Entering and Working in Confined Spaces
Reviewed January 2011
in accordance with the OSHA Permit-Required Confined Space Standard, 29 CFR 1910.146
working in confined spaces has been and will continue to be an integral part of daily
activity by Oklahoma State University employees. This document has been developed to
ensure the safety of personnel required to enter and conduct work in confined spaces. The
program contained herein describes reasonable and necessary policies and procedures for
any and all facilities, departments, and individuals who are associated with confined
space entry operations. This program and all parts of 29 CFR 1910.146 shall apply to all confined space entry operations conducted at Oklahoma State
institutions. As it is the policy of Oklahoma State University to provide its employees
with the safest work environment possible, the University requires compliance with the
procedures set forth in this manual. A site-specific program may be used, providing it
meets or exceeds the requirements set forth in this policy.
This manual has been organized into four sections:
- Identifying Confined Spaces--
Heads or their designated representatives should determine if any personnel under their
supervision are required to enter or conduct work in confined spaces as defined in this
- Identifying Confined Space Hazards--
gives information on the types of hazards that may be present in a confined space. It
should be reviewed whenever the hazards of a confined space are being evaluated.
- Conducting a Confined Space Entry --
If it is
determined that department personnel are required to perform duties in confined spaces,
the program outlined in The Permit System should be implemented.
- Responsibilities and Training Requirements--
This section lists the responsibilities
and training requirements of each individual involved in a confined space entry.
is an important aspect of making a safe entry into a confined space. All confined spaces located within a facility or under the facility's control should be identified. Once the space has been identified as Confined, the OSU Environmental Health and Safety Department shall determine if a permit is required.
All employees shall be made aware of these confined spaces through training or instruction provided by their supervisor or designated representative. Assistance in this training shall be provided by EHS.
All employees shall be instructed by their supervisor or designated representative that entry into a confined space is prohibited without an authorized permit.
To clarify what constitutes a Confined Space, the
following definition will be used. A confined space is any space that has the following characteristics:
- It is large enough or so configured that an employee can bodily
enter and perform assigned work.
- It has limited or restricted means for entry or exit.
Confined-space openings are limited primarily by size and location. Openings may be small
in size and may be difficult to move through easily. However, in some cases openings may
be very large; for example, open-topped spaces such as pits or excavations. Entrance and
exit may be required from top, bottom, or side. In some cases, having to access the work
area by a fixed ladder may constitute limited or restricted entry or exit. Size or
location will generally make rescue efforts difficult.
- It is not designed for continuous employee occupancy.
Most confined spaces are not designed for employees to enter and work on a routine basis.
They may be designed to store a product, enclose materials and processes, or transport
products or substances. Because they are not designed for continuous occupancy, frequently
they will not have good ventilation or lighting. Therefore, occasional employee entry for
inspection, maintenance, repair, cleanup, or similar tasks, can be difficult and
dangerous. The danger associated with entry may come from chemical or physical hazards
within the space.
Not all confined
spaces will be considered permit-required confined spaces, and being able to identify the
difference between the two is important.
A Non-Permit Confined Space is a confined space that does not contain, nor
has the potential to contain, any hazard capable of causing death or serious physical
harm. Examples of non-permit required confined spaces might include the interiors of HVAC
units, certain air plenums and pipe chases, attics, walk-in freezers or refrigerators, and
some building crawl spaces.
A Permit-Required Confined Space
is a confined space that is potentially hazardous. A permit-required confined space
has one or more of the following characteristics:
- Contains or has a potential to contain a hazardous atmosphere.
- Contains a material that has the potential for engulfing an entrant.
- Has an internal configuration such that an entrant could be trapped
or asphyxiated by inwardly-converging walls or by a floor that slopes downward and tapers
to a smaller cross-section; or
- Contains any other recognized serious safety or health hazard.
Examples of serious safety or health hazards might include:
heat or cold
pipes or chemical lines
hazardous levels of dust (such as might occur at the Feed Mill)
the lack of ventilation in most confined spaces, they will have the potential for a
hazardous atmosphere. Therefore, they must be designated "permit-required," and
the procedures for making entry into a permit-required space must be followed. Examples of
permit-required confined spaces at OSU include sewers, electrical vaults, steam tunnels,
sump pits, certain mechanical rooms, some excavations, and other types of enclosures.
