Safe Work Practices (SWP) SWP (3) CONFINED SPACE ENTRY

Transcription

1 SWP (3) CONFINED SPACE ENTRY The below information has been derived from BC WSBC OHS Regulations, standards and guidelines. If working outside of BC in a confined space, the work jurisdictions OHS Regulations/Codes and client s procedures must be consulted prior to commencing work to ensure CCMET is in compliance and appropriate levels of training have been carried out. (a) CONFINED SPACE DEFINITION A confined space means an area, other than an underground working, that: Is enclosed or partially enclosed; Is not designed or intended for continuous human occupancy; Has limited or restricted means for entry or exit that may complicate the provision of first aid evacuation, rescue or other emergency response service; Is large enough and so configured that a worker could enter to perform assigned work. (b) COMMON CONFINED SPACES Tank Enclosed bridge deck under construction Tunnel Vats; Vessel Ducts; Live Sewer Storage containers/bins; Hoppers; Cofferdams; Columns; Caissons; Trenches; Pipes/Piles; Wells; Crushers; Boilers; Penstock. (c) COMMON CONFINED SPACE DANGERS Dangers of confined space entry include, but are not limited to, the following: Exposure to hazardous energies (hydraulic, electrical, compressed gas, mechanical or elevated object/part); Biological hazards (bacteria, viruses, parasites, fungi, mold); Entrapment (trench cave in, water egress, vertical entry/exit); Hazardous atmosphere (carbon monoxide, hydrogen sulphide, welding fumes, emissions from heavy equipment and vehicles, etc.); Inadequately trained or unauthorized employees, no standby person; Incorrect rescue procedures; Lack of communication between worker and standby person. (d) RESPONSIBILITIES OF CCMET Determine locations of confined spaces in all work areas; Determine whether any such space will require entry by a worker, either in scheduled work activities or as a result of a foreseeable system failure or other emergency. If a confined space exists at a work area but no worker entry is required, the Page1

2 employer must ensure that each point of access to the confined space is secured against entry and identified by signage. (Signage must explain prohibition of entry and that workers are instructed not to enter.) Control hazards related to confined space and that work within such a space is performed safely. Ensure adjacent piping (if any) near the confined space is controlled (disconnected, isolated, blank/blind) as per the work jurisdiction s OHS Regulations. Before a worker is required or permitted to enter a confined space, the employer must prepare and implement a written confined space entry program. Ensure adequate confined space training. No worker is to enter a confined space to undertake work until they have been trained by either Supervisory Personnel or an external accredited training source. Training will include the review of hazards/controls, PPE requirements, safe work practices and safe job procedures that apply to Confined Space Entry. Ensure experienced Underground Workings Supervisor (OFA L3/Site Safety Rep or Coordinator/ Confined Space training) and/or Supervisory Personnel are in charge of any confined space work. (e) RESPONSIBILITIES OF SUPERVISORY PERSONNEL /UNDERGROUND WORKING SUPERVISOR Development and Implementation of confined space program (may be developed internally or by an external consultant/subcontractor) Pre-entry testing and inspection is conducted based on the written procedures found in the confined space program, testing may be completed by an external consultant / subcontractor. Organize confined space training, PPE, air ventilation/testing, etc. The precautions identified in the program s written procedures and the precautions required by the work jurisdictions OHS Regulation for the health and safety of workers are followed Ensure only authorized workers enter a confined space they must be instructed and trained on the hazards of the space and the precautions found in the written procedures of the confined space program specific to the work area. Carry out safety meetings related to confined space entry work. (f) CONTENTS OF A CONFINED SPACE ENTRY PROGRAM Confined spaces will be determined on each project site. As a result, a confined space entry program will be prepared by CCMET (on site). The confined space entry program must contain the following information: 1. An assignment of responsibilities; 2. A list of each confined space or group of similar spaces 3. Hazard assessment performed for those spaces 4. Written corrective actions and safe job procedures for entry into and work in the confined space. 5. Procedures should address: Page2

