Confined space

Confined space is a term from labor-safety regulations that refers to an area whose enclosed conditions and limited access make it dangerous.

In a wide variety of industrial environments workers may be expected to enter a variety of areas and spaces, some of which, due to their particular characteristics will qualify as “Confined Spaces’ under current Victorian legislation.

It is essential that the OH&S professional have a clear, complete understanding of the issues involved in entering and working in these spaces, and the management of potential hazards to ensure on-going worker health and safety.

Description

A confined space is any space: 1) that has limited or restricted means of entry or exit; 2) is large enough for a person to enter to perform tasks; 3) and is not designed or configured for continuous occupancy A utility tunnel, the inside of a boiler (only accessible when the boiler is off), the inside of a fluid storage tank, a septic tank that has contained sewage, and a small underground electrical vault are all examples of confined spaces. The exact definition of a confined space varies depending on the type of industry. That is, confined spaces on a construction site are defined differently than confined spaces in a paper mill. Confined spaces that present special hazards to workers, including risks of toxic or asphyxiant gas accumulation, fires, falls, flooding, and entrapment may be classified as permit-required confined spaces depending on the nature and severity of the hazard.

In the U.S., entry into permit-required confined spaces must comply with regulations promulgated by the Occupational Safety and Health Administration. These regulations include developing a written program, issuing entry permits, assigning attendant(s), designating entrants, and ensuring a means of rescue.

According to the Occupational Safety and Health Administration, a permit-required confined space (permit space) has the three characteristics listed above (which define a confined space) and one or more of the following:

1. Contains or has the potential to contain a hazardous atmosphere
2. Contains a material that has the potential for engulfing the entrant
3. Has an internal configuration that might cause an entrant to be trapped or asphyxiated by inwardly converging walls or by a floor that slopes downward and tapers to a smaller cross section
4. Contains any other recognized serious safety or health hazards.

In addition to the hazards posed by the design of the space, work activities can also pose serious safety hazards (heat, noise, vapors, etc.) that must be taken into account when identifying safety measures that must be taken.

Entry certification

In many situations, certification of non-hazardous atmosphere by a trained or competent person is required before personnel may enter a confined space without the use of a respirator. In the United States Navy, that person is the designated shipboard gas-free engineer. Certification in civilian settings can be performed by an Entry Supervisor who, under O.S.H.A. regulations is designated by the employer and ensures that the space is safe to enter and all hazards are controlled.

In the United States, agricultural and construction operations are exempted from regulations governing permit-required confined spaces (which is specific to general industry), but they are still required to identify and control confined space hazards.

Injuries/Fatalities

Injuries and fatalities involving confined spaces are frequent and often involve successive fatalities when would-be rescuers succumb to the same problem as the initial victim. One example was in 2006 at the decommissioned Sullivan Mine in British Columbia, Canada when one initial victim and then three rescuers all died.

According to data collected by the U.S. Department of Labor, Bureau of Labor Statistics, Census of Fatal Occupational Injuries program, fatal injuries in confined spaces fluctuated from a low of 81 in 1998 to a high of 100 in 2000 during the five-year period, averaging 92 fatalities per year.

Regulations & Code of Practice for Confined Spaces (Australia)

Introduction • Regulations. State and Commonwealth Regulations exist covering entry and work in a Confined Space  Victorian Code of Practice. - The purpose of the Code is to provide practical guidance to persons on how they can meet the requirements of the Occupational Health & Safety (Confined Spaces) Regulations 1996. • For the identification of hazards. • Assessment and control of risks. • A detailed understanding of these issues is required to be able to be considered as competent persons associated with work in Confined Space.

Scope of the Code • The code of practice applies to all employers and employees as defined under section 4 of the Act ( definitions). • all designers, manufacturers, importers and suppliers to workplaces, which may include confined spaces. • self - employed are treated as an employer. • The Regulations & Code of Practice are not intended to cover work in spaces which are not at normal atmospheric pressure - such as decompression chambers. • at pressures higher or lower than normal atmospheric pressure, expert guidance should be sought. • provides guidance for eliminating or controlling the risks associated with hazards which may be found in a confined space, these include including asphyxiation, inhalation of toxic gases, fumes or vapours, engulfment and fire and explosions. • It is not the intention of this code to provide guidance on the full range of hazards, and general OH & S matters, which may be encountered in a confined space. • It is necessary for persons to have an understanding of these issues and know where to find this information in other regulations and codes.

RELATIONSHIP OF THE CONFINED SPACES REGULATIONS TO OTHER REGULATIONS.

(1) If, in relation to plant, these Regulations impose on any person a requirement which is inconsistent with or equivalent to a requirement imposed by the OH & S (Plant) Regulations 1995, the person is only required to comply with the requirement imposed by these Regulations.

(2) If, in relation to a confined space, any regulation made under the Act (other than these Regulations) which deals with a specific hazard imposes on any person a requirement which is inconsistent with or equivalent to a requirement imposed by these regulations, the person is only required to comply with the requirement imposed by the regulation which deals with a specific hazard.

OTHER REGULATIONS THAT MAY BE OF RELEVANCE.

• Manual handling regulations and code of practice 1999. • Noise regulations and code of practice 1992. • Asbestos regulations 1992. • Safety precautions in Trenching Operations code of practice. • Temporary Electrical Installations on Building and Construction Sites code of practice. • Dangerous Goods Act and regulations 1985.

RELATIONSHIP TO AUSTRALIAN STANDARD AS 2865.

• The Regulations & Code of Practice are based on AS 2865. • AS 2865 has no legal standing in Victoria. • AS 2865 can only be used for guidance. • The Regulations set down minimum performance standards that must be compiled with. • Code of Practice provides practical guidance on compliance with the Regulations and has evidentiary status in a court of law.

