WorkSafe BC (British Columbia) is proposing some thoughtful improvements to its Part 6, Substance Specific Requirements, sections 6.116 to 6.132 — Toxic Process Gases. The hazardous materials that this effort focuses on are:
- ammonia 7664-41-7
- chlorine 7782-50-5
- chlorine dioxide 10049-04-4
- ethylene oxide 75-21-8
- ozone 10028-15-6
- sulphur dioxide 7446-09-5
This standard reads much like OSHA’s PSM standard; however, this standard has a bit more specific requirements. Some Highlights of the proposed standard:
The proposed revisions require the employer to do either
(a) eliminate toxic process gases from the workplace, or
(b) if elimination is not practicable, comply with sections 6.118 to 6.132.
If the employer does not eliminate toxic process gases from the workplace, the employer must do the following:
(a) minimize the quantity of toxic process gases present in the workplace;
(b) in accordance with section 6.119, prepare a written assessment respecting
(i) each TPG system used in the workplace, and
(ii) each TPG system that the employer intends to use in the workplace;
(c) prevent the inadvertent or uncontrolled release of toxic process gases;
(d) prevent the exposure of persons to toxic process gases;
(e) minimize the health and safety consequences to persons if a toxic process gas is released or if a person is exposed to a toxic process gas.
The employer must prepare a written assessment respecting
(a) each TPG system used in the workplace, and
(b) each TPG system that the employer intends to use in the workplace.
An assessment under this section must, at a minimum:
(a) describe each known and each reasonably foreseeable circumstance that may result in the release of a toxic process gas, the exposure of a person to a toxic process gas, or both, and
(b) for each circumstance referred to in paragraph (a), set out an assessment of:
(i) the potential health and safety consequences that may arise in that circumstance,
(ii) the ways in which those health and safety consequences can be prevented,
(iii) the ways in which the released amount of a toxic process gas can be minimized, should a release occur, and (iv) the ways in which the exposure of a person to a toxic process gas can be minimized, should a release occur.
The employer must review and, if necessary, update an assessment under this section as follows:
(a) at regularly scheduled intervals that are determined in consultation with the persons referred to in section 6.120;
(b) any time the employer becomes aware of information indicating that the current assessment is inadequate or incomplete;
(c) any time the employer becomes aware of information indicating that existing control measures are no longer or may no longer be reliable or effective;
(d) any time a TPG system or a work practice associated with a TPG system is changed or modified, and the change or modification may affect the safe use or operation of the TPG system.
The employer must, when preparing, reviewing or updating an assessment under this section, consider the following:
(a) the properties of each toxic process gas that is or will be present in the workplace;
(b) each location in the workplace
(i) at which a toxic process gas is or will be present,
(ii) at which a toxic process gas may be released, and
(iii) to which a toxic process gas may migrate;
(c) the specifications, operating conditions and, if applicable, instructions and procedures associated with each TPG system, including the design limits and the safe operating limits of each TPG system;
(d) the manner in which the following interact with one another:
(i) what, where and how work is conducted in the workplace;
(ii) who is conducting the work;
(iii) how workplace operations are managed;
(e) the reliability and effectiveness of existing and planned control measures;
(f) factors that may lead to degradation of the components of each TPG system, including but not limited to the effects of aging, corrosion, weathering and physical damage;
(g) factors that may lead to a malfunction of the components of each TPG system; (h) the expected end of the service life of the components of each TPG system;
(i) any other relevant factors.
The employer must develop and implement effective control measures that
(a) minimize the amount of a toxic process gas that can be released from a TPG system during an inadvertent or uncontrolled release, and
(b) are promptly activated to stop any further release, should one occur.
The employer must ensure that the control measures described above:
(a) can be safely and reliably activated either automatically or manually from a safe location, and
(b) deliver a prompt alert to persons whose response to the activation of the control measures is necessary.
The employer must promptly conduct an investigation whenever there is, or may be, an unusual or unsafe condition in respect of a TPG system. The employer must, after undertaking an investigation, ensure that all necessary corrective actions are promptly taken to remedy any unusual or unsafe conditions that are found to exist. The employer must, in relation to an investigation and any corrective actions taken,
(a) keep and make readily available in the workplace records respecting the investigation and corrective actions, and
(b) ensure that the following persons are made aware of the findings of the investigation and of any corrective actions taken:
(i) the joint committee or the worker health and safety representative;
(ii) workers who were or may have been affected by the unusual or unsafe condition in relation to which the investigation was carried out;
(iii) workers or other persons who were using or were carrying out work on the TPG system under the unusual or unsafe condition in relation to which the investigation was carried out.
Requirements respecting enclosures
The employer must situate equipment and machinery in one or more enclosures that comply with this section if the equipment or the machinery is capable of releasing a toxic process gas at a concentration that could endanger a person.
An enclosure must meet the following requirements:
(a) the enclosure
(i) prevents the inadvertent or uncontrolled escape of toxic process gases from the enclosure whenever toxic process gases are released into the enclosure’s atmosphere, and
(ii) is capable of safely eliminating or removing toxic process gases from the enclosure’s atmosphere;
(b) the enclosure is equipped with a ventilation system that
(i) is capable of exhausting air from the enclosure in a manner that does not endanger any persons outside of the enclosure,
(ii) provides an effective flow of air into the enclosure,
(iii) is a standalone system that is fully separated from other ventilation systems, and
(iv) features an effective means to monitor the ventilation system for adequate air flow;
(c) the enclosure and its associated ventilation system is vapourproof and resistant to corrosion by the toxic process gases handled or stored by the equipment or machinery situated in the enclosure;
(d) there is a safe way to enter into and exit from the enclosure;
(e) the enclosure is a restricted work area into which only authorized persons may enter;
(f) there is a safe and effective way for a person to check or test conditions inside the enclosure prior to entry.
