Source: http://www2.worksafebc.com/publications/OHSregulation/GuidelinePart9.asp
Timestamp: 2013-05-19 09:26:50
Document Index: 733526780

Matched Legal Cases: ['art 9', 'art 9', 'art 9', 'art 9', 'art 9', 'art 9', 'art 9', 'art 9', 'art 9', 'art 9', 'art 9', 'art 10', 'art 4', 'art 3', 'art 8', 'art 9', 'art 9', 'art 10', 'art 9', 'art 9', 'art 8', 'art 9']

OHS Guidelines Part 9 Confined Spaces - Sun May 19, 2013
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Guidelines Part 9
Guidelines Part 9 Contents
G9.9-2 Visiting employers G9.11 Confined spaces - Qualified persons IDENTIFICATION AND ENTRY PERMITS
G9.18.1 Exemption to restriction on use of valves for isolation [Retired on February 1, 2011]
G9.26(2) Qualified person for calibration of confined space atmospheric testing equipment CLEANING, PURGING, VENTING, INERTING
G9.29 Notifying WorkSafeBC about inerting a confined space STAND-BY PERSONS
G9.34-2 Stand-by person for a low hazard atmosphere space G9.35 Stand-by person for a moderate hazard atmosphere space
Top G9.1-1 Excluded confined spaces Issued July 21, 2005, Revised June 18, 2008; Revised June 8, 2011
Section 9.1 of the OHS Regulation ("Regulation") states: "confined space", except as otherwise determined by the Board, means an area, other than an underground working, that
The purpose of this guideline is to identify the types of spaces that WorkSafeBC has determined, as contemplated by the above definition, not to be "confined spaces", and the conditions that apply. Also,it outlines the process for and criteria used in making the determination for other spaces. Enclosed spaces that are not "confined spaces" when certain conditions apply
The definition of confined spaces in section 9.1 of the Regulation permits WorkSafeBC to determine certain spaces to not be confined spaces for the purposes of the application of Part 9 of the Regulation. The spaces for which WorkSafeBC will make this determination are those that do not pose the hazards of confined spaces that are addressed by Part 9 of the Regulation. Specifically, there must be absolutely no potential for an atmospheric hazard to exist or develop immediately prior to any worker entering the space, nor any risk of entrapment or engulfment to workers entering the space. Provided that adequate controls are in place to ensure worker health and safety, a harmful substance (e.g., welding fume) may be temporarily introduced into the space as an intended or otherwise understood consequence of work activity without the space becoming a confined space. Controls will be adequate if they are in conformity with the requirements of section 5.55 (Types of controls), and the nature of the substance is such that it will not impair the ability of the worker to escape unaided in the event of failure of the control system.
In these circumstances and the further ones outlined below, the following are spaces that WorkSafeBC has determined not to be confined spaces for the purposes of Part 9 of the Regulation: Swimming pools
Crawl spaces under school portables or other non-industrial buildings, with openings to atmosphere allowing for continuous passive ventilation
Attic spaces with openings to atmosphere allowing for continuous passive ventilation
Open, unconnected manholes for storm or sewer hookups at new construction sites
HVAC plenums and related ventilation ductwork
Underwater spaces during occupational diving operations. (Note this exception does not apply to a space that contains an atmosphere, even if access to the space is by an underwater route)
The determination that the above are not "confined spaces" for the purposes of Part 9 of the Regulation is conditional on there being no factor that might give rise to any potential for an atmospheric hazard to exist or to develop prior to a worker's entry or to unexpectedly develop during any entry or occupation by a worker. Similarly, there can be no factor that may give rise to a risk of entrapment or engulfment within the space.
Whether the space might contain or might have contained a harmful substance (as defined in section 9.1 of the Regulation)
The presence of adjacent piping (as defined in section 9.1 of the Regulation) or other conveyance into the space which may contain a harmful substance
The presence of material conveyances into the space
Whether the space lacks openings to atmosphere, or otherwise does not allow for continuous passive ventilation
Other aspects of the design, construction, and use of the space that could give rise to a hazard Where there is any potential for
an atmospheric hazard to exist or develop prior to worker entry, or a risk of entrapment or engulfment developing within the space, or the space to unexpectedly contain an atmosphere other than clean respirable air during any entry and occupation by a worker
then the space is a confined space in accordance with the definition in section 9.1. In such a case the employer must comply with the applicable provisions of Part 9 of the Regulation. Determination regarding other spaces WorkSafeBC may determine other types of spaces to be excluded from the application of Part 9 of the Regulation in addition to the spaces listed above. Such determinations will be made based on an evaluation by a committee of WorkSafeBC personnel with expertise in confined spaces. Persons interested in having WorkSafeBC assess whether a certain type of space should be determined not to be a confined space for the purposes of Part 9 of the Regulation may contact the Regulatory Practices Department or the WorkSafeBC office in their region. Other hazards to be controlled
Although an enclosed space might not be considered to be a "confined space", it may have other hazards that must be controlled. The other parts of the Regulation still apply and must be considered when planning entry and work in these spaces. Other relevant provisions that the employer needs to consider include the following: Lockout (Part 10)
Working Alone (Part 4) Occupational First Aid (Part 3) Personal Protective Clothing and Equipment (Part 8)
G9.1-2 Definitions Issued August 1, 1999; Revised February 11, 2004; Revised April 9, 2008; Revised August 23, 2011
The definition of "confined space" in section 9.1 of the OHS Regulation ("Regulation") is
except as otherwise determined by the Board, means an area, other than an underground working, that
The definition of "high hazard atmosphere" in section 9.1 of the Regulation is
an atmosphere that may expose a worker to risk of death, incapacitation, injury, acute illness or otherwise impair the ability of the worker to escape unaided from a confined space, in the event of a failure of the ventilation system or respirator
The definition of "low hazard atmosphere" in section 9.1 of the Regulation is
an atmosphere which is shown by pre-entry testing or otherwise known to contain clean respirable air immediately prior to entry to a confined space and which is not likely to change during the work activity, as determined by a qualified person after consideration of the design, construction and use of the confined space, the work activities to be performed, and all engineering controls required by this Regulation;
This guideline provides information to further explain some of the terms that appear in section 9.1 (Definitions) of the Regulation. Matters discussed include
The definition for "confined space" in section 9.1 of the Regulation excludes underground workings. An underground working is defined in section 22.1 of the Regulation, as including "any adit, tunnel, underground excavation, chamber, caisson, raise, shaft, winze or natural entry." The exclusion applies while the underground area is under construction. Once construction is complete, the underground area will be a confined space if it meets the criteria listed in paragraphs (a) to (d) of the definition for confined space in section 9.1.