Any space that is accessed by lifting a
manhole cover shall be considered a permit-required confined space. Additionally, some
roofs, the Lake Carl Blackwell dam access tunnel, certain grain storage facilities, and
equipment access areas may be designated permit-required confined spaces even though they
don't technically meet the definition (i.e., they may not really have limited or
restricted means of entry or exit). These areas shall be clearly marked as permit-required
has two blanket designations concerning permit-required confined spaces:
tunnels, regardless of access, shall be considered permit-required confined spaces (i.e.,
as soon as you step into a steam tunnel, you are in a permit-required confined space, even
if you walked into it through a mechanical room).
are not considered to be permit-required confined spaces.
are directly responsible for ensuring the safety of their employees in regards to confined
spaces. It is their responsibility to evaluate potentially hazardous spaces within their
facilities and areas to ensure that the proper precautions are taken for safety. This
includes clearly marking permit-required confined spaces, training employees, and ensuring
proper entry procedures are followed. These responsibilities may be delegated to another
competent person provided he/she is qualified.
Plant supervisors are responsible for ensuring their employees are properly trained to do
the jobs they are sent to do. This includes recognition of confined spaces and proper
procedures for making entry into permit-required confined spaces whenever necessary.
No Physical Plant employee shall be sent on a job that potentially
involves work in a confined space unless they have been properly trained in confined space
may be determined that a confined space presents no real danger for employees. However, it
is recommended that all spaces be considered potentially dangerous until they have been
evaluated and tested. Once a space has been evaluated, the Environmental Health and Safety
Department shall determine if the confined space requires a permit and will apply
a space has been identified as confined, the hazards that may be present within the
confined space must be identified. Confined-space hazards can be grouped into the
confined space must be evaluated for these four types of hazards. The three types of
atmospheric hazards are often the most difficult to identify since they might not be
detected without the assistance of a gas monitor.
normal atmosphere is composed of approximately 21% oxygen and 79% nitrogen. An atmosphere
containing less than 19.5% oxygen shall be considered oxygen-deficient. The oxygen level
inside a confined space may be decreased as the result of either consumption or
There are a number of processes that consume oxygen in a confined space. Oxygen is
consumed during combustion of flammable materials, as in welding, cutting, or brazing. A
more subtle consumption of oxygen occurs during bacterial action, as in the fermentation
process. Oxygen can also be consumed during chemical reactions such as in the formation of
rust on the exposed surfaces of a confined space. The number of people working in a
confined space and the amount of physical activity can also influence oxygen consumption.
Oxygen levels can also be reduced as the result of oxygen displacement by other gases.
atmospheres are generally the result of flammable gases, vapors, dust mixed in certain
concentrations with air, or an oxygen-enriched atmosphere.
Oxygen-enriched atmospheres are those atmospheres that contain an oxygen concentration
greater than 22%. An oxygen- enriched atmosphere will cause flammable materials such as
clothing and hair to burn violently when ignited.
Combustible gases or vapors can accumulate within a confined space when there is
inadequate ventilation. Gases that are heavier than air will accumulate in the lower
levels of a confined space. Therefore, it is especially important that atmospheric tests
be conducted near the bottom of all confined spaces.
The work being conducted in a confined space can generate a flammable atmosphere. Work
such as spray painting, coating, or the use of flammable solvents for cleaning can result
in the formation of an explosive atmosphere. Welding or cutting with oxyacetylene
equipment can also be the cause of an explosion in a confined space and shall not be
allowed without a hot work permit. Oxygen and acetylene hoses may have small leaks in them
that could generate an explosive atmosphere and, therefore, should be removed when not in
use. The atmosphere shall be tested continuously while anyhot work is being conducted within the confined space.
Toxic atmospheres may be present within a confined space as the
result of one or more of the following:
The Product Stored in the Confined Space
When a product is stored in a confined space, the product can be absorbed by the walls and
give off toxic vapors when removed or when cleaning the residual material. The product can
also produce toxic vapors that will remain in the atmosphere due to poor ventilation.
The Work Being Conducted in the Confined Space
Toxic atmospheres can be generated as the result of work being conducted inside the
confined space. Examples of such work include: Welding or brazing with metals capable of
producing toxic vapors, painting, scraping, sanding, etc. Many of the solvents used for
cleaning and/or degreasing produce highly toxic vapors.
