Confined Space Program

Hazardous atmospheres are the leading cause of deaths in confined spaces. This condition is difficult to detect without proper air monitoring equipment. The lack of natural ventilation, the presence of stored materials (such as chemicals), or the work process to be performed in a confined space can result in one or more of the following hazardous atmospheres. If the condition exists or has the potential to exist, it must be eliminated or isolated prior to entry.

• Flammable gas, vapor, or mist in excess of 10 percent of its lower flammable limit (LFL/LEL). Sources of flammable gases may come from leaking acetylene hoses, methane gas, chemicals or other products used in the space. If the LEL shows a percentage less than 10 percent, but greater than 1 percent or 2 percent, it would be prudent to investigate possible sources prior to entry and take necessary precautions since conditions can change suddenly.
• Airborne combustible dust at a concentration that meets or exceeds its lower flammable limit (LFL) can result in an explosion. This concentration may be approximated as a condition in which the combustible dust obscures vision at a distance of 5 feet or less.
• Atmospheric oxygen concentration:
  • Below 19.5 percent (oxygen-deficiency) or 
  • Above 23.5 percent (oxygen-enriched).
• The atmospheric concentration of any substance for which a dose or a permissible exposure limit (PEL) is published by OSHA. Note: An atmospheric concentration of any substance that is not capable of causing death, incapacitation, impairment of the ability to self-rescue, injury, or acute illness due to its health effects is not covered by this definition. Common toxic substances found in confined spaces include:
  • Hydrogen sulfide
  • Carbon monoxide
  • Nitrogen dioxide (farm silage storage)
• Any other atmospheric condition that is immediately dangerous to life or health (IDLH). For air contaminants for which OSHA has not determined a dose or permissible exposure limit (PEL), other sources of information, such a Safety Data Sheets that comply with the Hazard Communication Standard, published information, and internal documents can provide guidance in establishing acceptable atmospheric conditions.

Other serious hazards that may pose an immediate danger to life or health must also be considered prior to entry. The determination of whether the resulting exposurepr to a hazard in a confined space would impair the person's ability to perform self-rescue is the aspect that must be considered and addressed prior to entry. Examples may include:

• Inherent fall hazards;
• Use of hazardous chemicals or degreasers;
• Performing welding and cutting in a confined space;
• Hazardous energy sources (i.e. electrical, steam, mechanical, hydraulic, pneumatic, liquids, chemicals, etc.); and
• Heat stress from high temperature, high humidity, and limited air movement.
   

Hazards must be evaluated by the entry supervisor and necessary controls implemented to eliminate or isolate the existing or potential hazard(s) in order to reclassify the space from a permit-required confined space to non-permit-required confined space. 

The departmental Entry Supervisor (or designee) must assess the confined space conditions prior to entry, using the Assessment Form, to determine if there are permit-required conditions that cannot be eliminated or effectively controlled. A detailed explanation of properly filling out the form, and posting requirements, are covered in Confined Space Entrant/Attendant/Supervisor training.

• Atmospheric testing must be conducted prior to entry. Results must be documented on the Assessment Form.
• All existing and potential hazards must be identified and indicated on the Assessment Form.
• All hazards must be effectively eliminated or controlled prior to entry and indicated on the Assessment Form.
• Specialized equipment required must be indicated on the form.
• What to do in the event of a confined space emergency must be discussed with the entrants and attendant prior to entry.
• The departmental Entry Supervisor must determine and document the appropriate entry procedure on the Assessment Form by checking one of the boxes and signing the bottom of the form approving entry. Entry will either be: 
  • Non-Permit Entry (i.e. no existing or potential hazards present, or hazards have been eliminated or effectively controlled without entry into the space) - If all hazards can be controlled from outside of the space and there are no atmospheric hazards, entry may be conducted using the Confined Space Entry Procedure;
  • Alternate Procedure: If the only uncontrolled hazard is either an actual or potential atmospheric hazard, entry may be conducted under the Forced Air Ventilation Entry Procedure; or
  • Permit-Required Confined Space - If all hazards have not been effectively eliminated or controlled, the supervisor must consult with Environmental Health & Safety prior to using the Permit Entry Procedure.

During any confined space entry, all safety rules and procedures shall be followed.