3 - Identification and Entry permits - Lockout and isolation - Verification and testing - Cleaning, purging, venting or inserting - Ventilation - Assignment of standby persons - Rescue information - Lifelines, harnesses and lifting equipment - Personal protective equipment and other precautions - Coordination of work activities. - WHMIS MSDSs for products being used within the confined space. (g) HAZARD ASSESSMENT AND WORK PROCEDURES FOR CONFINED SPACE ENTRY PROGRAM Qualified Person: The hazard assessment and written confined space entry procedures must be prepared by a qualified worker who has received adequate training and experience through recognition, evaluation and control of confined space hazards. Adequate training may include internal and external training. A certified industrial hygienist, registered occupational hygienist, certified safety professional, Canadian registered professional or professional engineer with appropriate training and experience may also carry out the hazard assessment and procedures. Hazards to be Assessed: As mentioned above, a hazard assessment must be performed for each confined space or similar confined spaces which share characteristics on each work site. The following considerations should be factored into the hazard assessment: The conditions which may exist prior to entry due to the confined space s design, location and use The conditions which may develop upon entry due to the confined space s design, location and use The potential for oxygen enrichment and deficiency The potential for flammable gas, vapour or must The potential for combustible dust The potential for other hazardous atmospheres Harmful substances which may require lockout and isolation Possibility of engulfment and entrapment Other hazardous conditions. Corrective action procedures should then be developed based on the findings in the hazard assessment. Page3

4 If you have difficultly preparing the procedures, consult with the work jurisdiction s OHS Officers / OHS Regulations or an external hygiene/confined space entry consultant. (h) CONFINED SPACE ENTRY PERMIT & RECORD When Permits / Record Required: An entry permit must be completed and signed by the responsible supervisor before a worker enters a confined space that : Has a high hazard atmosphere; Requires lockout or isolation procedures to be followed; Has a risk of entrapment or engulfment Permit / Record Content and General Information: Prior to entering a confined space, Supervisory Personnel in charge must complete a Confined Space Entry Permit sheet. Contents should include: - Identification of the confined space - Identification of the work activities to which it applies - Personnel who are authorized to work inside the space - Required precautions for the space - Time and expiration of permit. - WHMIS Material Safety Data Sheets which relate to the products being used within the confined space. Permits, related documentation and training records must be forwarded to CCMET Head Office on a monthly basis. CCMET must keep permits on file for at least one year. Permits/records must be reviewed / updated as necessary to ensure the ongoing safety of the workers inside the space. Every worker affected by a permit update must be informed if it involves changes to work procedures or activities. Permit may be re-authorized and signed by the responsible supervisor - If there is change in the work crew - After the shift change in the work crew - After a change of the responsible supervisor Permit may only be updated: - By the supervisor in charge who signed to the permit to update it. - By the standby worker to update the list of workers inside the confined space. - By the tester to record test results. (i) LOCKOUT AND ISOLATION Lockout Before worker enters confined space, any material conveyor equipment must be free of material that could present a hazard. Page4

5 Isolation Adjacent piping that contains or has contained a harmful substance must be controlled by disconnecting, blanking or blinding, or engineered system equivalent, double block and bleed system, pressure control, etc. (j) VERIFICATION AND TESTING General Information Before a worker enters a confined space, pre-entry testing and inspection must be conducted to verify that the required precautions have been put into effect and are controlling the identified hazards and that it is safe for the worker to enter. A qualified person must be able to re-calibrate confined space entry atmospheretesting equipment. Pre-Entry Testing Must be done as per the specified written work procedures Done not more than 20 minutes before a worker enters a confined space When all workers have vacated the confined space for more than 20 minutes, testing must be repeated. If working in a high hazard atmosphere, additional or continuous testing may need to be arranged If working in a moderate to high hazard atmosphere, continuous monitoring of the atmosphere must be done if a flammable or explosive atmosphere is excess 20% of the lower exposure limit Pre-entry testing is not required in a confined space in a low hazard atmosphere if the location/control of the space ensures that a more hazardous atmosphere could not inadvertently develop, such testing is not required to verify effectiveness of an isolation or other pre-entry control, prior representative sampling has demonstrated that the atmosphere within the space or group of similar spaces meets the low hazard atmosphere definition or written procedures do not require such testing. Pre-entry testing must be carried out by an adequately trained worker or external consultant. Test results other than continuous monitoring results - must be posted without delay at all points of entry to the confined space. Pre-entry testing is NOT required for LOW hazard atmosphere confined spaces if: Location and controls ensure a hazardous environment will not inadvertently develop; Such testing is not required to verify the effectiveness of an isolation or other preentry control; Prior representative sampling has shown clean breathable air; Written procedures (outlined in Confined Space Entry Program) do not require testing. Page5