- Areas Adjacent to the Confined Space
Toxic fumes produced by processes near the confined space may enter and accumulate in the
confined space. For example, if the confined space is lower than the adjacent area and the
toxic fume is heavier than air, the toxic fume may "settle" into the confined
Mechanical and Physical Hazards
such as rotating or moving mechanical parts or energy sources can create hazards within a
confined space. All rotating or moving equipment such as pumps, process lines, electrical
sources, etc., within a confined space must be identified.
Physical factors such as heat, cold, noise, vibration, and fatigue can contribute to
accidents. These factors must be evaluated for all confined spaces.
Excavations could present the possibility of engulfment. Employees shall be protected from
cave-ins by sloping, benching, or shoring systems when the depth of the excavation is more
than four feet, in accordance with 29 CFR 1926.652. In some circumstances, air-monitoring
may also be required. Please see OSU's Trenching and Shoring Manual for more
details regarding safe practices in excavations.
When a confined space must be entered, a permit shall be completed and authorized by department heads, supervisors, or their designated representatives prior to entry of the confined space. This permit shall serve as certification that the space is safe for entry. The permit shall contain the date, the location of the space, and the signature of the person providing the certification.
A permit shall not be authorized until all conditions of the permit have been met. Supervisors or their designated representatives shall instruct all employees to list their names on the authorized permit before they will be allowed to enter a confined space. The permit to be used by Oklahoma State University personnel can be found in the Appendix of this manual.
A. Plan the Entry
first step towards conducting a safe confined-space entry is to plan the entry. This will
allow for the identification of all hazards, and for the determination of all equipment
necessary to complete the project.
- Gather general data:
the confined space. Give the name or location of the confined space.
the reason for entering the confined space. Be specific. Also, identify if hot work will
the contents of the confined space. This refers to any chemicals or other materials and
energy that are usually present in the confined space.
- Identify the Hazards
Atmospheric testing shall be conducted prior to entering permit-required confined
spaces. It is recommended that the entry supervisor conduct these tests; however, any
competent person certified in confined space entry may do so.
entry supervisor will determine the oxygen content and record this on the entry permit.
entry supervisor will determine flammable gas content and record this on the entry permit.
entry supervisor will determine levels of H2S and Carbon Monoxide and record this on the
- If a
toxic substance is determined to be in the confined space during testing by the entry
supervisor, Environmental Health & Safety shall be contacted to assist in obtaining a
Material Safety Data Sheet or other chemical information to determine what type of
personal protective equipment is required, the potential health effects, the Permissible
Exposure Limits, and any other information needed to safely conduct the work.
supervisors will determine mechanical and physical hazards. They should list all items and
energy that will require lockout/tagout, blanking and bleeding, disconnecting, or
securing. Physical hazards should also be listed.
- Ventilate the Confined Space
whether mechanical or natural ventilation will be used. Describe the procedures to be
If mechanical ventilation is to be used, the exhaust must be pointed away from
personnel or ignition sources. Also, mechanical ventilators should be bonded to the
- Isolate the Confined Space
the procedures for disconnecting equipment or lockout and tagout. All mechanical,
electrical, or heat-producing equipment should be disconnected or locked and tagged out.
This would also include any pumps that pull fluid from, or pump fluid into, the confined
- Purge/Clean the Confined Space
if the confined space will be purged. Purging with inert gas is not recommended. If the
space must be purged, describe the procedures.
Indicate the type of cleaning methods to be used. If chemical cleaners are to be used, name the
type and describe the procedures. The MSDS for the chemical should be consulted prior to
When introducing a chemical into a confined space, the compatibility of that
chemical with the contents of the confined space must be checked. If in doubt, consult
Environmental Health & Safety.
If steam is to be used, the hose should be bonded to the confined space.
- Place Warning Signs
if warning signs or barriers will be needed to prevent unauthorized entry or to protect
workers from external hazards. If the confined space will be left open and unattended for
any length of time, warning signs, and barriers such as barricades and/or caution tape
will be required.
- Identify All Personnel
all employees that will be required to prepare the confined space and complete the work
inside the space.
- Identify Necessary Equipment
all equipment that will be necessary to complete the project.
practical, all personnel entering a confined space should be equipped with a
retrieval line secured at one end to the entrant by a full-body harness with its other end
secured to a tripod lifting hoist.
B. Conduct Pre-Entry Training
the entry has been planned, supervisors or their designated representatives must train all
employees who will be involved in the entry. The training should be conducted no earlier
than one day before entry is to be made following the procedure outlined below.