• Smoking in a confined space is prohibited.
• Any use of chemicals in a confined space must be pre-approved by the Environmental Health & Safety coordinator, departmental safety coordinator, and the supervisor. 
• Hot work, such as welding/cutting, conducted in a confined space must be in accordance with OSHA rules and regulations. 
• Adequate and approved lighting (appropriate for the conditions) shall be provided.
• Personal protective equipment (PPE) shall be provided to workers as necessary for safe entry. All PPE must be selected, used, and maintained in accordance with the Personal Protective Equipment Program.
• All PPE must be approved by the Environmental Health & Safety coordinator, departmental safety coordinator, or the supervisor.
• Electrical equipment (i.e.: power tools, extension cords) used in the confined space shall be appropriate for the hazard, such as explosion-proof or ground-fault circuit-interrupter (GFCI), and meet the requirements of the National Electric Code.
• Any condition making it unsafe to remove an entrance cover must be eliminated before the cover is removed.
• When the cover has been removed, the opening(s) shall be promptly guarded to prevent accidental falls into the opening and to prevent objects from falling into the opening. 
• Appropriate vehicle and pedestrian barriers shall be used to protect workers.
• Before entering the space, atmospheric testing must be performed with a calibrated, direct-reading instrument, for oxygen content, flammable gases and vapors, and potential toxic air contaminants.
• No hazardous atmosphere is permitted within the space whenever any employee is inside the space.

In the event that a confined space emergency occurs, regardless of the nature (entrant medical condition or a hazard with the space itself), the space reverts back to a permit-required confined space, and it must be reassessed prior to entry or re-entry.  

Begin implementation of the pre-defined rescue plan for the entry. Call 911 for emergency response, and indicate that the emergency involves a "confined space." Rescue plans include self-rescue, non-entry rescue, and entry rescue.

In the event that something goes wrong in a confined space, self-rescue would be the first response option. Self-rescue is where the entrant recognizes a problem early on, and exits the space on his/her own abilities. Problems could be inherent to the confined space, external events that adversely affect the space, or personal health/medical issues of an entrant. Regardless of the source, exiting the confined space on one's own at early warning signs is the best option. Examples include:

• Responding to air monitoring alarms as soon as they sound by exiting the space immediately,
• Recognizing early warning signs and symptoms of oxygen deficiency,  oxygen enrichment, carbon monoxide, and hydrogen sulfide exposure where continuous air monitoring is not required,
• Being aware of personal health concerns that are deteriorating and need to be addressed. 

At the first sign of trouble, the entrants leave the space, get fresh air, and proper medical attention (if indicated). The space reverts back to permit-required until it has been reassessed and any hazards with the space have been effectively eliminated or controlled.

Where self-rescue or non-entry rescue means and methods are not possible:

• The space must be reassessed prior to proceeding with entry rescue to verify that all hazard controls remain in place and are effective, and that no new hazards are now present.
• All hazards must be eliminated or isolated prior to entry (and the space determined to be non-permit-required).
• The event is determined to be an individual medical emergency (ex. heart attack, diabetic emergency, heat stress) by someone trained in first aid (or greater).
• Only trained and authorized personnel may enter the non-permit-required space provided the Entry Supervisor approves it.
• Extrication of the patient shall be coordinated with emergency responders.

If the space cannot be reclassified during the reassessment, rescue services shall be provided by local emergency medical and fire services. Virginia Tech personnel shall not enter a permit-required confined space for rescue purposes. Departmental efforts should be focused on cooperating with responding agencies to expedite rescue efforts, and/or providing support in the form of space accessment and expertise, available equipment, validation of controls, crowd control, etc.

Even with the best efforts to review and assess the potential hazards of a confined space entry, the potential for something to go wrong may still exist, such as unexpected events or individual medical conditions. Having a plan for emergencies prior to entry can save valuable time should an emergency occur. Confined space rescue pre-planning for departments that enter confined spaces on a regular basis is ongoing, and coordinated by Environmental Health & Safety with the department and emergency responders (police, fire, and rescue). Considerations include:

• Having a means of calling 911 on-site.
• Properly reporting the emergency to the 911 center so that emergency responders can arrive quickly and prepared.
  • Identify the emergency as involving a "confined space."
  • Provide the 911 address (street and building number). Give the nearest street and/or building if the space is not directly located at the address.
  • For remote spaces, such as high-voltage electrical vaults, provide the ELMH number of the vault.
• Implement one of the rescue protocols above, as predetermined prior to entry.

