Worker Fatalities Associated with Tank Gauging, Thieving, and Sampling

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1 Worker Fatalities Associated with Tank Gauging, Thieving, and Sampling Ryan Hill, MPH National Institute for Occupational Safety and Health The findings and conclusions in this report are those of the author(s) and do not necessarily represent the views of the National Institute for Occupational Safety and Health.

2 Tank Fatalities and Research Timeline Case Case Case Case 4 Case 5 Case 6 Case 7 Case 8 Case Case 10? 2015 NIOSH became aware of 2 fatalities in the Bakken 2013 NIOSH Science Blog 2014 NIOSH JOEH Pub 2014 NIOSH/ OSHA Review Case Files 2015 NIOSH FOG Database Report 2015 OSHA/ Industry Tank Alert 2015 NIOSH conducts exposure assessment field studies CDC Report on Tank Fatalities 2015 NIOSH/OSHA Hazard Alert 2016

3 Hydrocarbon Gases & Vapors An Emerging Hazard

4 Hydrocarbon Gases & Vapors An Emerging Hazard January year old victim had just finished gauging a crude oil tank when he was found non responsive. The medical examiner ruled the cause of death to be hydrocarbon exposure due to inhalation of petroleum vapors, including propane, butane, and ethane. Death was ruled work related by worker s compensation.

5 NIOSH Fieldwork Six well sites in CO, WY (2013) Operations: flowback, production watch, water transport Occupations: Flowback Leadman, Production Watch, Water Management, Water Haulers Spot measurements, real-time, directreading instruments Full-shift and short-term sampling for VOCs

6 Spot Measurements in Headspace of Tanks Tank type Benzene (ppm) Other VOCs (ppm) Flowback ,000 Production ,000 Water ,000

7 Full-shift Personal Breathing Zone Benzene Measurements 15/17 gaugers exceeded NIOSH REL 1/18 non-gaugers exceeded NIOSH REL TWA Range: Not Detected 0.65 ppm

8 Workplace Practices can Influence Exposure 1.2 ppm Benzene at 54 inches above hatch 149 ppm Benzene at 18 inches above hatch

9 Flammable/Explosive Hazards Direct reading instruments showed many instances of short term excursions measuring > 40% of the Lower Explosive Limit

10 Why were exposures elevated among workers gauging tanks? Headspace pressure and VOCs build up in tank before dumping to the combustor (emission control). Risks for exposures: opening hatches to gauge tank. Plume is emitted after hatch is opened

11 Behavior of Production Fluid Storage Vessels without NSPS* 0000 Controls (pre 2012) Tank is continuously vented to the atmosphere. Gases and vapors in tank are in equilibrium with outside air. No significant pressure on the tank. *New Source Performance Standard

12 Behavior of Production Fluid Storage Vessels with NSPS 0000 Controls (post 2012) Hatch is closed. No visible emissions, greater than 95% VOCs produced are controlled. Gases and vapors in tank are in equilibrium with gas and vapors in the liquid hydrocarbon. The different gases and vapors are exerting pressure on the container.

13 Hatch is opened. A large volume of gases (mostly propane and butane) rush out of the hatch very quickly. The cloud can displace oxygen in the immediate work area and presents an immediate asphyxiation hazard.

14 As hatch remains open, heavier hydrocarbons in the tank (pentane, hexane, heptane, BTEX) will evaporate and leave the tank and enter the workspace. Rate of flow is still high and these gases and vapors may be present at toxic and flammable concentrations.

15 Hatch remains open. Gases and vapors in tank are approaching equilibrium with the environment and the rate of emission slows down significantly. Heavy gas and vapors drop toward the ground.

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17 Asphyxiation Hydrocarbon gases/vapors can act as asphyxiants by displacing oxygen. Even if oxygen concentrations remain sufficiently high to support life, self-rescue may be impaired.

18 Narcosis At high concentrations, onset can be very rapid. It may only take a few breaths to induce light headedness, feeling dizzy or if the concentration in the air is high enough, a few breaths can rapidly induce unconsciousness The difference between concentrations producing narcosis and those leading to death may be small

19 Case # 7 A 59 year old oil tanker driver died while collecting crude oil samples from an open thief hatch. The employee was wearing a 4 gas monitor which showed an oxygen deficient atmosphere and the presence of hydrocarbons exceeding 100% of the LEL at the time of his death. Was examined in an Emergency Dept. for altered consciousness after tank gauging three week prior to his death.

20 Courtesy of Dr. Michael Kosnett, University of Colorado

21 Cardiac arrest High concentrations of hydrocarbons, can lead to abnormal heart rhythm and cardiac arrest, particularly where exposure is accompanied by stress and exercise Certain pre-existing cardiac conditions may lead to increased sensitivity from exposure

22 Identification of Cases Nine (9) worker deaths where inhalation of petroleum hydrocarbons was likely factor. fog/data.html

23 Case Summary All of the fatalities occurred at crude oil (production) tanks All workers who died were working alone or not being observed 5 fatalities occurred during sampling by pumpers/truckers 4 of the fatalities occurred during tank gauging In at least one case, the victim had previously experienced health effects and sought medical evaluation

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25 Case # 10? December 2015, WV A worker responsible for monitoring flowback was found on top of a tank slumped over and non responsive. There were no signs of physical trauma. Toxicological data are pending. The investigation is open.

26 What can you do? 1. Implement alternative tank gauging procedures 2. Train workers on the hazards associated with gauging tanks 3. Limit time spent in proximity to hydrocarbon sources 4. Ensure workers are trained on and correctly and consistently use calibrated multi-gas monitors 5. Where remote gauging is not feasible or has not yet been implemented, use of respiratory protection may be required to protect workers 6. Establish emergency procedures to provide medical response in the event of an incident.

27 Tank Gauging Hazard Alert Your life can change in a single breath or with just one spark.

28 For More Information 28

29 Respirable silica dust emitted from sand mover hatches

30 Respirable Crystalline Silica Up Close Worker exposures can exceed the maximum use criteria for respirators > 10 X NIOSH REL and up to 50 times the limit.

31 Progress: NIOSH Mini baghouse retrofit assembly Design goal: Effective Inexpensive A bolt-on control Uses pneumatic energy within the system In-field retrofit

32 Version 2 Evaluation, 2015

33 Phase 2 Field Trial Needed to evaluate: Bag change out schedule Static pressures Weather resistance Sealing surfaces Overall durability in actual field usage 2015

34 Contact Information Ryan Hill NIOSH Oil & Gas Homepage Follow us on