permit-required confined spaces

ONLINE SELF-STUDY

Permit Required Confined Spaces

OSHA 29 CFR 1910.146

Objectives

In this course, we will cover the following:

Definition of a confined space

Identify the difference between a confined space and permit required confined space

Discuss potential confined space hazards

Outline responsibilities for the entrant, attendant and entry supervisor

Identify rescue options

Identifying a Confined Space

What is a confined space?

is large enough to get the whole

body inside and perform work,

is not designed for continuous

occupancy (i.e., primary function is

not for human occupancy), and

has limited or restricted entrance or

exit.

It must have all three characteristics to be a confined space.

A confined space is a space that:

Identifying a Confined Space

What is limited or restricted entry or exit?

Physical configuration that requires

a person to twist or contort the

body or use hands to enter or exit

the space.

Safe egress is restricted by

obstructions within the space or by

the distance to reach the exit. Restricted exit

Exit not restricted

Note: Entry is defined as

breaking the plane of a confined

space with any part of the body.

Identifying Confined Spaces

Examples of confined spaces

Tanks

Manholes &

Sewers

Grain storage binsBoilers

Other examples include vaults, pipelines, tunnels, and open top spaces >4 feet deep

Identifying Confined Spaces

UNC-CH departments shall identify each space under their

jurisdiction which meets the definition of a confined space,

if any exist, and shall provide a list of such spaces to EHS.

The hazards of each permit space shall be catalogued on

the list.

Contact EHS (962-5507) for assistance with classifying

confined spaces.

Confined spaces shall be considered hazardous until an

evaluation is completed.

Hazards of Confined Spaces

Confined spaces can be deadly.

Some confined spaces are more hazardous than others.

Confined space conditions can change rapidly from

no hazards to life-threatening hazards.

Some confined spaces are so hazardous, a written

permit system is required for entry.

The hazards of confined spaces can often be

controlled or eliminated before entering.


What are the main hazards of confined spaces?

• Hazardous atmospheres

• Engulfing materials

• Entrapment

• Mechanical (moving parts)

• Electricity


Analysis of 10 years of oxygen deficiency fatalities related

to nitrogen asphyxiation revealed:

In 80% of the incidents, the confined space had been entered before

without any problems by the same person who died.

In 40% of the incidents, the hazard was not present at the time of

initial entry.

In 89% of the incidents, the entries were authorized by supervisors.

In 35% of the incidents, the fatalities were supervisors.

Source: AIHA-Challenging Confined Spaces Teleweb

What makes confined spaces so hazardous?

Hazard of Confined Spaces

When is a confined space so dangerous a written entry permit system is required?

• When there is an actual or potential

“hazardous atmosphere”, or

• When the space contains material that can

engulf a person, or

• When the space is configured in a way that

can trap a person, or

• When there is any other recognized serious

safety and health hazard.

Hazard Identification

A “hazardous atmosphere” in a confined space has one or

more of the following:

Flammable gas, mist or vapor

Oxygen content below 19.5% or above 23.5%

Air contaminant concentrations that would cause

death, incapacitation, or permanent health problems

Flammable dusts

You must do air monitoring to

determine if a hazardous

atmosphere exists.


Hazardous Atmospheres – Flammable Gases,

Vapors and Dusts

Flammable gases, vapors or dusts will ignite

from a spark or flame if above a level in the

air called the “lower flammable limit” (LFL).

Gas or vapor levels higher than 10% of the

LFL are considered hazardous and the

confined space cannot be entered until levels

are reduced.

The LFL and upper flammable limit (UFL) set

the boundaries of the flammable range.

LFL is sometimes called “LEL” – “lower explosive limit”


Air

100%

Methane

100%

Air

0%

Methane

0%

Too Rich

5.3%

LFL

15.0%

UFL

Example of flammable gas levels - Methane

Boom!

An open flame or a spark will cause an explosion when the methane amount is

between 5.3% and 15% (i.e., the LFL and UFL for methane).

Too Lean


Hazardous Atmospheres – Oxygen Deficiency

A reduction in oxygen may be caused by lack of ventilation, rusting,

microbe activity, or replacement by another gas.

Lack of oxygen can cause a person to immediately collapse and die.

