Confined Spaces SP# 1910.146

Quick Reference

1.0 Purpose
2.0 Scope and Applicability
3.0 Reference
4.0 Policy
5.0 General Responsibilities
6.0 Procedure
6.1 Definitions
6.2 General Provisions
6.2.1 Training
6.2.2 Confined Spaces
6.2.3 Hazards of Confined Spaces
6.2.4 Identifying Confined Spaces
6.2.5 Evaluating Confined Spaces
6.2.6 Permit-Required Confined Spaces Entry Requirements
6.2.7 Recordkeeping
6.3 General Responsibilities
6.3.1 Managers
6.3.2 Supervisors
6.3.3 Employees
6.3.4 Entrant
6.3.5 Attendant
6.3.6 Entry Supervisor
6.3.7 Qualified Person
6.3.8 Safety Risk Management
6.3.9 Division of Purchase and Services
APPENDIX A: Training Certification Form
APPENDIX B: Confined Space Inventory Form
APPENDIX C: Atmospheric Testing Procedure
APPENDIX D: Confined Space Evaluation Form
APPENDIX E: Confined Space Entry Permit
APPENDIX F: Confined Space Entry Program Element Contact List
APPENDIX G: Confined Space Entry Team Responsibilities
APPENDIX H: Confined Space Decision Tree Flowchart
APPENDIX I: Confined Space Entry Flowchart

1.0 Purpose

The purpose of this safety policy is to provide information and guidance for the protection of North Carolina Department of Environment and Natural Resources (NCDENR) employees who work around or enter confined spaces.

2.0 Scope and Applicability

A confined space/area by design has limited openings for entry and exit; has unfavorable natural ventilation, can contain or produce dangerous air contaminants, and is not intended for continuous employee occupancy.  Therefore, confined spaces can have, or create, hazards for NCDENR employees who perform work activities in them. Confined spaces may be permitted or non-permitted confined spaces. Confined spaces are located throughout the state and are present at many NCDENR worksites, jobsites and facilities; as well as client facilities served and inspected by NCDENR employees, each having its own set of hazards associated with them.

This safety policy provides guidelines for the protection of NCDENR employees that must work in or around confined spaces. It includes training components and discussion on what defines a confined space. This safety policy lists practices to identify confined spaces and notes the hazards of confined spaces. Additionally, it lists methods to evaluate confined spaces and the requirements for permit-required confined space entry. This document also provides recordkeeping requirements.

This safety policy details the areas of responsibility for NCDENR managers, supervisors, employees, entrants, attendants, entry supervisors, qualified persons, Safety Risk Management, and Division of Purchase and Services. It also applies to NCDENR employees who do not enter, but may be exposed to work around confined spaces.

This document applies to any operation that requires NCDENR employees to enter or work inside any existing tank, tower, sewer, manhole, sump, vault, vat, processing vessel, pit, tunnel, or similar confined spaces. This safety policy applies, but is not limited, to the following NCDENR employees and operations:

3.0 Reference

This safety policy is established in accordance with Occupational Safety and Health Standards for General Industry (29 CFR 1910.146), Occupational Safety and Health Standards for the Construction Industry (29 CFR 1926.65), Occupational Safety and Health Standards for the Maritime Industry (29 CFR 1915.11-16) and the NC Office of State Personnel's Workplace Safety Requirements policy (WRP 1910.146).

4.0 Policy

It is the policy of NCDENR to provide a place of employment that is free from recognized hazards to its employees and the general public by utilizing a proactive approach to safety. Therefore, at each NCDENR facility and/or jobsite, confined spaces will be identified and, as applicable, permitted and posted with warning signs. All confined spaces shall initally be considered permit-required confined spaces until pre-entry procedures confirm that conditions are not present to do so.

When a confined space hazard exists that cannot be eliminated, the following measures will be implemented to minimize the hazards and to ensure the safety of employees and the public:
 engineering practices, administrative practices, safe work practices, Personal Protective Equipment (PPE), and proper Confined Space Entry training.

NCDENR employees that provide on-site services to public or private facilities where confined spaces are known to exist or may be present shall be trained to recognize the hazard and the steps they may take to avoid injury from confined space dangers.

