Confined Space Rescue

Confined Space Rescue

Training Topics

IRespiratory Protection Anatomy and Physiology

II Confined Space Emergencies

IIIToxic Atmosphere Monitoring Equipment

IVBreathing Apparatus Review

VILifting Systems

Training Continued:

VII Confined Space Rescue Practical Exercises

References

NFPA 1670 Operations and Training for Technical Rescue Incidents

NFPA 1006 Professional Qualifications for Rescue Technicians

Confined Space and Structural Rope Rescue, Michael Roop/Tom Vines/Richard Wright. Mosby Press 1997

References

OSHA 29 CFR 1910.146 Compliance Directive for Permit Required Confined Spaces

Technical Rescue Field Operations Guide, Tom Pendley. Desert Rescue Research 2000

Respiratory Protection

The Respiratory Process

The exchange of gases (O2 & CO2) between the alveoli & the blood occurs by simple diffusion: O2 diffusing from the alveoli into the blood & CO2 from the blood into the alveoli.

Respiratory Process Cont.

We do this, of course, by breathing - continuously bringing fresh air (with lots of O2 & little CO2) into the lungs & the alveoli.

Breathing is an active process - requiring the contraction of skeletal muscles. The primary muscles of respiration include the external intercostal muscles (located between the ribs) and the diaphragm (a sheet of muscle located between the thoracic & abdominal cavities).

The Respiratory Process

Confined Space Emergencies

Confined Space Fatalities:

–__ % due to asphyxiation

–__ % of the fatalities are would be rescuers

Ex.-1990: 3 Firefighters die in Pennsylvania from Co poisoning from running portable pump

Example: PA Deaths

On May 1, 1990, a 39-year-old male volunteer firefighter died inside a 33-foot-deep water well in Pennsylvania while attempting to pump water out of the well. Also, two male volunteer firefighters (ages 40 and 20) died attempting rescue.

 (other examples)

C-Space Definition

OSHA 29 CFR 1910.146

–An OSHA confined space is defined as:

A.-

B.-

C.-

Examples

Examples include but are not limited to:

Permit Required C-Space

A confined space permit is required if the space has one or more of the following hazards:

–1.

–2.

–3.

–4.

Non-Permit C-Space

A non-permit required confined space is:

–1. Spaces that do not contain,

–2. Space in which all the hazards

C-Space Entry Risk Profile

A permit required confined space has less risk if it meets the following criteria:

–A. The internal configuration of the space is

Entry Risk Pro-file cont.

–B. The victim can be easily

–C. Rescuers can pass easily through

–D. The space can accommodate

–E. All hazards in and around the space

C-Space Entry Risk Profile

A permit required confined space has more risk if any of the following conditions or other hazardous conditions exist

–A.

–B.

–C.-

Entry Risk Profile cont.

–D.

(Interpreted from NFPA 1670)

C-Space Hazards

It should always be considered that the most unfavorable situation exists in every confined space and that the danger of -

Hazard Types

Hazards specific to a confined space are dictated by:

1.-

–Ex. Damp activated carbon in a filtration tank will absorb oxygen, creating an oxygen deficient atmosphere

Hazard Types cont:

2-:

–Such as the fermentation of molasses that creates ethyl alcohol vapors and decrease the oxygen content of the atmosphere

Hazard Types cont:

3-

–As in the case of sewer systems that may be affected by rising water, heavier than air gases, or flash floods

The most hazardous kind of confined space is the type that combines limited access and mechanical devices

C-Space Hazard Groups

Confined space hazards can be grouped into the following categories:

–1.

–2.

–3.

–4.

Oxygen Deficient Atmosphere

Normal atmosphere composed of % oxygen, % nitrogen and % argon

An atmosphere containing less than % oxygen shall be considered oxygen deficient

*O2 levels inside confined spaces may be decreased as the result of consumption or displacement*

Effects of decreasing O2 Levels

Level of 17 %

–

Between 14-16 %

–

Between 6-10 %

–

Less than 6 %

–

Consumption of O2

Takes place during ______of flammable substances

During bacterial action

During chemical reactions as in the formation of rust

Displacement of O2

Gas that ______oxygen and therefore reduce the O2 levels

Nitrogen, argon, helium and carbon dioxide are used as inerting agents to displace flammable substances and retard pyrophoric reactions

O2 Enriched Environment

An atmosphere containing more than % of oxygen is oxygen enriched and enhances the flammability of combustibles

Flammable materials such as clothing and hair burn violently when ignited

Flammable Atmospheres

Arise from enriched O2 atmospheres, vaporization of flammable liquids, byproducts of work, chemical reactions or concentrations of combustible dust

Work conducted in a c-space can generate flammable atmospheres

Flammable Atmosphere Terms

______is the lowest temperature at which a liquid can form an ignitable mixture in air near the surface of the liquid. The lower the flash point, the easier it is to ignite the material

(at the flash point, the flame does not need to be sustained).

