Confined Spaces

Confined Space / Hazardous Space Entry Program

NOTE: For a listing of confined and hazardous spaces, please refer to the inventories listed below. These inventories contains information on any special hazards of each confined space and list precautions necessary to enter these areas. Questions on procedures for confined spaces in academic areas of the campus should be referred to University Safety and Assurances at

Background Information on UWM Confined Space / Hazardous Space Entry Program:

Information and Forms:

Campus Inventory:

Confined Space Entry Training PowerPoint Presentation .pdf format, Adobe Acrobat required

Other Resources:

Confined Spaces: Air Monitoring and Ventilation

Multi-Gas Meters

Multi-gas meters measure “real-time” oxygen content, flammability/explosion potential, carbon monoxide (CO) and hydrogen sulfide (H2S) concentrations. Many deaths occur in the United States every year because of failure to conduct environmental monitoring when performing confined space entry work.

Air Quality Requirements

Interpretation from Wisconsin DILHR 32.64 Air Quality Requirements for Confined Spaces:

ILHR 32.64 Air quality. (1) ATMOSPHERE LIMITS. Except as provided in sub. (3), a confined space may not be entered, unless the atmosphere of the confined space has:

(a) An oxygen content of at least 19.5% or more but not more than 23.5%;

(b) A hydrogen sulfide content of less than 10 parts per million or a carbon monoxide content of less than 35 parts per million;

(c) A combustible gas content less than 10% of the lower explosive limit; and

(d) An exposure level, for any hazardous substance determined to be present, which is at or below the threshold limit value – short term exposure limit for any substance specified by the American Conference of Governmental Industrial Hygienists (ACGIH) in the publication adopted under s. ILHR 32.50 (4), or the short term exposure limits found in 29 CFR 1910.1000.


  • Our axial ventilation blowers (Model 1385D Air-Pac) are rated at 714 cfm for one 90 degree bend in hose, or 627 cfm if hose has two 90 degree bends.
  • Calculate purge times to achieve at least 7 air changes in the space prior to entry. Use the chart attached to the blower, or use the following equation: Minimum time required to ventilate space = ((7)*(volume confined space in cf))/(blower cfm).
  • As a general rule, always push clean air in.
  • If using a portable generator to power blower, make sure exhaust from blower is positioned downwind from the space.
  • Use GFCI protection if electrical devices must be used, including the blower.
  • Do not use blowers for enclosed spaces where damaged asbestos may exist (i.e., use blowers only in asbestos-free areas).

Confined Space Emergency Response Guidelines

All workers who must enter any confined space on the UWM campus must be familiar with these procedures before entry:

  1. Checklist

    Review and complete the Confined Space Entry Checklist prior to entry. The response to each question must be either “Yes” or “Not Applicable” in order to proceed with the entry.

  2. Prevention

    The best way to survive an emergency involving a confined space is to avoid having the emergency. These procedures assume that workers entering a confined space will follow procedures established for routine entry into confined spaces. While some of the requirements may seem unusual or cumbersome, the procedures are necessary to prevent emergencies or to help workers survive a confined space emergency. Workers must complete the “Confined Space Entry Checklist,” follow the precautions listed on the Campus Confined Space Inventory.pdf format, Adobe Acrobat Required and any other specific procedures established by your unit.

  3. Preparation

    Prior to any confined space entry, contact the University Police to provide information regarding the entry: location of the confined space, personnel involved, duration of entry, and any other relevant information. If the police have been pre-notified of your confined space entry, they will have fewer questions and there will be less confusion during the emergency. The University Police are trained “first responders” and can respond to an emergency at any location on campus within two minutes. In the event of a confined space emergency, the University Police will notify the City of Milwaukee Confined Space Rescue Team of the Milwaukee Fire Department’s HazMat Team.

    Another key to confined space emergency response is having adequate communication available to quickly summon trained assistance. Most confined space assessments require that two-way communication be established between the entrant and the safety attendant, or safety watch. Some preplanning is needed to establish who will contact emergency responders in the event of an emergency. The following hierarchy is offered as a possible plan.

