Formaldehyde: A New Concern for Air Permitting?

Transcription

1 Formaldehyde: A New Concern for Air Permitting? Stephen G. Zemba, Ph.D., P.E. and Russell H. Abell, P.G., LSP Sanborn Head & Associates, Inc. 20 Foundry Street, Concord, NH /3/2018 Page 1

2 Presentation Outline Formaldehyde Basics Relevance to Oil & Gas Industry Formaldehyde Health Effects Case Study Example 4/3/2018 Page 2

3 FORMALDEHYDE BASICS 4/3/2018 Page 3

4 4 Formaldehyde Facts Hazardous Air Pollutant Ubiquitous in outdoor and indoor air Highly soluble gas at ambient conditions Odor threshold: 600 1,200 µg/m 3 Atmospheric sources include: Fuel combustion Building materials Chemical formation 4/3/2018 Page 4

5 Formaldehyde Concentrations in Air in TX 2011 modeled estimates U.S. EPA National Air Assessment 2011 modeling study 5520 census tracts 4/3/2018 Page 5

6 Formaldehyde Concentration (µg/m 3 ) Formaldehyde Concentrations in Air in TX measured data TCEQ air monitoring 24-hr samples samples/site Dallas El Paso Houston Deer Park Harrison County Fort Worth 4/3/2018 Page 6

7 Formaldehyde Concntration (ug/m3) Formaldehyde Concentrations in Air in MA National Air Toxics Assessment vs MA Monitored Data Point and Other 2% Residential Wood Combustion 5% hr TEL NATA 2011 MA Monitored Biogenic 6% Vehicular/ Transportation 17% Secondary 70% Lynn Chicopee Boston Local Annual AAL 4/3/2018 Page 7

8 Indoor Exposure to Formaldehyde Indoor air exposure levels can greatly exceed outdoor concentrations due to indoor emission sources and use of formaldehyde in products 4/3/2018 Page 8

9 RELEVANCE TO OIL AND GAS INDUSTRY 4/3/2018 Page 9

10 Formaldehyde Emissions at Refineries 2015 AP-42 Section 5.1 (Aldehydes) 8.6 kg/1000 bbl 5.4 kg/1000 bbl 4/3/2018 Page 10 10

11 Emissions from Combustion Sources AP-42 Section 5.1 provides an aldehyde emission factor of 0.1 lb/ft 3 gas for a compressor engine (reciprocating) at 1,000 BTU/ft 3 and 40% electrical efficiency, translates to 0.64 g/bhp-hr Formaldehyde recognized as the key Hazardous Air Pollutant in EPA s 40 CFR 63 ZZZZ RICE MACT rule Flare emission factors lacking, but emissions likely FLAIR Study (Houston & Texas City, 2009) Flares release kg/hr at flare tip Secondary production much greater Texas City refinery complex released 18 ± 5 kg/hr 4/3/2018 Page 11

12 Formaldehyde Emissions from IC LFG Engines State # Tests Formaldehyde Emissions (g/bhp-hr) Min Max Average Arkansas Delaware Iowa Maryland Michigan New Jersey Pennsylvania Wisconsin Weighted Average => /3/2018 Page 12

13 Example Emissions Calculations Assume: 2 Stationary IC Engines at 2,233 hp each Formaldehyde emission factor = 0.42 g/bhp-hr 8760 hours/year operation Potential emissions = 18 tons/year Major HAP Source 4/3/2018 Page 13

14 FORMALDEHYDE HEALTH EFFECTS 4/3/2018 Page 14

15 Toxicity Summary Levels of Concern Regulatory Authority U.S. EPA Acute Exposure Guideline (AEGL-1) and Regional Screening Levels (RSLs) Risk-Based Concentration of Concern (µg/m 3 ) Acute Short-Term Chronic (Cancer) 10 (Non-cancer) Acute 1hr Short-term 8-24 hr Chronic 1 yr California Reference Exposure Levels (RELs) ATSDR Minimum Risk Levels (MRLs) OSHA Short-Term Exposure Limit (STEL) and Permissible Exposure Limit (PEL) NIOSH Short-Term Exposure Limit (STEL) and Recommended Exposure Limit (REL) Massachusetts Threshold Effects Level (TEL) and Ambient Air Limit (AAL) Classified by IARC as a human carcinogen Formaldehyde is also a respiratory irritant Texas Effects Screening Levels (ESLs) /3/2018 Page 15

16 Formaldehyde Unit Risk Factors A unit risk factor is the additional chance of getting cancer from breathing an average of 1 µg/m 3 of a chemical over a 70-year lifetime Unit risk values for formaldehyde Regulatory Authority and Date of Derivation Unit Risk Factor (m 3 /µg) 1 per Million Lifetime Risk Concentration (µg/m 3 ) U.S. EPA (1989) (Current) CA OEHHA (1992) (Current) U.S. EPA (2010) (Proposed) /3/2018 Page 16

17 CASE STUDY EXAMPLE 4/3/2018 Page 17

18 Case Study Example Landfill Gas-to-Energy Installation Three internal combustion engines fueled by landfill gas Beneficial production of electricity Certified formaldehyde emission factor = 0.42 g/bhp-hr Dispersion modeling (AERMOD) could not meet state air toxics standards Solution: Site-specific health risk assessment 4/3/2018 Page 18

19 Site-Specific Health Risk Assessment Consider more realistic exposure 30 years v. 70-year lifetime Health endpoints/targets Long-term risk of cancer 10 per million target Short-term irritation effects hazard quotient 1 Use current toxicity data Consider site-specific background? 4/3/2018 Page 19

20 Site-Specific Health Risk Assessment Incremental cancer risk 4/3/2018 Page 20

21 Site-Specific Health Risk Assessment Non-cancer short-term hazard quotient 4/3/2018 Page 21

22 Site-Specific Health Risk Assessment Non-cancer acute hazard quotient 4/3/2018 Page 22

23 Site-Specific Health Risk Assessment Key parameter values Parameter Value Inhalation Unit Risk Factor (IUR) m 3 /µg Fraction human lifetime (f life ) (for incremental cancer risk) Reference Concentrations (for hazard quotients) 30 yrs 70 yrs = Short-term 10 µg/m 3 Acute 55 µg/m 3 4/3/2018 Page 23

24 Site-Specific Health Risk Assessment Results Health Risk Endpoint Incremental Cancer Risk (target risk ) Non-Cancer Hazard Quotients (target value 1) Limiting Engine Emission Factor (g/bhp-hr) 1.34 Short-term Acute /3/2018 Page 24

25 Site-Specific Health Risk Assessment Short-term impacts / Reference concentration = 9.8 µg/m 3 4/3/2018 Page 25

26 26 For Further Information If you have questions or comments, you can Stephen Zemba at or Russ Abell at 4/3/2018 Page 26