1. Characterizing Toxicity and Risks of Hydraulic Fracturing Fluid Additives Andrew Pawlisz, DABT ERT(UK) - Senior Toxicologist/Risk Assessor Image placeholder December 2015 Dallas, TX

2. Outline 1.Introduction 2.Risk messaging to public in media 3.Risk assessment process 4.Reported events 5.Hypothetical drill rig worker risk assessment 6.Conclusions

3. Shale Gas & Oil Exploration Increased application of hydraulic fracturing worldwide First experiment in 1947 Over 40 North American shale plays Over 1 million operations completed in US Expansion projected despite the 2015 drop Lifting oil export ban?

4. Surface Spills Process Sensitive Receptor

5. Over 30,000 drilled wells in contiguous counties

6. Relatively clean alternate fossil energy source More energy per CO 2 than coal Reduction in reliance on imports Reduction in carbon emissions due to switching from coal Concerns with environmental impacts, groundwater, flowback/produced water, and air quality Regulatory, public, and political pressures Attribution challenge: conventional vs. unconventional Vidic (2013) Regulatory and Public Issues

7. Public Interest in Fracking Fxstreet (2015) Google Keyword Counts for “fracking” Production Drop

8. Risk Information: Media 2013

9. Risk Information: Media 2015

10. Risk Assessment Process Hazard Identification Toxicity Evaluation Exposure Assessment Risk Characterization Risk Management

12. Conceptual Exposure Model

13. Reported Events King (2011)

14. Reported Events Surface Water: - Illegal dumping (Hunt 2013) - Pennsylvania and North Dakota (Kusnetz 2012) - Blacklick Creek, PA - Stevens Creek, PA (PR 2013) - Monongahela River, PA - Mahoning River, OH - Brush Run, PA - Ten Mile Creek, PA

15. Reported Events Frac Fluid (on-Site): - Accidental releases (Wiseman 2013) - Alleged exposure of worker/nurse in Durango, CO (Tsou 2012) - Blow-outs (TCCG 2011) - BMPs and controls designed to prevent exposure (Nygaard 2013) Frac Fluid (off-Site): - Releases to pastures in PA (PP 2010) and LA (PP 2009) - Treatment system residual emissions in PA (Olmstead 2012) - Spills (Bamberger 2012&2015) - Transportation accidents (King 2012) - Blow-outs - Endocrine disruptor activity (Kassotis 2015)

16. Exposure Potential: Worker

17. Chemical Identity Inbound Media: −Typically a fresh water solution fortified with chemicals and propping media to aid in fracking −1:10,000 to 1:100,000 dilutions of chemicals (Gordalla 2013) Outbound Media: −E.g., NaCl, hydrocarbons (e.g., benzene), elements (e.g., As, Ba, Sr, Ra, Rn, U, Th, Fe, K) −Formation-specific −Not unique to fracking except for media additives −Proposed as more problematic (Gordalla 2013)

18. Chemical Identity USEPA identified 1,000 chemicals (USEPA 2012) 347 unique CAS entries Trade secret constituents generally exempt from public disclosure Frac fluid composition (Fontaine 2008): - Water (99%) - Proppants (1.9%) - Friction reducers (0.025%) - Disinfectants (0.05%) - Surfactants (0.002%) - Thickeners (not common) - Scale inhibitors - Corrosion inhibitors (0.5%) - Acids

19. Analytical Methods Proposed Analytical Methods (USEPA 2012): Alcohols: SW-846 Methods 5030 and 8260C Aldehydes: SW-846 Method 8315 Alkylphenols: No standard method Alkylphenol ethoxylates: No standard method Amides: SW-846 Methods 8032A and 8316 Amines (alcohols): No standard method Hydrocarbons: SW- 846 Methods 5030 and 8260C Carbohydrates: No standard method Ethoxylated alcohols: ASTM D7485-09 Glycols: Region 3 Draft SOP Halogens: SW-846 Method 9056A Inorganics: SW-846 Methods 3015A and 6020A Radionuclides: SW-846 Method 9310

20. Biocidal Agents: Uses Chemical NameUsesFreq. Tetrahydro-3,5-dimethyl-2H-1,3,5-thiadiazine-2-thioneBiocide19 Alkyl dimethyl benzyl ammonium chlorideDisinfectant15 Phosphonium, tetrakis(hydroxymethly)-sulfateBiocide11 2,2-Dibromo-3-nitrilopropionamideBiocide8 Dipropylene glycol monomethyl etherBiocide7 5-Chloro-2-methyl-4-isothiazolin-3-oneBiocide4 Methylene bis(thiocyanate)Biocide3 Magnesium chlorideBiocide3 Ethoxylated nonylphenol Disinfectant, surfactant, corrosion inhibitor, antiemulsant 3 2-(2-Methoxyethoxy)ethanolBiocide3 Oxydiethylene bis(alkyl dimethyl ammonium chloride)Bactericide3 Polyethylene glycolBiocide3 Diatomaceous earth, calcinedBiocide2 Ammonium lauryl sulfateBiocide2 Ethanol Biocide, disinfectant, corrosion inhibitor, foaming agent, surfactant 2 2-Bromo-3-nitrilopropionamideBiocide2 Didecyl dimethyl ammonium chlorideBiocide2 2-(Thiocyanomethylthio)benzothiazoleBiocide2 1,2-Bromo-2-nitropropane-1,3-diolBiocide2 Dialkyl dimethyl ammonium chlorideDisinfectant2 Heavy aromatic petroleum naphtha Biocide, antiemulsant, acid inhibitor, corrosion inhibitor, proppant, surfactant 1 GlutaraldehydeBiocide, corrosion inhibitor1

