Ken Arp Industrial Hygienist
Iowa OSHA Consultation and Ed.
515-281-0621 Direct
515-281-7629 General
Confined Spaces&
Three New Uses for the Backhoe
For the
Iowa Rural Water Association
OSHA and CONFINED SPACES Objectives
• Define “Confined Space”• Define “Permit Required Confined Space” • Explain the Hazards of Confined Spaces• What is a “Safe” Confined Space Entry?
Which would you rather have?
OSHA STANDARDS ON CONFINED SPACES
• 29 CFR 1910.146• 29 CFR 1910.252(b)(4) [welding]
• 29 CFR 1910.268(o) [telecommunications]
• 29 CFR 1926.21(b)(6)(i)• 29 CFR 1926.651 [excavations]
• 29 CFR 1915 Subpart B [shipyards]
1926.21(b)(6)(i) • “All employees required to enter into confined or
enclosed spaces shall be instructed as to the nature of the hazards involved, the necessary precautions to be taken, and in the use of protective and emergency equipment required. The employer shall comply with any specific regulations that apply to work in dangerous or potentially dangerous areas.”
Current Confined Spaces Standard for Construction
Current Confined Spaces Standard for Construction
1926.21(b)(6)(ii)
Means any space having a limited means of egress, which is subject to the accumulation of toxic or flammable contaminates or has an oxygen deficient atmosphere. … storage tanks, process vessels, bins, boilers, ventilation or exhaust ducts, sewers, underground utility vaults, tunnels, pipelines, and open top spaces more than 4 feet in depth such as pits, tubs vaults and vessels.
Confined Space
• large enough and so configured that an employee can bodily enter and perform assigned work; and
• has limited or restricted means for entry or exit (e.g., tanks, vessels, silos, storage bins, hoppers, vaults, pits); and
• is not designed for continuous employee occupancy
A space that is:
Standard Safety Requirements for Confined Spaces (ANSI Z117.1-2003)
“Restricted entry and exit is a physical configuration, which requires the use of the hands or contortion of the body to enter into or exit from a confined space”.
Questions to Ask
• Does the person have to use their hands to enter or exit the space?
• Is the person in an awkward posture when entering or exiting the space?
• Is a person’s entry into or exit from the space slowed down or impeded by physical obstructions (such as pipes, ductwork, walls, holes in the floor, flanges, etc.)?
• Would an employee be forced to enter or exit in a posture that might slow self-rescue or make rescue more difficult?
LARGE
RESTRICTEDENTRY/EXIT
CONFINEDSPACE
enough to bodily enter
Not designed for continuous occupancy
What about Dry Wells or Lift Stations? Confined Space? Depends
Permit-required Confined Space
• Hazardous Atmosphere– <19.5% O2 (Oxygen Deficient)
– > 23.5% O2 (Oxygen Enrichment)
– >10% LEL for gas or vapor– >100% LEL for combustible dust– > IDLH– > PEL + acute, serious & impairs ability to
escape
A confined space with hazards = a PRCS
Permit Space (cont’d)• ENGULFMENT• ENTRAPMENT• OTHER SERIOUS RECOGNIZED HAZARDS
– Energy Sources• Electrical• Mechanical• Pneumatic• Hydraulic, etc.
– Steam– Corrosives, etc.
He hasn’t moved in 15 minutes, should we do something?
Contingency Plan
GOT ONE?
Is this a confined space? ______
Why or why not? ___________________________________
Is this a confined space? ______
Permit Required? ___________________________________
Is this a confined space? ______ Permit Required? ___________________________________
Is this a confined space? ______
Why or why not? ___________________________________
Is this a confined space? ______
Permit required? _________________________________
I think our means of egress has just been restricted!Is this house (providing this is the only exit) now a confined space?