5.0 General Responsibilities

It is the responsibility of each manager, supervisor, and employee to ensure implementation of NCDENR's safety policy on Confined Space Entry.

It is also the responsibility of each NCDENR employee to immediately report  unsafe conditions to his or her supervisor. Specific responsibilities are found in Section 6.3.

6.0 Procedure

This section provides applicable definitions, establishes general processes, and identifies responsibilities required by NCDENR's Confined Space Entry safety policy.

6.1 Definitions

Person who remains outside the permitted space while the work is being done.

Confined Space
A confined space by design has limited openings for entry and exit, may lack adequate ventilation, and may contain or produce dangerous air contamination.

A employee who is authorized by the employer to enter a permitted space.

Entry Permit
A written document that is provided by the employer to allow and control entry into a permit required space.

Entry Supervisor
The person responsible for determining if acceptable entry conditions are present at a permit space where entry is planned, for authorizing entry and overseeing entry operations, and for terminating entry as required.

Hot Work Permits
A permit allowing employees to perform work involving welding, cutting, or any task that would deplete oxygen, create toxic fumes and vapors, or create the potential for fire or explosion.

Lower Flammable Limit (LFL)
The minimum concentration of a combustible/flammable gas or vapor in air which will ignite if an ignition source is present.

Non-permit confined space
A confined space that does not contain or, with respect to atmospheric hazards, have the potential to contain any hazard capable of causing death or serious physical harm.

Oxygen Deficiency
An atmosphere containing oxygen at a concentration of less than 19.5% by volume as measured by an oxygen measuring device.

Oxygen Maximum
An atmosphere containing oxygen at a concentration of more than 23.5% by volume as measured by an oxygen measuring device.

Permit-required confined space (permit space)
 A confined space that has one or more of the following characteristics:

(1) Contains or has a potential to contain a hazardous atmosphere;
(2) Contains a material that has the potential for engulfing an entrant;
(3) Has an internal configuration such that an entrant could be trapped or asphyxiated by inwardly converging walls or by a floor which slopes downward and tapers to a smaller cross-section; or
(4) Contains any other recognized serious safety or health hazard.

Permit System
The employer's written procedure for preparing and issuing permits for entry and for returning the permit space to service following termination of entry.

Qualified Person
A person who has been trained and authorized by the employer to perform atmospheric testing.

Upper Explosive Limit (UEL)
The maximum concentration of a combustible/flammable gas or vapor in air before its saturation point which will ignite if an ignition source is present.

6.2 General Provisions

This section notes the general areas of this safety policy with each area discussed in a separate subsection. The sections are:

6.2.1 Training

The formal written confined space training program will provide employees with the necessary understanding, skills, and knowledge to safely perform their jobs. The components of this formal written training program include instruction on:

Initial and refresher training are to be provided to employees. Refresher training must be conducted whenever an employee's duties change, whenever hazards in the confined space change, or whenever an evaluation of the confined space entry program identifies inadequacies in the employee's knowledge.

Employees designated to enter confined space work areas will be trained in the following areas (this includes entrant, attendant, and rescue team):

Appendix A lists a training certification form to document the affected employee training on confined space.

In addition to the above, the Qualified person shall be trained in:

Qualified persons shall receive initial and refresher training.

NCDENR employees that provide on-site services to public or private facilities where confined spaces are known to exist or may be present shall be trained to recognize the hazard and the steps they may take to avoid injury from confined space dangers.

The components of this "confined space awareness"  training shall include instruction on:

6.2.2 Confined Spaces

In NCDENR, a confined space is one that:

Confined spaces in NCDENR can include any existing tank, tower, sewer, sewer station, manhole, sump, vault, vat, grease pit, tunnel, or other similar confined spaces as shown in Figure 1.

Confined Spaces

Figure 1

6.2.3 Hazards of Confined Spaces

Due to the nature of a confined space's shape, size, lack of ventilation, proximity to toxic gases, and other contributing substances, confined spaces present many hazards to employees. Potential confined space hazards include hazardous atmospheres, and general safety hazards.