An enclosure must meet each of the following additional requirements unless, in the applicable circumstances, meeting the respective requirement would not be practicable:
(a) the enclosure must have exhaust fans that are located on the outside of the enclosure;
(b) the exhaust fans under paragraph (a) must allow ductwork to be maintained under a negative pressure differential if the ductwork is located within an indoor work area that a person may occupy.
The employer must, outside each entry point to an enclosure, post a sign that clearly identifies
(a) applicable hazards and entry restrictions respecting the enclosure, and
(b) the precautions that a person must take in order to enter safely.
Respirators and when they must be worn
In this section, “work task” includes, but is not limited to, the following:
(a) the changing of a cylinder or other container that contains a toxic process gas; (b) transferring a toxic process gas to or from a TPG system;
(c) the purging or draining of a line or system;
(d) leak detection and repair;
(e) a response to an emergency involving a TPG system or a toxic process gas.
The employer must ensure that a person
(a) is wearing an appropriate respirator if
(i) a work task that is being conducted or that is about to begin may result in the release of a toxic process gas, and
(ii) the release of the toxic process gas may endanger the health or safety of the person, and (b) continues to wear the respirator for as long as the conditions described in paragraph (a) exist.
The employer must ensure that a person who intends to enter an enclosure is wearing an appropriate respirator before entering the enclosure and continues to wear the respirator while in the enclosure if
(a) a hazardous atmospheric condition involving a toxic process gas is present or may develop in the enclosure, or
(b) a work task that is being conducted or that is about to begin may result in the release of a toxic process gas in the enclosure.
The employer must ensure that a person who enters and is present in an enclosure in circumstances other than those described in subsection (3) either
(a) wears an appropriate respirator, or
(b) has an appropriate respirator within arm’s reach at all times.
Continuous monitoring systems
In this section: “continuous monitoring system” means a fixed or portable system that
(a) detects, monitors and provides current information about the airborne concentration of a toxic process gas,
(b) promptly and effectively notifies persons of an unusual or unsafe condition by means of an alert, alarm or other warning system, and
(c) is capable of activating other control measures when appropriate;
For certainty, a portable continuous monitoring system may consist of one or more hand-held or wearable devices.
The employer must install or provide one or more continuous monitoring systems in accordance with the requirements of this section, unless subsection (4) applies.
If it is not possible to detect a specific toxic process gas because no continuous monitoring system is capable of detecting that toxic process gas, the provisions of this section do not apply in relation to the toxic process gas.
The employer must install a fixed continuous monitoring system in each of the following areas, unless doing so would not be practicable:
(a) an enclosure;
(b) an indoor area in which equipment or machinery is capable of releasing a toxic process gas at a concentration that may endanger a person;
(c) any other area in which a toxic process gas may be released at a concentration that may endanger a person.
The employer must ensure that an adequate number of portable continuous monitoring systems are in use in the following circumstances:
(a) a person is
(i) working on any portion of a TPG system,
(ii) responding to a release of a toxic process gas, or
(iii) required to enter or occupy an area in which a toxic process gas is or may be present;
(b) having regard to the results of the applicable assessment prepared under section 6.119, a person may be at an elevated risk of exposure to a toxic process gas while carrying out a specific work task, and a person is planning to carry out, or is carrying out, that work task.
The employer must ensure that each continuous monitoring system
(a) incorporates alarm set points that are established and implemented in consultation with a qualified person,
(b) incorporates alarms that promptly and effectively provide a warning to appropriate persons, and
(c) functions correctly at all times.
The employer must, in respect of each continuous monitoring system, carry out the following tests in accordance with the manufacturer’s specifications and instructions:
(a) testing of each sensor that is a component of the continuous monitoring system in order to verify that the sensor can accurately and precisely detect the applicable toxic process gas;
(b) testing of all alerts, alarms, warnings, and other control measures associated with the continuous monitoring system in order to verify that they function correctly in conjunction with each sensor referred to in paragraph (a).
If the manufacturer has not specified how often the tests are to be carried out, the following requirements apply:
(a) in the case of a portable continuous monitoring system, the tests must be performed prior to the system’s first use during the day;
(b) in the case of a fixed continuous monitoring system, the tests must be performed no less than once a month.
The employer must
(a) calibrate each continuous monitoring system in accordance with the specifications and instructions of the manufacturer,
(b) ensure that all necessary adjustments are promptly made to a continuous monitoring system if it does not function correctly, and
(c) carry out all other maintenance or servicing activities necessary to ensure that the continuous monitoring system functions correctly.
If the manufacturer has not specified how often the calibration of a continuous monitoring system is to be carried out, calibration must be carried out (a) no less than once every 12 months, and (b) any time the employer becomes aware of any information indicating that the continuous monitoring system cannot accurately and precisely detect, monitor or provide current information about the airborne concentration of the applicable toxic process gas.
The employer must ensure that the manufacturer’s specifications and instructions applicable to each continuous monitoring system are current and that they are readily available in the workplace.
Pressure relief devices
The employer must ensure that a toxic process gas that is released through a pressure relief device is released to a location where it will not endanger any person.
The employer must ensure that an alarm or other reporting system reliably and promptly informs appropriate persons if a pressure relief device is activated.
A nice cross-reference of the Proposed Changes to the Existing Requirements: