Section 2 – Pre-entry

    Table of Contents:

    Confined Space Entry Table of Contents

    Testing

    1. Before entry, it is necessary to test the atmosphere in the confined space for oxygen levels, flammability, and/or any contaminants that have a potential to be present in that confined space. This testing must be done by a qualified person using equipment which has been approved for use in such areas. The testing equipment itself should be checked to make sure it is working properly before using it. Follow the manufacturer’s recommended procedures.
    2. Testing of the confined spaces should be conducted throughout the entire portion of the space that workers will occupy during the entry. This testing shall be done without the use of ventilation systems. Where the entry is vertical into the confined space, it is recommended that remote probes be used to measure the atmosphere at various levels. This is necessary because some gases and vapors are lighter or heavier than air and can accumulate at different levels in the confined space. Test outside the confined space to make sure the surrounding air is not contaminated.
    3. Atmospheric conditions are considered unacceptable if oxygen levels are less than 19.5% or greater than 22.0%. Regulations define the following unacceptable levels of other hazards monitored:
      1. A flammable gas, vapor or mist greater than 10% of its lower flammable limit (LFL). LFL means the minimum concentration of the flammable material which will ignite if an ignition source is present.
      2. An airborne combustible dust at a concentration that obscures vision at a distance of five feet or less.
      3. An atmospheric concentration of a substance greater than the allowed limit in the Material Safety Data Sheet (MSDS) for that substance.
    4. If test results conclude that the atmospheric condition of the confined space is unacceptable, entry is prohibited until such conditions are brought into acceptable limits. This may be done by purging, cleaning and/or ventilating the space. Purging refers to the method by which gases, vapors, or other airborne impurities are displaced from a confined space. The confined space may also be made non-flammable, non-explosive or otherwise chemically non-reactive by displacing or diluting the original atmosphere with steam or gas that is non-reactive with respect to that space, a process referred to as “inerting”.

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    Training requirements

    1. St. Olaf College is responsible for certain training requirements. These are as follows:
      1. GENERAL – As an employer, St. Olaf College must ensure that all workers who must enter a permit entry confined space in the course of their work are informed of appropriate procedures and controls for entry into such spaces. These workers must be made aware of the fact that an unauthorized entry could be fatal, and that their senses are unable to detect and evaluate the severity of atmospheric hazards.
      2. TRAINING FOR AUTHORIZED ENTRANTS – St. Olaf College must ensure that all authorized entrants know the emergency action plan and have received training covering the following subjects prior to entering any permit entry confined space:
        1. Hazard Recognition: Each worker must understand the nature of the hazard before entering and the need to perform appropriate testing to determine if it is safe to enter.
        2. Use of Personal Protective Equipment: Each employee must be taught the proper use of all personal protective equipment required for entry or rescue, and the proper use of protective barriers and shields.
        3. Self Rescue: Each worker must be trained to get out of the confined space as rapidly as possible without help whenever an order to evacuate is given by the attendant, whenever an automatic evacuation alarm is activated, or whenever workers recognize the warning signs of exposure to substances that could be found in the confined space. They must also be made aware of the toxic effects or symptoms of exposure to hazardous materials he could encounter in the confined space. This includes anything that could be absorbed through the skin or which could be carried through the skin by any solvents that are used. They must be trained to relay an alarm to the attendant and to attempt self-rescue immediately upon becoming aware of these effects.
        4. Special Work Practices or Procedures: Each worker must be trained in any modifications of normal work practices that are necessary for permit entry confined space work.
      3. TRAINING FOR PERSONS AUTHORIZING OR IN CHARGE OF ENTRY – In addition to other requirements already covered, the person authorizing or in charge of entry shall be trained to recognize the effects of exposure to hazards that could be in the confined space. They must also carry out all duties that the permit assigns to them.
      4. TRAINING FOR ATTENDANT – Any worker functioning as an attendant at a permit entry confined space must be trained in the school’s emergency action plan, the duties of the attendant, and in;
        1. Proper use of the communications equipment furnished for communicating with authorized workers entering the confined space or for summoning emergency or rescue services.
        2. Authorized procedures for summoning rescue or other emergency services.
        3. Recognition or the unusual actions of a worker which could indicate that they could be experiencing a toxic reaction to contaminants that could be present in the space.
        4. Any training for rescuers, if the attendant will function as a rescuer also.
        5. Any training for workers who enter the confined space, if the permit specifies that the duty of the attendant will rotate among the workers authorized to enter the confined space.

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    Isolation

    1. In certain situations, it may be necessary to control energy sources (Lock-out/Tag-out) before any workers are permitted to enter the confined space. This may mean controlling energy sources to the confined space as well as inside it. All energy sources which are potentially hazardous to the workers in the space must be secured, relieved, disconnected and/or restrained. Energy sources include:
      1. Electrical
      2. Mechanical
      3. Hydraulic
      4. Pneumatic (air)
      5. Chemical
      6. Thermal
      7. Radioactive
      8. Gravity
    2. Methods of accomplishing this include:
      1. Disconnecting belt and chain drives and mechanical linkages on shaft-driven equipment.
      2. Securing mechanical moving parts within a confined space with latches, chains, chocks, blocks or other devices.
    3. The objective is to control any situation where the unexpected energization, start-up or release of stored energy would cause injury to the workers in the confined space.
    4. In certain other situations, it may be necessary to prevent flammable, toxic, irritating or oxygen displacing gases and vapors from entering the confined space. This includes all hazardous material, high pressure, high temperature and other lines that could introduce a hazard to the space. Methods for preventing entry of these materials includes:
      1. De-pressurizing and disconnecting contaminant supply lines and providing a blank or blind, often referred to as a “pancake”, on them. This is the absolute closure of the pipe, line or duct by fastening a solid plate or “cap” across it which is capable of withstanding the maximum upstream pressure.
      2. Isolating a confined space from a line, duct or pipe by locking or tagging two closed in-line valves, and locking or tagging the line between the two closed valves open to the outside atmosphere so that it can continue to drain or bleed.
      3. Using two blocking valves with an open vent between the blocking valves.
      4. Inserting a blank sized for the proper pressure in piping nearest the confined space.

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    Duties of the person authorizing or in charge of the entry

    1. The person who authorizes or is in charge of the permit entry confined space is to comply with the following:
      1. Make certain that all pre-entry requirements as outlined on the permit have been completed before any worker is allowed to enter the confined space.
      2. Make certain that any required pre-entry conditions are present.
      3. If an in-plant rescue team is to be used in the event of an emergency, make sure they would be available. St. Olaf College does not maintain an in-plant rescue team. Dial 9-911 on any St. Olaf College telephone for the Northfield Rescue Squad.
      4. Make sure that any communication equipment which would be used to summon either the in-plant rescue team or other emergency assistance is operating correctly.
      5. Terminate the entry upon becoming aware of a condition or set of conditions whose hazard potential exceeds the limits authorized by the entry permit.
    2. If the person who would otherwise issue an entry permit is in charge of the entry and present during the entire entry, then a written permit is not required if that person uses a checklist as provided in the section on “Permits”. This person may also serve as the attendant at the site.

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    Special considerations during a permit entry

    1. Certain work being performed in a permit entry confined space could cause the atmosphere in the space to change. Examples of this are welding, drilling, or sludge removal. In these situations, air monitoring of the confined space should be conducted on a continuous basis throughout the time of the entry.
    2. If the workers leave the confined space for any significant period of time, such as for a lunch or other break, the atmosphere of the confined space must be retested before the workers reenter the confined space.

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