Hazards of Silica Dust Exposure for Fracking Workers

Group 13: Marisol Chavez, Nicholas Ellinwood, Andres Guerrero, Amy Klapheke, Mikaela Miller EHOH 6614April 7, 2014

Outline

● What is fracking?● Who are the fracking workers?● How are they exposed to silica dust?● What are the health consequences of this exposure?● Findings from NIOSH Article ● What is being done to address this issue?

image source: http://en.wikipedia.org/wiki/File:Hydraulic_Fracturing-Related_Activities.jpg

Fracking Workers

• 2010: 435,000 workers in the US oil and gas industry, about half employed by well servicing companies, including those that perform fracking.

• Non-union crews, primarily young men.

• Often housed in trailers by the drilling companies.

Fracking Workers

• Fracking operations are exempt from most clean air and water laws

• Most health and safety concerns have been focused on the environment– especially groundwater contamination

• Due to lack of attention on workers’ health NIOSH initiated the Field Effort to Assess Chemical Exposures in Oil and Gas Extraction Workers: o Goal: develop partnerships with oil and gas industry to identify and

control workplace exposures

• Finding that workers are at risk of serious health issues due to exposures at fracking sites– crystalline silica exposure

Crystalline Silica Exposure ● Each stage of fracking involves

hundreds of thousands of pounds of crystalline silica, in the form of “frac sand.”1

● Sand is used as a proppant to hold open the fissures created by hydraulic fracturing and allow the gas to flow out of the shale into the well.1

● National Institute for Occupational Safety and Health (NIOSH), “1.7 million US workers exposed to respirable crystalline silica every year, although the true extent of the problem is likely greater” 2

Crystalline Silica Exposure

● The NIOSH recommended exposure limit (REL) is 0.05 milligrams of respirable silica per cubic meter of air (mg/m3) as a time-weighted average (TWA) for up to a 10hr day to reduce silica related diseases.

● In 2012, OSHA issued a hazard alert for silica after NIOSH found excessive silica exposure at 11 sites in 5 states2

● “Inhalation of respirable crystalline silica can cause silicosis, lung cancer, autoimmune disorders, kidney disease, and an increased risk of tuberculosis”3

Crystalline Silica Health Effects ● Silicosis: irreversible, sometimes fatal, lung disease that

is only caused by inhaling respirable silica dust. 2

● Mortality statistics undercount cases, death certificates show an average of 162 deaths annually from 2000-2005 (NIOSH)

● Develops over long periods of exposure, progresses gradually

● Acute silicosis: rapidly fatal cases, have been documented in several working groups

● Lung cancer, pulmonary tuberculosis, other respiratory diseases

● Autoimmune disorders Slice of Lung Affected by Silicosishttp://en.wikipedia.org/wiki/Silicosis

Occupational Exposures to Respirable Crystalline Silica During Hydraulic Fracturing Article

● August 2010- September 2011, NIOSH collected 111 personal breathing samples at 11 sites in 5 states to evaluate worker exposures to respirable crystalline silica during hydraulic fracking.

● Workers from 15 different job titles volunteered to participate for 3 consecutive days.

● At each 11 sites, full-shift samples exceeded OSHA REL or the ACGIH TLV by 10 or more times.

○ 93 of 111 (83.8%) of the samples exceeded the TLV.

○ 76 (68.5%) exceeded the REL.

○ 57 (51.4%) exceeded a calculated PEL for respirable dust containing silica.

Occupational Exposures to Respirable Crystalline Silica During Hydraulic Fracturing Article

1. Dust ejected from thief hatches (access ports) on top of the sand movers during refilling operations while the machines are running (hot loading).

2. Dust ejected and pulsed through open side fill ports on the sand movers during refilling operations

3. Dust generated by on-site vehicle traffic.

4. Dust released from the transfer belt under the sand movers.

5. Dust created as sand drops into, or is agitated in, the blender hopper and on transfer belts.

6. Dust released from operations of transfer belts between the sand mover and the blender;

7. Dust released from the top of the end of the sand transfer belt (dragon’s tail) on sand movers.

Occupational Exposures to Respirable Crystalline Silica During Hydraulic Fracturing Article

• Workers typically wore elastomeric half mask, air-purifying (or filtering-facepiece style) respirators.

• The half-masks may not be sufficiently protective.

Addressing Silica Exposure

What can be done in the workplace?

Hierarchy of controls

What can agencies do?