- Identify the confined space, the reason(s) for entry, and the work detail.
each employee the job(s) he/she is to perform in the entry project (entrant, standby
- If an
employee is required to use a piece of equipment, be sure that he/she is capable of using
the equipment properly.
all personnel that no one is to enter the confined space unless the attendant is present
at the work site
- Inform entrants of all known and/or suspected hazards
personnel of any access or exit problems.
personnel of all equipment that must be locked out or tagged out.
personnel of the contents of the confined space.
personnel of all atmospheric levels that must be maintained before entering and while
working in the confined space.
a toxic atmosphere or substance is present or could become present, the following
additional training must be completed:
respiratory protection is not going to be used, inform personnel of the maximum
permissible exposure level (PEL) that can exist within the confined space, and the method
used to monitor PEL.
personnel of the potential health effects of exposure to the toxic atmosphere or
personnel of the signs and symptoms of exposure to the toxic fume.
personnel of the personal protective equipment (PPE) that they will be required to wear.
entrants are unaware of the proper use of the PPE, they must be trained in the proper use
of this equipment.
Supervisors may request assistance from Environmental Health & Safety in providing the
should not be assigned to tasks requiring use of respirators
unless it has been determined that they are physically able to perform the work and use
the equipment. A local physician shall determine what health and physical conditions are
pertinent. The respirator user's medical status should be reviewed periodically
- Identify Isolation Procedures
the personnel responsible for the lockout/tagout of all
equipment that must be isolated.
the personnel responsible for performing this function of the methods to be used.
- Identify Purging and/or Ventilation Procedures
all personnel responsible for performing this function of the methods to be used.
- Identify All Equipment Needed
personnel involved in the project of all equipment that will be necessary to complete the
sure that all employees are capable of using their assigned equipment properly.
- Determine Necessary Personal Protective Equipment
personnel of all PPE that must be used to ensure their safety.
sure that all personnel required to use PPE are trained in the proper use of the
- Establish Communication
all entrants that they are required to maintain communication with the attendant.
attendant that he/she must maintain constant contact with all entrants.
personnel of the type of communication they are to use.
- Protect from External Hazards
personnel where signs and barriers will be placed to prevent unauthorized entry and
protect entrants from external hazards.
- Pre-Plan Rescue Procedures
designated attendant(s) should be informed of the rescue procedures to be
attendant should be informed that he/she can have no other duty but to maintain contact
with personnel inside the confined space.
the attendant(s) that they must not enter the confined space under any circumstances.
- Placing the Confined Space Back Into Service
personnel of the steps to be taken to place the confined space back into service.
C. Preparing the Confined Space for Entry
the entry has been planned and personnel have been trained, the next step is to prepare
the confined space for entry.
following steps are to be followed when preparing the confined space for entry:
- Place warning signs or barriers around the confined space to prevent
unauthorized entry as necessary.
- Place all tools, safety equipment, monitoring equipment, etc., near
the confined space.
- Isolate all mechanical and/or electrical hazards as necessary.
- Purge/ventilate the confined space as necessary.
- Test the atmosphere using an appropriate gas monitor.
oxygen content is less than 19.5% or greater than 21.5%, perform additional ventilation.
Then shut off ventilation equipment and re-test the oxygen content.
- If oxygen content is between 19.5% and 21.5%, continue entry
- Test for flammable gases.
the meter reading is less than 10% of the lower explosive limit (LEL), continue entry
the meter reading is above 10% of the LEL, continue ventilation of the confined space.
Then shut off the ventilation and have the atmosphere re- tested.
- If the meter reading is still above 10% of the LEL, the confined
space must be cleaned before entry is permitted. If the confined space must be entered for
cleaning purposes, the procedures outlined in Item 9 of this section must be followed.
- Test for toxics (If a toxic atmosphere is present, no person should
be permitted to enter the confined space at a level exceeding the Permissible Exposure
Limit without proper Personal Protective Equipment. Environmental Health & Safety
should be called to assist in identifying proper precautions and the protective measures
to be taken.
- Assemble all personnel involved and review rescue procedures. The
entry supervisor will then add any needed information, then complete and sign the permit.
Department Head or supervisor that entry is commencing. If Department Head or
supervisor is unavailable, notify EHS Department.
