Montana Tech Library Digital Commons @ Montana Tech Graduate Theses & Non-Theses Student Scholarship Spring 2016 COMPARISON OF SAMPLE METHODS AND RESULTS FOR HEXAVALENT CHROMIUM EXPOSURES AT LANGLEY AFB Ericka Crosley Montana Tech of the University of Montana Follow this and additional works at:http://digitalcommons.mtech.edu/grad_rsch Part of theOccupational Health and Industrial Hygiene Commons Recommended Citation Crosley, Ericka, "COMPARISON OF SAMPLE METHODS AND RESULTS FOR HEXAVALENT CHROMIUM EXPOSURES AT LANGLEY AFB" (2016).Graduate Theses & Non-Theses. 86. http://digitalcommons.mtech.edu/grad_rsch/86 This Non-Thesis Project is brought to you for free and open access by the Student Scholarship at Digital Commons @ Montana Tech. It has been accepted for inclusion in Graduate Theses & Non-Theses by an authorized administrator of Digital Commons @ Montana Tech. For more information, please [email protected]. COMPARISON OF SAMPLE METHODS AND RESULTS FOR HEXAVALENT CHROMIUM EXPOSURES AT LANGLEY AFB by Ericka Crosley A report submitted in partial fulfillment of the requirements for the degree of Master of Science Industrial Hygiene Distance Learning / Professional Track Montana Tech 2016 1 Abstract Various exposure limits and analytical methods are recommended for hexavalent chromium exposures. While the OSHA standard is legally binding, NIOSH and ACGIH recommendations should be considered as well when determining personnel overexposures. Hexavalent chromium is linked to severe acute and chronic effects, including cancer. The United States Air Force currently uses NIOSH methods 7600 and 7605 to sample for hexavalent chromium. This research analyzed if personnel are being overexposed, in addition to comparing NIOSH 7600 and NIOSH 7605 results to determine if both methods are required, or if one can be used in place of both. The results of the sample data analysis indicated that hexavalent chromium samples obtained with both NIOSH methods exceeded the OSHA PEL of 5 ug/m3In addition, this study revealed that there were no significant differences in hexavalent chromium samples concentrations obtained with both methods. Keywords: Hexavalent Chromium, NIOSH 7600, NIOSH 7605 2 Dedication To my late mother, my father and step-mother, thank you for all of your support. To my daughter Ella – mommy is almost done being busy and we will get to go on a real vacation very soon. 3 Acknowledgements Thank you to all the staff at Montana Tech of the University of Montana. 4 Table of contents ABSTRACT ................................................................................................................................................ 1 DEDICATION ............................................................................................................................................ 2 ACKNOWLEDGEMENTS ............................................................................................................................ 3 LIST OF FIGURES ....................................................................................................................................... 6 LIST OF EQUATIONS ................................................................................................................................. 7 1. INTRODUCTION ................................................................................................................................. 8 2. BACKGROUND ................................................................................................................................. 11 2.1. Coating and Primer .......................................................................................................... 11 2.2. Depaint/Paint Process ...................................................................................................... 11 2.3. Toxicology ........................................................................................................................ 13 2.4. Respiratory Effects ........................................................................................................... 14 2.5. Cancer .............................................................................................................................. 14 3. LITERATURE REVIEW ......................................................................................................................... 16 4. RESEARCH DESIGN AND METHODS ...................................................................................................... 19 4.1. Sampling Methods ........................................................................................................... 19 4.2. Data Collection ................................................................................................................. 20 4.3. Data Analysis .................................................................................................................... 21 4.4. Limitations........................................................................................................................ 22 5. RESULTS ......................................................................................................................................... 23 6. DISCUSSION, CONCLUSIONS, RECOMMENDATIONS FOR FUTURE RESEARCH .................................................. 32 REFERENCES CITED ................................................................................................................................. 33 APPENDIX A: SAMPLE DATA AND RESULTS ............................................................................................ 36 7. MINITAB DATA ................................................................................................................................ 42 5 APPENDIX B: SCREENSHOTS OF DATA PULL PROCESS ............................................................................ 44 6 List of Figures Figure 1 - NIOSH Method 7600 Sample Data 1................................................................23 Figure 2 - NIOSH Method 7605 Sample Data 1................................................................24 Figure 3 - Lognormal Plot Method 7600 1 ........................................................................25 Figure 4 - Lognormal Plot Method 7605 1 ........................................................................26 Figure 5 - Comparison of methods 1 ................................................................................27 Figure 6 - Method 7600 Histogram 1 ................................................................................28 Figure 7 - Method 7605 Histogram 1 ................................................................................28 Figure 8 - Test for Equal Variances 1 ................................................................................29 Figure 9 - Confidence Interval Plot 1 ................................................................................30 Figure 10 - Minitab Data Point Plot 1 ...............................................................................30 Figure 11. Line of Best Fit 1 ............................................................................................31 7 List of Equations Equation (1) – Assigned Protection Factor(APF) .............. Error! Bookmark not defined. Equation (Equation 1- APF calculation .............................................................................12 (1) 12 Equation 3- Sample Concentration Calculation .................................................................22 Equation Equation 1- APF calculation ..............................................................................12 (1) 12 Equation 3- Sample Concentration Calculation .................................................................22 8 1. Introduction United States Air Force flightline personnel assigned to the Aerospace Ground Equipment shop at Langley Air Force Base are responsible for maintaining aircraft and missile (weapons systems) structure by removing and re-applying coatings that help protect the weapon systems’ metallic and/or composite surface. Maintenance of the coatings is important in order to prevent corrosion and/or deterioration, which can shorten the life-span of the weapons systems, thus endangering personnel and negatively impacting mission accomplishment (IERA, 2000). The coatings used by the Air Force protect the weapons systems from oxidation reactions that degrade the surface and structural support capabilities of the metal or composite material. Since oxygen is present in all environments, it is important for the Air Force to inhibit corrosion of these coatings. Hexavalent chromium (CrVI) is a corrosion inhibitor, and is present as chromic acid in the pretreatment and as metallic chromate in the primer used for aircraft corrosion control. The most common worker exposures occur during application and/or removal of the pretreatment or primer (IERA, 2000). Application usually occurs via pressurized hoses or hand-held spray guns, during which aerosols are generated that can enter the workers’ breathing zone and present an inhalation hazard. Removal, or depainting, is typically performed by mechanical sanding, which can cause release of airborne particulates containing chromates into the worker’s breathing zone. Hexavalent chromium is corrosive to the eyes, skin, and respiratory tract (ICSC, 2016). Repeated or prolonged exposures via inhalation may cause asthma, kidney impairment, and may cause heritable genetic damage to human germ cells; animal tests show that hexavalent chromium may cause toxicity to human reproduction or development (ICSC, 2016). It is a well- established carcinogen associated with lung cancer and nasal and sinus cancer, in addition to