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Field Investigation of the Chemistry and Toxicity of TPH in Petroleum Vapors:

Field Investigation of the Chemistry and Toxicity of TPH in Petroleum Vapors: Implications for Potential Vapor Intrusion Hazards. Roger Brewer & Lynn Bailey Hazard Evaluation and Emergency Response Hawai‘i Department of Health April 2012. There are three methods to gain knowledge:

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Field Investigation of the Chemistry and Toxicity of TPH in Petroleum Vapors:

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  1. Field Investigation of the Chemistry and Toxicity of TPH in Petroleum Vapors: Implications for Potential Vapor Intrusion Hazards Roger Brewer & Lynn Bailey Hazard Evaluation and Emergency Response Hawai‘i Department of Health April 2012

  2. There are three methods to gain knowledge: The first, reflection, is the noblest; The second, imitation, is the easiest; And the third, experience, is the bitterest. Confucius

  3. Reference: Field Investigation of the Chemistry and Toxicity of TPH in Petroleum Vapors, Implications for Potential Vapor Intrusion Hazards: Hawai’i Department of Health, Hazard Evaluation and Emergency Response, http://www.hawaiidoh.org/ Note: Significant vapor intrusion problems have not been identified for existing buildings at any of the study sites included in this presentation. The site data are presented for example only.

  4. Acknowledgements • Field study funded under a grant from USEPA Region IX; • Hickam AFB/NAVFAC Hawai’i past work and field assistance • Field work carried out by HDOH HEER & UST staff with assistance by several local consultants; • Numerous consultations with regulators and consultants on the mainland.

  5. HDOH Petroleum Vapor Intrusion Guidance • HEER EHE guidance (2005; last updated Fall, 2011) • HEER Technical Guidance Manual (Section 9); • Test for TPH plus BTEXN and methane in soil gas; • TPH soil gas action levels: • 2005: Residential = 26,000 ug/m3 (based on limited, published information); • 2011: Residential = 130,000+ ug/m3 (based on this study).

  6. Vapor Intrusion vapor diluted advective flow into building Indoor Air Action Level Slab or crawl space Subslab Soil Gas Action Level diffusion to slab base Soil Gas ALres = 1,000 x Indoor Air AL Soil Gas ALC/I = 2,000 x Indoor Air AL contaminated soil or groundwater

  7. Do We Really Need to Worry About TPH? How can something that smells so bad or can catch on fire pass a “risk assessment”?

  8. Key Questions… 1. Are BTEXN and especially benzene in soil gas adequate to screen for potential vapor intrusion hazards at petroleum-contaminated sites? 2. Could TPH still pose a vapor intrusion risk even though BTEXN meet acceptable risks? a. What is the toxicity of TPH in petroleum vapors? b. What is carbon range makeup of vapor-phase TPH?

  9. Fuels and Carbon Ranges Gasolines Diesel Fuels Fuel Oils Volatile/Semi-Volatile 69'C 126'C 216'C 343'C 402'C 449'C C6 C4 C12 C2 C8 C24 C16 C20 C0 C32 C28 C36 Methane BTEX PAHs

  10. Toxicity of Total Petroleum Hydrocarbons TPH Working Group (mid/late 1990s) • Subsequent Guidance • Massachusetts DEP (1997+) • Washington DOE (2006) • California EPA (DTSC 2009) • USEPA (2009)

  11. Massachusetts DEP TPH Carbon Ranges Aromatics Gasolines Aliphatics Diesel Fuels Fuel Oils Potential Vapor Phase C9 -10 C11-22 C5-8 C9-12 C13-18 C19-36 C6 C4 C12 C2 C8 C24 C16 C20 C0 C32 C28 C36 TPH = Sum of Aromatics + Aliphatics (excluding BTEXN, etc.)

  12. Vapor-Phase Carbon Ranges Aromatics Gasolines Aliphatics Diesel Fuels Fuel Oils Less Toxic More Toxic C9-16 C6 C4 C12 C2 C8 C24 C16 C20 C32 C28 C36 C5-8 C9-18 C0 TPH = Sum of Aromatics + Aliphatics (excluding BTEXN, etc.)

