Confined Spaces Code of Practice PDF

Figure 4 Open end of pipe capped with the nearest valve closed, locked and tagged − Inserting a suitable full-pressure spade or blank in piping between the flanges as close as practicable to the confined space (see Figure 5). The full-pressure spade or blank should be tagged to indicate its purpos...

Figure 4 Open end of pipe capped with the nearest valve closed, locked and tagged − Inserting a suitable full-pressure spade or blank in piping between the flanges as close as practicable to the confined space (see Figure 5). The full-pressure spade or blank should be tagged to indicate its purpose. Figure 5 Insertion of full pressure spade or blank Confined spaces Code of Practice Page 31 of 54 − Closing, locking and tagging at least two valves in the piping leading to the confined space (see Figure 6). A drain or vent valve between the two closed valves should be locked open to atmosphere as part of this method. Figure 6 Closing, locking and tagging at least two valves Moving parts and stored energy Before entry is permitted to any confined space that can move, or in which agitators, fans or other moving parts that may pose a risk to workers are present, the possibility of movement should be eliminated. Equipment or devices with stored energy, including hydraulic, pneumatic, electrical, chemical, mechanical, thermal or other types of energy, should be reduced to a zero energy condition so that no energy is left in devices and systems that could cause injury or illness. If the confined space has agitators, blades and other moving equipment, consider chocking, wedging, chaining or removing these parts. Alternatively de-energise the equipment, lockout and tag out machinery, mixers, agitators and other equipment containing moving parts in the confined space. This may require additional isolation, blocking or de-energising of the machinery itself to guard against the release of stored energy. Confined spaces Code of Practice Page 32 of 54 Using a lock When a lock is used, the key should be kept in the possession of the person placing the lock. Spare keys should not be accessible except in emergencies. The tag should indicate that a person is in the confined space and that such isolation should not be removed until all people have left the confined space. Examples where this procedure may be used include: − − an open circuit breaker or open isolating switch supplying electrical power to equipment with hazardous moving parts, and where a power source cannot be controlled readily or effectively, requiring a belt or other mechanical linkage to be disconnected and tagged. 4.5. Atmosphere As a PCBU, you must eliminate or minimise risks associated with the atmosphere in a confined space, so far as is reasonably practicable. A safe atmosphere in a confined space is one that: − − − has a safe oxygen level is free of airborne contaminants or any airborne contaminants are in concentrations below their allowable exposure standard (if any), and any flammable gas, vapour or mist in the atmosphere is at concentrations below 5 per cent of its lower explosive level (LEL). A safe atmosphere can be achieved within the confined space using methods such as cleaning, purging and ventilation. WHS Regulation clause 71(1)(b) Specific control—flammable gases and vapours The WHS Regulation prohibits pure oxygen or gas mixtures with oxygen in a concentration greater than 21 per cent by volume being used for purging or ventilating a confined space because of the risk of increased flammability. Consideration should be given to engaging the services of a specialist in ventilation or a hygienist. Purging Purging is the method used to displace any contaminant from a confined space. Purging is usually done using an inert gas, such as nitrogen, to clear flammable gases or vapours before work in the confined space begins. Purging must be carried out, so far as is reasonably practicable, where a risk assessment identifies the potential for the confined space to contain an unacceptable level of contaminants. After purging, the confined space should be adequately ventilated with sufficient fresh air to ensure that oxygen has returned to a normal level of 21 per cent. Purging should be done in a way that ensures any contaminants removed from the confined space are expelled to a location where they present no further risk. Atmospheric testing should be carried out before entry to check that the purging and ventilation have been effective. Confined spaces Code of Practice Page 33 of 54 When flammable contaminants are to be purged, purging and ventilation equipment designed for use in hazardous areas must be used. A hazardous area is an area in which an explosive atmosphere is present, or may be expected to be present, in quantities that require special precautions during the construction, installation and use of potential ignition sources. Ventilation Ventilation of a confined space with fresh air by natural, forced or mechanical means may be necessary to establish and maintain a safe atmosphere and temperature for as long as anyone is in the confined space. If the confined space has sufficient openings then natural ventilation may be adequate, but