Hazardous atmospheres expose employees to the risk of death, incapacitation, injury, or acute illness. Hazardous atmospheres include:

General safety hazards include but are not limited to: Physical hazards include non-chemical, physiological stressors and include noise, vibration, slick/wet surfaces, falling objects, temperature extremes, employee fatigue, and engulfment.

Structural hazards include confined space areas that may contain structural defects.

Electrical hazards include shock, burns, and/or electrocution due to exposed or ungrounded electrical energy sources.

Mechanical hazards include any inadvertent mechanical movement of or within a confined space that threatens the safety of the employee working in the confined space.

Biological hazards include bacterial action that can consume oxygen to produce carbon monoxide or emit hydrogen sulfide or methane.

Radiation hazards include those sources that can inadvertently expose employees to dangerous levels of radiation.

6.2.4 Identifying Confined Spaces at a Facility

All confined spaces at each NCDENR worksite/facility must be identified and located so the permit-required confined space permit program can be established. Visually survey your worksite/facility to identify confined spaces that are present and that will be included in the confined space inventory list for your site. List all suspected confined spaces.

If a work space meets the confined space criteria, note it for inclusion into your worksite/facility's confined space inventory. Appendix B provides a convenient format for inventorying your confined spaces.

For non-DENR sites where DENR employees provide services and inspections, ask the facility/site to provide you with a list of any confined space areas where you will be subject to work in as part of your jobtask. Do not enter any confined spaces at those sites unless you are trained to the Permit-Required Confined Space Entry Requirements level.

6.2.5 Evaluating Confined Spaces

Once all the confined spaces have been identified, then those confined spaces must be evaluated to determine the hazards that may be present. Hazardous atmospheres and general safety hazards must be evaluated for all the confined spaces.

A hazardous atmospheric evaluation must be conducted through atmospheric testing to assess the conditions in the confined space. Appendix C lists atmospheric testing procedures that will be followed by the qualified person. Results of the atmospheric testing should be documented for later use.

General safety hazards should be assessed by visual observation. This observation should include a visual assessment of:

Additionally, assessment should be based on knowing the existing conditions and normal use/function of the confined space, along with the actual and potential hazards posed by materials and substances in the confined space. Appendix D provides a Confined Space Evaluation Form for use.

A confined space is a "permit-required confined space" if any of the above listed hazards are present.

If none of these hazards are present, then the space or area is not designated as a permit-required confined space.

If a change in use or configuration of a non-permit-required confined space increases hazards to an entrant, then the space must be reevaluated for possible reclassification to a permit-required confined space.

A permit-required confined space may be reclassified to a non-permit-required confined space if:

Reclassification is effective only as long as the hazard(s) remain eliminated.

Surge flow and flooding. Employees who work in confined spaces that can suddenly be flooded by rain, or receive flammable/hazardous effluent
(e.g., sewer lift stations, manhole, drain pipes and culverts) due to the emergency or accidental release by industry or transportation accidents shall check the local weather bureau reports and be cognizant of local weather conditions in order to plan, delay or stop the confined space work during such events.

6.2.6 Permit-Required Confined Space Entry Requirements

The permit system for each worksite/facility shall include a listing of all permit-required confined spaces, a warning sign/label at each permit-required confined space, and permit issuance by a qualified supervisor or safety professional.

Once all permit-required confined spaces are identified, each one will be marked with a sign (examples shown in Figure 2) advising personnel and the general public as to the dangers involved. Where practical, all permit-required confined spaces will be locked or blocked to prevent entry.

A qualified entry supervisor must authorize entry, prepare and sign written permits, order corrective measures if necessary, and cancel permits when work is completed. The entry permit is completed and posted in a conspicuous location near the entrance. Permits must be available to all permit space entrants at the time of entry and should extend only for the duration of the task. They must be retained for a year to facilitate review of the confined space program.

Confined Space Signs
confined space permit sign jpeg
Figure 2

Once all permit-required confined spaces have been identified, no employee may enter that space until several requirements are met. These requirements include:

Pre-entry atmospheric testing for the confined space shall be performed prior to employee entrance. See Appendix C for atmospheric testing procedures.