Everyone involved in a confined-space
entry project has certain responsibilities and requires a certain amount of training. It
is very important that every individual is familiar with his/her responsibilities. This
section outlines the responsibilities and training requirements of each individual
involved in a project.
of Environmental Health & Safety or his/her designated representative shall be
responsible for the following:
- Reviewing and updating the Oklahoma
State University Confined Space Entry Program to conform to current CFR standards.
- Ensuring compliance with standards set forth in the program by
periodic inspection of entry sites and canceling permits where unsafe conditions are
- Assisting Supervisors with:
training as set forth in the program,
of confined spaces,
spaces that require a permit for entry,
- labelling Permit-Required Confined Spaces.
a single annual review covering all entries performed during a 12-month period to ensure
employees participating in entry operations are protected from permit space hazards.
Supervisors or Their Designated Representatives are Responsible for:
- Identifying confined spaces within facilities or areas under their
- Identifying hazards within a confined space under their control.
that all training requirements for a specific confined space entry have been met by
signing the pre- entry authorization space on the entry permit.
Entry Supervisors shall be responsible for the following:
- Ensuring that the required atmospheric tests are performed at the
confined space and results recorded on the permit prior to entry authorization.
- Obtaining and maintaining all equipment necessary to complete the
confined-space entry project.
- Authorizing entry by signing the Entry Authorization space on the
entry permit after all conditions for a safe entry have been met.
- Terminating the entry and canceling the permit when:
operations covered by the entry permit have been completed.
- A condition that is not allowed under the entry permit arises in or
near the permit space.
whenever responsibility for a permit space entry operation is transferred, and at
intervals dictated by the hazards and operations performed within the space, that entry
operations remain consistent with terms of the entry permit and that acceptable entry
conditions are maintained.
Authorized Entrants are Responsible for and shall receive training in the Following:
- The knowledge of hazards that may be faced during entry, including
the mode, signs or symptoms, and consequences of the exposure.
- Proper use of equipment, which includes:
testing and monitoring equipment.
equipment needed to obtain acceptable entry conditions.
equipment necessary to maintain contact with the attendant.
protective equipment as needed.
equipment as needed.
and shields as needed.
such as ladders, needed for safe ingress and egress.
and emergency equipment as needed.
- Any other equipment necessary for safe entry into and rescue from
- Communication with the attendant as necessary to enable the
attendant to monitor entrant status and to enable the attendant to alert entrants of the
need to evacuate the space if required.
- Alert the attendant (standby person) whenever:
entrant recognizes any warning sign or symptom of exposure to a dangerous situation, or
- The entrant detects a prohibited condition.
- Exiting the permit space as quickly as possible whenever:
order to evacuate has been given by the attendant or the entry supervisor;
entrant recognizes any warning sign or symptom of exposure to a dangerous situation;
entrant detects a prohibited condition; or
- An evacuation alarm is activated.
authorized to perform duties as attendant shall be responsible for and receive training in
- Knowing the hazards that may be faced during entry, including
information on the mode, signs or symptoms, and consequences of exposure.
- Awareness of possible behavioral effects
of hazard exposure in authorized entrants.
- Continuously maintaining an accurate
count of authorized entrants in the permit space and ensuring that the means used to
identify authorized entrants accurately identifies who is in the permit space.
- Remains outside the permit space during entry operations until
relieved by another attendant.
- Attempting non-entry rescue if proper equipment is in place and the
rescue attempt will not present further hazards to the entrant or attendant.
- Communicating with authorized entrants as necessary to monitor
entrant status and to alert entrants of the need to evacuate the space when conditions
- Monitoring activities inside and outside the space to determine if
it is safe for entrants to remain in the space and ordering the authorized entrants to
evacuate the permit space immediately under any of the following conditions:
the attendant detects a prohibited condition.
the attendant detects the behavioral effects of hazard exposure in an authorized entrant.
the attendant detects a situation outside the space that could endanger the authorized
- If the attendant cannot effectively and safely perform all the
duties required by this program.
- Summoning rescue and other emergency services as soon as the
attendant determines that authorized entrants may need assistance to escape from permit
- Taking the following actions when unauthorized persons approach or
enter a permit space while entry is underway:
the unauthorized persons that they must stay away from the permit space.
the unauthorized persons that they must exit immediately if they have entered the permit
- Informing the authorized entrants and the
entry supervisor if unauthorized persons have entered the permit space.
no duties that might interfere with the attendant's primary duty to monitor and protect
the authorized entrants.
End of Manual