  13. Carbon Ranges - Vapor Sample Collection • Volatile Petroleum Hydrocarbons (VPH): • C5-C8 Aliphatics • C9-C12 Aliphatics • C9-C10 Aromatics • Extractable Petroleum Hydrocarbons (EPH): • C13-C16 Aliphatics • C11-C16 Aromatics • VPH Compounds: Summa canisters OK • EPH Compounds: Sorbent tubes required

  14. TPH Carbon Range Action Levels • USEPA 2009 Reference Concentrations • Target Hazard Quotient = 1.0 • Assumes indoor air:subslab soil gas Attenuation Factor of 0.001 • Odor Threshold (ug/m3) approximately 1,000 ug/m3 • Use same as action levels for BTEXN and other individual VOCs

  15. TPH Mixtures: Weighted Toxicity & Action Levels Weighted TPH RfC= 216 ug/m3 TPH Indoor Airres = 250 ug/m3 TPH Soil Gasres = 250,000 ug/m3 C5-C8 Aliphatics C9-C18 Aliphatics C9-C16 Aromatics Weighted TPH RfC (ug/m3) =

  16. Critical TPH:Target Compound Ratios • Point where relative proportion of “less toxic” vapor-phase TPH will overwhelm “more toxic” individual compounds Least Stringent TPH Action Level Most Stringent Target Compound Action Level Critical TPH Ratio = 630 ug/m3 (C5-C8 aliphatics) 0.31 ug/m3 (10-6 cancer risk) Critical TPH:Benzene Ratio = Critical TPH:Benzene Ratio = 2,032 • TPH will always drive vapor intrusion risk if the TPH:Benzene ratio exceeds 2,032:1 • Useful as initial screening tool to evaluate potential vapor intrusion risk drivers

  17. TPH vs Benzene in Vapor Intrusion Risk Notes High: Ratio of least stringent TPH action level to most stringent benzene action level. Low: Ratio of least stringent TPH action level to most stringent benzene action level.

  18. TPH Will Always Drive VI Risk if… • Based on least conservative TPH action level (630 ug/m3) and most conservative VOC action level (e.g., 10-6 cancer risk and HQ 1.0). • TPH could drive vapor intrusion risk below these ratios depending on carbon range makeup and target risk applied to the individual VOC.

  19. Off To The Field! • Key sites for collection of soil gas samples identified; • Two phases of sampling: • Phase I: Summas, TO-15 & MA-APH • Phase II: Summas+Sorbent Tubes, TO-3, TO-15, TO-17 & MA-APH

  20. Summas or Sorbent Tubes for Soil Gas? (Summas will miss heavier VOCs) (Hayes 2007) Summas Sorbent Tubes • Up to C24+ • Small volume (50ml) • Saturation limitation • Less familiar • Larger volume • Familiarity • Limited to C12 TO-15 TO-17 C6 C4 C12 C2 C8 C24 C16 C20 C32 C28 C36 C0 Summa Range Sorbent Tube Range

  21. Key Study Sites Site A Site D Site C Site E Site B

  22. Sample Collection Sorbent Tubes (60 ml syringes) Summa Canisters (1liter summas) Max Draw = 50ml Two Tubes to Evaluate Breakthrough

  23. Results of Field Data • Following summaries based on Summa canister data • Sorbent tube data very similar to Summa data • Minimal VOCs greater than C12 in soil gas • Naphthalene was usually ND and not a significant risk driver in comparison to TPH (or benzene) • TEX likewise not significant risk drivers

  24. TPH Dominates BTEXN in Vapors (BTEXN component decreases in aged releases?) *Exhaust samples 30-40% BTEXN

  25. TO-15 Gas Chromatograph Fresh Gasoline Vapors C5-C8 C9-12 C13 C5 C9 Benzene Naphthalene

  26. Carbon Range Chemistry and Weighted TPH Toxicity Fresh Gasoline Vapors Weighted RfC= 565 ug/m3 Indoor Airres = 590 ug/m3 Soil Gasres = 590,000 ug/m3 TPH:Benzene = 170 C5-C8 Aliphatics C9-C12 Aliphatics C9-C10 Aromatics Based on TO-15 Summa Data

