16 Draft Supplemental Information on Releases and Occupational
Total Page:16
File Type:pdf, Size:1020Kb
PEER REVIEW DRAFT – DO NOT CITE OR QUOTE United States Office of Chemical Safety and Environmental Protection Agency Pollution Prevention Draft Risk Evaluation for Methylene Chloride (Dichloromethane, DCM) DCM Supplemental File: Supplemental Information on Releases and Occupational Exposure Assessment CASRN: 75-09-2 H Cl H Cl October 2019 NOTICE: This information is distributed solely for the purpose of pre-dissemination peer review under applicable information quality guidelines. It has not been formally disseminated by EPA. It does not represent and should not be construed to represent any Agency determination or policy. It is being circulated for review of its technical accuracy and science policy implications. Page 1 of 294 PEER REVIEW DRAFT, DO NOT CITE OR QUOTE TABLE OF CONTENTS ABBREVIATIONS ..................................................................................................................................13 1 INTRODUCTION ............................................................................................................................15 1.1 Overview .....................................................................................................................................15 1.2 Scope ...........................................................................................................................................15 1.3 Components of the Occupational Exposure and Environmental Release Assessment ...............22 1.4 General Approach and Methodology for Occupational Exposures and Environmental Releases 22 Process Description ............................................................................................................... 22 Facility Estimates and Number of Workers and Occupational Non-Users ........................... 22 Worker Activities ................................................................................................................... 23 Inhalation Exposure Assessment Approach and Methodology ............................................. 23 1.4.4.1 General Approach ........................................................................................................... 23 1.4.4.2 Approach for this Risk Evaluation ................................................................................. 25 1.4.4.3 Respiratory Protection .................................................................................................... 25 Dermal Exposure Assessment Approach ............................................................................... 27 Water Release Assessment Approach ................................................................................... 27 2 ENGINEERING ASSESSMENT ....................................................................................................28 2.1 Manufacturing .............................................................................................................................28 Process Description ............................................................................................................... 28 Number of Sites and Potentially Exposed Workers .............................................................. 29 Exposure Assessment ............................................................................................................ 30 2.1.3.1 Worker Activities ........................................................................................................... 30 2.1.3.2 Inhalation Exposures ...................................................................................................... 30 Water Release Assessment .................................................................................................... 31 Uncertainties .......................................................................................................................... 33 2.2 Processing as a Reactant .............................................................................................................33 Process Description ............................................................................................................... 33 Number of Sites and Potentially Exposed Workers .............................................................. 33 Exposure Assessment ............................................................................................................ 34 2.2.3.1 Worker Activities ........................................................................................................... 34 2.2.3.2 Inhalation Exposures ...................................................................................................... 34 Water Release Assessment .................................................................................................... 35 Uncertainties .......................................................................................................................... 35 2.3 Processing - Incorporation into Formulation, Mixture, or Reaction Product ..............................36 Process Description ............................................................................................................... 36 Number of Sites and Potentially Exposed Workers .............................................................. 36 Exposure Assessment ............................................................................................................ 37 2.3.3.1 Worker Activities ........................................................................................................... 37 2.3.3.2 Inhalation Exposures ...................................................................................................... 37 Water Release Assessment .................................................................................................... 38 Uncertainties .......................................................................................................................... 39 2.4 Repackaging ................................................................................................................................39 Process Description ............................................................................................................... 39 Number of Sites and Potentially Exposed Workers .............................................................. 40 Page 2 of 294 PEER REVIEW DRAFT, DO NOT CITE OR QUOTE Exposure Assessment ............................................................................................................ 41 2.4.3.1 Worker Activities ........................................................................................................... 41 2.4.3.2 Inhalation Exposures ...................................................................................................... 42 Water Release Assessment .................................................................................................... 43 Uncertainties .......................................................................................................................... 43 2.5 Batch Open-Top Vapor Degreasing ............................................................................................44 Process Description ............................................................................................................... 44 Number of Sites and Potentially Exposed Workers .............................................................. 45 Exposure Assessment ............................................................................................................ 45 2.5.3.1 Worker Activities ........................................................................................................... 45 2.5.3.2 Inhalation Exposures ...................................................................................................... 45 Water Release Assessment .................................................................................................... 46 Uncertainties .......................................................................................................................... 46 2.6 Conveyorized Vapor Degreasing ................................................................................................46 Process Description ............................................................................................................... 46 Number of Sites and Potentially Exposed Workers .............................................................. 50 Exposure Assessment ............................................................................................................ 50 2.6.3.1 Worker Activities ........................................................................................................... 50 2.6.3.2 Inhalation Exposures ...................................................................................................... 50 Water Release Assessment .................................................................................................... 51 Uncertainties .......................................................................................................................... 51 2.7 Cold Cleaning ..............................................................................................................................51 Process Description ............................................................................................................... 51 Number of Sites and Potentially Exposed Workers .............................................................