    1. First, the two way communications between the entrant and the safety watch may also link to others who can notify the University Police. The two-way radios have a direct link to the University Police. You can request that the police monitor this channel when you call to alert them of your confined space entry.
    2. If the two way communication does not reach other assistance, enlist the help of any passers-by. Direct them to contact the University Police from the nearest Emergency Call Box (the yellow boxes with the purple beacons). Stay at the confined entry location until emergency responders arrive and do NOT attempt a rescue entry.
    3. If no one is in the vicinity who can call the University Police for you, inform your co-worker that you are going for help and call from the nearest campus phone or Emergency Call Box. Return to the confined space location until trained assistance arrives, but do NOT attempt a confined space rescue.
    4. If the emergency involves a person hurt or unconscious within a confined space and if the victim is connected to an emergency retrieval system and if you have been trained in the proper procedures for the retrieval system, first try to call for help, if feasible. Then, try to retrieve your co-worker if you are trained to operate the retrieval system.
    5. Do NOT move the victim if a back or neck injury is suspected. The proper use of the fall protection system (an integral part of our emergency retrieval system) should prevent these types of injuries in most cases. Be aware of incidents which could still happen involving damage to the spine or neck.

Contacting The University Police:

  • From any campus telephone: Dial 9-911
  • From any Emergency Call Box: Push the red button and hold until the dispatcher answers. Once the call is answered, release the button.
  • From a cell phone: Dial 229-9911. You will be connected with the UWM Police Department Dispatcher. UWM University Police will arrive in addition to other emergency responders.
  1. State that you have a confined space emergency
  2. Describe the nature of the emergency (injury, entrapment, fire)
  3. State the location of the incident
  4. Give your name
  5. Stay on the line until the police have finished asking you for any further information. Let the police hang up, not you.

If you are able to contact the police directly, less confusion will occur than if some untrained intermediary is involved. However, in an emergency, just about anyone should be able to coherently contact the police from one of the Emergency Call Boxes. The police can at least identify which box is being used to make the call. Clearly stating that the incident involves a confined space is crucial to prompt mobilization of trained rescue personnel.

Again, remember to use the established precautions listed on the Confined and Hazardous Space Inventory.pdf format, Adobe Acrobat Required. Copies of the inventory are available from Physical Plant Services or the Department of University Safety and Assurances.

If you notice any hazards not addressed by the precautions on the Confined and Hazardous Space Inventory, bring those concerns to the attention of your supervisor, the PPS Safety Committee and/or the Department of University Safety & Assurances.

Confined Space Entry Checklist

Confined Space Entry Checklistpdf format, Adobe Acrobat Required

Space Name:


Are confined spaces thoroughly emptied of any corrosive or hazardous substances, such as acids, caustics or asbestos before entry? Yes No NA
Are all lines to a confined space, containing inert, toxic, flammable, or corrosive materials valved off and blanked or disconnected and separated before entry? Yes No NA
Are all impellers, agitators, or other moving parts and equipment inside confined spaces locked-out if they present a hazard? Yes No NA
Is either natural or mechanical ventilation provided prior to confined space entry? Yes No NA
Are appropriate atmospheric tests performed to check for oxygen deficiency, toxic substances and explosive concentrations in the confined space before entry? Yes No NA
Is adequate illumination provided for the work to be performed in the confined space? Yes No NA
Is the atmosphere inside the confined space frequently tested or continuously monitored during conduct of work? Is there an assigned safety standby employee outside of the confined space when required, whose sole responsibility is to watch the work in progress, sound an alarm if necessary, and render assistance? Yes No NA
Is the standby employee appropriately trained and equipped to handle an emergency? Yes No NA
Is the standby employee or other employees prohibited from entering the confined space without lifelines and respiratory equipment if there is any question as to the cause of an emergency? Yes No NA
Is approved respiratory equipment required if the atmosphere inside the confined space cannot be made acceptable? Yes No NA
Is all portable electrical equipment used inside confined spaces either grounded and insulated, or equipped with GFCI ground fault protection? Yes No NA
Before gas welding or burning is started in a confined space, are hoses checked for leaks, compressed gas bottles forbidden inside of the confined space, torches lighted only outside of the confined area and the confined area tested for an explosive atmosphere each time before a lighted torch is to be taken into the confined space? Yes No NA
If employees will be using oxygen-consuming equipment-such as salamanders, torches, and furnaces in a confined space, is sufficient air provided to assure combustion without reducing the oxygen concentration of the atmosphere below 19.5 percent by volume? Yes No NA
Whenever combustion-type equipment is used in a confined space, are provisions made to ensure the exhaust gases are vented outside of the enclosure? Yes No NA
Is each confined space checked for decaying vegetation or animal matter which may produce methane? Yes No NA
Is the confined space checked for possible industrial waste which could contain toxic properties? Yes No NA
If the confined space is below the ground and near areas where motor vehicles will be operating, is it possible for vehicle exhaust or carbon monoxide to enter the space? Yes No NA
Are confined space entrants wearing proper personal protective equipment (i.e., hardhats, boots, etc.)? Yes No NA
Do you know the location of the nearest campus phone? Yes No NA

