Ken Arp Industrial Hygienist

Iowa OSHA Consultation and Ed.

515-281-0621 Direct

515-281-7629 General

arp.kennan@dol.gov

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