OBJECTIVE. • Is to protect people at work against the risks to OH & S arising from work in confined spaces. • The risks posed are significant, and incidents in such spaces have resulted in multiple fatalities. • The Regulations require that adequate steps be taken to eliminate the risk arising from hazards, or • where this is not practicable, to reduce the risk, so far as practicable. • The code of practice aims to assist persons achieve compliance with certain provisions of the Regulations. • Confined spaces present a special OH&S problem because the hazards which are present may not be readily apparent.

BACKGROUND. • Confined spaces usually have poor ventilation and may be of small volume. • Hazardous atmospheres can accumulate quickly. • Work in confined spaces can increase the risk of injury or death by making employees work closer to hazards than they would otherwise, such as engulfment. • Workers from many different occupations and industries enter confined spaces to perform work-related tasks, unaware that they are entering a potentially hazardous environment. • Many hazards, such as toxic gases and vapours, can also be exacerbated in confined spaces.

Examples of confined space incidents

These incidents are from a range of Australian and overseas jurisdictions. Prosecution details are not available for the overseas incidents.

Fatality In L.P.G. Tank from Oxygen Deficiency A worker collapsed in an LPG storage tank at a service station due to lack of oxygen. The tank had been purged with nitrogen several times and left to stand for an hour. The supervisor then put his head in the opening of the tank and sniffed the atmosphere without detecting the smell of L.P.G. An employee then entered the tank without any safety equipment. Shortly afterwards he collapsed. A second person then entered the tank to attempt a rescue and also collapsed. The supervisor then introduced pure oxygen instead of air into the tank (this was dangerous as it added to the risk of explosion). The service station employee survived, although there was a delay during the rescue process due to difficulties of access. The first man to collapse in the tank was rescued, but died 9 months later in hospital from bronchopneumonia and brain damage as a result of the accident. The companies and the supervisor were subsequently prosecuted.

Brothers Die As A Result Of Carbon Monoxide Poisoning Two brothers aged twenty four and twenty six died of carbon monoxide poisoning in an underground water tank on their father’s farm. They had been using two petrol driven pumps over two days to pump the water out. On the second day, when the water level was lower, it became apparent that neither of the pumps was fitted with a hose long enough to reach to the bottom of the tank. To overcome the problem, one pump was lowered about a metre into the tank and secured by ropes. One brother got into the tank when it was nearly empty. He collapsed and the other brother and a friend quickly climbed in and attempted to rescue him. The second brother collapsed. The friend attempted to rescue the two brothers, but he was also affected by fumes and had to get out of the tank. Neighbours pulled the two brothers from the tank, but both were dead on arrival at the local hospital.

Tests later revealed that the petrol driven pump was discharging a very high level of carbon monoxide from its exhaust. Calculations confirmed that a lethal concentration of carbon monoxide would be generated in quite a short period of time after lowering the pump into the tank.

Hazardous Atmosphere and Oxygen Deficiency Fatality In Sewer In 1991 a district water board employee was working to clear a blocked sewer. The equipment the employee was using to unblock the sewer became caught and the employee entered the sewer to free the equipment. The clearing of the blockage produced a gush of water and release of sewerage gases and the employee collapsed as he was about to climb out of the access hole. A boy on work experience with the employee attempted to pull him out but was unsuccessful. The employee fell back into the sewer and the boy went for help. The employee was unable to be resuscitated after being pulled from the sewer.

The Magistrates’ Court subsequently found that the water board had breached the Occupational Health and Safety Act 1985 by failing to provide a safe system of work and fined the board.

Employees Overcome A carbon monoxide poisoning occurred when two employees were overcome by smoke while in a silo that contained smoking wood chips. The silo had a side door opening onto a landing about 3 metres above the floor, and access was provided by a steel ladder. A fire erupted in the silo which was extinguished by employees from outside the silo. 30-45 minutes after the fire had been put out, 3 employees entered the silo to shovel out the burnt wood chips. As a result of exposure to the atmosphere in the silo one employee became dizzy, and had to be given oxygen and taken to hospital. Work then continued in the silo until yet another employee became dizzy and also had to be given oxygen and hospitalised.

The Magistrates’ Court subsequently found that the two companies employing the men had breached the Occupational Health and Safety Act by failing to provide safe plant and systems of work and adequate information, instruction, training and supervision. The companies were fined.

Near Miss In Sewer In 1994, two employees entered a shaft connected to a sewer. The men were working at the bottom of the 22 metre shaft when the gas detector they carried emitted an audible alarm indicating the presence of a gas. The employees donned their self rescue units and tried to contact the stand-by employees waiting at the top of the shaft. One of the self rescue units allegedly failed and the employee wearing the unit was affected, and started to become disorientated, falling over several times. After alerting personnel at the entrance to the shaft, the two employees were raised to the surface and taken to hospital for examination.

Another Lucky Escape Employees of a contract company lining a tank with rubber were overcome by fumes. Two of the employees were inside the tank applying glue to sheets of rubber which were then attached to the walls of the tank. The walls of the tank also had glue applied to them. The two employees were overcome by fumes generated by the glue, one collapsing and the other becoming disorientated after he removed his face mask to help his co-worker. One of the employees had to be helped from the tank, while the other was dragged out. A similar incident had occurred the previous week.

Engulfment incident A large bin used by a poultry feed processing firm to load poultry feed into a weighing hopper became blocked. A worker wearing a safety harness entered the bin to clear the blockage. While clearing the blockage the worker fell, went through approximately 3 metres of feed, and dropped out into the weighing hopper below. A stand-by person opened the weighing hopper to empty it of feed, and the worker was subsequently winched back out of the bin. Investigators subsequently recommended that the firm look at different feed formulation methods to reduce the number of bin blockages; that alternative methods of clearing blockages be explored; and that appropriate risk control measures be introduced for any further entries into the bins.