Confined Spaces: Hierarchy of Permit-Spaces

What is a “Permit Required Confined Space”?

A permit-required confined space means 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.

At UWM, the best option is no entry into permit-required confined spaces! In other words, perform the work without entering the permit space. When this isn’t possible, then follow the “hierarchy” listed below. All references are to OSHA 29 CFR 1910.146:

Permit Space Entry – Hazards Cannot Be Eliminated nor Controlled (c)(4):

  • written program and procedures (d)
  • permit specifications (e and f)
  • training specifications (g)
  • attendant specifications (d)(6)
  • entry supervisor specifications (e)(2)
  • testing specifications (d)(5), (see CPL 2.100, pgs. 23-24)
  • rescue specifications (k)

Alternate Entry – Hazards Controlled (by continuous forced air ventilation)(c)(5):

  • Only hazard is actual or potential hazardous atmosphere. Continuous forced air ventilation alone is sufficient to maintain safe entry.
  • No formal written program required for this option (i.e., a “mini-program”); requirements in (c)(5)(ii) act as a substitute written program for this option.
  • Document determinations and supporting data. The determination and special requirements will be included in the UWM Confined Space Inventory. ((c)(5)(i)(E), see CPL 2.100, pgs. 19-20).
  • No permit system or permits; however, a signed, written certification is required.
  • Certification is made available to entrants (c)(5)(ii)(H). Document determinations and supporting data (i.e., write down your air monitoring data and submit to your supervisor for evaluation and documentation).
  • Will work operations within the space introduce any new hazards? (e.g., Will welding be conducted or flammable or hazardous cleaners be used?) If yes, the space is ineligible for (C)(5) procedures.
  • No attendant or supervisor required (but may be necessary depending on the circumstances).
  • No rescue provisions required (but may be necessary depending on the circumstances).
  • Training is required.

Reclassification – Hazards Eliminated (c)(7):

  • Space poses no actual or potential atmospheric hazards.
  • Certify that all hazards within the space have been eliminated. Consider atmospheric hazards, engulfment, configuration, and energy hazards.
  • Document the “reclass” determination in writing. This information will be included in the UWM Confined Space Inventory.
  • Certification made available to entrants (c)(7)(iii).
  • No rescue provisions required (but may be necessary depending on the circumstances).
  • Training is required.

Remember: If the conditions change, you must re-evaluate the space!

Source: OSHA Training Institute, Course 226-Permit-Required Confined Space Entry, December 1998, Madison, Wisconsin.

Confined Space Program — Questions & Answers

Questions and Answerspdf format, Adobe Acrobat Required


Why do we have to do this?
State and Federal regulatory agencies have determined that confined spaces have a higher potential for serious harm than other locations in the workplace. Every year several hundred people are killed or injured in confined spaces, most of them, while they were just doing their job. This program is for your safety.

Source: Worker Deaths in Confined Spaces, A Summary of Surveillance Findings and Investigative Case Reports, NIOSH/CDC, January 1994.

The State of Wisconsin has recently adopted the federal regulations, while OSHA has continued to clarify aspects of their confined spaces regulations.

How are we going to train new people?
Supervisors will be responsible for arranging the training of new workers.
What if someone tells me I don’t need to do all of this?
Governor Thompson’s Executive Order #194 mandates that state government should lead by example by complying with all state and federal health and safety requirements, including confined space entry requirements. This program has the support of all levels of management.
What are the different classes of confined spaces?
  • Permit Spaces (C4)
  • Alternate Entry Spaces (C5)
  • Hazards Eliminated Spaces (C7)
Why not treat all confined spaces as Alternate Entry – Continuous Ventilation Required (C5) spaces until they can be proven to be Reclassed as Hazards Eliminated (C7) spaces?
Good strategy.
Why aren’t all the spaces labeled? Or even identified?
This will be an ongoing effort, with continual review and improvement. OSHA does not require labeling of confined spaces. OSHA does require you to be familiar with the confined space policies and procedures. Appropriate signs and labels are part of that familiarity.