21. Biocidal Agents: Toxicity Chemical Name Reference Dose (mg/kg BW-day) Reference Concentration (mg/m 3 ) Acrolein5.00E-042.00E-05 Naphthalene2.00E-023.00E-03 2-(Thiocyanomethylthio)benzothiazole3.00E-021.70E-01 Glutaraldehyde5.00E-028.00E-05 Methyl-4-isothiazolin5.30E-02Not Available Methylene bis(thiocyanate)5.50E-02Not Available Didecyl dimethyl ammonium chloride8.40E-02NA 2,2-Dibromo-3-nitrilopropionamide1.18E-015.33E-02 Tetrahydro-3,5-dimethyl-2H-1,3,5-thiadiazine-2-thione1.20E-018.40E+00 2-Bromo-3-nitrilopropionamide1.78E-015.33E+01 1,2-Bromo-2-nitropropane-1,3-diol1.80E-015.00E+00 5-Chloro-2-methyl-4-isothiazolin-3-one2.10E-01Not Available Dibromoacetonitrile2.45E-01Not Available Phosphonium, tetrakis(hydroxymethly)-sulfate2.48E-019.17E-01 Trichloroisocyanuric acid, dry4.06E-018.33E+01 Alkyl dimethyl benzyl ammonium chloride4.26E-01Not Available Magnesium nitrate5.00E-01Not Available Tetrasodium ethylenediaminetetraacetate6.30E-01Not Available N, N'-Methylene bis(5-methyl oxazolidine)9.00E-013.33E-01 Ethoxylated nonylphenol1.31E+002.10E-01 Sodium dichloro-s-triazinetrione1.42E+00Not Available

22. Worker Exposure Model Incidental Oral Ingestion Incidental Skin Contact Total Exposure = + Exposure Assumptions: - Each shift of 8 hrs - Oral ingestion of 16 mL fracking fluid per shift - 14% transdermal influx via exposed hands and arms - 250 days per year - Occupational exposure of 10 years

23. Biocidal Agents: Exposure Ranking Chemical Name Fracturing Fluid Concentration (mg/L) Incidental Consumption Exposure (mg/kg-day) Incidental Contact Exposure (mg/kg BW-day) Total Exposure Polyethylene glycol4.20E+015.75E-031.16E-011.22E-01 Diatomaceous earth, calcined3.28E+014.49E-039.04E-029.49E-02 Ethanol1.88E+012.57E-035.18E-025.43E-02 Glutaraldehyde1.29E+011.77E-033.57E-023.74E-02 2,2-Dibromo-3-nitrilopropionamide6.85E+009.38E-041.89E-021.98E-02 Alkyl dimethyl benzyl ammonium chloride2.54E+003.48E-047.00E-037.35E-03 5-Chloro-2-methyl-4-isothiazolin-3-one1.91E+002.62E-045.27E-035.53E-03 Magnesium nitrate1.91E+002.62E-045.27E-035.53E-03 Tetrahydro-3,5-dimethyl-2H-1,3,5-thiadiazine-2-thione1.90E+002.60E-045.24E-035.50E-03 Dibromoacetonitrile1.09E+001.49E-043.00E-033.15E-03 Didecyl dimethyl ammonium chloride9.80E-011.34E-042.70E-032.84E-03 Phosphonium, tetrakis(hydroxymethly)-sulfate9.10E-011.25E-042.51E-032.63E-03 Magnesium chloride3.90E-015.34E-051.08E-031.13E-03 1,2-Bromo-2-nitropropane-1,3-diol3.80E-015.21E-051.05E-031.10E-03 Methyl-4-isothiazolin1.30E-011.78E-053.58E-043.76E-04 2-Bromo-3-nitrilopropionamide3.00E-024.11E-068.27E-058.68E-05

24. Worker Risk Model Reference Dose Total Exposure Hazard Quotient = Risk Decision Process: - HQ ≤ acceptable exposure - HQ > estimated exposure may be associated with elevated risks

25. Biocidal Agents: Risk Ranking Chemical Name Total Exposure (mg/kg-day) RfD (mg/kg-day) HQ Glutaraldehyde3.74E-025.00E-020.749 2,2-Dibromo-3-nitrilopropionamide1.98E-021.18E-010.168 Tetrahydro-3,5-dimethyl-2H-1,3,5-thiadiazine-2-thione5.50E-031.20E-010.046 Didecyl dimethyl ammonium chloride2.84E-038.40E-020.034 Polyethylene glycol1.22E-014.00E+000.030 5-Chloro-2-methyl-4-isothiazolin-3-one5.53E-032.10E-010.026 Ethanol5.43E-023.00E+000.018 Alkyl dimethyl benzyl ammonium chloride7.35E-034.26E-010.017 Dibromoacetonitrile3.15E-032.45E-010.013 Magnesium nitrate5.53E-035.00E-010.011 Phosphonium, tetrakis(hydroxymethly)-sulfate2.63E-032.48E-010.011 Methyl-4-isothiazolin3.76E-045.30E-020.007 1,2-Bromo-2-nitropropane-1,3-diol1.10E-031.80E-010.006 2-Bromo-3-nitrilopropionamide8.68E-051.78E-010.000 Magnesium chloride1.13E-032.80E+000.000 Tetrasodium ethylenediaminetetraacetate5.79E-056.30E-010.000

26. Summary Studies are generating data to support additional risk assessments No widespread impacts on groundwater (except surface spills, non- spec operations, and accidents) Air exposures findings variable (except silica dust exposure) Highest hypothetical worker exposures are to polyethylene glycol, diatomaceous earth, ethanol, glutaraldehyde, and brominated nitrilopropionamide Highest hypothetical relative risks are to glutaraldehyde, brominated nitrilopropionamide, methylated thiodiazine, methylated ammonium chloride, and polyethylene glycol

27. Thank You