If welding is to be performed in the confined space (permit-required or non permit-required), a hot work permit must also be obtained. See chapter 19,  Welding, SP # 1910.252 for additional information.

Appendix E shows a Confined Space Entry Permit. This permit must be completed prior to a permit-required confined space entrance.
Appendix F shows a Confined Space Entry Program Element Contact List. These forms shall be maintained at each facility or operation by the individual charged with administering the Confined Space Permit Program.

Energy sources will be completely isolated by physical disconnection, double blocking, bleeding, or by lockout/tagout procedures. Figure 3 shows some typical lockout/tagout devices. Also, see chapter 7,  SP# 1910.147, Lockout/Tagout, for additional details.

LO/TO Examples
Figure 3

Ventilation and cleaning shall be performed to empty, flush, or purge spaces using outside air, where feasible. Figure 4 shows a typical ventilation configuration to empty, flush, or purge a confined space.

Ventilation Config Example
Figure 4

During pre-entry ventilation, the blowing duct outlet should be positioned for uniform dilution and elimination of any hazardous atmospheric pockets as shown in Figure 5.

Extra Confined Spaces
Figure 5

When a hazardous atmosphere is detected, ventilation will continue until:

The atmosphere will be tested a minimum of 3 times until safe levels are maintained.

The appropriate PPE shall be worn based on the hazard(s) and include:

See chapter 15,  SP# 1910.132, Personal Protective Equipment, for details on matching PPE to the hazard.

Appropriate equipment and tools
must be in place and in good condition. See chapter 16,  SP# 1910.241, Hand and Portable Power Tools, for additional details.

The attendant shall be stationed immediately outside of the permit-required confined spaces and shall:

The attendant shall be physically capable of assisting any employee inside the confined space in the event of an emergency. This individual will be responsible for alerting others that a rescue is in progress and for taking appropriate measures to ensure the safety of all co-workers in the area.
No employee is to enter a confined space if another employee goes down! The attendant shall always seek assistance.

Appropriate communications shall be established, such as radios or walkie-talkies, if the employee gets out of sight or hearing range.

Rescue teams
must be available for permit-required confined spaces. Rescue equipment and self contained breathing apparatus must be available.

Contractors who perform permit-required confined space entry must comply with all the OSHA requirements.

6.2.7 Recordkeeping

Recordkeeping requirements include:

6.3 General Responsibilities

6.3.1 Managers

Managers are responsible for ensuring that adequate funds are available and budgeted for the purchase of confined space equipment for their affected employees. They will also be responsible for identifying the employees affected by this safety policy.

Managers shall be responsible for ensuring that confined spaces at their worksite/facility are identified and labeled. Additionally, they will be responsible for ensuring all confined spaces are evaluated to determine if a permit is required prior to entry. Managers shall also designate entry supervisors and qualified persons. Managers will obtain and coordinate the required training for affected employees. Managers will also ensure compliance with this safety policy through their auditing process.

6.3.2 Supervisors

Supervisors will not allow any employee who has not received the required training to perform any of the tasks or activities associated with this safety policy.

Supervisors will be responsible for communicating appropriate needs to managers and/or supervisors.

Supervisors will be responsible for knowing where confined and permit-required confined spaces are located at their worksite/facility. They will also be responsible for ensuring permit-required confined spaces are posted with warning signs.

Supervisors will ensure employees are provided with PPE as necessary for their job.

Supervisors are responsible for ensuring that only employees trained and qualified will operate material handling equipment.

Supervisors will be responsible for ensuring that
the training required in this safety policy is provided to employees that provide services to public or private facilities that have confined space issues.

As applicable, supervisors will request that air monitoring data be evaluated by an Industrial Hygienist for completeness, accuracy, and precision.

6.3.3 Employees

Employees shall comply with all applicable guidelines contained in this safety policy and with division/program site specific practices and guidelines related to confined space.

It is the responsibility of the employee to follow all instructions pertaining to confined spaces. Employees are never to enter confined spaces unless authorized by training and job duties.