You may well recognize additional confined spaces in your workplaces which have not been identified. Please report these to your supervisor or to your safety committee representative. We will try to evaluate the space and add it to the inventory. Your contributions are vital to the success of this program.

The labeling of the confined spaces is an on-going effort by your safety committee. Please report any unlabeled confined space to your supervisor by filling out a trouble report, if you think labeling that space would increase the awareness of the hazard and the required precautions.

What about the inventory?
The inventory catalogs all the documented confined spaces on campus, at Kenilworth and the Great Lakes WATER Institute (GLWI), and at some of the other remote work places at UWM. We hope the confined space inventory will be used as a training tool and a reference. Additions, omissions and corrections to the inventory should be brought to the attention of your supervisor. You should become familiar with the inventory and know its usefulness and limitations.
What if a space is missing from the inventory?
Report it to your supervisor.
Can we still use the tripod/retrieval system if it isn’t a Permit Required Space (C-4)?
Yes. The requirements listed should be considered the minimum requirements. If you think additional safety systems are needed, inform your supervisor before you enter.
What if we have been in a pit a hundred times; can’t we just reclass that pit as a Hazards Eliminated Space (C7) based upon no air contamination ever happening there?
OSHA requires that each Reclassified Space – Hazards Eliminated (C7) space undergo a hazard evaluation for the reclass. This evaluation has to be documented and made part of the written confined space plan. While previous entries can be part of the evaluation, air monitoring records that show no contamination over time is what is expected by OSHA and the Department of Commerce.
How often do people need to be retrained?
Training is necessary whenever a significant change occurs in the work practices or in the regulations.

General Procedures

What type of communication should be on site for all these spaces?
  • For Alternate-Entry Continuous Ventilation Required spaces, or Hazards Eliminated Space, notify your supervisor when you intend to enter the space. Provide an estimate of the amount of time you plan to be in the confined space. Estimate the maximum time you’ll work there. Notify your supervisor after you leave the space.
  • For Permit Confined Spaces, two-way radios, cellular phones or another reliable 2-way device must be used unless direct line of sight is maintained and noise levels do not hinder voice communications. The method must be specified on the permit.
How many people are allowed in the confined space?
One, if the space is determined to be a permit-required (C4) space. If you want more people to enter, more equipment for potential emergencies must be obtained. If the space is rated as an Alternate Entry – Ventilate (C5) space, or a Reclassified – Hazards Eliminated (C7) space, as many people as can safely work in the space are allowed.
Do I need an attendant every time I go into one of these spaces?
Check the inventory. All permit confined space will require a second person as an attendant. Any other space which requires the Emergency Retrieval System, also requires an attendant.
What other personal protective equipment is required for confined space entry?
Each work space must be evaluated separately. The need for shoes, eye wear, hard hat, protective clothing and gloves should be evaluated separately from the confined space hazards. Respirators should only be worn in conjunction with an approved respiratory protection program, which includes medical surveillance, fit testing, written plans and more.
What about confined spaces that don’t have fixed ladders?
A portable ladder may be used to gain entry into a confined space. The tripod and winch assembly may be used to lower a person into a confined space. However, if a winch is used for lowering someone into a pit greater than six feet deep a second system of fall protection must be added. In other words, the same winch and cable can be used for fall protection and retrieval, but not for all three (lowering, fall protection and emergency retrieval).
How do we protect openings when working in confined spaces?
When the opening is in a public walkway, ADA-compliant barricades must be set up to protect the public. You must set up barricades to protect pedestrian traffic from all possible directions. Barricades must be lit during hours of darkness.

When out of pedestrian traffic lanes and sidewalks, the tripod and attendant should be sufficient to protect the public from the confined space openings. The attendant should not be distracted from their attendant responsibilities by having to direct traffic or otherwise protect the opening at the expense of attending to the entrant.

For an Alternate Entry using continuous ventilation, use the pedestrian barricade to protect the opening.