Degreasing fatality A partner in a metal finishing firm was found collapsed inside a degreasing tank containing trichloroethylene. The tank measured approximately 0.7m x 2m x 2m. The partner apparently had decided to empty and de-sludge the tank while working alone. He entered the tank without breathing apparatus (none was available) and without leaving the tank to ventilate. The tank had not been emptied in six months. The partner subsequently died.

The Victorian State Coroner, investigating fatalities in confined spaces in Victoria, has also made a number of recommendations about ways of reducing risks, the coroner has recommended that; • persons entering or working in such spaces undergo specific training. • The atmosphere in confined spaces be subject to both initial and ongoing testing when entries are being performed. • Stand-by persons monitor work in confined spaces. • Rescue procedures be developed and rehearsed. • Rescue equipment be made available on site.

DEFINITION OF A CONFINED SPACE.

The Regulations define “confined space” as follows: “Confined space” means a space in any vat, tank, pit, pipe, duct, flue, oven, chimney, silo, reaction vessel, container, receptacle, underground sewer, shaft, well, trench, tunnel or other similar enclosed or partially enclosed structure. In the AS this is followed by the definition:

An enclosed or partially enclosed space that is at atmospheric pressure during occupancy and is not intended or designed primarily as a place of work, and— (a) is liable at any time to— (i) have an atmosphere which contains potentially harmful levels of contaminant; (ii) have an oxygen deficiency or excess; or (iii) cause engulfment; and (b) could have restricted means for entry and exit.

The definition of “confined space” in the Regulations should be used in order to determine whether something is, or is not, a confined space. If a space fits within the regulatory definition of confined space, then the Regulations apply.

Some of the risks associated with the presence of chemical or physical hazards in confined spaces include: • loss of consciousness, injury or death due to the immediate effects of contaminants; • fire or explosion from the ignition of flammable contaminants; • asphyxiation resulting from oxygen deficiency; • enhanced combustibility and spontaneous combustion resulting from an excess of oxygen; • asphyxiation resulting from engulfment by “stored” material including grain, sand, flour or fertiliser.

Examples of Confined Spaces

SYSTEMS OF WORK.

The term “systems of work” is used in the code. “Systems of work” describe a wide range of activities which can contribute to safe work.

COMPETENCY OF PERSONS CARRYING OUT DUTIES.

Employers have a responsibility to ensure that people carrying out duties under the Regulations on their behalf have the appropriate competency to enable that person to correctly perform the tasks. The competency may be acquired through training, education or experience or through a combination of these. The necessary training, education and experience will vary according to: • the nature of the confined space, • the type of any plant being used in the space or adjacent to the space and associated systems of work, and • the complexity of the tasks to be undertaken and • emergency procedures required.

CONSULTATION.

If practicable, an employer must consult with a health and safety representative of a designated work group when undertaking hazard identification, risk assessment or control of risk processes under these Regulations which relate to work in a confined space that may affect the health or safety of any member of the health and safety representative’s designated work group.

Consultation should take place as early as possible in planning the introduction of new or modified tasks or procedures associated with entry or work in a confined space to allow for changes arising from consultation to be incorporated.

Consultative procedures should allow enough time for the health and safety representatives to consult with members of the designated working group and to discuss the issue with the employer.

It is suggested that identification, assessment and control of risks associated with entry or work in a confined space be carried out by the employer in consultation with employees required to carry out the tasks as well as with the health and safety representatives for the designated work groups.

Employees are a valuable source of information, particularly in relation to confined space work methods, conditions, plant and processes. It is also useful to consult with employees before particular control measures are introduced and when the effectiveness of implemented control measures are being reviewed.

HAZARD IDENTIFICATION

An employer must ensure that all hazards associated with work in a confined space are identified, having regard to the state of knowledge about the hazards.

“Hazard identification” is the process of identifying all situations or events that could give rise to the potential of injury or illness. Thus, it involves identifying all the sources that have a potential to cause injury or illness.

SOURCES OF INFORMATION.

There are a range of sources that may assist the employer to ensure that the hazard identification process reflects the current state of knowledge on hazards that may be associated with work in a confined space. Examples include: • Discussions with designers, manufacturers, suppliers or other employers with similar workplaces or processes. • Advice obtained from specialist professionals including occupational hygienists, engineers and chemists. • Workplace incident, injury and accident reports involving confined spaces. • Available accident or incident information, hazard alerts and other relevant reports from the Victorian Workcover Authority and counterparts, Worksafe Australia, unions and employer associations and professional bodies; and • Relevant reports and articles from OH&S journals, technical references or data bases from both Australia and overseas.

WHEN MUST HAZARD IDENTIFICATION BE CARRIED OUT ?

• A space becomes a confined space for the purpose of the Regulations when it meets the criteria in the definition. • One of the criteria is that the space “is, or is intended to be, or is likely to be, entered by any person”. • It therefore follows that hazard identification must be carried out before entry takes place. • If the space is to be entered on subsequent occasions, the hazard identification should have regard to any change in the state of knowledge.

HAZARDS ASSOCIATED WITH CONFINED SPACES.

The identity and nature of what substances the confined space has previously held, however briefly, will give an indication of what kind of hazard may be present, such as: • a lack of oxygen. • atmospheric contaminants. • flammable atmospheres. Other hazards may arise from processes, products and by-products, waste, storage and from work activities associated with work in the confined space or its environs. There are many hazards that may be associated with work in a confined space, some of these being:

1. HAZARDOUS SUBSTANCES.

The major routes of possible worker exposure to hazardous substances are: • Inhalation. • Skin uptake. • Ingestion.

• Exposure to hazardous substances may result in acute or chronic injury. • Health effects may include acute lethal effects, non-lethal but irreversible effects after a single exposure, or severe effects from repeated or prolonged exposure. • This will depend on factors such as the duration of exposure, the exposure concentration, and the health effects associated with the substance, which may be carcinogenic, teratogenic, mutagenic, corrosive, toxic irritant or sensitising.

2. FLAMMABLE CONTAMINANTS.

Flammable atmospheric contaminants may result in explosion or fire. Two things make an atmosphere flammable: • the oxygen in the air, and • a flammable gas, vapour or dust in the proper mixture. Different gases have different flammable ranges. If a source of ignition, such as a sparking or electrical tool, is introduced into a space containing a flammable atmosphere, an explosion will result. Flammable atmospheres in confined spaces may result from the evaporation of a flammable residue, from flammable materials used in the space, from a chemical reaction ( such as formation of methane), or from the presence of combustible dust ( such as that in flour silos ).

3. UNSAFE OXYGEN LEVEL.

(a) Deficiency in oxygen.- An oxygen deficient atmosphere may result in injury or death. Symptoms may include emotional stress, fatigue, headache, nausea and vomiting, collapse and unconsciousness. (b) Excess of oxygen.- Oxygen is normally present in air at a level of 21%. When oxygen content exceeds 21%, flammable materials, such as clothing and hair, will burn more violently if ignited. Oxygen excess may reduce the lower explosive limit (LEL) of a contaminant. Effects of Oxygen at different levels see the enclosed diagram

4. ENGULFMENT.

Engulfment means to plunge into and be immersed by material. It may result in injury or death from asphyxiation or from being crushed by loose granular material stored in containers such as silos, bins and hoppers. Examples of materials which are often stored in a way which results in the risk of engulfment include: • plastics, chemicals and agricultural products, such as sand, fertiliser, grain, and coal, coal products and wood chips.

Working above or below a bridge of material is most dangerous.

5. OTHER HAZARDS.

Undertaking work in confined spaces may greatly increase the risk of injury from: • Mechanical hazards. • Ignition hazards. • Electrical hazards ( electrocution). • The presence of, or uncontrolled introduction of, substances. • Noise. • Manual handling. • Radiation. • Environmental hazards. • Biological hazards. • Traffic hazards.

RISK ASSESSMENT.

If a hazard is identified under regulation 14, an employer must ensure that an assessment is made to determine whether there is any risk associated with that hazard.

Circumstances within a confined space may alter, or hazards may exist which could not be identified initially. Therefore the processes of identifying hazards and assessing the risks associated with work for confined space situations will often overlap.

HOW TO ASSESS RISKS.

• “Risk Assessment” is the process of determining whether there is any risk associated with EACH of the hazards identified, that is, whether there is any likelihood of injury or illness. • For each hazard identified, the employer should ensure the risk assessment involves consideration of any likelihood for people to be exposed to the hazard. • A person carrying out a risk assessment should determine a method of assessment that is appropriate for the confined space and the hazards identified.

FACTORS TO BE CONSIDERED WHEN UNDERTAKING A RISK ASSESSMENT.

An employer must ensure that an assessment takes into account- (a) the nature of the confined space, and (b) if a hazard is associated with the level of oxygen or the level of any contaminant in the atmosphere of the confined space, any change that may occur in the level of oxygen or contaminant; and (c) the work required to be carried out in the confined space, the range of methods by which the work can be done and the selected method of working; and (d) any work required to be performed outside the confined space that may be associated with a hazard; and (e) the means of entry to and exit from the confined space; and (f) the type of emergency procedures required.

THE NATURE OF THE SPACE.

The nature of the space may contribute to the risks associated with hazards present in a confined space. • The type of space (vat, tank, pit etc); • Where it is located; • What processes are adjacent to it that may effect the risk associated with the hazard; • the size and internal structure of the space, for example, whether it lacks room for movement or equipment that is likely to trap the person or hinder or block their progress; • the material the space is constructed of; • the soundness and security of the space, such as whether the space could be moved inadvertently; • whether there is poor illumination and visibility.

ANY CHANGE THAT MAY OCCUR IN THE LEVEL OF OXYGEN OR CONTAMINANT.

• Information on the likelihood of change relating to the level of contaminants or oxygen can be used for consideration of the level of respiratory protection that may be required and/or the need for personal direct monitors to be worn. • Ongoing monitoring or retesting may also be required.

THE WORK TO BE CARRIED OUT, THE RANGE OF METHODS AND SELECTED METHOD OF WORKING.

In the assessment the employer should consider whether the work to be carried out or the method of working will introduce a new hazard into the space or contribute to the risks associated with work in the confined space. Consider work methods that eliminate the need to enter: • can work activities, such as inspection, cleaning or retrieval of parts be carried out without entry Consider work methods to reduce risk: • in a flammable atmosphere, can a method of work and equipment be selected which does not introduce sources of ignition into the space ? • Can a work method be selected which does not result in the release of harmful atmospheric contaminants?  Can a work method be selected which reduces time spent in the space or the number of persons that have to enter the space? The work method analysis should involve consideration of all the tasks associated with work in the confined space: for example, the steps needed to bring the confined space to atmospheric pressure, or the need for cleaning (the latter can also reduce risk). Consideration should also be given to any risks associated with the use of personal protective equipment (PPE) in a confined space. Use of PPE may introduce new risks by placing extra load on the persons entering or working in the confined space, such as the weight or discomfort of protective clothing and hearing protection. Another risk may be entanglement of air lines when using air line respirators.

WORK PERFORMED OUTSIDE THE CONFINED SPACE.

Hazards arising from work performed outside the confined space which may be associated with a hazard must also be included in the assessment. The breathing atmosphere inside the confined may be contaminated by sources outside the confined space, such as exhaust of an internal combustion engine. There may be potential for fire or an explosion ignited by hot work in adjacent areas or from the movement of equipment such as fork lifts.

THE MEANS OF ENTRY AND EXIT.

Small openings may make it difficult to get equipment in or out of the space, especially PPE such as respirators or life saving equipment when rescue is needed. Some openings are difficult to access and escape from such areas may be very difficult in emergency situations. Openings need to be examined to see whether they are obstructed by fittings or equipment. In taking the means of entry and exit into account in the risk assessment, consideration should be given to: • The number, size and location of entry and exit openings; • Entry and exit routes; • Equipment to be used to gain entry and exit; and • Whether the means of entry and exit are adequate for the proposed method of work to enable rapid entry, exit and rescue of employees from the space.

THE TYPE OF EMERGENCY PROCEDURES REQUIRED.

Emergency procedures will vary according to the nature of the confined space, its hazards and associated risks. The employer should consider the following: • procedures for rescue, first aid and resuscitation; • the number of persons occupying the space. • Procedural arrangements necessary to maintain equipment for the confined space task and measures to control risks, such as arrangements to ensure adequate communication with the persons within the confined space, and to properly initiate rescue procedures; • Whether the procedures address the availability and adequacy of appropriate PPE, protective clothing and rescue equipment for all persons likely to enter the confined space.

PHYSIOLOGICAL AND PSYCHOLOGICAL FACTORS.

Entering or working in a confined space can be hazardous and may impose extra physiological and psychological demands. Consideration should be given to demands: • arising from working under stressful conditions (such as in a high temperature environment); • relating to working in a restrictive space; and • from the wearing of PPE as this places an extra workload on the body. Employers should have regard to the guidance in AS 1715 on medical fitness for the wearing of respiratory protective devices. Consideration should also be given to the physical fitness of the person carrying out work in the confined space.

OUTCOMES OF THE ASSESSMENT.

The outcome of the assessment will determine what method of working is selected. Risk control measures to be applied are to be determined having regard to the outcomes of the risk assessment.

REVISION AND REASSESSMENT.

An employer must ensure that an assessment under this regulation is revised, or another assessment is carried out, whenever changed circumstances indicate that the assessment is no longer adequate to determine the risks associated with the hazard.

RECORDING THE OUTCOMES OF RISK ASSESSMENTS.

An employer must ensure that the results of any assessment are recorded and retained by the employer while the assessment is relevant to the confined space.

RISK CONTROL.

An employer must ensure that any risk associated with work in a confined space is-

(a) eliminated; or

(b) if it is not practicable to eliminate the risk, reduced so far as is practicable.

CONTROLLING RISK .

“Risk control” is the process of determining and implementing appropriate measures to control risks assessed. Under the Regulations the primary duty of the employer in relation to risk control is to eliminate where practicable, any risk associated with work in the confined space. It is only if elimination of risk is shown not to be practicable in a given circumstance, that the employer must ensure the risk is reduced so far is practicable. “Practicable” is defined in the Act as meaning: “Practicable having regard to- (a) the severity of the hazard or risk in question: (b) The state of knowledge about the hazard or risk and any ways of removing or mitigating that hazard or risk: (c) the availability and suitability of ways to remove or mitigate that hazard or risk; and (d) the cost of removing or mitigating that hazard or risk.”

CATEGORISATION OF RISK CONTROL MEASURES

The Regulations require that elimination of the risk associated with work in a confined space must be the employer’s first consideration. If elimination is not practicable then the risk must be reduced so far as is practicable. In addition, the Regulations require that other specific risk controls be carried out, including the isolation of plant and services and the provision of PPE.

HIERARCHY OF CONTROLS. • Design • Substitution • Redesign • Separation • Administration • P.P.E.

REVIEW OF CONTROL MEASURES.

Control measures should be reviewed and improved, maintained, extended or replaced as necessary to ensure adequate control. Reviews should take place at regular intervals or as indicated by the risk assessment record, in the event of changes to the confined space or plant and process used in the space.

ISOLATION OF PLANT AND SERVICES.

An employer must ensure that any risk associated with work in a confined space in relation to- (a) the introduction of any substance or condition from or by any plant or services connected to the space; or (b) the activation or energising in any way of any plant or services connected to the space- is eliminated, or if it is not practicable to eliminate the risk, reduced so far as is practicable. Isolation is a term which describes the measures used to prevent: • the introduction of contaminants or conditions through equipment such as piping, ducts, drains, conveyors, service pipes and fire protection equipment; • the introduction of conditions such as hot or cold conditions; • the activation or energising of plant or services which may be external to, but still capable of adversely affecting, the confined space (such as heating or refrigerating methods); • the activation or energising of machinery in the confined space; • the use of electrical equipment.

PURGING OR VENTILATION OF CONTAMINANTS.

An employer must ensure, in relation to work in a confined space, that- (a) so far as is practicable, purging or ventilation of any contaminant in the atmosphere of the space is carried out; and (b) pure oxygen or gas mixtures with oxygen in a concentration greater than 21% by volume are not used for purging or ventilation of any contaminant in the atmosphere of the space.

PURGING

The Regulations define “purging” as the method by which any contaminant is displaced from a confined space. The confined space may be purged, for example with an inert gas such as nitrogen, to clear flammable gases or vapours before work in the confined space. After purging with inert gases the confined space should be adequately ventilated, and re-tested. The purging of a space should be undertaken in a manner that precludes rupture or collapse of the enclosure due to pressure differentials, and the methods employed should ensure that any contaminant removed from the confined space are exhausted to a location where they present no hazard.

VENTILATION.

Ventilation of a confined space by natural, forced or mechanical means, may be necessary to establish and maintain a safe atmosphere. Ventilation should be continued throughout the period of occupancy. The method and equipment used will be dependent on size of space, openings, gases to be exhausted etc. Natural ventilation may be adequate but in most cases mechanical ventilation is likely to be needed. Where the maintenance of a safe oxygen level in a confined space is dependent on mechanical ventilation equipment, the equipment should: (1) be continuously monitored while the confined space is occupied; and (2) have the controls (including any remote power supply ) clearly identified and tagged to guard against unauthorised interference.

SAFE OXYGEN LEVEL, CONCENTRATION OF CONTAMINANT OR LEL.

(2) An employer must ensure, during work in a confined space that- (a) the atmosphere of the space has a safe oxygen level; or (b) if it is not practicable to comply with paragraph (A), the employee uses air supplied respiratory protective equipment. (3) An employer must ensure during work in a confined space that if there is any contaminant in the atmosphere of the space and the exposure standard (if any) of the contaminant is exceeded in respect of the circumstances of that work- (a) the concentration of the contaminant is reduced to or below the exposure standard for that contaminant; or (b) if it is not practicable to comply with paragraph (A), the employee uses air supplied respiratory protective equipment or other appropriate PPE.

SOME DEFINITIONS RELEVANT TO THIS REGULATION.

“Safe oxygen level”. • Is equal or greater than 19.5 % • is equal or less than 23.5 % • At pressures significantly higher or lower than normal atmospheric pressure, expert guidance should be sought. “contaminant” • means any substance which may be harmful to health or safety. “breathing zone” • means a hemisphere of 300mm radius from the front of a persons face. The term “exposure standard” is defined as the airborne concentration of that contaminant in a persons breathing zone, as set out in: “Adopted National Exposure Standards for Atmospheric contaminants in the Occupational Environment” This refers to an airborne concentration of a particular substance in the person’s breathing zone, exposure to which, according to current knowledge, should not cause adverse health effects nor cause undue discomfort to nearly all persons. The exposure standard can be of three forms. • TWA -Time weighted average. The average airborne concentration of a particular substance when calculated over a normal 8 hour day, 5 day week. • STEL- Short term exposure limit. Exposure at the STEL should not be longer than 15 minutes and should not be repeated more than 4 times per day. • PEAK -A maximum or peak limitation of airborne concentration.

TESTING THE ATMOSPHERE TO DETERMINE THE LEVEL OF OXYGEN OR CONTAMINANT.

The senses should not be trusted to determine if the air in a confined space is safe. Many toxic gases and vapours, such as carbon monoxide, cannot be seen or smelt, nor can the level of oxygen. Canaries, mice or other animals cannot be used to test the atmosphere as the results are unreliable. Where indicated by a risk assessment, arrangements should be made to test the atmosphere within a confined space. How and with what frequency the atmosphere within the confined space should be tested needs to be determined.

TESTING THE ATMOSPHERE TO DETERMINE THE LEVEL OF OXYGEN OR CONTAMINANT.

Where appropriate, the atmosphere should be tested for: • oxygen content; and/or • airborne concentration of flammable contaminants; and/or • airborne concentration of potentially harmful contaminants. Atmospheric testing should be carried out in the above sequence. • Testing for thermal extremes may also be necessary. • Testing and analysis should be carried out using suitable equipment and techniques by a competent person such as an occupational hygienist or safety professional. • A competent person has acquired the knowledge and skills to conduct appropriate atmospheric testing and interpret the results in a consistent and reliable manner.

WHERE TO TEST.

Initial testing should be performed from outside the space by inserting a sample probe at appropriately selected access holes. Telescopic extension probes or probes attached to a line can be used to reach remote regions. Some gases air heavier than air, eg. Hydrogen sulphide and will settle in the bottom of a confined space. Also, some gases are lighter that air, eg. Methane and will be found around the top of the confined space. Some contaminants will settle at different levels. Horizontal spaces should also be tested at intervals along their length, to reflect accurately the conditions within the space. • It is essential that the whole atmosphere is tested, it may be necessary for the tester to enter the confined space. • This should only be done after performing appropriate monitoring from outside the space. • If it is necessary to enter the space to test remote regions, then: • air supplied respiratory protective equipment needs to be worn; and • the entry should be undertaken in accordance with the Regulations and Code of Practice.

WHEN TO TEST.

• The appropriate time to test the atmosphere will vary, depending on the circumstances. • However, unless testing is undertaken immediately prior to entry, the test results may not be relevant. • Testing of the confined space should be carried out from outside the space before the entry permit is issued. • The tests should also check on chemical deposits. • If testing reveals oxygen deficiency, or the presence of toxic gases or vapours, the space may require ventilating, or purging and ventilating, and re-testing before employees enter. Re-testing and continuous monitoring of the atmosphere may be necessary: • if determined under the risk assessment. • As indicated from the initial testing of the atmosphere; or • because of the potential for later release or disturbance of hazardous material. • Because of the work undertaken in the space, for example, heat or fumes from welding.

INTERPRETATION OF MEASUREMENT RESULTS.

• It is necessary for the employer to ensure that measurements of “safe oxygen level” and all relevant airborne contaminants and the interpretation of results have been performed by a competent person. • The results of measurements should be compared with the relevant exposure standard, • Safe oxygen level should be determined in accordance with the definition.

RECORDING OF TEST RESULTS

• The results should be recorded on the written entry permit.

PERSONAL PROTECTIVE EQUIPMENT (PPE).

Employers should determine the appropriate protective equipment to be used in the confined space. The following points should be considered: • the hazard identification and risk assessment as required under regulations 14 and 15; • Results of the evaluation of the atmosphere including testing; • the process to be conducted within the confined space; • the contaminants that may be encountered; and • the extra load placed on persons when wearing PPE.

RESPITORY PROTECTIVE EQUIPMENT (RPE).

• Respiratory protective equipment (RPE) refers to a range of breathing equipment, including air-supplied and self-contained breathing apparatus. • Regulation 18(2) requires that suitable air-supplied RPE must be worn where a safe oxygen level cannot be established and maintained. • RPE should also be worn when the nature of the work procedure within the confined space is likely to degrade or contaminate the atmosphere in the confined space, eg. Hot work, painting, removal of sludge. • Regulation 18(3) requires the employer to ensure that where any contaminant in the space has an exposure standard, and it is not practical to reduce the concentration of a contaminant to or below the exposure standard for that contaminant, employees use air supplied RPE or other appropriate PPE. • Employers should have regard to the guidance in AS 1715 on the selection, use and maintenance of RPE and the source of breathing air.

SAFETY HARNESS, SAFETY LINE/RESCUE LINE

• Suitable safety harnesses and safety lines or rescue lines should be worn where there is a hazard of falling during ascent or decent or where engulfment is a hazard. • The selection of the type of safety harness, safety line or rescue line should take into account of the possible hazards and of rescue arrangements. • Employers should have regard to the guidance in AS 2626 on the selection, use and maintenance of industrial safety belts and harnesses.

OTHER PPE.

The level of PPE to be worn will depend on the nature of the confined space and the work to be done, the following needs to be considered: • Eye and face protection. • Head, foot and body protection. • Hearing protection. • Hand protection.

Control of Risk in relation to:Fire, Explosion and Flammable Gases or Vapours.

(1) If there is a likelihood of fire or explosion in a confined space an employer must ensure that no source of ignition is introduced to the space, whether introduced from within or outside the space. (2) An employer must ensure during work in a confined space that- (a) the concentration of any flammable gas or vapour in the atmosphere of the space is below 5 % of its LEL; or (b) if it is not practicable to comply with paragraph (A) and the concentration of any flammable gas or vapour in the atmosphere of the space- (1) is equal to or greater than 5% but less than 10% of its LEL, any employee is removed immediately, or continuous monitoring takes place, whilst the employee is in the space; or (2) is equal to or greater than 10% of its LEL, any employee is removed immediately from the space.

Ignition sources.

• Ignition requires the presence of three elements: • Where a flammable atmosphere is likely to exist, all sources must be eliminated, both inside and outside the space.

Concentration of flammable contaminants.

• Results of measurements to test for flammable gas or vapour should be compared with the LEL of the substance. • MSDS should help for LEL of the product. • AS 2430 & AS 2381 may need to be consulted in relation to dust fires and explosions.

Flammable gas detectors.

• Calibration is carried out using manufacturers directions. • External calibration every year. • Spot checks before every entry. • Equipment should be fitted with latching, visible and audible alarms, if LEL of 10% reached. • AS 2275 gives guidance for flammable gas indicators. • Additional guidance is provided for flammable gas detection strategy.

Re-testing after purging.

• After atmospheric purging to clear the flammable atmosphere has been completed, forced draft devices should be turned off for sufficient time to allow for a normal atmospheric condition to exist for gas testing of the confined space. • If an acceptable level cannot be obtained without continuous forced draft ventilation, then the ventilation device should be suitably tagged and/or locked to ensure it is not disconnected while the work proceeds within the space.

Signposting.

During work in a confined space, including preparation and completion of that work, an employer must ensure, so far as is practicable, that signs are erected in the immediate vicinity of the space which- (a) identify the space; and (b) notify employees that they must not enter the space unless they have an entry permit; and (c) are clear and prominently positioned.

Maintenance of Plant Used to Control Risk.

An employer must ensure that any plant- (a) used to control risk associated with the entry to and work in a confined space; or (b) for use in the emergency procedures- is maintained so that it is fit for the purpose.

WRITTEN APPROVAL FOR ENTRY TO A CONFINED SPACE.

(1) An employer must ensure that- (a) any employee who enters a confined space has an entry permit to enter the space; and (b) the permit complies with this regulation. (2) An entry permit- (a) must only apply to one confined space; and (b) may approve one or more employees to enter that space. (3) An entry permit must list- (a) the confined space that the permit applies to; and (b) the measures to control risk for the confined space; and (c) the name of any employee approved to enter the confined space; and (d) if an employer assigns any employee to carry out any function in relation to regulation 23 (l), the name of the employee; and (e) the period of time that the permit is in operation.

Control measures to be listed.

• The control measures listed in the permit should be based on the hazard identification and risk assessment processes. • The permit should include the control measures which must be carried out before work commences or which must be carried out or continued during work. • The control measures may be listed so as to allow for employees or supervisors to indicate that the control measures may be listed so as to allow for employees or supervisors to indicate that the control measures have been completed and/or are in place. • A record of the space that the permit applies to. • Names of employees entering the space. • Name of any person assigned to carry out any stand-by function for the confined space. • Entry permit validity. • Instruction in the contents of entry permits. • Availability of the entry permit.

STAND-BY ARRANGEMENTS.

An employer must ensure, in relation to work in a confined space, that from outside the space- (a) there is continuous communication between the employer or a person authorised by the employer and any employee in the space; and (b) the emergency procedures can be initiated.

Continuous communication.

Continuous communication is necessary to: • monitor the status of employees entering under the permit; • alert such employees of the need to evacuate the space; • initiate the emergency procedure in a rapid timely manner. Communication can be achieved by a number of means, including voice, radio, hand signals. Where visual or oral communication is not possible, then a system of rope signals could be devised. Long wave or low frequency radio equipment can be used.

Ability to initiate appropriate emergency procedures.

The stand-by person needs to be trained in all aspects of emergency procedures. In an emergency there can be a strong urge to enter the space to help the injured person. A high level of training is needed to ensure that the emergency plan is adhered to and the stand-by person and others do not become casualties. The stand-by person should have the authority to order persons in the space to exit if hazardous conditions exist. The stand-by person should have available means to call for assistance. The stand-by person should order employees to leave the space if: • any dangerous or prohibited condition is detected, an alarm showing a change in atmospheric conditions. • If any employee in the space exhibits behavioural or other symptoms; or • if, for any reason, the stand-by person is unable to perform the functions prescribed by regulation 23.

Additional guidance.