Normal air contains 21% oxygen. A space with oxygen content

below 19.5 % is considered “oxygen deficient”.

21% 0%19.5%

Oxygen deficiency exists

Oxygen content


Effects of Oxygen Deficiency

% Oxygen Symptoms

19.5% - 16% Fatigue, mild impaired coordination

16% - 12% Increased breathing rate and pulse; impaired

coordination, perception or judgment

12% - 10% Further increased breathing rate, blue lips, mental

confusion

10% - 8% Fainting, nausea, vomiting, mental confusion within few

minutes

8% - 6% Collapse, death within 8 minutes

6% - 0% Coma within 40 seconds, death

Using an “inerting gas” like nitrogen to counteract flammable

vapors will result in an oxygen deficiency.


A word about oxygen-enriched atmospheres

A confined space with an oxygen

amount above 23.5% is considered

“oxygen-enriched”.

A potential source of “extra” oxygen

is a leaking oxygen cylinder used for

an oxy-acetylene torch.

Oxygen above 23.5% is a fire or

explosion hazard.

Green tanks contain oxygen


Hazardous Atmospheres – Toxic Chemicals

At very high levels, chemicals in the air can

be immediately life-threatening or cause

permanent bodily harm.

Some chemicals have “occupational

exposure limits” (OELs) which will cause

harm if exceeded.

Even non-toxic or low-toxic chemicals can replace

oxygen if levels are high enough.

Even at lower levels, chemicals in the

air can still cause harm.


Hazardous Atmosphere – Toxic Chemicals

The most common toxic chemicals in confined

spaces fatalities are hydrogen sulfide and

carbon monoxide.

Other toxic chemicals can include welding

fumes, vapors from liquid residues in storage

tanks, or chemical products used in the confined

space.

Chemicals can quickly reach toxic levels in the

air of a confined space, especially gases, solvent

vapors or sprayed products.

Contact EHS (962-5507) for more information on toxic chemicals.


Hazardous Atmospheres–Hydrogen Sulfide (H2S)

Hydrogen sulfide gas is produced by decaying matter and is

commonly found in sewers.

It can be instantly fatal at higher levels in a confined space.

The OELs for H2S prescribed by EHS are 1 ppm as a 8-hr

TWA1 and 5 ppm as a 15-min STEL2.

H2S in parts per million (ppm)

30 200 2000100 1000

Death in

minutes

Smell

strong

odor

Instant

collapse

Coughing,

red eyes

Loss of

smell

600

Unconscious in

30 min.

1 Time-Weighted Average, 2 Short-Term Exposure Limit


Hazardous Atmospheres – Carbon Monoxide (CO)

Carbon monoxide comes from

operating internal combustion

engines in or near a confined space.

Propane-powered engines also emit

carbon monoxide.

Fatal levels of CO are quickly

reached in confined spaces.

The OEL for CO is 25 ppm

as an 8-hr TWA. To see the

effects of CO, click here

http://ehs.okstate.edu/kopykit/cotox.htm


What are the Hazards of Engulfing Material?

Engulfing materials include liquids or loose

solids such as grain, sand or other granular

material.

People cannot escape when caught in

moving loose solids and can suffocate.

Workers often get engulfed when inlet or

outlet lines are inadvertently opened or

activated.


What is Entrapment?

The space is configured in a way that can trap a worker, for

example, sides sloping towards the center

Gravel hopper Sawdust Cyclone


Other Recognized Hazards

Electrical lines, steam lines or

hydraulic lines

Mechanical hazards

(moving parts)

Hazards caused by the work

(welding, painting etc.)

Controlling the Space

• Prevent employee entry.

• Remove or reduce hazards in the space

first, before a person enters.

• If hazard cannot be removed or

controlled, you must use a written permit

system to enter safely.

The hazards of a confined space can be controlled in

the following ways:

Controlling the Space

Warning employees and controlling access

Limit employee access to confined spaces by

using entry barriers or locks.

Post warning signs at the entrance of

confined spaces.

Make sure that unauthorized workers do not

enter the confined space.

Hazard Control

How To Control Hazardous Atmospheres

Drain or pump out liquid contents, if

any.

Blank off all in-feeding lines.

