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Part 9 Confined Spaces
Lockout and Isolation
9.17 Lockout
Before a worker enters a confined space, any material conveyance equipment that transports material to or from the space must be free of material if the material could present a hazard.
[Enacted by B.C. Reg. 312/2003, effective October 29, 2003.]
| * See also Part 10 (De-energization and Lockout) of the OHS Regulation. |
9.18 Isolation
(1) Except as provided in subsection (2), before a worker enters a confined space, adjacent piping which contains or has contained a harmful substance must be controlled by
(a) disconnecting, blanking or blinding, or equivalent engineered system, or
(b) if the adjacent piping contains a harmful substance that is not a gas or a vapour, nor a liquid of sufficient volatility to produce a hazardous concentration of an air contaminant in the discharge of the piping, a double block and bleed system.
(2) If adjacent piping contains or has contained a substance that is hazardous only because of its pressure, temperature or quantity, before a worker enters the space, the pressure must be controlled
(a) to meet the requirements of subsection (1),
(b) provided there is no other pressure source or head pressure, by de-energizing and locking out the pressure source and depressurizing the line, or
(c) by other effective means.
(3) Repealed [B.C. Reg. 243/2006, effective January 1, 2007.]
(4) Except when used in an acceptable double block and bleed system, the closing of one or more valves in a line is not an acceptable means of isolation.
(5) Isolation of a confined space from gases found in a gravity-flow municipal or domestic sanitary or storm sewer system may be accomplished by a p-trap, provided that
(a) the integrity of the trap is ensured immediately upon entry, and
(b) the atmosphere is continuously monitored and shown to contain clean respirable air.
[Amended by B.C. Reg. 243/2006, effective January 1, 2007.]
9.18.1 Exemptions
(1) In this section:
"public water supply system" includes valve and meter chambers and pressure reducing stations;
"dam water passageway" includes conduits, pipes, penstocks, power generating chambers, valves and related structures located within storage, diversion or other dams.
(2) Section 9.18 (4) does not apply to water piping that is part of a public water supply system if the piping and associated equipment is designed, constructed, maintained and certified by a professional engineer to American Water Works Association standards.
(3) Section 9.18 (4) does not apply to a dam water passageway if the structures of the passageway, including a gate valve or other flow control device, are certified by a professional engineer as being safe for workers to enter to perform the intended work.
[Enacted by B.C. Reg. 320/2007, effective February 1, 2008.]
9.19 Isolation points
(1) The employer must keep a record which identifies the location of every isolation point.
(2) Every isolation point must be visually checked or otherwise verified to ensure that the confined space is effectively isolated before a worker enters the space.
9.20 Blanks and blinds
(1) Unless certified by a professional engineer to provide adequate safety for the particular conditions of anticipated pressure, temperature and service, a blank or blind must be manufactured in accordance with the specifications of one of the following standards:
(a) ANSI Standard API 590-1985, Steel Line Blanks;
(b) ANSI Standard ASME/ANSI B16.5-1988, Pipe Flanges and Flanged Fittings;
(c) ANSI Standard ASME B31.1-1992, Power Piping;
(d) ANSI Standard ASME B31.3-1993, Chemical Plant and Petroleum Refinery Piping.
(2) If a blank or blind is certified by a professional engineer, the employer must keep a record of its certification, location and conditions of service.
(3) If required, an allowance for corrosion must be made in the design of a blank or a blind.
(4) A blank or blind must be stamped with or otherwise indicate its pressure rating.
(5) If a line is to be opened for disconnection or to insert a blank or a blind, written safe work procedures must be prepared and followed to prevent hazardous exposure of workers to its contents.
(6) Visual indication that a blank or blind has been installed must be provided at the point of installation.
(7) If required to prevent leakage, gaskets must be installed on the pressure side of blanks or blinds and flanges must be tightened to make the blanks or blinds effective.
(8) If threaded lines are used, threaded plugs or caps must be used to blind the lines.
[Amended by B.C. Reg. 312/2003, effective October 29, 2003.]
| * See also section 4.4 of the OHS Regulation. |
9.21 Double block and bleed
If a double block and bleed isolation system is used
(a) the diameter of the bleed line must be no less than the diameter of the line being isolated, unless certified by a professional engineer,
(b) the bleed for a liquid system must be at a lower elevation than the block valves,
(c) all valves must be locked out in their proper open or closed position,
(d) the downstream block valve must be checked to ensure that it is capable of safely withstanding the line pressure,
(e) the bleed must be checked to ensure that it remains clear of obstructions while the confined space is occupied, either by continuous automatic monitoring or by manually checking within 20 minutes before worker entry, or before re-entry after the confined space has been vacated for more than 20 minutes, and
(f) in the event of discharge from the bleed line resulting from failure of the upstream block valve, all workers must immediately exit the confined space and the space must be effectively re-isolated before a worker enters the space.
9.22 Alternate procedures
(1) If isolation using the measures specified in section 9.18 is not practicable, the employer may implement alternate measures acceptable to the Board.
(2) All workers affected by measures implemented under subsection (1) must be informed of the measures taken and instructed in any applicable work procedures.
[Amended by B.C. Reg. 243/2006, effective January 1, 2007.]
9.23 Discharge area
The area of potential discharge from a disconnected line or from the bleed of a double block and bleed isolation system must be controlled to ensure that any accidental discharge will not present a hazard to workers.
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