Confined Space Entry

1. 1 Confined Space Entry PUBH 3310 Occupational Health and Safety October 31, 2011

2. 2 Supplemental Resources The Basics of Occupational Safety (course text) Chapter 16, “Industrial Hygiene and Confined Spaces” Selected Internet websites, as noted in this presentation

3. 3 Objectives This presentation is an overview of confined space hazards and control Students should: Understand the extent of the problem Know applicable definitions Recognize hazards of confined spaces Know about methods to control these hazards

4. 4 Outline Introduction Definition, examples Hazards Confined Space Safety Recognition, Evaluation, Control Permit Space Programs Standards

5. 5 Introduction Hazards of confined spaces have been know for a long time Industrial “Vessel Entry” precautions have been “Standard Operating Procedure” at least 50 years Utah confined space regulations for agriculture were in effect well before OSHA http://www.rules.utah.gov/publicat/code/r614/r614-003.htm#T11 NIOSH criteria document in 1979 http://www.cdc.gov/niosh/80-106.html ANSI standard for confined spaces, 1989 However, there was no OSHA standard until 1993

6. 6 Confined Space Definitions Confined Space: Limited openings for entry and exit Unfavorable natural ventilation Not designed for continuous worker occupancy OSHA “Permit-required confined space” definition also includes a hazardous condition: Potential to contain a hazardous atmosphere; Engulfment potential Internal configuration can trap or asphyxiate Other recognized serious safety or health hazard.

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8. 8 Confined Space Risk Confined spaces are deadly For every 1,400 accidents reported, one results in a death or serious injury. In confined spaces, it is one in 10. http://www.graphicproducts.com/tutorials/magazine-articles/confined-space-communication.html 63 annual fatalities and 5000 serious injuries Up to 60% of victims are would-be rescuers http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=PREAMBLES&p_id=843

9. 9 Confined Space Risk Confined spaces are deadly NIOSH has issued many warnings Preventing Entrapment and Suffocation Caused by the Unstable Surfaces of Stored Grain and Other Materials (1987)  http://www.cdc.gov/niosh/88-102.html Preventing Deaths of Farm Workers in Manure Pits (1990)  http://www.cdc.gov/niosh/90-103.html Worker Deaths in Confined Spaces (1994) http://www.cdc.gov/niosh/94-103.html

10. 10 Confined Space Risk Utah has many fatalities A 54 year old city employee was found dead in a 20 foot deep manhole in Riverton. 2009 Two relatives (uncle and nephew) died inside an asphalt truck tank, 2000 A Sanpete County dairy worker was asphyxiated when he fell into a manure pit, 1998 Two welders died inside a pipe from argon asphyxiation, 1997 An employee died after being buried under salt while cleaning a bin, 1995 Two maintenance workers (one was a "rescuer") died from nitrogen asphyxiation while working in an oil-refinery tank, 1995 A father, son, and the sheriff (a would-be rescuer) died in a Beaver, Utah manure pit in 1980. Another “rescuer” aspirated liquid manure but survived the “dung lung”. http://www.ncbi.nlm.nih.gov/pubmed/7271092

11. 11 Confined Space Risk Selected recent events 5 workers died after a fire in a pipeline October 2007, Georgetown, Colorado. http://www.csb.gov/videoroom/detail.aspx?VID=46 Two Las Vegas casino workers died in a sewer pit, February 2007. Another would-be rescuer nearly died and is permanently disabled Two California recycling plant workers die from hydrogen sulfide gas while cleaning a tunnel, October 2011. Two sewer workers killed in a Maine sewage tank from hydrogen sulfide gas, October 2011.

12. What is the most common cause of death in confined space fatalities? Fire Engulfment Hazardous atmosphere Electricity 12

13. 13 Causes of Death (NIOSH) Atmospheric hazards - 56% of fatalities

14. 14 Engulfment (34% of fatalities) Causes of Death (NIOSH)

15. 15 Atmospheric Hazards Oxygen deficient atmospheres Oxygen may be consumed by combustion or chemical reaction Other gases may displacing oxygen

16. 16 Atmospheric Hazards Combustible atmospheres Flammable gas, vapor or dust Oxygen enrichment Caution: combustible concentrations usually are very toxic as well

17. 17 Atmospheric Hazards Toxic atmospheres Product stored in the space Activity in the confined space Sources outside the confined space

18. 18 Engulfment Workers are buried when unstable material collapses Bridging Slumping Hang-up Rat hole

19. 19 Safety and Physical hazards Temperature extremes Converging walls or floors Mechanical hazards Electrical hazards Falls - slick/wet surfaces Falling objects