6 (k) CLEANING, PURGING, VENTING AND INERTING General Information When practicable, confined spaces to be entered must contain clean-respirable air If pre-testing or confined space is known 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 prior to worker entry. If clean respirable air cannot be assured, all workers entering space must wear appropriate PPE including respiratory protection, concentrations of flammable gas and vapours are maintained below 20% of the lower explosive limit, sources of ignition must be eliminated or adequately controlled. If inerting, the work jurisdiction s OHS Regulator must be notified in writing, submit proposed work/procedures 7 days before worker enters the confined space the board may prescribe additional procedures to be followed, every worker must be equipped with supplied air respiratory protection meeting regulatory PPE requirements, and ignition sources controlled. (l) VENTILATION General Information Every confined space must be ventilated continuously while a worker is inside the space, except if it has been inerted, is a low hazard atmosphere or during an emergency rescue (not practicable). If working in a low hazard atmosphere, 85m3 / Hr of clean respirable air is supplied for each worker inside a confined space. It must also be continuously monitored and shown to contain clean respirable air and the space has an internal volume greater than 1.8m3 per occupant and is occupied for less than 15 minutes and the work inside the space generates no contaminants other than exhaled air. Mechanical Ventilation Ventilation system for control of airborne contaminants in a confined space must be designed, installed and maintained in line with established engineering principles and have written procedures. Ventilation equipment must be located and arranged to adequately ventilate all areas occupied. If contaminant created from work, it must be controlled at the source by a local exhaust ventilation system. If practicable, a mechanical ventilation system for a confined space must be sufficient to maintain concentrations of airborne contaminants below the applicable exposure limits. Page6

7 Natural Ventilation If natural ventilation is relied on for control of airborne contaminants in a confined space, the rate of airflow through the space must be monitored and be sufficient to maintain contaminants below applicable exposure limits. Natural ventilation SHOULD NOT be used to ventilate a high hazard atmosphere or if it could draw non respirable air into the confined space. Hazardous Atmosphere Classification and Standby Person Requirements: 1. Low Hazard Atmosphere Clean respirable air; Atmosphere not likely to change due to design/construction of space, use of space, work activities involved in space, engineering controls; Standby person must be assigned with a continuous means of contact (i.e. radio). The standby person should do checks every 20 minutes and must have a means of contacting rescue personnel immediately. Follow applicable OHS Regulations. 2. Moderate Hazard Atmosphere Does not contain clean respirable air; Atmosphere unlikely to impair workers ability ; Workers ability to escape unaided if respirator or ventilation fails; Standby person(s) must be assigned and be stationed at or near the entrance. Standby persons must conduct visual or other check at least every 20 minutes and have a continuous means of summoning workers inside space and be able to contact rescue personnel immediately. Follow applicable OHS Regulations. 3. High Hazard Atmosphere where entrapment/engulfment may happen! May expose workers to risk of death; Atmosphere may otherwise impair workers ability; Standby persons (with no other duties) must be stationed at the entrance and carry out continuous or visual or other form of check. Standby persons must have a continuous means of summoning workers inside space and be able to contact rescue personnel immediately. Follow applicable OHS Regulations. Page7