According to the definition of a confined space in section 9.1 of the Regulation, if an enclosed or partially enclosed space is designed or intended for continuous human occupancy, then it is not a confined space. When identifying confined spaces for the purposes of Part 9, an employer needs to include the following principles in determining whether each space is designed or intended for continuous human occupancy. If a space is designed or intended for continuous human occupancy, it will generally:
Rely in its design on relevant codes as applicable, including the BC Building Code, National Fire Code, BC Electrical Code, BC Plumbing Code, Mechanical Refrigeration Code and municipal by-law requirements
Include installed utility services that anticipate human occupancy e.g. hard-wired lighting rather than portable lamps, plumbed water lines rather than hoses etc.
A space is so small or configured that there is insufficient room for a first aid attendant to provide injury treatment in the space, or for a worker to be prepared for transport.
The exit port is so constructed that a person carrying the device has no alternative but to put it down in order to get through the port or pass it to another person through the port. The transport device needs to be lifted at any time to shoulder height or higher when exiting the space with the injured worker in it. (Such lifting might be needed, for example to get a stretcher over top of a piece of machinery on the way to the exit port, or if the exit port was well above floor level and access on a stairway or ramp was not possible.)
Other emergency response services: Depending on the space, other emergency response scenarios could include services such as fire fighting or controlling hazardous material spills. If emergency response workers in these situations would need to wear an SCBA or other personal protective gear, and the means of entry or exit is so constructed that that any of the gear must be removed when entering or exiting, then the provision of the emergency response will have been complicated by the means of entry and exit. 4. Entering the space Paragraph (d) of the definition for confined space in section 9.1 requires that the area in question be "large enough and so configured that a worker could enter to perform assigned work." A worker should be considered to have entered a confined space when the breathing zone of the worker crosses the plane of the confined space access.
5. High hazard atmosphere The exposure limits in the Table of Exposure Limits for Chemical and Biological Substances (see OHS Guideline G5.48-1) are not used to define the boundary between a moderate and high hazard atmosphere confined space. Section 1.1 of the Regulation defines IDLH atmosphere as "an atmosphere containing a substance at a concentration which is immediately dangerous to life or health (IDLH) because the concentration is greater than that from which one could escape without any escape-impairing symptoms or irreversible health effects, and includes an atmosphere with an unknown concentration with the potential to be immediately dangerous to life or health."
IDLH levels for specific contaminants are available from sources such as Documentation for IDLH Concentrations, NIOSH May 1994, or may be specified on the MSDS for the substance. An atmosphere meeting this definition would be high hazard under section 9.1. However, the definition of high hazard also covers other situations. In determining whether a confined space contains a high hazard atmosphere, consideration should be given to
The definition of low hazard atmosphere includes a reference to a qualified person. Qualified is generally defined in section 1.1 of the Regulation. However, the determination whether an atmosphere is low hazard is part of the hazard assessment required to be done by a qualified person under sections 9.9 and 9.11. Section 9.11 sets out specific requirements for who is a qualified person for this purpose. See also OHS Guideline G9.11.
The definition also refers to "an atmosphere which is shown by pre-entry testing or otherwise known to contain clean respirable air...." Paragraph 9.25(7)(c) states "Pre-entry atmospheric testing is not required in a confined space with a low hazard atmosphere if...prior representative sampling has demonstrated that the atmosphere within the space or group of similar spaces meets the low hazard atmosphere definition." See also OHS Guideline G9.25. This sampling will commonly be the basis for it being "otherwise known" that a space contains clean respirable air.
Section 9.3 states "If a confined space exists at a workplace but no worker entry is required, the employer must ensure that each point of access to the confined space is secured against entry or identified by a sign or other effective means which indicates the nature of the hazard and the prohibition of entry, and that workers are instructed not to enter".
Section 9.4 of the OHS Regulation states The employer must ensure that all confined space hazards are eliminated or minimized and that work is performed in a safe manner .
This may require the employer to take measures in addition to the other requirements of part 9. The employer should consider alternative ways of doing the work that avoid or reduce the need to enter a confined space. For example, increasing the interval time between entries to perform routine maintenance in a confined space may be a way to reduce the overall total time workers must work in the space. New methods may eliminate or substantially reduce the need for a worker to enter a confined space. For example, consider an in-place cleaning system for tanks, such as brewery tanks, that flushes and cleans the tanks automatically. If either of these alternatives is practicable, they should be considered. G9.5 Confined space entry program
Section 9.6 of the OHS Regulation states "The employer must assign overall responsibility for administration of the confined space entry program to a person or persons adequately trained to do so".
Section 9.7(1) of the OHS Regulation states "The employer must assign responsibility for supervision to a person who is adequately trained to supervise the job before any worker enters a confined space".
Paragraph 9.9(2)(b) states that the hazard assessment required under section 9.9(1) must consider a list of specific circumstances as well as "other hazardous conditions". In general, the conditions referred to here represent requirements addressed in other parts of the OHS Regulation. These include, but are not limited to, fall protection, hearing conservation, radiation, heat stress, extreme climactic conditions such as flooding from heavy rains, and lockout of equipment and processes. G9.9-2 Visiting employers
The visiting employer need not repeat the process of identifying and placing signs on confined spaces as required by sections 9.2 and 9.3 if this has already been done by an effective confined space entry program of the resident employer. The visiting employer should, however, inform its workers of the location and nature of any confined spaces that might affect their work and activities. The owner of a workplace, or the employer controlling a workplace, should provide this information. See also section 118 of the Workers Compensation Act and section 20.3 of the OHS Regulation.
(a) certified industrial hygienist (CIH) or registered occupational hygienist (ROH) with experience in confined space entry, (b) certified safety professional (CSP), Canadian registered safety professional (CRSP) or professional engineer (P. Eng.), provided that the holders of these qualifications have experience in the practice of occupational hygiene as it relates to confined space entry, or (c) other combination of education, training and experience acceptable to the Board."
The purpose of this guideline is to provide direction to employers on how to meet their obligations to select qualified persons to create confined space hazard assessments and work procedures. It also provides contact information on some of the accrediting agencies that issue professional certifications referenced in section 9.11. Employer due diligence
Employers are responsible for selecting qualified persons, as defined in s. 9.11 of the Regulation, to undertake confined space hazard assessments and written entry procedures. The employer must exercise due diligence in the selection of the qualified person. This is especially necessary if the person being engaged does not hold one of the certifications or the license credentials specified in section 9.11(2) (a) or (b). While each case must be considered on its merits, reliance by an employer on a person holding a certification or license specified in section 9.11(2) as being a "qualified person" for the purposes of section 9.11 would normally be considered reasonable, however, due diligence in all cases includes a review of the person's experience as well as their accredited credentials. Section 9.11(2)(c) permits persons not certified or licensed to be considered qualified for the purposes of this section. Anyone experienced, knowledgeable and capable of doing the required hazard assessments and writing appropriate safe work procedures may be considered to be a "qualified person." The education, training and experience required to complete a particular confined space entry assessment and to write appropriate procedures will depend on the complexity of each situation and the hazards to be controlled. Factors employers should evaluate in determining whether a person selected to undertake the confined space hazard assessment and entry procedures under 9.11(2)(c) is qualified include:
air monitoring ventilation use of lifeline, harness and lifting equipment
A deficient confined space risk assessment or work procedure may be an indication the person selected was not qualified to do the hazard assessment and/or develop the written confined space entry procedures. In all such situations, whether the person selected purports to be a qualified person under subsection (a), (b) or (c), prevention officers will enquire what steps the employer took to assess the person's qualifications. It should be noted that when evaluating the qualifications of a person who has prepared a hazard assessment and confined space procedures, the officer's primary focus will be the quality of the assessments and procedures rather than the person's credentials. Where prevention officers encounter hazard assessments and work procedures that are deficient and the person selected meets the definition of "qualified person" in s. 9.11 (2) (a) or (b), the employer who engaged the "qualified person" may file a complaint with the accrediting agency. Note that in addition to engaging qualified persons, employers are also responsible for ensuring that the confined space hazard assessment contains the required elements, and that the written confined space entry procedures have been developed based on the hazard assessment (see s. 9.9(2) and s. 9.10).
Among other things, accrediting agencies often maintain web sites with contact information on accredited persons. For example, the Canadian Registration Board of Occupational Hygienists maintains contact information on persons with ROH's, which can be accessed at http://www.crboh.ca/page.cfm?onumber=1. A list of persons with CIHs can be found on the American Board of Industrial Hygiene web site at http://www.abih.org. Lists of persons with CRSPs, which are issued by the Board of Canadian Registered Safety Professionals, are available at http://www.bcrsp.ca
G9.18 Control of harmful substance in adjacent piping Issued April 9, 2008; Editorial Revision to include February 1, 2011 regulatory amendment
Section 9.18 (Control of harmful substance in adjacent piping) of the OHS Regulation ("Regulation") states:
Orifices between spaces: In some configurations there are adjacent spaces with one or more orifices in a common wall between them. Section 9.18 is based on the use of control measures such as blanks, blinds, disconnects, and double block & bleed devices. A wall between two spaces is typically of a width and configuration that the use of such devices is not possible. As such, an orifice in a wall between a confined space and another space is not adjacent piping. Therefore, the blank, disconnect, double block and bleed, and blind requirements do not apply.
This provision specifies three basic options for isolating adjacent piping: disconnection, blanks, and blinds. Disconnection: Disconnecting is defined in section 9.1 of the Regulation as follows:
For example, if a pipe is disconnected, either a length of the pipe at least 10 times its diameter should be removed or the open ends of the disconnected pipe should be moved out of line so that leaks will not bypass the disconnection and continue into the confined space. In any disconnect procedure the requirements of the Regulation related to the protection of workers from contents of the piping must be complied with. Blanking and blinding: Blanks and blinds are defined in section 9.1 of the Regulation as follows:
This provision applies to materials that are not toxic or corrosive, and are harmful only because of pressure, temperature, or quantity. Typically this requirement applies to systems carrying water or steam. Three isolation options are outlined in the Regulation.
Controls meeting the requirements of section 9.18(2): This alternative specifies the options of disconnecting, blanking, blinding, or a double block and bleed system. Isolation per engineering certification (section 9.18(3)(b)): This alternative enables an employer to have a professional engineer certify a means of isolation as making the confined space safe for a worker to carry out the intended work in the confined space. Refer to OHS Guideline G9.18(3)(b) for more details
The use of one or more valves as a means of isolation is not permitted except in certain specified cases for substances that are not volatile liquids, gases, or vapours or are harmful only because of pressure, temperature, or quantity. If a substance is corrosive, toxic, or has poor warning properties, then the use of valves as a means of isolation is not permitted.
Where a double block and bleed system is permitted under section 9.18(2) and 9.18(3)(a)
Application of section 9.18(4) and (5) - Gravity flow sewer systems
G9.18.1 Exemption to restriction on use of valves for isolation Retired on February 1, 2011
G9.18(3)(b) Certification of isolation by a professional engineer Issued February 1, 2011 Regulatory excerpt
Section 9.18(3)(b) of the OHS Regulation ("Regulation") states: (3) Before a worker enters a confined space where adjacent piping contains a substance that is harmful only because of the temperature, pressure or quantity of the substance, the harmful substance must be controlled...
(b) by isolating the adjacent piping in a manner that a professional engineer has certified will make the confined space safe for a worker to carry out the intended work, or...
This guideline provides general information on the application of section 9.18(3)(b) and specific information on two circumstances where an employer might choose for a professional engineer to certify that the adjacent piping is isolated in a manner that makes it safe for a worker to carry out the intended work inside the confined space. Application of section 9.18(3)(b) This section applies to substances that are harmful only because of the temperature, pressure, or quantity of the substance (and are not classified as harmful by virtue of their toxic, irritant, corrosive, or other harmful properties). Section 9.18(3)(b) does not apply if the substance can create a hazard while at the same time providing poor warning of the hazard. The lack of warning that a potential hazard exists is an additional hazard. For instance, this section does not apply to nitrogen or inert gases. Mainly this section will apply to water or steam. WorkSafeBC recognizes that, for these substances, there are circumstances where it is impracticable to isolate the substance by disconnecting, blinding, blanking, or using double block and bleed technology, and this section provides for an alternative manner of isolation.
Engineering certifications specifically need to address worker safety and should typically include consideration of the amount of leakage, age, and maintenance history of the piping components and any other means in place to make the confined space safe for a worker to carry out the intended work. Certifications are expected to be site specific and time limited, and the engineer will need to make the determination of the applicable time period as part of the certification process. A professional engineer may not always have sufficient information about a valve that is to be used to control potential flow into the confined space and may not be able to examine it. In this case, the engineer could consider information such as the age, history, and maintenance records for the adjacent piping system, leakage rates, and measures such as leak control or line pressure reductions that can be accomplished etc. Certifications by engineers under section 9.18(3)(b) will need to be available for review by a WorkSafeBC prevention officer where necessary to assess compliance with the requirements. If a prevention officer has concerns about an engineering certification under this section, the prevention officer should discuss the concerns with the WorkSafeBC Engineering Department (refer to OHS Guideline G1.1).
Two common circumstances where section 9.18(3)(b) applies are public water supply systems (e.g., valve and meter chambers where work may affect the integrity of piping systems passing through the confined space) and dam water passageways. Public water supply systems provide water for domestic uses such as human consumption, food preparation, and cleaning purposes. They also provide water distribution networks for fire suppression, which are typically an integral part of public water supply systems. Note: In some cases, public water will be used downstream for industrial uses, for example in a process industry or a manufacturing facility. Section 9.18(3)(b) does not apply to such industrial systems if chemical additives could be present or the spaces present hazards other than just temperature (e.g., hot or cold), pressure (e.g., force of the flow), or quantity (immersion hazard). The system of isolation may be one or more closed valves, use of inflatable bladders, or some other means of isolation. The professional engineer must certify that the adjacent piping is isolated in a manner that makes it safe for a worker to carry out the intended work. The engineer will need knowledge of the valves or other closure devices as well as the nature of the substance in the adjacent piping. Dam water passageways: At a dam and associated hydroelectric station there may be a number of confined spaces, for example, fuel storage tanks, which are not part of the dam water flow system, and for which this section would not apply. The application of section 9.18(3)(b) is restricted to dam water passageways at the site.
G9.22-1 Alternate measures - Making submissions Issued August 1, 1999; Editorial Revision October 2004; Editorial Revision February 7, 2006; Editorial Revision June 6, 2006; Editorial Revision June 22, 2007; Revised April 9, 2008; Editorial Revision to include February 1, 2011 regulatory amendments
Section 9.22 (Alternative measures of control or isolation of adjacent piping) of the OHS Regulation ("Regulation") states:
Section 9.18 does not apply if
(1) (a)	a measure specified in section 9.18 to control or isolate harmful substances contained in adjacent piping from a confined space is not practicable, and
(2)	All workers affected by measures implemented under subsection (1) must be informed of the measures taken and instructed in any applicable work procedures.
Purpose of guideline	This guideline outlines who an employer should contact at WorkSafeBC to determine if alternate measures under section 9.22 of the Regulation are acceptable, and the types of information to include in the submission. It also provides information on how WorkSafeBC will issue its decisions.
This guideline is the first in a series of guidelines on section 9.22. Additional guidelines (e.g., G9.22-2) provide guidance for developing submissions on alternate measures in specific situations. Further guidelines in this series will be developed as required.
Contacting WorkSafeBC for acceptance of alternate measures
If an employer develops a set of alternate measures for a type of confined space covered by one of the guidelines in the G9.22 series, the employer should contact the regional office of WorkSafeBC to determine acceptability. The applicant may be an employer who owns or operates the confined space, or may be a contractor doing work on or in it.
If an employer wants to implement alternate measures in circumstances that are not covered by one of the guidelines in the G9.22 series, the employer will need to contact the Regulatory Practices Department of the Worker and Employer Services Division of WorkSafeBC.
A submission may cover a single confined space or a group of confined spaces that share similar characteristics. It should focus on the issues associated with isolation of the confined space, and cover the elements outlined below.
A brief description of the space, or the group of confined spaces with similar characteristics for which the submission is made
Why isolation using the measures specified in section 9.18 of the Regulation are not practicable
Contact information for the person who administers the confined space program, and for the qualified person who conducted the hazard assessment and prepared the alternate measures
A description of the hazards to be addressed by the alternate measures
The alternate measures that will be used to address the hazards, and how workers will receive protection from the hazards through use of the measures
How workers who are required to use the proposed measures will be informed of the measures taken and instructed in the applicable work procedures, as required by section 9.22(2)
How use of the alternate measures will be supervised
The time period for which the alternate measures will be needed
The submission should also include information from the joint OHS committee, or worker health and safety representative, as applicable, indicating their comments on the proposal, or other information that indicates the affected party has been consulted on the alternate measures. (Section 9.11(1)(b) of the Regulation requires consultation with these parties on confined space hazard assessments and written procedures.)
Hazards associated with the isolation of the confined space typically involve those arising from fluids such as liquids, gases, and vapours, and other materials such as slurries, dusts, and powders that could flow into the space. The submission should address matters such as the following, where applicable:
Other hazards associated with the flow of material into the space, such as slips and falls, electric shock, reduced visibility, moving machinery or equipment
Any potential for work being done in the space to contribute to the likelihood of material flow into it
Information needed for Element #5 - alternate measures to be used
The measures chosen should be based on careful consideration of the hazards, and provide the most effective means of dealing with them. The submission should cover matters such as the following, where applicable: Engineered means of controlling flow, and related procedures
Ventilation, where applicable, to ensure that hazardous gases, vapours, and other air contaminants from adjacent piping are kept below exposure limits, and no circumstances immediately dangerous to life and health, including oxygen deficiency, could occur
Atmospheric testing, where applicable, if air contaminants could enter the space from adjacent piping while the space is occupied
Monitoring of flow rates of materials and/or levels in the confined space
Decision made by a WorkSafeBC prevention officer: Where the circumstances of the confined space(s) for which the application is made are addressed by a guideline in the G9.22 series, a prevention officer responsible for the firm may make the decision on behalf of WorkSafeBC. As needed, the prevention officer may contact Engineering Department or Regulatory Practices Department for advice. The prevention officer will record his/her decision, including the terms of the decision and time period for which it is issued, in the text of an inspection report for the firm. The prevention officer will provide a copy to the employer, who must post a copy at the worksite as required by the Regulation. Once the decision is made, the prevention officer will forward the request and decision to the Regulatory Practices Department.
Decision made by the Regulatory Practices Department: Where an application for acceptance involves a situation not covered by a guideline in the G9.22 series, the Regulatory Practices Department will issue the decision to the applicant using the standard format for Acceptance Request (AR) decisions. The applicant will post a copy of the acceptance and ensure copies are distributed to workplace parties, as required by the terms of the acceptance. Copies will be sent to the WorkSafeBC regional prevention manager and prevention officer responsible for the firm, and to others who contributed information to the decision-making process.
Note: All decisions will focus on the issue of alternate measures for isolation of the confined space under section 9.22 of the Regulation. They will not, as a rule, address the issue of compliance with other provisions of the Regulation and must not be taken as an endorsement of the overall confined space program for the site.
G9.22-2 Alternate measures for confined spaces - Municipal sewage systems Issued April 9, 2008; Editorial Revision June 10, 2010; Editorial Revision to include February 1, 2011 regulatory amendment; Revised September 21, 2011
This guideline outlines some issues to consider when developing alternate measures for municipal storm and sanitary sewage systems under section 9.22(1), where the isolation of adjacent piping under section 9.18 is not practicable.
Among other things, the guideline discusses
How to make submissions on alternate measures to WorkSafeBC for circumstances covered by the guideline
Matters considered by WorkSafeBC prevention officers when making a decision in the circumstances covered by the guideline
General hazard and control issues that can arise throughout sewage systems
Information specific to three parts of sewage systems: piping, pumping stations and treatment plants
This guideline should be used in conjunction with OHS Guideline G9.22-1, which outlines elements that need to be addressed in any submissions to WorkSafeBC. Also, note that OHS Guideline G9.18, which provides interpretive information on terminology used with isolation procedures, may be of assistance.
NB: None of the information in this guideline is to be used as a substitute for the conduct of a site-specific hazard assessment and development of associated safe procedures by a qualified person, as required under sections 9.9 - 9.11 of the Regulation.
A submission may cover a single confined space or a group of confined spaces that share similar characteristics. After developing proposed alternate measures for a space or spaces in a municipal sewage system, the employer will need to contact the local regional office of WorkSafeBC to have the measures reviewed by a prevention officer for acceptability.
The focus of any submission on alternate measures should be on the fluids (including liquids, gases, and vapours), and other flowable materials that would be controlled by the isolation measures listed under section 9.18.
For details on what information should be included in the submission to a prevention officer with regards to alternate measures for municipal storm and sanitary sewage systems, please refer to OHS Guideline G9.22-1.
For other land-based sewage systems, such as industrial systems which are not connected to municipal sewers, submissions should be made to the Regulatory Practices Department of the Worker and Employer Services Division of WorkSafeBC in Richmond.
Acceptance by a prevention officer As stated above, after developing proposed alternate measures for a confined space or spaces in a municipal sewage system, the employer will need to contact the local regional office of WorkSafeBC to have the measures reviewed by a prevention officer for acceptability.
