................................................................................................................................7 EXECUTIVE SUMMARY .......................................................................................................................9 1 INTRODUCTION ............................................................................................................................11 1.1 Overview .....................................................................................................................................11 1.2 Scope ...........................................................................................................................................11 1.3 General Approach and Methodology for Occupational Exposures ............................................17 Process Description and Worker Activities ........................................................................... 17 Number of Workers and Occupational Non-Users ................................................................ 17 Inhalation Exposure Assessment Approach and Methodology ............................................. 17 1.3.3.1 General Approach ........................................................................................................... 18 1.3.3.2 Approach for this Risk Evaluation ................................................................................. 19 Dermal Exposure Assessment Approach and Methodology ................................................. 19 Environmental Release Assessment Approach and Methodology ........................................ 20 2 ENGINEERING ASSESSMENT ....................................................................................................21 2.1 Domestic Manufacturing .............................................................................................................21 Process Description ............................................................................................................... 21 Exposure Assessment ............................................................................................................ 21 2.1.2.1 Worker Activities ........................................................................................................... 21 2.1.2.2 Number of Potentially Exposed Workers ....................................................................... 22 2.1.2.3 Occupational Exposure Results ...................................................................................... 23 2.2 Import and Repackaging .............................................................................................................24 Process Description ............................................................................................................... 25 Exposure Assessment ............................................................................................................ 25 2.2.2.1 Worker Activities ........................................................................................................... 26 2.2.2.2 Number of Potentially Exposed Workers ....................................................................... 26 2.2.2.3 Occupational Exposure Assessment Methodology ........................................................ 27 2.2.2.4 Occupational Exposure Results ...................................................................................... 27 2.3 Processing as a Reactant or Intermediate ....................................................................................27 Process Description ............................................................................................................... 27 Exposure Assessment ............................................................................................................ 28 2.3.2.1 Worker Activities ........................................................................................................... 28 2.3.2.2 Number of Potentially Exposed Workers ....................................................................... 28 2.3.2.3 Occupational Exposure Assessment Methodology ........................................................ 30 2.3.2.3.1 Inhalation Exposure Assessment Results Using Monitoring Data ......................... 30 2.3.2.3.2 Inhalation Exposure Assessment Results Using Surrogate Data ............................ 31 2.4 Incorporation into Formulation, Mixture, or Reaction Product ..................................................31 2.5 Specialty Uses – Aerospace Industry ..........................................................................................32 2.6 Specialty Uses - Department of Defense Data ............................................................................32 Data Overview ....................................................................................................................... 33 OBOD Clean-Up Process Description................................................................................... 34 Exposure Assessment ............................................................................................................ 34 2.7 Reactive Ion Etching ...................................................................................................................35 Page 2 of 94 PEER REVIEW DRAFT -DO NOT CITE OR QUOTE Process Description ............................................................................................................... 35 Exposure Assessment ............................................................................................................ 35 2.7.2.1 Worker Activities ........................................................................................................... 35 2.7.2.2 Number of Potentially Exposed Workers ....................................................................... 36 2.8 Industrial Processing Agent/Aid .................................................................................................36 Process Description ............................................................................................................... 36 Exposure Assessment ............................................................................................................ 38 2.8.2.1 Worker Activities ........................................................................................................... 38 2.8.2.2 Number of Potentially Exposed Workers ....................................................................... 38 2.8.2.3 Occupational Exposure Assessment Methodology ........................................................ 39 2.8.2.4 Occupational Exposure Results ...................................................................................... 39 2.9 Additive .......................................................................................................................................39 Process Description ............................................................................................................... 39 Exposure Assessment ............................................................................................................ 40 2.9.1.1 Worker Activities ........................................................................................................... 40 2.9.1.2 Number of Potentially Exposed Workers ....................................................................... 40 2.9.1.3 Occupational Exposure Assessment Methodology ........................................................ 41 2.9.1.4 Occupational Exposure Results ...................................................................................... 41 2.10 Laboratory Chemicals .................................................................................................................41 Process Description ............................................................................................................... 41 Exposure Assessment ............................................................................................................ 41 2.10.2.1 Worker Activities ........................................................................................................... 41 2.10.2.2 Number of Potentially Exposed Workers ....................................................................... 42 2.11 Disposal/Recycling......................................................................................................................43 Process Description ............................................................................................................... 43 Exposure Assessment ............................................................................................................ 47 2.11.2.1 Worker Activities ........................................................................................................... 47 2.11.2.2 Number of Potentially Exposed Workers ....................................................................... 48 2.11.2.3 Occupational Exposure Assessment Methodology ........................................................ 49 2.11.2.4 Occupational Exposure Results .....................................................................................