Test air and ventilate.

Continue ventilating constantly.

If possible, remove any sludge from

outside the confined space.

Exit space if conditions deteriorate.

Hazard Control

Hazardous Atmospheres Dangers

It is difficult to eliminate hazardous

atmospheres in most sewers lines.

Tank sludge or sewer sludge can

release toxic gases during cleanup.

Toxic or flammable gases can exist

in pockets or layers within the space.

Hazard Elimination

How To Eliminate Physical Hazards

Lock-out and Tag-out moving parts

De-energize electrical parts or wiring

Blank or block steam pipes and

product in-feeding pipes.

If Hazards Can’t Be Eliminated

If hazards cannot be completely eliminated, there are

only two options:

a complete written permit system, or

“alternate procedures.”

Both require training of employees.

Entry into a Confined Space

How is entry into a confined space classified?

Written Permit System – required for any high

hazard entry

Alternate Entry Procedures – allowed for

controlled atmospheric hazards only

Reclassified Non Permit – allowed only if all

hazards are eliminated

Hazards must be determined before entering a confined space.

Confined Spaces Entry Procedures

If the atmosphere can’t be controlled or there are other uncontrolled hazards, you must use the written permit system for entry into a confined space.

If you are unsure about the hazards, you must assume a high hazard and use a written permit system for entry.

Only if you are sure there are no hazardous atmospheres or other hazards, can you avoid the required permit procedures for entry.

What Determines Your Options

Confined Space Entry Procedures

What are “alternate entry procedures”?

These procedures have fewer requirements.

If the only hazard is atmospheric (toxic gas or oxygen

deficiency) and it is controlled by continuous ventilation, then

you may use less restrictive alternate entry procedures.

Don’t assume that the only hazard is atmospheric without

investigation and reliable information.


What are alternate entry requirements?

Employees must be trained on confined

space hazards,

The atmosphere in the confined space

must be tested before and during entry,

Continuous ventilation must be used,

If a hazardous atmosphere is detected,

or ventilation stops, the space must be

promptly exited.


What are alternate entry requirements?

The acceptable concentration for LEL is

lowered to <5% as a protection factor.

Provide vehicle and pedestrian barriers.

No harness or lifeline required.

However, EHS recommends entrants wear

a harness and a have a retrieval device in

the vicinity to aid in rescue during medical

emergencies such as heart attacks.


What are reclassified non-permit entry requirements?

If the gas monitor alarms the entrant must evacuate the

space and reclassify the space as a permit space until the

contaminant is identified and eliminated.

If all hazards are eliminated (as opposed to controlled), then

you may reclassify a space as non-permit. OSHA expects

that this option will apply primarily to spaces containing

hazardous energy sources or engulfment hazards.

Employees must be trained on confined space hazards.

The atmosphere in the confined space must be tested before

and during entry.


What are reclassified non-permit entry requirements?

Acceptable atmospheric conditions are listed below:

Oxygen between 19.5% and 23.5%

Flammable gases (LEL) is at or lower than 10%

Carbon monoxide is at or lower than 25 parts per million (ppm)

Hydrogen sulfide is at or lower than 5 ppm

Provide vehicle and pedestrian barriers.

No harness or lifeline required.

However, EHS recommends entrants wear a harness and a

have a retrieval device in the vicinity to aid in rescue during

medical emergencies such as heart attacks.


The Importance of Air Monitoring

Air monitoring is required whenever

there is a possibility of hazardous

atmospheres.

Atmospheric conditions can

change quickly in a confined

space.

A portable gas monitor with an

alarm should be used by the

person entering the confined space

and checked frequently.Confined space gas monitor


Acceptable Atmospheric Conditions

Confined Space entry may proceed only if tests indicate:

Oxygen between 19.5% and 23.5%

Flammable gases (LEL) is at or lower than 10%

Carbon monoxide is at or lower than 25 ppm

Hydrogen sulfide is at or lower than 5 ppm

The amount(s) of other identified air contaminants is/are at

or lower than the OEL prescribed by EHS

Detected hazards must be eliminated or controlled.


Gas Monitor Alarm Setpoints

Alarm setpoints must be set low enough to allow self-rescue

before atmospheric conditions impair an entrant.

EHS requires the following gas monitor alarm settings which

are based on the most stringent OELs for the hazards:

Sensor Low High STEL TWA

O2 19.5 23.5 -- --

LEL 10 20 -- --

CO 25 100 100 25

H2S 5 10 5 1

Contact EHS (962-5507) for assistance with setpoints.


Atmospheric Testing Frequency

EHS recommends performing atmospheric tests every 5 mins

for the first 20 minutes of the entry, then every 20 minutes

thereafter.

The testing frequency will help identify atmospheric changes

before alarm setpoints on the gas monitor are reached.

This frequency applies to testing for alternate entry

procedures, reclassified non-permit, and permit-required

spaces.


Limitations of Air Monitoring Instruments

LEL readings for gases other than

the calibration gas may be incorrect.

Temperatures outside of the

operation range for the monitor may

affect LEL readings.

The presence of any detectable LEL

indicates an abnormal condition and

the source should be evaluated.


The Importance of Daily Bump Testing

Perform a daily bump test prior to using a gas monitor.

On a given day, 1 in every 2,500 untested gas monitors

will fail to respond to a dangerous concentration of gas.

A bump test is a functionality test of sensors and alarms.

Perform a bump test by briefly exposing the instrument to

known concentrations of the target gases and verifying

that the instrument responds.

Source: Industrial Scientific


Ventilation of Confined Spaces

Fresh air blowers or exhaust fans

are typically used.

Watch out for pockets of

unventilated contaminated air.

A blower intake must be placed in

an area of clean air, (i.e., upwind of

combustible engine exhaust).

Exhaust ventilation must be used

when welding or using chemicals in

a confined space.

Don’t place a blower intake near a

running engine!

Written Permit Space Program

If employees enter permit spaces, the employer shall

develop and implement a written permit space

program.


Identify and evaluate permit space hazards

Ensure safe entry operations

Provide proper entry equipment

Designate and train entry team

Develop rescue emergency procedures

Perform annual program review

What are the goals of a written program?


What is required in a written permit program?

A written permit for each entry

Extensive employee training

Employee assigned duties

The Written Permit

The permit states what is done and who does it:

Describes each individual’s roles and

responsibilities,

Specifies safety equipment

and respiratory protection,

Tells how long the job will take,

States hazards found in the space.

Provides written entry authorization,

The Written Permit

The written permit also includes the following:

• Name and telephone of the rescue service

• Methods used to control the hazards

• Acceptable entry conditions

• Air monitoring testing results

• Communication procedures

• Necessary equipment including PPE

Designated Jobs

Any permit-required confined space entry has designated jobs for employees:

Entrant – person who enters into the

permit space

Attendant – person stationed outside

the space who monitors the entrant

Entry Supervisor – person

responsible for planning, authorizing,

and terminating the entryEach position has assigned duties.

Permit System Job Duties

Entrant’s Knowledge and Duties

Knows and understand the hazards in the space,

Knows and uses equipment properly,

Is able to communicate with the attendant.


Entrant’s Knowledge and Duties

Knows what the acceptable entry

conditions for the space are,

Exits the space when ordered,

when alarm sounds, or when

dangerous situation is noted.

Knows how to contact the

attendant if conditions become

unacceptable,


Attendant’s Knowledge and Duties

Knows and understands the hazards in the space,

Knows the behavioral effects from exposures to

hazards in the space,

Knows and tracks who is in the space at all times,

Warns away an unauthorized person who

gets near or enters the space.


Attendant’s Knowledge and Duties

Remains outside the confined space at all

times and monitors activity constantly,

Communicates with entrants to monitor

conditions and knows when to order an

evacuation,

Knows how and when to summon emergency help

and does not enter space to rescue,

Knows how to perform non-entry rescues.


Entry Supervisor Knowledge and Duties

Knows the hazards in the confined space,

Verifies completion of all tests and permit procedures,

Terminates or cancels the permits as needed,

Verifies that rescue services are available,

The attendant and entry supervisor may be the same person.

Removes any unauthorized person from the space,


If the entry was successfully completed, the Attendant shall:

Indicate such by checking the appropriate block on the permit;

Oversee the completion of post-entry actions listed on the permit;

Verify completion by signing in the appropriate location;

Add any pertinent information concerning the entry on the permit;

Return the permit to the Entry Supervisor.

Completion of Entry Duties


Program Records Coordinator Duties

Departments shall also designate a departmental Program

Records Coordinator that is responsible for maintaining

cancelled permits and documentation.

Canceled Permits shall be retained by the Coordinator not

less than one year following the date of entry.

They, along with the entry supervisor, conduct annual

program reviews.

They provide EHS with training records, confined space

evaluation forms and any changes associated with the hazard

status of confined spaces.

Safety/Rescue Equipment

Depending on the hazards of the space and the work

activities the following equipment may be required:

Hard hat

Fire

extinguisher

Ladder

GogglesRadio

Retrieval device & ventilation equipment

Safety/Rescue Equipment

Respirators may be required to enter a confined space safely

EHS employees are the only campus

employees trained or fit tested with supplied

air respirators. Other employees are not

permitted to enter spaces with oxygen

deficiency or toxic levels above the OEL.

Respirators must be worn to enter a space

with an oxygen deficiency or toxic chemical

levels above the PEL.

For these conditions, a respirator that

supplies fresh air is recommended for

use in a confined space.

Procedures for Joint Spaces

There may be situations in which a department

must perform work in a confined space

controlled by another department.

The requesting Entry Supervisor or representative must

coordinate with and obtain approval from the UNC-CH

department controlling the space prior to entry.

Upon completion of the entry, the Entry Supervisor shall

immediately meet with the controlling entity to provide

information on unexpected hazards or problems within the

space of which the controlling entity was unaware.

Procedures for Contractors

Contractors must use their permit system that meets the

requirements of 29 CFR 1910.146 or other applicable

standard.

Contractors and their employees must have training that

meets the requirements of 29 CFR 1910.146 or applicable

standard.

The responsible UNC-CH supervisor must inform the

contractor of the hazards within the space.

Procedures for Contractors

The Contractor or designee shall meet with the responsible

UNC-CH supervisor after completion of the entry to

provide notification of:

Any new permanent hazards created by the work; and/or

Any unidentified hazards encountered during the entry.

If University employees shall enter the space with contracted

employees, the UNC-CH supervisor shall ensure that entry

operations are coordinated with the contractor or designee.

Rescue in a Confined Space

Confined space rescue is very dangerous

60% of all confined space fatalities

are would-be rescuers.

Rescuers often enter a confined

space without thinking about the

hazards.

Rescues cannot be done without

proper equipment and training.

Rescue Services

Using Outside Services

The campus uses South Orange Rescue

Squad for confined space rescues.

Tell the operator the location and about

the hazards inside the space.

SORS periodically practices mock

rescues in campus confined spaces.

Call 911 (Public Safety) to summon SORS

when rescue is required.

Non-entry Rescue

What is a non-entry rescue?

Non-entry rescue is retrieving a person

out of a confined space without going

into the space.

Entrants must wear full body

harnesses with a retrieval line

attached.

Best suited for manholes and tanks

and cannot be used in every situation.

Non-entry Rescue

Non-Entry Rescue Equipment

A retrieval line is attached to a

mechanical device or a fixed anchor

point outside the space.

The mechanical device must be capable

of lifting a person from a space.

Special rescue tripods are available.

It is usually impossible to pull a person

out of a confined space unassisted.

Employee Training

General Requirements

Train before assigning duties

Train before changing duties

Train whenever operations present a new hazard

Employee Training


Retrain whenever there is reason to believe:

• There are deviations from the established

procedures,

• There are inadequacies in the employee’s knowledge

of procedures.

Employee Training


Training must establish proficiency.

The employer must certify that this training has been done and

meets the confined space regulations.

Annual Program Review

The Program Records Coordinator/Entry Supervisor shall

review the effectiveness of the Program annually using

canceled permits and other documentation from the preceding

twelve months.

The department shall view and initiate whatever changes

necessary to address confirmed weaknesses.

Contact EHS (962-5507) to assist with the annual review and

provide the format to conduct the review.

UNC-CH EHS would like to acknowledge the Washington State Department of Labor & Industries for providing portions of the training content.

permit-required confined spaces

Education