in most cases mechanical ventilation is likely to be needed. Consideration should also be given to where the fresh air is drawn from and where the exhaust air is finally vented to, so that the fresh air is not contaminated either by exhaust air or by other pollutants, and the exhaust air does not cause other risks. Mechanical ventilation may be either local exhaust ventilation (LEV) or dilution ventilation. LEV is effective where the source of contaminant generation is localised, the extraction point can be located close to the source, and adequate make-up air is available (for example in the capture or extraction of welding fumes). Where dilution ventilation is used, air needs to be introduced in a way that will ensure effective circulation throughout the confined space, taking account of the configuration of the space, the position of the openings and the properties of the contaminants. The source point of the air must be such that the air is fresh, breathable and free of contaminants such as gases arising from the operation of plant and equipment, for example combustible engines. During operations likely to generate contaminants, mechanical ventilation equipment may not be adequate or sufficiently reliable to maintain contaminants at acceptable levels or to ensure a safe oxygen level. Where mechanical ventilation equipment is likely to be necessary to maintain acceptable contaminant levels in a confined space, the equipment should: − − be monitored to ensure continuous operation while the confined space is occupied, and have the controls (including any remote power supply) clearly identified, tagged and protected to guard against unauthorised interference. Flammable gases and vapours WHS Regulation clause 72 Confined spaces—Specific control—flammable gases and vapours A PCBU must, while work is being carried out in a confined space, ensure that the concentration of any flammable gas, vapour or mist in the atmosphere of the space is less than 5 per cent of its LEL, so far as is reasonably practicable. If this is not reasonably practicable, and the concentration of any flammable gas, vapour or mist in the atmosphere of the confined space: − − is equal to or greater than 5 per cent but less than 10 per cent of its LEL—the PCBU must ensure that any worker is immediately removed from the space unless a suitably calibrated, continuous-monitoring flammable gas detector is used in the space, or is equal to or greater than 10 per cent of its LEL—the PCBU must ensure that any worker is immediately removed from the space. Confined spaces Code of Practice Page 34 of 54 Where a flammable atmosphere may exist in a confined space and there is a risk of fire and explosion, all ignition sources in the vicinity must be eliminated. Examples of potential ignition sources, both inside and outside the space, include: − − − − − − open flames and hot surfaces electrical equipment internal combustion engines metal tools striking metal surfaces spark-producing equipment for example grinding wheels, and welding, grinding, oxy acetylene cutting, combustion engines and battery-operated equipment. Respiratory protective equipment (RPE) If it is not reasonably practicable to ensure the confined space contains a safe oxygen level, or safe levels of airborne contaminants, then appropriate air-supplied respiratory equipment (RPE) must be provided. RPE should also be provided and worn in situations where there is no exposure standard for a substance, or where the substance is present in an unknown concentration. ‘Respiratory protective equipment’ refers to a range of breathing equipment, including airsupplied and self-contained breathing apparatus. The appropriate RPE should be based on the level and type of contaminants and the work to be done. Whenever there is any doubt about the airborne contaminant and/or type of RPE required, a conservative approach should be adopted (for instance, use air-supplied respiratory equipment). Further guidance is available in AS/NZS 1715:2009: Selection, use and maintenance of respiratory protective equipment. 4.6. Communication and safety monitoring WHS Regulation clause 69 Confined spaces—Communication and safety monitoring As a PCBU, you must ensure that a system of work is provided that includes: − − continuous communication with the worker from outside the confined space, and monitoring of conditions within the confined space by a stand-by person who is in the vicinity of the confined space and, if practicable, observing the work being carried out. A communication system is needed to enable communication between people inside and outside the confined space and to summon help in an emergency. Depending on the conditions in the confined space, communication can be achieved by voice, radio, hand signals or other suitable methods. Before a worker enters a confined space, a stand-by person must be assigned to continuously monitor the wellbeing of those inside the space, if practicable observe the work being carried out, and initiate appropriate emergency procedures when necessary (see Figure 7). The stand-by person should: − understand the nature of the hazards inside the confined space and be able to recognise signs and symptoms that workers in the confined space may experience Confined spaces Code of Practice Page 35 of 54 − − − − remain outside the confined space and do no other work which may interfere with their primary role of monitoring the workers inside the space have all required rescue equipment (for example safety harnesses, lifting equipment, a lifeline) immediately available have the authority to order workers to exit the space if any hazardous situation arises, and never enter the space to attempt rescue. Figure 7 Stand-by person monitoring the confined space with rescue equipment and sign in place 4.7. Entry and exit procedures For the entire period for which the confined space entry permit is valid, procedures should be in place to indicate when any worker is in the space, for example by using tags, a system of signing in and out on the entry permit, or having a stand-by person record who is in the space. 4.8. Signs and barricades Before any work in relation to a confined space starts, signs must be erected to prevent entry of persons not involved in the work. Confined spaces Code of Practice Page 36 of 54 Signs must warn against entry by people other than those who are listed on the confined space entry permit, and must be placed at each entrance to the confined space. Signs must be in place while the confined space is accessible, including when preparing to work in the space, during work in the space, and when packing up on completion of the work. Signposting alone should not be relied on to prevent unauthorised entry to a potential confined space. Security devices, for example locks and fixed barriers, should be installed. 4.9. Maintaining and reviewing control measures WHS Regulation clause 37 Maintenance of control measures Control measures must be maintained so they remain fit for purpose, suitable for the nature and duration of the work and be installed, set up and used correctly. To allow the chosen control measures to operate effectively, you should develop work procedures on how to correctly install, use and maintain the control measures. The procedures should include a planned program of inspections and maintenance for the control measures. The inspection regime should include details of: − − − − − − the equipment to be inspected including its unique identification the frequency and type of inspection, for example pre-use checks, detailed inspections action to be taken on finding defective equipment means of recording the inspections training of users, and the system of monitoring the inspection regime to verify inspections are carried out appropriately. The manufacturer or supplier of the equipment should be consulted for product specific requirements. If signs of excessive wear or other defects are found during the inspection the defective equipment must be withdrawn from use. WHS Regulation clause 38 Review of control measures The control measures put in place to protect health and safety should be regularly reviewed to make sure they are effective. If the control measure is not working effectively it must be revised to ensure it is effective in controlling the risk. You must review and as necessary revise control measures so as to maintain, so far as is reasonably practicable, a work environment that is without risks to health or safety. For example: − − − − − when the control measure does not control the risk so far as is reasonably practicable before a change at the workplace that is likely to give rise to a new or different risk to health and safety that the measure may not effectively control a new or relevant hazard or risk is identified the results of consultation indicate a review is necessary, or a health and safety representative (HSR) requests a review if that person reasonably believes that: Confined spaces Code of Practice Page 37 of 54   a circumstance in any of the above points affects or may affect the health and safety of a member of the work group represented by the HSR, or the control measure has not been adequately reviewed in response to the circumstance. Common review methods include workplace inspection, consultation, testing and analysing records and data. Equipment that should be regularly inspected includes: − − − − − − − − atmospheric testing and sampling equipment PPE including respirators ventilation equipment safety harness and lines emergency rescue equipment gas detectors respirator filters, and safety harnesses, lines and rescue retrieval equipment. You can use the same methods as in the initial hazard identification step to check control measures. You must consult your workers involved in the confined spaces work and their health and safety representative (HSR) and consider the following questions: − − − − − − − − − Are the control measures working effectively in both their design and operation? How effective is the risk assessment process? Are all hazards being identified? Are workers actively involved in the risk management process? Are they openly raising health and safety concerns and reporting problems promptly? Have new work methods or new equipment made the job safer? Are safety procedures being followed? Have instruction and training provided to workers been successful? If new legislation or new information becomes available, does it indicate that current controls may no longer be the most effective? Is any change planned to any plant or structure that may create a confined space or change the nature of an existing confined space? Has an incident occurred as a result of work carried out in a confined space? If problems are found, go back through the risk management steps, review your information and make further decisions about risk control. Confined spaces Code of Practice Page 38 of 54 5. Emergency procedures WHS Regulation clause 74 Confined spaces—Emergency procedures A person conducting a business or undertaking (PCBU) must establish first aid and rescue procedures to be followed in an emergency and ensure that workers practise those procedures to ensure that they are efficient and effective. First aid and rescue procedures must be initiated from outside the confined space as soon as practicable in an emergency. As a PCBU, you must also ensure that openings for entry and exit are of a sufficient size to allow emergency access, openings are not obstructed, and any plant, equipment and personal protective equipment (PPE) provided for first aid or emergency rescue are maintained in good working order. When establishing emergency procedures, the following factors must be taken into account to manage risks associated with confined spaces: − − − − − whether the work can be carried out without the need to enter the confined space the nature of the confined space any changes in hazards associated with the concentration of oxygen or the concentration of airborne contaminants in the confined space the work to be carried out in the confined space, the range of methods by which the work can be carried out and the proposed method of working, and the type of emergency and rescue procedures required. You should also take into account the considerations in Table 3. Table 3 Considerations when establishing emergency procedures for confined spaces Relevant consideration Questions Location of the confined space − − What is the geographic location of the space? How accessible is it in an emergency? and How far away is it from appropriate medical facilities? Communications − How can workers working inside the space communicate to people outside in an emergency? Exactly how will the alarm be raised and by whom? Has planning been done to ensure that rescue and emergency personnel can access the workplace during night shift, weekends and holiday periods? − − − Rescue and resuscitation equipment − − What kinds of emergencies are contemplated? Have you identified and provided suitable rescue and resuscitation equipment dependent on the potential emergencies? For example taking into account:    − Confined spaces Code of Practice the nature of the work being carried out at the workplace the size and location of the workplace, and the number and composition of the workers and other persons at the workplace. Is the selected rescue equipment kept in close proximity to the confined space so that it can be used immediately? Page 39 of 54 Relevant consideration Questions Capabilities of rescuers − − First aid Local emergency services—if they are to be relied on for rescue Are rescuers properly trained, sufficiently fit to carry out their task and capable of using any equipment provided for rescue (e.g. breathing apparatus, lifelines and firefighting equipment)? How will rescuers be protected during the emergency operation? − Is appropriate first aid available for immediate use? Are trained first aid personnel available to make proper use of any necessary first aid equipment? − How will the local emergency services (e.g. fire brigade) be notified of an incident? What information about the particular dangers in the confined space will be given to them on their arrival? Have prior arrangements been made with local emergency services to ensure they are able to respond in a reasonable time and have the specialist confined space retrieval equipment readily available? − − − First aid and rescue procedures should be rehearsed with relevant workers to ensure that they are efficient and effective. Rescue should be performed from outside the confined space, if possible. Workers performing a rescue must be adequately trained, and must be provided with air-supplied respiratory protective equipment if they enter a confined space in an emergency in which: − − − the atmosphere in the confined space does not have a safe oxygen level, or the atmosphere in the space has a harmful concentration of an airborne contaminant, or there is a serious risk of the atmosphere in the space becoming affected in the way referred to above while the worker is in the space. If a person inside a confined space has been overcome by lack of oxygen or by airborne contaminants, it should always be assumed that entry for rescue is unsafe unless airsupplied respiratory protective equipment is used. Potential problems with the size of entrances and exits must be addressed when developing emergency and rescue procedures. Where openings are found to be inadequate, their size should be increased, or an alternative safe means of entry and exit should be provided. Confined spaces Code of Practice Page 40 of 54