When an application for acceptance is made under section 9.22(1) of the Regulation, the prevention officer may request additional information from the employer. For instance, the prevention officer may ask for a written statement justifying why the measures specified in section 9.18 of the Regulation are not practicable. The prevention officer may also request copies of the confined space procedures and the name of the qualified person involved in the preparation of the procedures. The prevention officer may also request any other information that is necessary for making a decision under section 9.22(1) of the Regulation. If the alternate measures are accepted, the prevention officer's decision will state that the measures set out in the application package must be followed. It may also include additional terms. Some of the matters that are covered by the additional terms may include:
Monitoring of bladder pressure devices
Measurement and documentation of flow conditions
Implementation (and testing) of the means of communicating changing conditions to workers in the confined space Emergency response and rescue plan drills
Safe means of flushing and cleaning the space in case of contamination
When making a decision, the prevention officer may consider whether the acceptance will apply to one firm or to multiple firms depending on the specific circumstances.
General comments on hazards and alternate control measures in sewage systems 1. Hazards
For any sewage system, storm or sanitary, hazards that can be encountered include engulfment or immersion, exposure to toxic gases or vapours, oxygen deficiency, flammable atmospheres, slipping or tripping hazards, and electrical hazards where energized conductors or electrical equipment are exposed to damp conditions or liquid contact.
2. Alternate control measures
Various aspects of alternate control measures are discussed below, from fluid control to instruction and training.
Examples of fluid control techniques are
Performing work when events such as tides ensure that the fluid level does not present a hazard
If devices that control the fluid flow are capable of being locked out then the requirements of Part 10 (De-energization and lockout) of the Regulation apply.
The analysis of valves as a control measure should assume that all valves leak. However, there is no expectation that a properly installed and maintained valve will fail catastrophically if no work is being performed on it.
Leakage of liquid and pumping: It is recognized that systems will often permit some leakage, and in that event, a means of pumping out the fluid may be necessary. A means of monitoring leakage coupled with procedures for evacuation in the event leakage rates or fluid levels exceed safety criteria is often a necessary feature of the safety system. Liquid level alarms or visual checks may be required to monitor liquid levels. It may be possible to set up a leakage check system from a central control location using camera monitors or other means.
Ventilation must be adequate, and be provided in conformity with the requirements in Part 9 (Confined spaces) of the Regulation.
Personal protective equipment: Workers must be supplied with and use appropriate personal protective equipment as required by the Regulation to protect against hazards that cannot be eliminated.
Evacuation planning: Where there is a danger from the uncontrolled entry of liquid into the confined space, the time required to evacuate workers from the confined space needs to be shorter than the minimum possible time it would take fluid entering the confined space to create a condition that would impede exit from it. In general, the time is calculated using the maximum possible flow from the pipes that could be created by the failure of any single system element, and the relationship of that flow to the floor area of the space. The time required for evacuation should make allowance for possible problems during evacuation. The number, location, and types of exits are relevant in determining the evacuation time. Means of access and egress should be made as convenient as possible.
It is recognized that in some cases catastrophic failure of the control system could lead to immediate danger to workers from fluid flow. For that reason isolation measures need to provide a high level of assurance that such circumstances will not occur. Evacuation measures need to be designed to minimize the time needed to exit, and rescue plans must be in place
Evacuation times in the event of development of harmful atmospheres may be more difficult to predict, and steps must be taken to ensure that personal protective equipment and rescue measures are up to the task. Depending on the potential exposure, workers in the confined space may be required to be permanently attached to a lifeline.
Instruction and training: All workers affected by alternate measures must be informed of the measures taken and instructed in any applicable work procedures, including emergency measures. Workers also need to be informed of any residual hazards not fully controlled by other measures.
Some considerations are provided in the remainder of this guideline for three typical parts of sewage systems: piping, pumping stations and sewage treatment plants.
Specific comments on piping, pumping stations, and treatment plants
When a worker enters a sewage pipe, the pipe itself is the confined space, not "adjacent piping" from which the space must be isolated as required by section 9.18. However, the feeder pipes that discharge into the pipe that is entered can be considered to be adjacent piping.
Often in such cases it may be impracticable to isolate the adjacent piping. In some cases partial or complete isolation may be possible with temporary dams, inflatable bladders, or other means such as rerouting of fluid flow.
However, in most cases alternate measures to ensure worker safety will involve a set of occupational hygiene and safety precautions other than or in addition to isolation.
2. Sewage pumping stations For pumping stations that are confined spaces the adjacent piping will typically be the sewer lines that feed into a reservoir or sump and the pipes used to discharge the sewage. There may also be drains that are arranged so that the contents of the drain could enter a sump and merge with the general sewage flow. Gases must be considered as well as liquids. Various means of controlling fluid flow may be possible. Given the proximity to a point of access, and the limited space involved, it should always be possible to provide effective ventilation into a pumping station.
The timing of events must also be considered in the hazard analysis. For instance the level and composition of off-gassing may depend on how long it has been since a channel or pipe has been emptied of residue. It may also be affected by the extent of liquid agitation and the surface area in contact with the atmosphere in partially filled pipes.
3. Sewage treatment plants Many of the hazards from fluid flow in sewage treatment plants are similar to those encountered elsewhere in sewage systems. Treatment plants offer certain advantages in terms of hazard control given that work activities occur at fixed sites and often above ground. The design of the system at the site may help ensure that the need for alternate measures is minimized.
A means of fluid control that is possible in some circumstances is to channel fluid flow around the space in which worker entry is required. Alternate fluid control measures that can be used include sealing devices that are installed through holes drilled in the side of pipes and inflatable bladders. In such cases ensure that the manufacturer's instructions and other necessary safe procedures are followed.
Section 9.24 of the OHS Regulation states "Before a worker enters a confined space, pre-entry testing and inspection must be conducted to verify that the required precautions have been effective at controlling the identified hazards and that it is safe for a worker to enter".