Where appropriate, the stand-by person should be able to operate and monitor plant used to control risk. This would include: • operate atmospheric monitoring equipment which is monitoring levels, or being used to test for the presence, of harmful or flammable contaminants and oxygen levels; • interpret monitoring results so that appropriate control or emergency measures can be taken; • operate and monitor the operation of a ventilation device being used to provide continuous ventilation of the space; and • operate and monitor other equipment, for example, fall protection/retrieval apparatus and air supplied respirator airlines and related compressors.

Monitoring of multiple spaces.

Stand-by persons may be assigned to monitor more than one confined space provided the requirements prescribed by regulation 23 can be effectively achieved for each space that is monitored.

PROCEDURE TO KNOW WHEN EMPLOYEES ARE IN, AND HAVE EXITED A CONFINED SPACE.

19.1 During the time that an entry permit is in operation, an employer must ensure that procedure is in place so that the employer or a person authorised by the employer knows when any employee is in a confined space. 19.2 An employer must ensure that- (a) all employees have exited a confined space on completion of work for which an entry permit is in operation; and (b) for the purpose of paragraph (A), there is a record in writing that all employees have exited the confined space.

EMERGENCY PROCEDURES, RESCUE AND FIRST AID.

(1) An employer must ensure, in relation to work in a confined space, that emergency procedures are established for the control and management of an emergency situation in the space, including procedures for- (a) the rescue of any employee from the space; and (b) first aid to be provided to any employee in the space and after rescue from the space.

(2) An employer must ensure that the emergency procedures take into account-

(a) the functions carried out in relation to regulation 23(1); and (b) the results of any risk assessment relevant to the confined space.

(3) An employer must ensure that the emergency procedures are-

(a) rehearsed by the relevant employees; and (b)carried out as soon as possible after an emergency situation arises in a confined space.

(4) An employer must ensure that any risk associated with the carrying out of the emergency procedures is -

(a) eliminated; or (b) if it is not possible to eliminate the risk, reduced so far as is practicable.

First aid.

• Procedures should specify the first aid training competencies required by employees. • First aid qualifications. • How many employees trained. • Their availability. • First aid equipment. The first aid in the workplace Code of Practice should be referred to for additional guidance.

Rescue equipment.

• Appropriate plant for the rescue of employees may be set out in procedures. • Additional sets of breathing apparatus. • Lifelines. • Lifting equipment. • AS 1715 on selection, use and maintenance of RPE. Removal of trapped, injured or unconscious persons from confined spaces is extremely difficult. While one person may be adequate to keep watch and raise alarms. Even the strongest person is unlikely to be able to lift, or handle on their own, an unconscious person, using only a rope.

Public emergency services.

• How the public emergency services are to be alerted and arrangements for effective liaison, and response should be planned in advance. • If local emergency personnel are unfamiliar with the confined space hazards at the workplace, then vital time may be lost while the situation is assessed and a plan of action developed.

Rehearsal of procedures by relevant employees.

• An employer must ensure that emergency procedures are rehearsed by the relevant employees. • It is desirable that all employees who have a function in relation to work in a confined space, including supervisors and managers should have an understanding of all the emergency procedures in place.

Use of PPE for entry in an emergency.

(5) An employer must ensure that any employee who enters or carries out emergency procedures in a confined space in an emergency situation - (a) arising from an atmosphere that does not have a safe oxygen level; or (b) where there is a likelihood of the condition under paragraph (a) arising while the employee is in the space -uses air supplied respiratory protective equipment. (6) An employer must ensure that any employee who enters or carries out emergency procedures in a confined space in an emergency situation - (a) arising from an atmosphere that has a harmful level of any contaminant or from engulfment; or (b) where there is a likelihood of the condition under paragraph (a) arising while the employee is in the space -uses air supplied respiratory protective equipment or other appropriate PPE.

Entry and Exit Size to Permit Rescue.

(7) An employer must ensure that -

(a) openings for the entry to and exit from a confined space are of adequate size to permit the rescue of any employee in the space and are not obstructed by fittings or plant that could impede rescue; or

(b) if it is not practicable to comply with paragraph (a), an alternative means of entry to and exit from the space for rescue purposes is provided. (8) If an alternative means of entry to and exit from a confined space for rescue purposes is provided, the employer must ensure that any risk associated with the alternative is -

(a) eliminated; 

(b) if it is not practicable to eliminate the risk,reduced so far as is practicable.

TRAINING, INFORMATION AND INSTRUCTION OF EMPLOYEES.

An employer must ensure, in relation to work in a confined space, that the relevant employees are provided with information, instruction and training in - (a) the nature of any hazard and risk associated with the space; and (b) the need for, and proper use of, measures to control risk; and (c) the selection, use, fit, testing and storage of any PPE; and (d) the contents of any entry permit relevant to the employees; and (e) the emergency procedures. Employees Requiring Training.

“Relevant employee” is defined by: (a) any employee required to enter a confined space. (b) any employee who has any function in relation to the entry to or work in a confined space or the emergency procedures, but who is not required to enter the space; or (c) any person supervising any employee referred to in paragraph (a) or (b). Training should be given to employees who: • enter confined spaces and perform work; • perform hazard identification and risk assessments; • are involved in rescue and first aid procedures; • issue entry permits; • design or modify a confined space; • manage or supervise persons including contractors; • maintain equipment; • purchase, distribute, fit, wear and maintain PPE for confined spaces. Detailed in the regulations are the points in regard to training: • Outcomes of training. • Training methods. • Review of training

External links

• United States Occupational Safety and Health Administration (OSHA) page on confined spaces
• California Occupational Safety and Health Administration (Cal/OSHA) Confined Space Guide: "Is It Safe To Enter A Confined Space?"
• Guide to confined space regulations from Alberta Canada
• Canadian Confined Space Rescue and Training Facilities
• National Institute for Occupational Safety and Health - Confined Space Page

he:מקום מוקף