  27. Who’s Driving…? TPH vs Benzene as VI Risk Driver • Calculate equivalent TPH concentration for sample/site at target benzene action level based on TPH:Benzene ratio • Divide by weighted site-specific TPH action level • Gasoline Vapor Example (using indoor air action levels): • Target Benzene Action Level = 0.31 ug/m3 (10-6 risk) • TPH:Benzene = 170:1 • Equivalent TPH = 53 ug/m3 • Weighted TPH Action Level = 590 ug/m3 • TPH noncancer HQ = 53/590 = 0.1 • Benzene drives vapor intrusion risk (TPH HQ <1.0 when benzene risk = 10-6)

  28. TPH vs Benzene Vapor Intrusion Risk Fresh Gasoline Vapors Benzene Cancer Risk TPH Hazard Quotient 10-6 TPH HQ=0.1 Benzene 0 Based on TO-15 Summa Data Benzene adequate to evaluate vapor intrusion provided that a target 10-6 cancer risk is used. (TPH noncancer HQ still <1 when benzene risk 10-6)

  29. TO-15 Gas Chromatograph Fresh Diesel Vapors C5-C8 C9-12 C5 C9 C13 Benzene Naphthalene

  30. Weighted RfC= 216 ug/m3 Indoor Airres = 250 ug/m3 Soil Gasres = 250,000 ug/m3 TPH:Benzene = 206 Carbon Range Chemistry and Weighted TPH Toxicity Fresh Diesel Vapors C5-C8 Aliphatics C9-C12 Aliphatics C9-C10 Aromatics Based on TO-15 Summa Data

  31. TPH vs Benzene Vapor Intrusion Risk Fresh Diesel Vapors Benzene Cancer Risk TPH Hazard Quotient 10-6 Benzene TPH HQ=0.3 0 Based on TO-15 Summa Data Benzene adequate to evaluate vapor intrusion provided that a target 10-6 cancer risk is used. (TPH noncancer HQ still <1 when benzene risk 10-6)

  32. Gas Chromatograph Fresh JP-8 Vapors C5-C8 C9-12 C13 C5 C9 Benzene Naphthalene

  33. Carbon Range Chemistry and Weighted TPH Toxicity Fresh JP-8 Vapors Weighted RfC= 225 ug/m3 Indoor Airres = 230 ug/m3 Soil Gasres = 230,000 ug/m3 TPH:Benzene = 301 C5-C8 Aliphatics C9-C12 Aliphatics C9-C10 Aromatics Based on TO-15 Summa Data

  34. TPH vs Benzene Vapor Intrusion Risk Fresh JP-8 Vapors Benzene Cancer Risk TPH Hazard Quotient 10-6 TPH Benzene HQ=0.4 0 Based on TO-15 Summa Data Benzene adequate to evaluate vapor intrusion hazards provided that a target 10-6 cancer risk is used. (TPH noncancer HQ<1 when benzene risk 10-6)

  35. Gas Chromatograph Site A (AVGAS) C5-C8 C9-12 C13 C5 C9 Benzene Naphthalene

  36. Carbon Range Chemistry and Weighted TPH Toxicity Site A (AVGAS) Weighted RfC= 510 ug/m3 Indoor Airres = 530 ug/m3 Soil Gasres = 530,000 ug/m3 TPH:Benzene = 1,513! (reduced benzene in soil gas) C5-C8 Aliphatics C9-C12 Aliphatics C9-C10 Aromatics Average TPH in Soil Gas 71,000,000 ug/m3 Based on TO-15 Summa Data

  37. TPH vs Benzene Vapor Intrusion Risk Site A (AVGAS) Benzene Cancer Risk TPH Hazard Quotient 10-6 TPH Benzene HQ=0.9 0 Based on TO-15 Summa Data Benzene adequate to evaluate vapor intrusion hazards provided that a target 10-6 cancer risk is used. (TPH noncancer HQ<1 when benzene risk 10-6)

  38. Where’s the BTEXN? Partitioning of Compounds in Soil Aromatics Prefer to be in the Water Aliphatics Prefer to be in the Vapors *Theoretical ratio of vapor-phase mass to dissolved-phase mass at equilibrium. Dissolved-phase dominates if H’ <1.0.