In addition, it is necessary to inspect before entry to ensure that all required controls are in place. These are similar to requirements for supervisor responsibility stated in section 9.7(2). G9.25 Testing the atmosphere
Section 9.25(4) of the OHS Regulation states "While a worker is inside a confined space with a moderate or high hazard atmosphere, additional testing must be conducted as necessary to ensure the worker's continuing safety".
Section 9.25(5) states "Whenever practicable, continuous monitoring of the atmosphere must be done".
"Practicable" is defined in section 1.1 of the OHS Regulation as meaning "that which is reasonably capable of being done". In determining what is "practicable", the relevant factors include: the availability in the marketplace of continuous monitoring devices,
Section 9.26(4) of the OHS Regulation states "Test results, other than continuous monitoring results, must be posted without delay at all points of entry to the confined space".
Section 9.26(2) of the OHS Regulation ("Regulation") states: Each confined space test must be carried out by a qualified person who has training and experience to calibrate, operate and monitor testing equipment and interpret readings from the testing equipment.
Under section 4.3(2) of the Regulation, employers must ensure that the calibration of confined space testing equipment is done in accordance with the manufacturer's instructions or the instructions of a professional engineer.
When atmospheric testing is performed in a confined space as required under section 9.25, section 9.26(2) specifies that it be performed by a qualified person who has training and experience to calibrate the equipment. Calibration of testing equipment is a rigorous process and may require laboratory equipment or specialized procedures available only to the manufacturer or manufacturer's representative. The Regulation does not require that the qualified person identified in section 9.26(2) perform laboratory or factory calibration of the equipment. However, the qualified person (tester) needs to understand the calibration process in order to understand instrument setup and performance. The manufacturer's instructions will usually also specify more frequent field calibrations and calibration checks (bump tests) than a periodic laboratory or factory calibration. In this case, the qualified person must be trained to perform this field calibration or calibration check. Back to Top
Section 9.27(1) of the OHS Regulation states "When practicable, the employer must ensure that a confined space to be entered contains clean respirable air". Section 9.27(2) states "If a confined space is known, or shown by pre-entry testing to contain other than clean respirable air, the hazard must be controlled by cleaning, purging or venting the space and the atmosphere must be retested before a worker enters the space".
More than one cleaning, purging or venting may be required to achieve a confined space with clean respirable air. It depends on what is practicable and reasonable in the circumstances. If continued cleaning, purging or venting will further the objective of having a clean respirable atmosphere, these processes should be repeated. If continuing these processes will not effectively improve the residual atmospheric quality, then the employer may proceed with entry in accordance with section 9.28 of the OHS Regulation. G9.29 Notifying WorkSafeBC about inerting a confined space
Issued August 1, 1999; Revised May 9, 2006; Editorial Revision to include February 1, 2011 regulatory amendment
Section 9.29 (Inerting) of the OHS Regulation ("Regulation") states:
(2) The employer must follow any additional precautions that are prescribed by the BoardBoard after review of the notification.
This guideline provides information for employers on how to notify WorkSafeBC prior to inerting a confined space, and the types of information to include in the submission. It also provides information to WorkSafeBC prevention officers to assist with reviewing applications. How to notify WorkSafeBC
Information can be sent by post, fax, or by e-mail. However, regardless of the means of communication, the written communication must be received by WorkSafeBC at least seven calendar days before planned entry. It is not sufficient to call WorkSafeBC seven days or more before entry and then submit the written request in less than the required time. The request should be sent to the nearest WorkSafeBC office, to the attention of the Prevention Regional Manager, or to the Occupational Hygiene Officer responsible for the worksite where the entry will occur. Notifications often arise from refining and fuel manufacturing operations in the oil and gas sector. Typically such operations are found in Northeast or Northwest B.C., or in the Lower Mainland. For these locales, inspectional programs are handled, respectively, from the Prince George, Terrace and the Burnaby/Coquitlam offices of WorkSafeBC.
Information on how to contact offices of WorkSafeBC is found on the web site at www. worksafebc.com. Click on the "Contact Us" button on the home page. Or alternatively, the information is available by calling the Prevention Information Line at 604-276-3100, or toll free in B.C. at 1-888-621-7233. Preparing the submission
While section 9.29 of the Regulation deals with requirements specific to inerting, other requirements of Part 9 (Confined spaces) also apply. Of central concern is that the necessary hazard assessment has been done and associated work procedures developed, as required by sections 9.9 to 9.11. Under these provisions the hazard assessment and work procedures must be prepared by a qualified person(s) and, as applicable, the joint occupational health and safety (OHS) committee or worker OHS representative must be consulted. The work associated with inerting is often highly specialized, and may involve the services of a contractor. Where a prime contractor or owner arranges for a contractor to conduct the work, then the contractor's joint OHS committee or worker OHS representative will need to be consulted. Where workers of the prime contractor will be engaged in any of the work associated with the confined space, for example, in preparation of the space, work in it or in an emergency rescue, then consultation with the prime contractor/owner's joint OHS committee or worker OHS representative will also be needed. To permit proper assessment by WorkSafeBC, the submission will need to include the following:
The written hazard assessment of the confined space to be inerted. The assessment, which is key to developing safe work procedures, will address the factors outlined in section 9.9 of the Regulation, including any factors related to inerting, such as the presence of any pyrophoric (spontaneously flammable), oxidizing, flammable or other reactive materials, and any sources of ignition.
precautions for high hazard atmospheres a supplied-air respirator control of ignition sources the necessity that the inert atmosphere will be in place for the entire time that workers are inside the confined space
Material safety data sheet(s) or hazardous waste profile sheet(s) for any waste material to be removed from the space. Reviewing the submission
The assigned prevention officer will be responsible for reviewing the application and making a determination of any concerns or issues with the proposed procedures to be addressed by the applicant. Precautionary information should be entered into inspection text on an Inspection Report and communicated to the employer prior to entry. Where work is being done by a contractor, both the prime contractor and contracted employer will need to be advised. To assist with the review, the prevention officer may wish to examine previous decisions related to inerting confined spaces, or consult with persons who have been involved with such decisions. This may include the Occupational Hygiene Variance Coordinator or Senior Occupational Hygienist, the Senior Prevention Adviser or, as applicable, other prevention officers and the Regional Manager. Consultation may be particularly appropriate in circumstances such as reviewing procedures for types of spaces not previously considered by WorkSafeBC.