OSHA, NIOSH, National STEPS

Hierarchy of Controls Elimination of silica dust

● Proppants cannot be eliminated from the fracking process

Elimination of hydraulic fracturing

● Fracking itself can not be eliminated, otherwise the energy demands of the USA will depend on expensive imports

○ 43% of total U.S. oil production and 67% of natural gas

production comes from fracking4

● Alternative energy sources may supplement energy supply, but will not completely replace oil and gas anytime soon

Hierarchy of Controls

Substitution

• Alternative materials as proppants

• Sintered bauxite, ceramics

• Respirable particulate matter still a concern

● May have similarly harmful effects

Hierarchy of Controls

Engineering Controls1

• Enclose points where dust is released

• Use enclosed cabs or booths with HEPA filters and climate controls

• Use local exhaust ventilation

• Replace transfer belts with screw augers on sand movers in new designs or retrofits

http://www.lubing.com/auger-conveyor.html

Hierarchy of Controls

Administrative Controls1

• Mandate the capping of unused fill ports (e.g., cam lock caps) on sand movers.

• Reduce the drop height between the sand transfer belt and T-belts and blender hoppers.

• Limit the number of workers, and the time workers must spend in areas and consider ways to perform dusty operations remotely

• Apply fresh water to roads and around the well site to reduce the dust.

Hierarchy of Controls

Personal Protective Equipment

• Masks for all workers that meet maximum exposure levels

o Simple measure

o Only required when exposure exceeds the relatively high OSHA standard

o NIOSH study found many exposures exceeded levels approved for masks used

Hierarchy of Controls

Education

• Improve training and awareness in work force

o Various companies, short-term contracts, and a transient work force make education measures not feasible

o Least effective measure in hierarchy

Addressing Silica Exposure Various controls and guidelines exist5

http://www.ussilica.com/uploads/files/product-group-msds/msds/silica-msds-english.pdf

Addressing Silica Exposure

No harmonized classification of crystalline silica6

TSCA No.: Appears on the EPA TSCA inventory

RCRA: Not classified as a hazardous waste under the Resource Conservation and Recovery Act.

CERCLA: Not classified as a hazardous substance under Comprehensive Environmental Response Compensation and Liability Act

Emergency Planning and Community Right to Know Act: Not an extremely hazardous substance or a toxic chemical

Clean Air Act: Does not contain any Class I or Class II ozone depleting substances.

NTP: Classified as a known human carcinogen.

OSHA Carcinogen: Crystalline silica is not listed.

California Proposition 65: Classified as a substance known to the state of California to be a carcinogen.

California Inhalation Reference Exposure Limit (REL): The California chronic REL for respirable crystalline silica is 3 ug/m3

Massachusetts Toxic Use Reduction Act: Considered toxic

Pennsylvania Worker and Community Right to Know Act: Considered hazardous

Addressing Silica Exposure

• OSHA has proposed a new regulation

• Current PEL’s for crystalline silica exposure were adopted in 1971 and based on research from the 1960s

• Proposed regulation would provide consistent levels of protection for workers in all sectors covered by the rule

• Exposures would be limited to 50 µg/m3 of respirable crystalline silica averaged over an 8 hour day

Conclusion

● There are many hazards for fracking workers

● Crystalline silica exposure needs to be controlled

● We need to work towards a standard exposure limit

● More research!

Resources OSHA. (2012). Worker Exposure to Crystalline Silica During Hydraulic Fracturing. Retrieved from

https://www.osha.gov/dts/hazardalerts/hydraulic_frac_hazard_alert.html1

Grossman, E. (2013). Silica exposure in fracking: Over 60 percent of workers may be excessively exposed. The Pump Handle. 2

Esswein, J. E., Breitenstein, M., Snawder, J., Kiefer, M., and Sieber, K. W. (2013). Occupational Exposures to Respirable Crystalline Silica During Hydraulic Fracturing. Journal of Occupational and Environmental Hygiene. 10: 347-356.3

US Dept. of Energy. (2013). How is Shale Gas Produced? Retrieved from http://energy.gov/sites/prod/files/2013/04/f0/how_is_shale_gas_produced.pdf.4

Proppant Specialists, LLC. (2008). Silica Sand [Material Safety and Data Sheet]. Retrieved from http://oilandgas.ohiodnr.gov/portals/oilgas/_MSDS/fractech/Silica_Sand.pdf.5

U.S. Silica Company. (2012). Silica Sand and Ground Sand [Material Safety and Data Sheet]. Retrieved from http://www.ussilica.com/uploads/files/product-group-msds/msds/silica-msds-english.pdf.6