  39. Gas Chromatograph Site B (Mixed Fuels) C5-C8 C9-12 C13 C5 C9 Benzene Naphthalene

  40. Carbon Range Chemistry and Weighted TPH Toxicity Site B (Mixed fuels) Weighted RfC= 443 ug/m3 Indoor Airres = 460 ug/m3 Soil Gasres = 460,000 ug/m3 TPH:Benzene = 4,174! (reduced benzene in soil gas) C5-C8 Aliphatics C9-C12 Aliphatics C9-C10 Aromatics Average TPH in Soil Gas 44,000,000 ug/m3 Based on TO-15 Summa Data

  41. TPH vs Benzene Vapor Intrusion Risk Site B (Mixed Fuels) Benzene Cancer Risk TPH Hazard Quotient TPH HQ=2.8 10-6 Benzene 0 Based on TO-15 Summa Data TPH always drives potential vapor intrusion hazards. (TPH noncancer HQ>1 even when benzene risk 10-6)

  42. Gas Chromatograph Site C (JP-8 +/- J-4) C5-C8 C9-12 C5 C9 C13 Benzene Naphthalene

  43. Carbon Range Chemistry and Weighted TPH Site C (JP-8 +/- JP-4) Weighted RfC= 251 ug/m3 Indoor Airres = 260 ug/m3 Soil Gasres = 260,000 ug/m3 TPH:Benzene = 18,710!! (minimal benzene in soil gas) C5-C8 Aliphatics C9-C12 Aliphatics C9-C10 Aromatics Average TPH in Soil Gas 17,000,000 ug/m3 Based on TO-15 Summa Data

  44. TPH vs Benzene Vapor Intrusion Risk Site C (JP-8 +/- J-4) Benzene Cancer Risk TPH Hazard Quotient TPH HQ=22 10-6 Benzene 0 Based on TO-15 Summa Data TPH always drives potential vapor intrusion hazards. (TPH noncancer HQ>1 even when benzene risk 10-6)

  45. TO-15 Gas Chromatograph Site D (JP-4) C5-C8 C9-12 C5 C9 C13 Benzene Naphthalene

  46. Carbon Range Chemistry and Weighted TPH Site D (JP-4) Weighted RfC= 211 ug/m3 Indoor Airres = 220 ug/m3 Soil Gasres = 220,000 ug/m3 TPH:Benzene = 9,135! (minimal benzene in soil gas) C5-C8 Aliphatics C9-C12 Aliphatics C9-C10 Aromatics Average TPH in Soil Gas 630,000 ug/m3 Based on TO-15 Summa Data

  47. TPH vs Benzene Vapor Intrusion Risk Site D (JP-4) Benzene Cancer Risk TPH Hazard Quotient TPH HQ=13 10-6 Benzene 0 Based on TO-15 Summa Data TPH always drives potential vapor intrusion hazards. (TPH noncancer HQ>1 even when benzene risk 10-6)

  48. Gas Chromatograph Site E (Diesel) C5-C8 C9-12 C5 C9 C13 Benzene Naphthalene

  49. Carbon Range Chemistry and Weighted TPH Site E (Diesel) *Reference site for default TPH RfC in Fall 2011 TPH soil gas action levels. Weighted RfC= 127 ug/m3 Indoor Airres = 130 ug/m3 Soil Gasres = 130,000 ug/m3 TPH:Benzene = 18,600!! (minimal benzene in soil gas) C5-C8 Aliphatics C9-C12 Aliphatics C9-C10 Aromatics Average TPH in Soil Gas 2,900,000 ug/m3 Based on TO-15 Summa Data

  50. TPH vs Benzene Vapor Intrusion Risk Site E (Diesel) Benzene Cancer Risk TPH Hazard Quotient TPH HQ=44 10-6 Benzene 0 Based on TO-15 Summa Data TPH always drives potential vapor intrusion hazards. (TPH noncancer HQ>1 even when benzene risk 10-6)

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