If the applicant is a visiting contractor, it may be necessary for the contractor to do a final hazard assessment after arrival on site. It is expected in such cases that the assessment process will ensure that all significant hazards are addressed in the submission to WorkSafeBC, and that a final hazard assessment would only be for the purposes of fine tuning work procedures on minor issues. The hazard assessment and work procedures submitted to WorkSafeBC should be as specific as possible to the conditions on the site where the work will be done. For example, if the contractor had previously done inerting work in a confined space, then the assessment and procedures should, at minimum, be based on the specific circumstances of that previous work, coupled with any adjustments arising from additional information received from the prime contractor or owner prior to the present job. Any final minor adjustments to the hazard assessment and procedures will be done by a qualified person in consultation with workplace parties, as required by section 9.11. The prevention officer may, in these or other circumstances, attend the site prior to the confined space being inerted. Copy to Regulatory Practices
Once the prevention officer's review is complete, materials will be entered into a firm file following normal procedures. A copy of the submission, any additional relevant materials, and the prevention officer's determination regarding the need for further precautions will also be forwarded to the Regulatory Practices Department of WorkSafeBC. Back to Top
Section 9.39 of the OHS Regulation requires the notification of rescue persons before workers enter a confined space. Section 9.39(3) states "If more than one confined space is to be entered at the same time, notification of rescue personnel to be on alert status at the commencement of work is adequate".
Examples of industries that may involve several confined space entries at the same time are petroleum refineries, pulp mills, tank and rail car cleaning operations and bulk storage facilities. G9.41 Rescue procedures
Section 9.41(3) of the OHS Regulation states "A rescue worker must not enter a confined space unless there is at least one additional worker located outside to render assistance".
Paragraph 9.36(e) requires that in a high hazard atmosphere confined space the stand-by worker must be "equipped and capable of immediately effecting rescue using lifting equipment if required, or otherwise performing the duties of rescue persons". Wherever possible, rescue procedures and plans should rely on rescue of workers in a manner that does not require additional personnel to be placed at risk. For example, rescue from outside the space using lifting devices, and the stand-by worker as the rescue worker, puts no rescue workers at risk. In addition, rescue without entry would not necessarily require an additional rescue worker to render assistance under section 9.41(3). The means of supplying rescue services are part of the hazard assessment under section 9.9 and covered by the written procedures under sections 9.5 and 9.10.
Section 9.42(4) of the OHS Regulation states "The use of a lifeline is not required if the risk assessment identifies obstructions or other conditions that make its use impractical or unsafe". "Risk assessment" refers to the "hazard assessment" done under section 9.9.
Section 9.47 states "Workers entering a confined space which contains a high hazard atmosphere must carry on their person or have within arm's reach an emergency escape respirator sufficient to permit them to leave the confined space without assistance".
The selection and use of appropriate escape respirators for high hazard atmosphere confined spaces must be in accordance to the requirements of part 8 of the OHS Regulation, particularly section 8.36.
When practicable, torches and hoses used for welding, brazing or cutting must be removed from a confined space when not in use and when the confined space is vacated. A "Note" is included under section 9.49. It states:
It may be impracticable to remove hoses for some short duration breaks of 60 minutes or less, particularly where the confined space is large or where the removal of hoses may create some risks to workers, for example, when hoses are removed from scaffolding. If removal is impracticable, alternate measures must be adopted under sections 9.4 and 9.5. The preferred method in most cases is to disconnect at source with safe venting procedures together with procedures to ensure no inadvertent reconnection while workers are on the break or, if this is not practicable, closing and putting a tag on connections located outside the confined space. Other applicable requirements in Part 9 must also be followed including those on ventilation, standby persons and retesting prior to re-entry. For further information, see the OHS Guideline on section 9.49 on the Board's Internet site. The intent of section 9.49 is to minimize the possibility of oxygen and/or fuel gas accumulating in the confined space due to leaks or improperly closed valves. Gas can accumulate rapidly in a confined space and present a high risk of fire or explosion when workers return to the space to resume work. An action such as lighting a torch could result in a catastrophic explosion and fire. Hence, when using an oxy-fuel process in a confined space, the priority is to remove the hose and torch from the confined space upon completion of the work or whenever the worker using the equipment leaves the confined space.
Due to the lay-out, size, and complexity of some confined spaces and the number and lengths of oxy-fuel hoses involved, removal of torches and hoses is not always practicable for short duration breaks (such as for coffee or lunch; typically a maximum of 60 minutes). Examples of confined spaces where removal may be impracticable include a pulp mill recovery boiler and a workspace inside the hull of a large ship berthed for repairs in a shipyard. For the latter, oxy-fuel hoses are typically fed from the dock (the usual location of the regulator/manifold), over the sides of the ship, along the deck, and extended down into the ship, to the workspace. Depending on the work required on a large vessel, many (5 - 15) oxy-fuel hoses may be required, each extending up to 45 metres (150 feet) in length.
Where it is not practicable for a worker to remove an oxy-fuel hose and torch from a confined space when taking a short break, the following protocol is acceptable, when it forms part of a confined space entry program (see section 9.5 of the OHS Regulation).
http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=10337