Employees that provide service to public or private water and sewer treatment facilities are responsible for inquiring about any confined space issues at those facilities and notifying their immediate supervisor of any thus noted. 

6.3.4 Entrant

The entrant does the assigned task and is responsible for reviewing the permit before entry. Appendix G lists additional details on the entrant's responsibilities.

6.3.5 Attendant

The attendant is responsible for maintaining communication with the entrant at all times. Appendix G lists additional details on the attendant's responsibilities.

6.3.6 Entry Supervisor

The entry supervisor is responsible for ensuring that only confined space trained employees are allowed to enter confined spaces. The entry supervisor is responsible for ensuring proper permits and safety procedures are followed closely at the jobsite.

The entry supervisor must also be familiar with all hazards associated with the entry operation. He is responsible for all safety precautions, rescue procedures, and safety equipment needed for the operation. Appendix G lists additional details on the entry supervisor's responsibilities.

6.3.7 Qualified Person

The Qualified person is responsible for checking the atmosphere of a confined space and correctly reading and using the gas detection instruments. This individual will request from the manufacture guidelines for using the air monitoring and gas detection equipment that they are using. This individual shall be responsible for conducting calibration of the air monitoring/measuring equipment according to the manufactures requirements.
The Qualified Person is responsible for documenting all confined space atmospheric measurements.

6.3.8 Safety Risk Management

Safety Risk Management will provide prompt consultative assistance to managers, supervisors, or others as applicable on matters concerning this safety policy. Upon request, Safety Risk Management will assist in securing the required training. 

Where requested, training, expertise, and guidance for the qualified person on atmospheric testing will be located.

To ensure effective implementation of this safety policy, Division/Office/Program Safety Consultants and Safety Officers shall be responsible to provide consultative, training and audit assistance on this safety policy for their Division/Office/Program.

6.3.9 Division of Purchase and Services

Division of Purchase and Services will ensure that any confined space equipment and instruments purchased through their oversight have been reviewed by the requesting Division/Office/Program's New Equipment Safety Review Subcommittee, or the staff Safety Consultant, or Safety Officer prior to any new purchase.

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Click here for printable forms you can use from below.

APPENDIX A: Confined Space Training Certification Form
Employee Name:_________________________
Employee ID#:

Has the OSHA required training been completed in the following categories?
Topic Completion Date Instructor's Signature Employee's Initial
Types of Confined Spaces      
Confined Space Hazards      
Atmospheric Testing of Confined Spaces      
Evaluating Confined Spaces      
Cleaning and Ventilation      
Lockout of Confined Spaces      
Respirator Use and Care      
Buddy System and Emergency Procedures      
Communication Procedures      
Emergency Rescue      
Employee designated to enter confined spaces (includes entrant, attendant, and rescue team) shall also be trained in the following topics      
Emergency Entry and Exit Procedures      
Applicable Respirators      
First Aid and CPR      
Lockout Barriers at Worksites      
Safety Equipment at Worksites      
Rescue Equipment      
Permit Systems      
Work Practices      
Use and Retain a Course Roster for classes with more than five employees  
(Printable form here)

APPENDIX B: Division/Office/Program Confined Spaces Inventory
DENR Facility/Work Site:_____________________________________________
Inventory Date:_______________________________________

All permit-required confined spaces shall be posted with signs stating it is permit-required.
Confined Work Space or Area
Purpose Hazard Work Done Permit Req'd

This inventory must be kept up to date. All operational changes shall be evaluated for impact on this facility's confined spaces.

APPENDIX C: Atmospheric Testing Procedures

A qualified person shall test spaces a minimum of three (3) times at all levels immediately prior to entry. Figure 6 illustrates the common gases found at each of these levels.

Using a calibrated direct-reading instrument with remote sampling capacity, the qualified person shall test for oxygen content, for flammable gases and vapors, and for potential toxic air contaminants, in that order. The testing shall assess for:

Atmospheric Testing
Figure 6

The qualified person shall record all atmospheric test results on the permit. A qualified person shall perform atmospheric testing while the employee is inside the confined space/area as follows:

Each testing instrument shall be:

APPENDIX D: Confined Space Evaluation Form

Space:_____________________________ Location:_________________________
Date:______________________________ Evaluator:________________________

Answer the following questions about this confined space.