Example

Gasoline has a flash point of -50 degrees F (-45 C) and is more flammable than ethylene glycol (antifreeze) which has a flash point of 111 degrees C (232 F)

Flammable Atmosphere Terms

______the temperature at which the flame becomes self-sustained so as to continue burning the liquid

The fire point is usually a few degrees ______the flash point

Flammable Atmosphere Terms

______apply generally to vapors and are defined as the concentration range in which a flammable substance can produce a fire or explosion when an ignition source (such as a spark or open flame) is present

The concentration is generally expressed as percent fuel by volume

UEL/LEL

______(UFL) the mixture of substance and air is too rich in fuel (deficient in oxygen) to burn. This is sometimes called the upper explosive limit (UEL)

______(LFL) the mixture of substance and air lacks sufficient fuel (substance) to burn. This is sometimes called the lower explosive limit (LEL)

Example UEL/LEL

It is usually quite easy to reach the lower flammable limit. There are numerous cases where individuals have used a solvent, sealer, or other flammable materials in a basement or closed room with inadequate ventilation...and have been injured when the vapors were ignited by a pilot light, electric spark or other ignition source

Example UEL/LEL

Newcastle in September of 2003

–A pipe fitter left an acetylene cylinder inside his vehicle over the weekend. Either the cylinder had a small leak or the valve was not fully closed. The flammable limits for acetylene are extremely broad, _____% to ____% in air

–When the worker opened the door, an undetermined spark source (the door light switch, light bulb, cellular phone, static etc.) ignited the mixture with catastrophic results

Acetylene Explosion

Flammable Atmosphere Terms

______(PEL) is the maximum amount or concentration of a chemical that a worker may be exposed to under OSHA Regulations

______(TWA) - are an average value of exposure over the course of an 8 hour work shift

Flammable Atmosphere Terms

______(IDLH) atmospheres poses an immediate threat to life, would cause, irreversible adverse health effects, or would impair an individual's ability to escape from a dangerous atmosphere

Flammable Atmospheres

Flammable gases such as

or vapors from hydrocarbons can be trapped in c-spaces

Gases than air will seek lower levels as in pits, sewers, storage tanks/vessels

Flammable Atmospheres

In a closed top tank, lighter than air gases may rise and develop a flammable concentration if trapped the opening

Combustible dust concentrations are found during loading/offloading, conveying grain products, nitrated fertilizers and finely ground chemical products

Toxic Atmospheres

The source of toxic atmospheres encountered in c-spaces may arise from:

–

–

–

Toxic Atmospheres

Carbon Monoxide

–Odorless, colorless gas, approximately the same density of air

–Formed from incomplete combustion of organic materials

–Can be formed from mircobial decomposition of organic materials in sewers/silos and fermentation tanks

Measuring Toxicity

Measured in terms of permissible exposure limit (PEL)

PEL is the concentration of a toxin that most people could safely be exposed to for an 8 hour period

Any toxin in a confined space greater than its PEL is hazardous

Irritant (Corrosive) Atmospheres

Irritant gases vary widely among all areas of industrial activity

They can be found in plastic plants, chemical plants, petroleum industry, tanneries, refrigeration industries, paint manufacturing and mining operations

Irritant (Corrosive) Atmospheres

Prolonged exposure at irritant or corrosive concentrations in a c-space may produce little or no evidence of irritation

Danger in this situation is that worker is usually not aware of any toxic exposure

Examples: nitrogen dioxide, sulfur dioxide, ammonia

Mechanical/Physical Hazards

Vibrations/moving machinery

–Augers, hydraulics, steam, etc.

