Confined Space Program

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.