Confined Space Entry Procedures PDF

Objective 6 Define and identify confined spaces, and describe a typical confined space entry permit and entry procedure. CONFINED SPACE ENTRY CAUTION The following information on confined space entry is based on information that is available from the BC OH&S Regulation. It is presented as an examp...

Objective 6 Define and identify confined spaces, and describe a typical confined space entry permit and entry procedure. CONFINED SPACE ENTRY CAUTION The following information on confined space entry is based on information that is available from the BC OH&S Regulation. It is presented as an example only and should not be construed as exact or applicable to all jurisdictions. Nor should the wording be accepted as the exact wording in the BC OH&S Regulation. Confined space means an area (other than an underground work space) to which the following applies: • The area is enclosed or partially enclosed. • The area is not designed or intended for continuous human occupancy. • The area has limited or restricted means for entry or exit that may complicate the provision of first aid, evacuation, rescue, or other emergency response service. • The area is large enough and configured in such a way that a worker can enter to perform assigned work Workers must be protected from dangerous substances that can be discharged from pipes or conduits leading to the confined space. In these situations, the closing and securing of valves is not adequate to isolate workers from the danger. Piping must be disconnected, blanked, or blinded. A blank is a solid plate installed to block the end of a pipe. When pipes have threaded joints, threaded plugs or caps must be used to blind (shut off) the line. A spectacle blank has a visual indication that a blank has been installed. Blanks are also referred to as blinds Examples of confined spaces include the following: • • • • • • • Manholes Sewers Storage tanks and vats Evacuations Trenches Pits Tunnels • • • • • • • • Lift and access shafts Ducts Pipes Chambers Silos Flues Boilers Vaults • • • • • Hoppers Wells Cargo holds in ships Unventilated areas and rooms in buildings Vessels Page 22 of 56 Notice that some of the examples are recognizable as confined spaces, while some do not appear to be confined spaces at first glance. Figure 5 shows a typical horizontal vessel being ventilated with air. Ventilating the vessel prepares the atmosphere within so the workers can enter the space without the use of breathing apparatuses. Notice the presence of a confined space entry sign to alert workers of danger and the requirement of a permit while working in the confined space. Figure 6 illustrates another horizontal vessel in which a welder is performing work. Notice the numerous safety precautions being used to protect the workers both inside and outside of the confined space. These precautions include a standby worker, safety railing, ladder, alarm horn, emergency self-contained breathing apparatus (SCBA), lifeline, safety harness, and gas/fume extractor. Page 23 of 56 General Information for Confined Space Entry Before a worker can be required or permitted to enter a confined space, the employer must prepare and implement a written confined space entry program, which includes: a) An assignment of responsibilities b) A list of each confined space or group of similar spaces, and a hazard assessment of those spaces c) Written safe work procedures for entry into and work within the confined space that address the following, where applicable • Identification and entry permits • Lockout and isolation • Verification and testing • Cleaning, purging, venting, or inerting • Ventilation • Standby persons • Rescue • Lifelines, harnesses, and lifting equipment • Personal protective equipment (PPE) and other precautions • Coordination of work activities Identification and Entry Permits When a confined space requires entry by a worker, each point of access that is not secured against entry must be identified by a sign or other effective means that indicates the hazard and prohibits entry by unauthorized workers. A confined space entry permit must be completed and signed by a responsible supervisor before a worker enters a confined space. An entry permit must also be posted at a minimum of one designated point of entry to a confined space. Lockout and Isolation Before a worker enters a confined space where adjacent piping contains a harmful substance, the adjacent piping must be controlled by either disconnecting it, isolating it using blanks or blinds, or using a double block and bleed system. The employer must keep a record that identifies thelocation of every isolation point. Every isolation point must be visually checked or otherwise verified to ensure that the confined space is effectively isolated before a worker enters the space. A blank or blind must be stamped with (or otherwise indicate) its pressure rating. If a line is to be Page 24 of 56 opened for disconnection or to insert a blank or blind, written safe work procedures must be prepared and followed to prevent hazardous exposure of the lines contents to workers. Gaskets must be installed on the pressure side of blanks or blinds if required to prevent leakage, and flanges must be tightened to make them effective. If threaded lines are used, threaded plugs or caps must be used to blind the lines. If a double block and bleed isolation system is used, all valves must be locked out in their proper open and closed positions. Verification and Testing Before a worker enters a confined space, pre-entry testing and inspection must be conducted. This is to verify that the required precautions are effective at controlling the identified hazards, and that it is safe for a worker to enter. The pre-entry testing must be conducted as specified in the written work procedures and completed no more than 20 minutes before a worker enters the confined space. While a worker is inside a confined space, additional testing must be conducted and, wherever practicable, the atmosphere of the confined space must be continuously monitored. Cleaning, Purging, Venting, or Inerting When practicable, the employer must ensure that the confined space that is to be entered contains clean, respirable air. If pre-entry testing has indicated that the atmosphere of a confined space is not respirable air, the hazard must be controlled by cleaning, purging, or venting the space. The atmosphere of the confined space must then be retested before a worker enters the space. Inerting involves the purging of oxygen from a confined space using an inert gas such as nitrogen to remove the hazard of fire or explosion. The concentration of oxygen is then decreased below the level that can support combustion. If a confined space has been inerted, all workers must be equipped with a self-contained breathing apparatus (SCBA) or a supplied air breathing apparatus (SABA). The atmosphere inside the confined space must remain inerted while workers are inside and, as a precaution, all possible ignition sources must be controlled. Page 25 of 56 Ventilation Every confined space must be ventilated continuously while a worker is inside the space. One exception is when the confined space is intentionally inerted. Types of ventilation include natural ventilation and mechanical ventilation. If natural ventilation is used for the control of airborne contaminants in a confined space, the airflow through the space must be monitored and must be sufficient to maintain concentrations of airborne contaminants below the applicable exposure limits. Pre-entry testing will ensure that the natural ventilation has provided the airflow necessary to maintain the air levels required for workers to enter A mechanical ventilation system for the control of airborne contaminants in a confined space must be designed, installed, and maintained to control concentrations of airborne contaminants below the applicable exposure limits. Ventilation equipment must be located and arranged so as to adequately ventilate every occupied area inside the confined space. Standby Persons A standby person monitors the internal and external activities in and around an ongoing job in a confined space. This person is stationed at the entry point of the confined space to monitor the job and to sound the alarm in the event of an emergency. The duties of a standby person will vary depending on the level of hazards in and around the confined space. Some of the common duties include maintaining a record of workers inside the space, checking on the well-being of workers inside the space, monitoring the atmosphere in the space, summoning rescue personnel in the event of an emergency, and monitoring any equipment outside the confined space that serves a purpose for workers inside the space. Rescue The employer must provide the services of rescue persons when a worker enters a confined space Every person assigned rescue duties must be properly equipped and adequately trained to carry out such duties. A standby person must notify rescue personnel when workers are entering and exiting a confined space Page 26 of 56 Lifelines, Harnesses, and Lifting Equipment When entering a confined space that contains a high-hazard atmosphere, a risk of entrapment or engulfment, or any other recognized, serious health or safety hazard, the worker must wear a harness to permit rescue if necessary. If deemed necessary, a lifeline must be attached to the harness. This lifeline is tended to by the standby person stationed outside the entrance to the space. The standby person must be equipped with suitable lifting equipment to perform or aid in a rescue. Personal Protective Equipment (PPE) and Other Precautions Workers entering a confined space that contains a high-hazard atmosphere must carry (or have within arms reach) an emergency escape respirator to allow them to leave the space without assistance. Any other unique PPE required to enter a confined space and perform work must be provided to the worker. Examples of such PPE include face shield, goggles, dust mask, chemical boots, chemical suit, or special gloves. Any electrical tools and equipment used in a confined space must be protected by an approved ground fault circuit interrupter (GFCI). Any electrical tools and equipment that are to be used where flammable or explosive gases, vapours, or liquids are present must be approved for hazardous locations. Coordination of Work Activities The coordination of work activities includes those activities both inside and just outside of the confined space. Managing work activities inside the confined space is done for the safety of all workers involved and to maintain a momentum of work towards completion. For example, welding inside the space, if required, would likely not be done at the same time as cleaning. For another example, an auxiliary air compressor fueled by diesel would not be run just outside of a confined space in which work is being performed. In this situation, exhaust fumes from the diesel air compressor may contaminate the atmosphere in the confined space. In addition, the incessant noise from the compressor would prevent the standby person from effectively communicating with workers or knowing when to perform a rescue if necessary CONFINED SPACE ENTRY PERMIT CAUTION Information on the confined space entry permit is based on information available from the Canadian Centre for Occupational Health and Safety (CCOHS) website. This information is presented as an example only and should not be construed as exact or applicable to all jurisdictions Page 27 of 56 A confined space entry permit is an administrative tool used to document the completion of a hazard assessment for each confined space entry. Someone who is fully trained and experienced in confined space work should complete the permit. A confined space entry permit is required for confined space work where the hazard and risk assessment determine that the measures to control the risk involve the following: • Atmospheric monitoring • Energy isolation • Energy lockout • Ventilation • Safeguarding devices • Respiratory protection • Any other control required by the risk assessment to be verified by a permit Before entering a confined space, a confined space entry permit must be completed. A copy of the completed permit should be posted at the confined space and remain there until the work is finished. A confined space entry permit should contain at least the following information: • The length of time that the permit is valid for • The name(s) of the worker(s) that are authorized to enter the confined space • The name(s) of the attendant(s) (standby person) and/or supervisor • The location and description of the confined space • The scope of the work that is to be done in the confined space • Possible hazards that may be encountered inside and outside the space • Possible hazards that may develop during the work activity • The date and time of entry into the confined space and the anticipated time of exit • The details of any atmospheric testing done in the confined space • Hazard control measures including The use of mechanical ventilation, protective equipment, and other precautions that must be followed by every worker who will enter the confined space • Means of communication between the persons working in the confined space and the attendant(s) Page 28 of 56 • An emergency plan, including the protective equipment and emergency equipment to be used by any person(s) who takes part in a rescue or responds to other emergency situations in the confined space • The signature of the worker who did the confined space air testing • An authorization signature by a supervisor certifying that the confined space has been properly evaluated, prepared, and is safe for entry and work CONFINED SPACE ENTRY PROCEDURE CAUTION Information on the confined space entry procedure is based on information available from the University of British Columbia Safety and Risk Services. This information is general information from one confined space entry procedure that is used in one particular process facility. This information is presented as an example only and should not be construed as exact or applicable to all jurisdictions. A confined space entry procedure is another administrative tool used to document the completion of information in each confined space entry. Someone who is fully trained and experienced in confined space work should complete the procedure. A confined space entry procedure is required for all confined space work and should include at least the following: • General information and location details: Name of space, site address or location, atmospheric hazard classification, and a photo of the space • Work overview: A description of the work activities to be completed • Required equipment on-site: A list of the equipment required for the work area, including any equipment needed for security, entry, rescue, and personal protection (PPE), as well as any relevant equipment documentation • Hazard overview: A summary of identified hazards and required controls to mitigate them • Ventilation requirements: The type of ventilation best suited for the particular confined space and any other information necessary for ventilation • Procedures: Pre-entry review of documentation, work area setup, confirming lockout of energy sources, ventilation, atmospheric testing, communication, final preparation, entry into space, exit from space, and clean up • Procedure sign-off: The signature of a qualified person indicating their approval of the procedure For more detailed information about a confined space program, refer to the Canadian Centre for Occupational Health and Safety (CCOHS) website. Page 29 of 56 Objective 7 Explain the hazards of excavation, and describe typical excavation procedures and permits EXCAVATION DEFINITIONS CAUTION The information on excavation below is based on information available from the British Columbia OH&S Regulation. This information is presented as an example only and should not be construed as exact or applicable to all jurisdictions. Nor should the wording be accepted as the exact wording in the BC OH&S Regulation. An excavation is any cut, cavity, trench, or depression in the earth’s surface resulting from rock or soil removal. A trench is an excavation that is less than 3.7 m wide at the bottom, over 1.2 m deep, and of any length. Another term often associated with excavation and trenching is ground disturbance. Ground disturbance is any work, operation, or activity that results in a disturbanceor displacement of the earth to a depth greater than 30 cm. The following are the hazards associated with ground disturbance, excavation, and trenching: • Caving in, sloughing, or collapsing of walls or sides • Contact with buried services • Contact with foundations, adjacent structures, or buildings • Creation of confined or restricted spaces during or after excavation • Excavated material • Falling objects or objects near the excavation • Flooding and water accumulation • Powered mobile equipment • Slips, trips, and falls • Formation of a toxic or explosive atmosphere All these hazards must be removed, secured, or mitigated so as not to endanger workers. To protect workers from the caving in, sloughing, or collapsing of walls or sides in an excavation or trench, methods such as shoring, or sloping are used. Shoring is a system of aluminum, steel, or wood panels that are installed in the excavation or trench to support the walls or sides. Sloping involves cutting back the excavation or trench wall at an angle that is inclined away from the work area. Figure 7 shows an example of a trench with shoring. Figure 8 shows an example of an excavation with sloped sides. Page 30 of 56