Confined Space Entry Learning Outcome When you complete this module you will be able to: Describe procedures needed to enter into, or work safely in confined spaces. Learning Objectives Here is what you will be able to do when you complete each objective: 1. Define confined space and list some confined spaces. 2. Describe the hazards of being in a confined space. 3. Refer to Alberta Regulations and describe procedures to be used when performing a confined space entry, including completion of an entry checklist. 1
WHAT IS A CONFINED SPACE? Confined Space means any enclosed or partially enclosed space having restricted access and egress, and which due to its nature may form a trap to become a life threatening environment. This includes, but is not limited to, such things as bins, tanks, trenches, tunnels, silos, sewers, vaults, pipelines, pits, and vessels. During the course of our everyday lives we are called upon to enter into confined spaces, and in most cases we don t even give any thought to them. These could include areas in our homes, our work, as well as our recreational activities. Most often we think of a confined space only in terms of an enclosed tank or vessel, but as you can see from the definition, the term can apply to many common areas of our worksites. Many times we enter confined spaces without giving them any serious consideration. AG_4_0_3.jpg P POTENTIAL HAZARDS of Confined Spaces Confined space entry presents a number of potential hazards: 1. Escape and/or rescue in an emergency may be difficult, since entry and/or exit, and possibly movement within the confined space is restricted. 2. Lack of proper air ventilation may be, or become, a life threatening problem, because of design or construction. 3. The atmosphere within the area may be deficient in oxygen and thus unable to sustain life. The minimum level should not be below 20% O 2 by volume. 4. The atmosphere within the area may contain elements which make it toxic, explosive, and/or flammable. 5. Harmful substances and/or creatures may be present. 6. The environment, or work in progress, may cause equipment being used to become a hazard. 7. The use of improper equipment (for example, 110 volt equipment being used in a vessel) creates potentially dangerous conditions. 8. Improper lighting makes it difficult to see or identify hazards. 2
ALBERTA REGULATIONS for Confined Spaces All jurisdictions in Canada have the same or similar legislation in place concerning safety and health. Since it is impossible to refer to them all, the Alberta acts, regulations, and codes are referred to in this module. You are encouraged to refer to the appropriate documents for your province. Alberta Occupational Health and Safety (OH&S) Regulations governing the requirements for confined space entry are summarized in this section. 1. No worker shall be required or permitted to enter a confined space: - Unless an approved ventilation system is being used to ensure the removal of any harmful gases, vapors, smoke, fumes, mists, or dusts from within the confined space, or; - Until appropriate tests have been made immediately prior to entry to confirm the absence of any harmful gases, vapors, smoke, fumes, mists or dusts; or that a deficiency of oxygen has not developed. AG_4_0_5.jpg P 2. When tests indicate the presence of any harmful gases, vapors, smoke, fumes, mist, or dusts; or a deficiency of oxygen, the entry may only be made after: - The confined space has been, and is kept, adequately ventilated, or; - The worker has been provided with and is wearing approved respiratory protective equipment, and; AG_4_0_1.jpg P - All sources or potential sources of ignition have been controlled or eliminated when flammable or explosive gases are present. 3. A worker required or permitted to enter a confined space where a harmful atmosphere exists or may develop, shall in addition to the requirements in 1. and 2.: - Wear a safety belt to which is attached a lifeline tended at all times by another worker stationed outside the entrance, and so equipped as to be capable of affecting rescue, and; - When the worker has entered from the top, wear a safety belt or harness of a type which will keep the worker in a vertical position in case of rescue. 3
4. A worker required, or permitted, to enter a confined space being ventilated and in which a harmful atmosphere cannot develop shall: - Be attended by and in communication with another worker stationed at or near the entrance, or; - Be provided with a means of continuous communication with a worker outside, or; - Be visually checked by a designated worker at intervals as often as may be required by the nature of the work to be performed. 5. The person assigned to attend a worker who has entered a confined space must: - Never leave the station while the worker remains within the confined space, unless properly relieved by a qualified person. - Be in possession of a means of summoning assistance without leaving the station should any emergency arise, and be able to sound alarm. - Remain alert at all times to conditions that may affect the safety of the worker in the confined space. - Frequently monitor the environment within the confined space to ensure the safety of the worker inside. Many unfortunate accidents have resulted because of failure to recognize a deterioration of the environment due to the work being carried out. 4
PLANNING AND PROCEDURES It is vitally important to carefully plan a confined space entry. This may be done quickly in case of a trench in the relative open, or may be extensive in a complex industry application. The important thing to remember is to plan, and not make quick unqualified assumptions. Some important questions to consider are: Is the confined space structurally safe to enter; that is, in the case of a trench, has sufficient provision been made to prevent cave-in? If not, what more is required? Has the space been made secure from outside contamination; that is, are vessel nozzles and all connections disconnected, and blinds installed or ventilation equipment situated so that contaminants are not introduced into the confined space? Is the required oxygen level measured and assured (minimum level 20% oxygen)? Has the area been tested for the presence of hydrocarbon, or other explosive or toxic gases? If found present, have procedures been made to clear them from the work area, or to provide equipment to work safely with them? AG_4_0_4.jpg P Is the temperature within the space within tolerable working limits? In preparation for a confined space entry, it is useful to write or review a confined space entry procedure. Following is an example of a form that can be used. The final step then would be to issue a safe work agreement or permit to indicate what further steps are required so that the entry can be completed in a safe workmanship manner. AG_4_0_2.jpg P 5
CONFINED SPACE ENTRY LIST ITEMS TO CHECK YES NO IF NO, EXPLAIN 1. 2. Has the purpose of the procedure been well established? Are all the potential hazards unique to this entry listed? Are all the potential operating problems unique to this entry listed? MATERIALS HAZARDS: Has the procedure listed the material hazards unique to this entry: Pyrophoric materials? Toxic chemicals? Toxic gases, i. e. H 2 S and chlorine? Flammable gases? Corrosives? 3. MECHANICAL HAZARDS: Are all the potential mechanical hazards unique to this entry listed? 4. WATER POLLUTION: Can steam condensate from steaming operations go to the pit or disposal? Can drainings from vessels go to the pit or disposal? Can tank hydrocarbons be flooded to the pit or disposal? Can chemicals go to the pit or disposal? 6
5. NOISE POLLUTION: Can excessive noise be prevented when venting or steaming high pressure vessels? Is there a provision for ear protection in noisy areas? 6. AIR POLLUTION: Can hydrocarbon and/or toxic gases be vented to the atmosphere? Will flaring be excessive? 7. STATIC ELECTRICITY HAZARD: Is grounding of trucks, hose lines, air movers, etc. required: Has steam purging of tanks been avoided? 8. ENTRY PREPARATION: Has the procedure provided for: complete and adequate purging? gas testing for H 2 S? gas testing for LEL, oxygen, and toxic materials? calibration of gas tester? complete and adequate blanking? blanking as close as possible to the confined space? lock out and tagging of mechanical equipment? possibility of a dust explosion? adequate ventilation and nitrogen displacement? 7
temporary equipment such as patches, diversion lines, tie-ins, etc? checking of roof strength by mechanical inspectors? safety net installed in furnace? decking or flooring support for workers? protection from falling, splashing or dripping material? 9. EMERGENCY PREPARATION: Has the procedure provided for: adequate fresh air breathing equipment? adequate arrangements for removing a worker: worker trained in artificial respiration? aerosol emergency horn? (good in warm weather only) unit evacuation and assembly point? barricading of roads and adjacent areas? 10. Has the procedure provided for changing conditions, such as: stirring up sludge during cleaning? changing temperatures? smoke or toxic releases due to welding or burning? 11. Has the procedure provided for inspection of hydrocarbon trapped in pockets, such as: high suction on tanks? total draw off pans on towers? baffles in treaters? 8
12. HOT WORK: Has the procedure specified: no hot work on metal unless the opposite side has been inspected and cleaned? no hot work outside of the confined space while there are valid confined space entry permits issued? periodic gas testing of confined space atmosphere? 13. Has the procedure provided for: limitations of work? adequate confined space cleanliness? 9
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