20. 20 Confined Space Safety Recognition Identify confined spaces Confined Space Entry Permits, Written Programs Evaluation Test before entry Test during entry Control Ventilate Isolate Protective equipment Emergency preparations

21. 21 Identify Confined Spaces Find and evaluate spaces Place labels and signs to warn workers

22. 22 Initial Atmospheric testing Test the atmosphere before entry Direct-reading instruments Calibrate instruments, train users Oxygen Test oxygen first - at least 19.5% Low oxygen interferes with combustible reading Combustible gases/vapors Less than 10% of lower explosive limit Combustible dust - Toxic gases/vapors Less than TLV/PEL

23. 23 Additional atmospheric testing Test the atmosphere after initial testing After ventilating the space To verify effectiveness Upon first entry To be sure conditions are still “safe” Continue monitoring if conditions could change Use personal alarms (for entrants) Periodically (or continuously) re-test the atmosphere

24. 24 Controlling Confined Space Hazards Ventilate to control atmospheric hazards Lock out to secure mechanical equipment Isolate to keep toxic materials from entering the space Control ignition and electrical hazards Use Personal Protective Equipment (PPE) if these methods are insufficient to control the hazard

25. 25 Ventilation Inerting Inert gas is added to the space to displace oxygen This controls the flammable hazard Inert atmospheres are oxygen deficient Natural ventilation may be used to clear hazardous atmospheres Requires multiple openings for flow-through ventilation The force of wind may be sufficient to ventilate the space Convection (“chimney effect”) may work when the space is hotter than outside air

26. 26 Ventilation Mechanical ventilation is recommended Compressed air is often used However, direct ventilation using compressed air is very inefficient, suitable for small spaces only Venturi blowers make more efficient use of compressed air 20x to 40x more air moved than consumed

27. 27 Ventilation Air movers Placed at openings to move air through the space At least 10 air changes recommended before entry Continued ventilation during entry

28. 28 Ventilation Guidelines

29. 29 Ventilation Example How long must you ventilate before entry is allowed? 10,000 cubic foot tank 5000 cfm (ft3/min) fan At least 10 air changes required Good air mixing and negligible contaminant release

30. 30 Lock out Tag and lock out circuits and lines Disconnect drives and linkages Secure moving parts

31. For normal operation For combined space entry 31 What are proper valve positions for “double block and bleed” arrangement?

32. 32 Isolation Blind and bleed (vent) lines "Double Block and Bleed “ valve arrangements often are installed in lines "Blind" flanges can be used to stop flow in lines with no valves

33. 33 Ignition control, electrical Ignition control Non-sparking tools Classified electrical equipment (“explosion proof") Electrical hazard control Grounding Ground Fault Circuit Interrupters (GFCI) Isolating transformers

34. 34 Personal protective equipment Atmosphere supplying respirators Required for oxygen deficient or IDLH (Immediately Dangerous to Life or Health) situations

35. 35 Personal protective equipment Air purifying respirators When levels are >OEL and <IDLH Protective clothing also may be required

36. 36 Retrieval devices Retrieval systems Safety harness, lanyards, winch OSHA required for top entry Prepare for rescue before entry

37. 37 Standby/Rescue Communications Never enter confined spaces alone! “Outside monitor” person at all times Continuous communication with entrants Rescue Rescue team on standby The “monitor” summons help Never attempt an unplanned confined space rescue! http://cms.firehouse.com/content/article/article.jsp?sectionId=45&id=19557

38. 38 Confined Space Programs Permit space programs Identify spaces, control hazards, provide rescue, train employees, etc. Entry regulated by a written entry permit system Test space before entry Specify precautions and conditions and duration of permit Sign permit and post on site Permit cancelled at end of job or if conditions change

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40. 40 Confined Space Standards OSHA General Industry 1910.146, Permit Required Confined Spaces Prevent employees from entering confined spaces, or establish permit space entry program Grain Elevators, 1910.272(g) Procedures for silo and tank entry Construction General Duty clause, Section 5(a0(1) 2007 OSHA proposed standard for construction ANSI, NIOSH UTAH OSH (agriculture) R614-3-11. Requirements for Confined Space Entry

41. 41 Utah OSHA (Agriculture) R614-3-11. Requirements for Confined Space Entry Employees shall not enter unless: Atmosphere supplied respirators, ventilation system, or tests Control sources of ignition Employees who enter hazardous atmosphere: Lifeline, attended by rescue person Safety belt or harness to keep employee in vertical position Avoid tangling air and life lines Entrant must be in communication with outside attendant where a ventilation system controls the hazard

42. Conclusions Questions Discussion 42