Hazard Determination
Yes  No
Is there an engulfment potential?
Does the internal configuration restrict entry or exit (converging walls or sloping and tapered floors)?

Atmospheric Testing

Is the measured oxygen content below 19.5 or above 23.5 percent? If not, what’s the measurement? __________________________________%
Are flammable gases, vapors, and mists above 10 percent of the lower flammable limit? If not, what’s the measurement? ___________________%
Are airborne combustible dusts at or above the lower flammable limit? If not, what’s the measurement? ___________________________________
Are toxic contaminants in excess of the Permissible Exposure Limit (PEL) and are they capable of causing death, incapacitation, etc.?
Are there any other atmospheric conditions that are immediately dangerous to life or health? If so, what are they?___________________________
If any of the above questions were answered yes, then the confined space is a permit-required confined space.

APPENDIX E: Confined Space Entry Permit

(Valid for one 8-hour shift only)

All copies of permit will remain at jobsite until job is completed
Location and Description of Confined Space:___________________________________________ Date:__________________________
Scheduled Work to be Done:___________________________________ Time Started:________________________
Division/Branch:______________________________________ Time Completed:_____________________
Persons Authorized to Enter:_________________________________________________________

Supervisor(s) in Charge of Crew      Type of Crew                                           Phone/Pager Number


LockOut - De-energize Escape Harness     Escape Harness    
Lines Broken - Capped or Blanked     Tripod emergency escape unit    
Purge - Flush and vent Lifelines     Lifelines    
Ventilation Fire Extinguishers     Fire Extinguishers    
Secure Area Spark Resistant Lighting     Spark Resistant Lighting    
Breathing Apparatus Protective Clothing     Protective Clothing    
Resuscitator - Inhalator Respirator (Air Purifying)     Respirator (Air Purifying)    
  Hot Work Permit    
(Valid for one 8-hour
shift only)
P.E.L.* Levels:
At Initial Check
Checks after Isolation
and Ventilation
Periodic Checks
Hr 1 Hr 2 Hr 3 Hr 4 Hr 5 Hr 6 Hr 7 Hr 8
% of Oxygen 19.5% to 21%                    
% of L.E.L. * * Any % over 10                    
Carbon Monoxide 35 ppm                    
Aromatic Hydrocarbon 10 ppm                    
Hydrocyanic Acid 4.7 ppm                    
Hydrogen Sulfide 10 ppm                    
Sulfur Dioxide 2 ppm                    
Ammonia 25 ppm                    
Qualified Person (Atmospheric Tester) Name: ______________________________________________________________
Note: Continuous/periodic tests shall be performed throughout the job.

SAMPLING EQUIPMENT Name Type Date Calibrated Identification Number


If an emergency should occur-first summon help. Do not enter a confined space until qualified help arrives and entry can be safely made.  If a person is incapacitated for no apparent cause you must assume that toxic gases or oxygen deficiency could exist-do not enter without full protective gear and self contained breathing device.

Emergency Call #___________
Signed :
(Entry Supervisor)______________________________________________________
*P.E.L. Permissible Entry Level
**L.E.L Lower Explosive Level

APPENDIX F: Confined Space Entry Program Elements



Hazard Identification  ____________________________________________
Hazard Control  ____________________________________________
Written Permit System  ____________________________________________
Posting Confined Spaces  ____________________________________________
Training  ____________________________________________
Special Safety Equipment  ____________________________________________
Written Rescue Plan and Procedures  ____________________________________________
External Hazard Protection  ____________________________________________
Contractor Notification  ____________________________________________
Communication Equipment  ____________________________________________

NOTES:  ________________________________________________________

APPENDIX G: Confined Space Entry Team Responsibilities

A confined space team performs four functions:

The entrant: The attendant: The Entry Supervisor (person authorizing permits)  :
APPENDIX H: Confined Space Decision Tree Flowchart

confined decision tree

APPENDIX I: Confined Space Entry Flowchart

Confined Space Entry Flowchart

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Updated 4/2007 Printable forms link