Is this a confined space? ______ Is this a permit-required confined space? ______ If yes, what hazards make this confined space a permit space? ___________________________________________
Is this a confined space? ______ Is this a permit-required confined space? ______ If yes, what hazards make this confined space a permit space? ___________________________________________
Is this a confined space? ______ Is this a permit-required confined space? ______ If yes, what hazards make this confined space a permit space? ___________________________________________
Sanitary Sewer Manholes
Is this a confined space? ______ Is this a permit-required confined space? ______ If yes, what hazards make this confined space a permit space? ___________________________________________
Respect these places
• Pits (e.g., elevator, escalator, pump, or valve) • Manholes (e.g., sewer, electrical, or communication)
• Tanks (e.g., fuel, water, or other liquid/solid/ gas)
• Boilers • Transformer vaults
Examples of Confined Spaces
Examples of Non-Permit Confined Spaces
• From FR 1/14/93, p. 4475:– Vented vaults– Motor control cabinets– Dropped ceilings
• Other examples MAY include:– Crawl space under buildings– Air handling units (HVAC
systems)*
Is this a confined space? ______ Is this a permit-required confined space? ______ If yes, what hazards make this confined space a permit space? ___________________________________________
Again, these can be very dangerous
Is this a confined space? ______ Is this a permit-required confined space? ______ If yes, what hazards make this confined space a permit space? ___________________________________________
Elevator Pit
Is this a confined space? ______ Is this a permit-required confined space? ______ If yes, what hazards make this confined space a permit space? ___________________________________________
Is this a confined space? ______ Is this a permit-required confined space? ______ If yes, what hazards make this confined space a permit space? ___________________________________________
Confined Space?Permit Required? Hazards?
Actual or Potential?
Confined Space Incidents
• >60% of the fatalities resulted from hazardous atmospheres.
• 60 - 70% of fatalities are would-be rescuers.• Usually entrants nor rescuers fully recognized
the potential hazards associated with confined spaces.
• Most common hazardous atmospheres were– <O2, methane, CO, H2S (in order)
Safe Conditions?
4 Gas Meter
Or would this look better?
Limitations of Air Testing Devices• You need to know how to use it WELL• Sensitivity varies• Interference• Poisoning/Shelf Life of Sensors• Temp/Humidity Operating Range• Some Not Intrinsically Safe• Must Be Zeroed/Recalibrated• Battery Life• Hazards must be known
Clearing the Air
• Why do atmospheres account for a majority of the fatalities?
BAD AIR Will incapacitate YOU
• 20,000• Gas Meters • Oxygen Deficient • Hydrogen Sulfide• Carbon monoxide• Carbon dioxide• Nitrogen
Quickly
Oxygen Deficiency
• 21% - Normal O2 level• 19.5% - Minimum permissible O2 level• 15-19% - Impaired coordination • 12-14% - Pulse up, impaired judgement• 10-12% - Respiration increases further, lips blue• 8-10% - Fainting, ashen face• 6-8% - 100% fatal in 8 minutes, 50% fatal in 6 minutes,
4-5 minutes recovery with treatment• 4-6% - Coma in 40 seconds, convulsions, death
The Incidents
• 2 employees die from hydrogen sulfide at oil well – gas meters with employees
• Sioux City lagoon deer rescue• Carbon dioxide 1 fatality• Nitrogen – 2 fatalities - Tanker• Anhydrous Ammonia fatality
Ventilation “controls”
What is a “Safe” Atmosphere
• Less than 10% of lower flammable limit• 19.5% to 23.5% Oxygen• Atmosphere below the permissible
exposure limit
Is 20% Oxygen “Safe?”
• How much oxygen is missing if your meter reads 20%?
• What’s 1% in parts per million?• 10,000• Are there any gasses at 10,000 ppm that
could harm you? • Hundreds• Carbon Monoxide is deadly at 500ppm• ALWAYS TEST THE ATMOSPHERE
Which would you rather have?
And Finally, Last, and least important
Three new uses for that backhoe
backhoe bucket / trench box - NOT
Knocking Down Really Tall Stuff - NOT
Shade on a hot day - NOT
Thank You, It’s time to run