A new method for assessing worker exposure to diesel-based drilling fluids. Michael Breitenstein John Snawder Disclaimer: The findings and conclusions in this presentation are those of the authors and do not necessarily represent the views of the National Institute for Occupational Safety and Health. Mention of company name or products does not constitute endorsement by NIOSH
Field Studies- identify and characterize workplace exposures and evaluate their significance. Become familiar with process operations Perform the preliminary, qualitative surveyidentify hazards Perform workplace monitoring (quantitative evaluation) Interpret the sampling results and communicate with stakeholders Develop controls if needed Re-evaluate to determine effectiveness of controls
Conducted Site Visits on Drilling Rigs September 13-15, 2016 2 Rigs Safety orientation and briefing Rig Tour HSE personnel and rig crew explained processes, operations and answered questions Minimal direct reading instrument sampling Direct reading instrument sampling Area samples Personal samples April 20-24, 2017 single rig Direct reading instrument sampling Area samples Personal samples October 13-23, 2017 single rig Direct reading instrument sampling Area samples Personal samples
Methods Used Standard Industrial Hygiene Methods NMAM and OSHA Numbered Methods Personal and Area Samples Direct Reading Methods Real Time Instruments, Meters and Monitors Video Exposure Monitoring Radiation monitors
What We Sampled Where We Sampled Vapors and emissions from diesel based mud Hydrocarbon gas and vapors from the well/production zone Combustible gas/vapors, CO, H 2 S, Oxygen Total hydrocarbons Special treatment chemicals Over mud tanks In the mixing room Over/around shakers In the trip room Areas around the site Personal breathing zone samples on workers
What we measured
Chemicals Measured and Occupational Exposure Limits Hydrocarbon gases (C 1 -C 5 ) Saturated alkanes Gasoline range (C 4 -C 12 ) Aliphatics Aromatics Diesel Range (C 7 -C 24 ) Aliphatics Polyaromatic hydrocarbons Total Petroleum Hydrocarbons Chemical PEL (ppm) REL (ppm) TLV (ppm) Propane 1000 1000 2500 N Butane 800 1000 N Pentane 1000 120 600 Hexane 500 500 50 Benzene 10 0.1 0.5 Ethylbenzene 100 100 100 Toluene 200 100 100 Xylenes 100 100 100 Octane 500 75 300 Naphthalene 10 10 10 TPH (diesel) mg/m3 (ppm) TPH (naptha) mg/m3 (ppm) 100 (15) 100 (15) 100 (15) 350 (86) 350 (86) 350 (86)
Why are these chemicals of concern Benzene Exposure Routes: inhalation, skin absorption, ingestion, skin and/or eye contact Symptoms: irritation eyes, skin, nose, respiratory system; dizziness; headache, nausea, staggered gait; anorexia, lassitude (weakness, exhaustion); dermatitis; bone marrow depression; [potential occupational carcinogen] Target Organs: Eyes, skin, respiratory system, blood, central nervous system, bone marrowcarcinogen Toluene Exposure Routes: inhalation, skin absorption, ingestion, skin and/or eye contact Symptoms: irritation eyes, nose; lassitude (weakness, exhaustion), confusion, euphoria, dizziness, headache; dilated pupils, lacrimation (discharge of tears); anxiety, muscle fatigue, insomnia; paresthesia; dermatitis; liver, kidney damage Target Organs:Eyes, skin, respiratory system, central nervous system, liver, kidneys Xylenes Exposure Routes: inhalation, skin absorption, ingestion, skin and/or eye contact Symptoms:irritation eyes, skin, nose, throat; dizziness, excitement, drowsiness, incoordination, staggering gait; corneal vacuolization; anorexia, nausea, vomiting, abdominal pain; dermatitis Target Organs:Eyes, skin, respiratory system, central nervous system, gastrointestinal tract, blood, liver, kidneys
Why are these chemicals of concern Diesel fuel Exposure Routes: inhalation, ingestion, skin and/or eye contact Symptoms: irritation eyes, skin, nose, throat; burning sensation in chest; headache, nausea, lassitude (weakness, exhaustion), restlessness, incoordination, confusion, drowsiness; vomiting, diarrhea; dermatitis; chemical pneumonitis (aspiration liquid) Target Organs: Eyes, skin, respiratory system, central nervous system Total Petroleum Hydrocarbons Exposure Routes: inhalation, ingestion, skin and/or eye contact Symptoms:irritation eyes, nose, throat; dizziness, drowsiness, headache, nausea; dry cracked skin; chemical pneumonitis (aspiration liquid) Target Organs: Eyes, skin, respiratory system, central nervous system