What are the attendant’s responsibilities?
Other than assisting and protecting the entrant, protecting the public is the most important task for the attendant. The attendant must not be given duties which could interfere with either of these responsibilities. If the attendant cannot accomplish both simultaneously, extra attendants or barricades must be established before the entry can continue.

The attendant must also be able to effectively operate the emergency retrieval system. In an emergency, the attendant must be able to make timely and accurate decisions to ensure emergency procedures are effective.

What about bringing chemicals into confined spaces?
Be sure that this additional potential hazard is controlled. Chemicals can add additional atmospheric hazards in a confined space, which must be monitored. Chemicals may contribute additional hazards (fire risk, contact hazards, etc.) which must be controlled. Supplemental ventilation and other controls may be needed. Be sure that a competent confined space supervisor and safety professional have reviewed the design of the additional precautions. These special requirements will be added to the confined space inventory for future reference.

Air Monitoring


What if gas detector alarm goes off before I go into the space?
Do Not Enter the Space! Notify your supervisor. The source for the abnormal condition(s) must be identified and controlled. Additional precautions will be necessary.
What if the gas detector registers an oxygen deficit, combustible or toxic potential but it doesn’t alarm? Then what?
Do Not Enter the Space! If you’re already in the space, you should leave immediately. Reentry must be postponed pending further investigation. Notify your supervisor. The source for the abnormal condition(s) must be identified and controlled. Additional precautions will be necessary.
What if the gas detectors alarm while I am in the space?
Leave the Confined Space Immediately! Seconds may count. Notify your supervisor. The source for the abnormal condition(s) must be identified and controlled. Additional precautions will be necessary.

Non-Entry Rescue


What do I do in an emergency situation?
Written emergency response guidelines have been adopted. Be sure to be familiar with these guidelines before beginning confined space entry.
What if the person in the space is incapacitated and needs immediate rescue? What should I do first?
Do Not Enter the Space Yourself! Call for help. Use your two-way communication to get assistance. Call the campus police at 9-911. Relay your location, the nature of the incident and emphasize the incident has occurred in a confined space. Once help has been called, you may use the retrieval system to get your partner out of the space, only if the rescue is a simple vertical withdrawal.

Do not attempt a non-entry rescue if your partner might be dragged around a corner or between obstacles which could entangle or injure him/her. Do not move your partner if you suspect a head or neck injury may have occurred.

Special Cases

What if I can’t fit in the space?
Engineering or administrative controls will be needed. A smaller person might need to be assigned to a task requiring entry into a small space.
What if the space doesn’t have a standard opening?
Most spaces which require an Emergency Retrieval System allow for the use of the tripod and the standard issue retrieval equipment. Those spaces where the tripod cannot be used, such as vertical access openings, will require alternate methods of retrieval. Some of these spaces will have engineered solutions specific to that one space. Anchor points may need to be mounted across from vertical openings or other engineered solutions may be required. These exceptions will be noted on the inventory.
What if space doesn’t allow putting up the tripod?
An engineered solution may be needed. Notify your supervisor or safety committee representative.

Fall Protection


What’s the rule-of-thumb on fall protection for confined spaces?
Any potential fall over 6 feet requires fall protection, excepting ladder or elevated lifts (cherry picker, scissors lift). So if fall potential exceeds 6 feet and you are not on a ladder or lift, then you need fall protection equipment.



What if I have to weld in confined spaces?
As with other welding operations, sufficient precautions must be taken. In a confined space the atmospheric conditions become vitally important and must be monitored. Welding can both introduce new contaminants and use up limited oxygen. The multi-gas detector is vital in these situations.

Supplemental ventilation and special Personal Protective Equipment (PPE) may be necessary. In most circumstances, reclassification to a Permit Required Space (C4) will be necessary.



What if a space requires respiratory protection?
Requirements of both respiratory protection and confined space entry will need to be followed. Respirator programs require medical monitoring, training, fit testing, respirator selection and more. If a confined space entry requires a respirator, question whether you should be involved in the entry. Respirator use CANNOT override the multi-gas detector alarm.



After all this has been said, what basic equipment is always required?
It really depends on the circumstances. Generally all spaces will require air monitoring. Also, two-way communication or a pre- and post- supervisor notification is usually required. Look on the inventory for additional requirements.
What if something appears unsafe despite the precautions mandated?
Contact your supervisor. Your training and experience should give you a good basis for using sound judgment when working in confined spaces. Do Not Take Shortcuts!