If entry/exit is restricted or limited, which it typically is, then an attic would be considered to be a confined space; however, they typically are not considered to be permit-required confined spaces because they usually have either natural or mechanical ventilation and other hazards typically are not present. The attic would need to be evaluated using the Assessment Form prior to entry.

Outside personnel must have approval from the Division of Campus Planning, Infrastructure, and Facilities prior to entering the steam tunnels to perform a specific task or provide a specific service.

• Contractor's bidding on a project, architects and engineers designing for the project, and outside inspection/certification services in the steam tunnels must be escorted by trained Facilities personnel working on the project (typically renovations or capital project managers or project coordinators or mechanical utilities).
• Once a contract has been awarded for the project, outside personnel entering the steam tunnels for the scope of the project must enter under their own Confined Space Program, which includes an assessment of the space including air monitoring and employee training. Virginia Tech personnel will enter under Virginia Tech's Confined Space Program and perform a separate assessment and air monitoring.
• Contracted labor working under the direct supervision of Virginia Tech personnel must have proof of training by their company prior to being assigned work in a confined space. The supervisor in charge should make a copy of the training document and keep it on file.

Yes, provided that the means of entry/exit is limited or restricted.

Yes. Where the steam tunnels must be entered through a manhole or similar access, they are considered to be a confined space, and may be considered a permit-required confined space depending on hazards associated with a specific section of the tunnel, such as cross sections where there is a greater potential for a toxic atmosphere, extreme temperatures, or work being performed.

Yes. The type of "dust" that can result in an explosion is that from any material in its bulk form that will burn, such as coal, cotton, grain, sugar, etc. It does not include dust from soil, which will not burn in its bulk form.

Although there is no set parameter for excessive dust in a confined space, there is a rule of thumb that can be followed. When the concentration of dust in the confined space is such that vision is obscured at a distance of 5 feet, it is considered to be potentially explosive and should be controlled through ventilation, wet methods, etc.

In order for dust to explode, the right concentrations of dust and oxygen must be present, in addition to an ignition source, which could be electrical equipment, metal striking tools, illegal smoking, etc.

Is training mandatory? If so, when? Yes. Persons who work around, but not in, confined spaces must have this training.

Class length: 1 hour.

Available online: Yes.

When is refresher training required? Every 5 years.

Please see the online class schedule for more information.

Is training mandatory? If so, when? Yes. Persons who enter confined spaces and their supervisors must have this training.

Class length: 3 hours.

Available online: No.

When is refresher training required? Every 3 years.

Please see the online class schedule for more information.

Yes. Air monitoring must be performed to verify the absence of a hazardous atmosphere and that conditions are safe for entry. Oxygen, carbon monoxide, hydrogen sulfide and the LEL (Lower Explosive Limit) must be monitored. If there are additional potential contaminants, monitoring may be required for those as well.

First, air monitoring should be conducted from outside of the confined space. A pump may be necessary to draw air from the space. All levels of the confined space should be checked - the top, mid-section, and bottom. Gases can be lighter than air, heavier than air, or similar to air. Testing all levels of a space ensures that all gases are detected.

Continuous air monitoring is a best practice and should be used whenever possible. It is required where ventilation is the control method for a potentially hazardous atmosphere (i.e. initial air monitoring indicated conditions unacceptable for entry).

A large number of confined spaces have been identified at Virginia Tech including utility vaults, tunnels, silos, tanks, equipment, and crawl spaces. Only personnel trained and knowledgeable of related hazards may enter confined spaces.

Prior to entry, each space must be assessed by a trained supervisor and documented. Identified hazards must be eliminated, isolated, or controlled prior to entry.

The list includes, but is not limited to:

• Carbon monoxide
• Hydrogen cyanide
• Hydrogen sulfide
• Arsine
• Chlorine
• Ammonia
• Oxides of nitrogen

In general, carbon monoxide is a colorless, odorless, tasteless gas that can result in asphyxiation by preventing oxygen transport in the blood. It is created from incomplete combustion from burning fuels or microbial decomposition or organic matter in sewers, silos, and fermentation tanks.

At 200 ppm exposure for a few hours, mild frontal headache may be experienced. At 400 ppm, headache and nausea can occur. At 800 ppm, headache, dizziness, and nausea may occur after 45 minutes of exposure and possible collapse and death in 2 hours. At 1600 ppm, headache, dizziness, nausea in 20 minutes, and possible collapse and death in 1 hour. At 3200 ppm, headache and dizziness in 5-10 minutes and unconsciousness and danger of death in 30 minutes. At 6400 ppm, headache and dizziness within 1-2 minutes and unconsciousness and danger of death in 10-15 minutes. An at 12800 ppm, immediate effects such as unconsciousness and danger of death in 1-3 minutes.

Continuous air monitoring is the best means of protection. Detecting early signs and symptoms of exposure and getting to fresh air can also prevent overexposure.

Hydrogen sulfide is a colorless gas with a rotten egg like odor. It can appear naturally or as a byproduct of decomposition. Hydrogen sulfide is considered a highly toxic gas because it reacts with enzymes in the blood stream and can inhibit cell respiration. Although hydrogen sulfide is easily detected by sense of smell, it is a desensitizer at 100 ppm after 2-5 minutes of exposure. Common signs and symptoms include:

• At 100 ppm, coughing and eye irritation.
• At 200-300 ppm, eye inflammation and respiratory tract irritation after 1 hour.
• At 500-700 ppm, loss of consciousness, stopping or pausing of respiration, and death.
• At 1000-2000 ppm, immediate unconsciousness and death within a few minutes.

Continuous air monitoring and ventilation are the best means of prevention.

Normal air contains approximately 20.8 percent oxygen by volume.  The minimum safe level for confined space entry is 19.5 percent.  As the oxygen level decreases, the following signs and symptoms may be experienced:

• At 15 percent, impaired muscle coordination, increase heart rate, rapid fatigue, and intermittant respirations.
• At 12 percent, judgment may become impaired and respirations continue to increase due to the lack of oxygen.
• At 10 percent, lips may begin to turn blue, respirations increase, nausea, and inability to perform simple tasks.
• At 8 percent, fainting and vomiting can occur.
• At 6 percent, death can occur in about 8 minutes.
• At 4 percent, likely coma in about 40 seconds, with possible recovery within 4 minutes.

Continuous air monitoring and ventilation is the best means of prevention. 

Silo gas is the common name for nitrogen dioxide. It is a yellowish-brown or reddish-brown gas that has a pungent, acrid odor. It can be found in diesel fuel when burned, or in silos containing corn silage.  Signs and symptoms include:

• At 5-10 ppm, eye and throat irriatation.
• At 20 ppm, eye irritation.
• At 50 ppm and above, tightness in the chest, acute bronchitis, and death from prolonged exposure.

Continuous air monitoring with monitor that detects nitrogen dioxide and ventilation are the best means of prevention, in addition to avoiding exposure during the initial phases of corn silage fermentation, which can last up to 2 weeks after filling the silo.

A confined space is an area that meets all three of these criteria:

1. Is large enough for the entire body to enter
2. Has limited or restricted means of egress; and
3. Is not designed for continuous human occupancy (i.e. does not have lighting, ventilation, adequate room to work, etc.).

According to OSHA, a permit-required confined space is a confined space that meets any of the following criteria:

1. Contains, or has the potential to contain, a hazardous atmosphere;
2. Contains a material the 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. Other recognized health or safety hazards.

IDLH means immediately dangerous to life and health. The hazard, such as a toxic gas, poses an immediate threat to health or life, would cause irreversible adverse health affects, or would interfere with your ability to escape a confined space unaided. Examples of gases which may pose an IDLH atmosphere include oxygen-displacing gases, such as argon, nitrogen, carbon dioxide, helium, or even steam. The IDLH level for carbon monoxide is 1200 ppm, for example.

Any person using a respirator, whether in a confined space or not, should be properly trained and fitted through Environmental Health & Safety. Contact 540-231-3600 for more information.

Asphyxiation can occur when a substance, such as carbon dioxide, interferes with the oxygenation of tissue. Suffocation can occur when the air supply to the body is blocked from entering the body. Unfortunately, the results can be the same - death.

An attendant is required whenever the space is considered permit-required. At Virginia Tech, a permit space is one where all hazards have not been eliminated, isolated, or controlled through ventilation. If a permit space is to be entered, the Entry Supervisor should contact Environmental Health & Safety to coordinate entry activities.

Many departments use a best practice of having an attendant where one is not required (i.e. space is not permit-required). The attendant should attend training for entrants/attendants/supervisors in order to recognize potential hazards and perform associated duties.

Contact our Program Coordinator Robin McCall-Miller by e-mail or at 540-231-2341.