Noise

–Noise problems intensified in c-space because interior causes sound to reverberate

–May disrupt verbal communication with emergency personnel on the exterior of the space

Toxic Atmosphere Monitoring Equipment

Atmospheric monitoring should take place continuously or at frequent intervals during the rescue operation

All atmospheric monitoring equipment should meet OSHA standards

Equipment should be calibrated according to manufacturer’s recommendations

Atmospheric Testing Procedures

First set of tests should be performed by remote probe prior to entering the space

All levels of the space need to be metered due to (weight of a vapor compared to air)

Principles of Air Monitoring

 meters to manufacturer’s spec

If O2 level is not normal, readings will be affected

Spaces may have stratified atmospheres, levels of space must be metered

Allow for air intake in sampling hose/probe, approx. sec per of hose

______ppm = ______%

Meters

Oxygen Levels

According to OSHA, air containing less than 19.5 % or more than 23 % oxygen is unacceptable

If oxygen level is not normal, flammability readings will be effected

Atmosphere Flammability

Measured in the % of the lower explosive limit (LEL)

The LEL is the lowest concentration of a product that will explode or burn when it contacts a source of ignition of sufficient temperature

OSHA -> C-space is hazardous if it contains more than ______% of the LEL

Lower Explosive Limit LEL

A flammable gas must reach 100 % of its LEL to ignite and burn

Meters are usually calibrated with a flammable gas such as methane, heptane or pentane

Lower Explosive Limit LEL

Methane LEL -> approximately 5 %

Different gases have different LELs

Meter calibrated to methane will give an inaccurate reading for a gas with a different LEL

Meter reading of 10 % or less of the LEL should ensure that an atmosphere is below the LEL of most gases

Common Gas Examples

Methane (CH4):

–

–

–LEL %, UEL %

Nitrogen (N2):

–

–

–

Common Gases

Carbon monoxide (Co):

–

–

–PEL =

–TWA =

–LEL ____%, UEL ____ %

–IDLH =Common Gases

Hydrogen Sulfide (H2S):

–

–

–Odor thresh hold = ppm

–

–LEL = ____ %, UEL = ____ %

–

Hydrogen Sulfide Cont:

–PEL =

–TWA =

–IDLH =

Toxic Atmospheres

Known materials:

-Use meter specific to that ______to test for these products

Unknown materials:

-Use meters to take readings and narrow the spectrum of chemicals

-Broad spectrum analysis

-Colormetric tubes

Hazard Abatement

Hazard Reduction

Reducing or abating hazards of a confined space emergency-

In addition to protective equipment, SCBA, other measures should be taken externally

OSHA requires that measures be taken before permit spaces are entered

Electrical

Usually isolated by a combination of:

–1.

–2.

Hydraulic

Includes liquids, finely divided solids that if not secured may cause exposure or engulfment

Usually isolated by:

–1.

–2.

Mechanical

Hazards in the space or introduced into the space

Includes energy from:

–

–

Ventilation

Why Ventilate??

When atmospheric conditions is a c-space do not meet the limits for O2, flammability and toxic vapors, the c-space must be ventilated to bring the atmosphere into those limits.

Methods of Ventilation

1.

2.

3.

Positive Pressure (Supply)

Direction of fresh air flow ______space creating a positive pressure diluting any contaminants by the addition of fresh air

______operated fans should be used to prevent unacceptable levels of Co into space by use of gasoline blowers

Air flow should be introduced into the space and the flow should be at the level at which rescuers will be working

Positive Pressure

Fan should be allowed to operate long enough to exchange the air content of the space several times

Capacity of fan in cubic feet per minute (CFM) divided into the volume of the space in cubic feet = the time it takes to exchange air one time

Positive Pressure (Supply)

Positive pressure (supply) can force air into space ______times the distance exhaust (negative) pressure can draw it

Examples

Super Vac's AirPac 25 duct canister allows the 25 ft. x 8 in. duct to be easily stored and rapidly deployed

Negative Pressure (Exhaust)

Exhausts contaminants from the space (using negative pressure) by pulling contaminated air out of a space

A slight vacuum is created that can draw other contaminants into the space

May draw flammable gases over motor

Positive-negative/push-pull

Flushes the atmosphere by supplying and exhausting large volumes of air

Two portals must be present, positive air flow into space while negative pressure pulls contaminants out

Most ______method for ventilation

Consider where the contaminated exhaust is going and if it will pose an additional hazard

Respiratory Protection

Types of SCBA

OSHA CFR 1910 direct that unless the cause of the emergency can be established as NOT atmosphere related, fresh air breathing apparatus must be worn

Types:

–Self contained breathing apparatus (SCBA)

–Supplied air respirator (SAR)

Self Contained Breathing Apparatus

Positive pressure since 1983

Prevents contamination of the air inside the face piece if a leak occurs in the face piece’s seal

Limited amount of air supply (based on wearers personal characteristics)

Supplied Air Respirators

During C-space rescue, conventional SCBA’s size often makes it difficult to use

SCBA small enough to pass through narrow openings may limit duration of its air supply to impractical levels

Supplied Air Respirators are a viable option

SAR Components

SAR consists of:

–Open circuit face piece

–Regulator

–Egress cylinder attached via a low-pressure air line to remote source air supply (restricted to maximum distance allowed by manufacturers, usually no more than 300 feet from point of attachment)

SAR Components

OSHA requires an SAR used in an atmosphere that is immediately dangerous to life and health (IDLH) have an additional supply

Must be capable of providing enough air for the wearer to escape the atmosphere in the event the primary supply is interrupted

SAR Components

“Escape” requirement addressed by attaching small breathing air cylinder rated at 5 minutes to the SAR unit

5 minute cylinder are intended to provide enough air for escape although they may be incapable of doing so

SAR

Air Carts

Survivair Air Cart

 Contains up to two independently operated 30-,45-, or 60-minute high pressure (4500 psi) cylinders

Or to two independently operated 30 minute low pressure (2216 psi) cylinders

 An optional accessory case can hold a variety of Hip-Pac and hose combinations

Survivair Air Cart

Two inlets allow regulated or unregulated external air sources to be used

Built-in manifold has four Foster or Schrader quick-disconnect couplings to supply air for up to four workers

Used in any confined space where an SCBA would reduce or restrict worker movement

OSHA Respiratory Standard

1910.134(e)(3)(iii) requires, when an IDLH atmosphere exists, A stand by man or men with suitable self contained breathing apparatus shall be at the nearest fresh air base for emergency rescue

Safe Respiratory Work Practices

1. Rescuers should immediately

2. Rescuers should wear

3. Minimum capacity of of the source air should be ______the volume of the total needs of all rescuers connected to it for the anticipated duration of the rescuer’s entry

Safe Work Practices cont:

4. A minimum team of ______rescuers should be utilized for all permit space rescue entries

Lifting/Raising Systems

Miller Tripod

Miller Tripods provide a highly portable anchorage system for typical confined space entry and rescue systems

Made of high-strength aluminum, the tripod withstands up to 5,000 lbs of pull yet weights only 42 lbs

Legs lock independently and adjust with integral push pins allowing set up on uneven surfaces

SKED EVAC Tripod

Features aircraft-grade, gold-anodized aluminum legs and a cast-aluminum head

Three heavy-duty rigging anchors have exceptionally large holes for easy attachment and are located in the center

SKED EVAC Tripod

Legs adjust in 5-inch increments for a maximum height of 10 feet and a minimum length for transport of 7 feet

Holes in the feet allow the tripod to be bolted into position

119 inch height / 5,280 lbs (23kN)

SKED EVAC Tripod

Mechanical Advantage Systems

Retrieval Systems

1910.146 (k)(3) requires that retrieval systems be used except when the retrieval equipment would increase the risk to an entrant or would not contribute to the rescue of an entrant.

When a retrieval system is not used, alternate methods of retrieval must be developed.

MA Systems

Rescuer hauler 4:1 system

–3-inch double pulley with a cam

–rope can move in only one direction when the cam is engaged

–allows rescuer to raise a load by pulling on the tail end of the rope, releasing it, and getting another grip

MA Systems

Rescuer hauler 4:1

–cam can be released manually by pulling on the attached cord

–accommodates rope sizes from 3/8” (10mm) to 1/2” (12/5mm).

–Minimum break strength when in use is 12,000 lb

Patient Evacuation Devices

Patient packaging devices that can be used in confined spaces include but are not limited to the following:

–Prefabricated Class III Ha

–

–

–

–

–

–

–C-Space Rescue

Priority 1: Make the scene safe

–

–

Priority 2: Victim contact by Primary Rescuer

–

–

–

–

C-Space Rescue

Priority 3: Size-up

-

-

-

-

Priority 4: Preparation

-

-

-

C-Space Rescue

Priority 5: Access Victim

-

-

-

Priority 6: Stabilize and package victim

-

-

C-Space Rescue

Priority 7: Evacuate

-

-

-

Priority 8: Response Termination

-

-

-

Rescue Response

Non-IDLH Atmosphere

–Incident Commander