NMAM Methods Charcoal tube samples Area and PBZ C5-C12 (NMAM 1500) Sept 2016, April 2017, October 2017 BTEX (NMAM 1501) Sept 2016, April 2017, October 2017 Total hydrocarbons (NMAM 1550) Sept 2016, April 2017, October 2017 PVC Filter XAD-2 Tubes Area Oil Mist (NMAM 5026) Sept 2016 Polycyclic Aromatic Hydrocarbons (PAHs; NMAM 5506) Sept 2016 PTFE Filter-XAD-2 Tubes Area Polycyclic Aromatic Hydrocarbons (PAHs; NMAM 5506) Sept 2016 PTFE Filter Area Benzene-Soluble Fraction and Total Particulate (Asphalt Fume NMAM 5042) April 2017 Metalworking Fluids (MWF) (NMAM 5524) April 2017
NMAM Methods IH exposure assessment methodologies for drilling mud mist/gases/vapors: October 2017 Side-by-side sample media sets: 2 in-line charcoal tubes: Hexane, heptane, octane, nonane, decane, etc. (NMAM 1500) Benzene, toluene, ethylbenzene, xylenes, etc. (NMAM 1501) Napthalene (NMAM 1550) Filter + 2 in-line charcoal tubes: Drilling mud mist (NMAM 5524, metalworking fluids) Gases and vapors same as above
Direct Reading
Area Samples
Area Short Term Shakers
Chemical Mud Tanks (ppm) Shakers (ppm) Propane nd nd N Butane nd nd N Pentane 0.020 0.071 Hexane 0.011 0.053 Benzene 0.002 0.212 Ethylbenzene 0.012 0.519 Toluene 0.012 0.538 Xylenes 0.045 1.942 Octane 0.145 3.92 Naphthalene 0.020 0.232 Benzo(a)pyrene nd nd TPH (diesel) mg/m3 (ppm) 19.5 (3.05) 615.2 (96.3)
SHALE SHAKERS Charcoal Tubes 9/2016 4/2017 Benzene ND -.07 ppm THC n-hexane ND 174 ppm STEL Benzene ND 0.14 ppm THC n-hexane ND 352 ppm Benzene ND - 0.17 ppm THC dodecane ND 75 ppm
SHALE SHAKERS: Above Shaker 2 2 tubes Benzene ppm 2 tubes + filter Benzene ppm 2 tubes total hydrocarbons mg/m 3 2 tubes + filter total hydrocarbons mg/m 3 2 tubes + filter oil mist/mwf mg/m 3 filter oil mist/mwf mg/m3 October 13 0.42 0.14 24.06 12.84 0.4 0.3 October 14 * 0.19 * 46.02 15.4* 9.8* * Pump failure Occupational Exposure Limit: 0.1 (NIOSH) 0.10 (NIOSH) 0.5 mg/m 3 (NIOSH) 0.5 mg/m 3 (NIOSH)
Problems with Existing Methods Most sampling methods collect only the aerosol phase and not the vapor phase. Evaporative losses from sampling filters during collection and storage Charcoal tube as a backer cannot handle the flow rate Metal Working Fluid (NMAM 5524) PTFE filters with charcoal tubes as backers The charcoal tube can have 30 ppm total hydrocarbons as dodecane and the PTFE filter is Non-Detect. Benzene Soluble (NMAM 5042) Evaporative losses from sampling filters during collection and storage Oil Mist (NMAM 5026)
New Method Diesel Mist by ASTM Red Dye Methods D6258 and D6756 Red Dye from off-road diesel would deposit on the filter with no evaporation losses Dye extracted from filter, analyzed and expressed as equivalent diesel in drilling fluid
New Method (continued) ASTM Method D6258 17 Standard Test Method for Determination of Solvent Red 164 Dye Concentration in Diesel Fuels In response to the Internal Revenue Service (IRS) dyeing requirement Tax-exempt diesel fuels contain Solvent Red 164 at a concentration spectrally equivalent to 3.9 pounds of solid dye standard Solvent Red 26 per thousand barrels (bbl) (11.1 mg/l) of diesel fuel Has a list of reagents Solvent Red 26 Kerosene conforming to Specification D3699 Xylene Calibration and Standardization
New Method (continued) ASTM Method D7657 17 Standard Test Method for Determination of the Red Dye Concentration an Estimation of the ASTM Color of Diesel Fuel and Heating oil Using a Portable Visible Spectrophotometer. Red dye concentrations are determined at levels equivalent to 0.1 mg/l to 20 mg/l of Solvent Red 26 in samples with ASTM color ranging from 0.5 to 5. Gives details of the apparatus Filter Spectrophotometer equipped with a specimen chamber, visible wavelength, four 10 nm + bandpass wavelength discrimination filters (450 nm, 520 nm 650 nm and 700 nm all with a + 2nm Quality Control Check Confirm the performance of the spectrophotometer 3 known controls.
New Method (continued) Made Standard according to D6858 17 Purchased spectrophotometer based on D6757-17 Added two lower concentration standards 0, 0.747, 1.49, 2.99, 5.92, 8.95, 11.94, 14.95 mg/l Tested Recovery Percentage from 3 different filter types PTFE, PVC and Glass Fiber Determine the Primary Solvent
PTFE Filters 1.4 1.2 1 0.8 PPM 0.6 0.4 0.2 y = 0.8173x + 0.0365 R² = 0.9527 Limit of Detection =0.1 ppm 0 0 0.2 0.4 0.6 0.8 1 1.2 PPM
PTFE Filters 120 Recovery Percent 100 80 Percent 60 40 20 0 0 0.049767 0.099533 0.199 0.398 0.597 0.796 0.995 PPM
Glass Fiber Filters 1 0.9 0.8 0.7 PPM 0.6 0.5 0.4 0.3 0.2 0.1 0 y = 0.7457x + 0.0064 R² = 0.9732 Limit of Detection =0.1 ppm 0 0.2 0.4 0.6 0.8 1 1.2 PPM
Glass Fiber Filters 120 Percent Recovery 100 80 Percent 60 40 20 0 0 0.05 0.1 0.2 0.4 0.6 0.8 1 PPM
Off Road Diesel 100 Off Road Diesel Recovery 90 80 70 Percent 60 50 40 30 20 10 0 PTFE PVC Glass Fiber Filter Material
Problems and Future Work How low can the spectrophotometer see. Need to test different Muds