The Occupational Health and Safety Act (OHSA) sets out the duties for all workplace parties including owners, constructors, employers, supervisors and workers. In recognition that constructors, employers and supervisors have some of the main responsibilities to ensure the health and safety of all workers, the OHSA imposes general and specific duties on them and provides for other duties to be prescribed by regulation.
The OHSA applies to all “workers” (as defined in the OHSA) in the Live Performance Industry in Ontario whether they are employees, independent contractors, self-employed, on contract or on honorarium, and whether they are from inside or outside the province or country.
Beyond their obligations under the OHSA, as a best practice, workplace parties should protect visitors and volunteers with the same health and safety policies that have been established for workers.
The failure of any temporary performance/event structure, no matter how large or small, can have devastating results. Factors in these failures may include severe weather, overloading of the structure, improper design, unstable ground conditions, component failure, inadequately trained workers, improper installation, or any combination of these factors. Particular attention should be given to these factors when designing the structure and throughout its erection, use and dismantling.
This guideline has been prepared by the Health and Safety Advisory Committee for Live Performance to help workplace parties understand some of their obligations under the OHSA and its regulations related to the design, erection, use, dismantling and maintenance of temporary performance/event structures that are used either indoors or outdoors (not including scenery – see separate Scenery Safety Guideline for the Live Performance Industry). Information specific to outdoor use is included in several sections of this guideline. The key to the safety of these temporary performance/event structures involves:
- Choice of appropriate design and materials;
- Correct positioning on the site including ground conditions and foundations;
- Proper planning and control of work practices;
- Ongoing inspection of the finished structure during use; and
- The development of an Operations Management Plan (OMP) that includes provision for routine and emergency procedures including monitoring weather conditions.
This guideline is not intended to be a comprehensive exploration of all the engineering aspects of these structures. It identifies some of the occupational health and safety considerations to be incorporated into their design and construction process and use, and leaves it to the workplace parties to decide how to address those needs.
Reference must always be made to the OHSA and its regulations. As well, reference should be made to related guidelines set out in the Safety Guidelines for the Live Performance Industry in Ontario, including:
Note: Electrical materials and equipment must always be installed and used in compliance with OHSA’s regulations and shall be installed and used in accordance with the Ontario Electrical Code. In most cases an inspection by the Electrical Safety Authority is required for all electrical installations, renovations and alterations prior to power-up.
The following definitions are found under subsection 1 (1) of the OHSA:
- Competent person
- “a person who,
- (a) is qualified because of knowledge, training and experience to organize the work and its performance;
- (b) is familiar with this Act and the regulations that apply to the work; and
- (c) has knowledge of any potential or actual danger to health or safety in the workplace”
- “a person who undertakes a project for an owner and includes an owner who undertakes all or part of a project by himself or by more than one employer”
- “includes erection, alteration, repair, dismantling, demolition, structural maintenance, painting, land clearing, earth moving, grading, excavating, trenching, digging, boring, drilling, blasting, or concreting, the installation of any machinery or plant, and any work or undertaking in connection with a project but does not include any work or undertaking underground in a mine”
- “a person who employs one or more workers or contracts for the services of one or more workers and includes a contractor or subcontractor who performs work or supplies services and a contractor or subcontractor who undertakes with an owner, constructor, contractor or subcontractor to perform work or supply services”
- Industrial establishment
- “an office building, factory, arena, shop or office; and any land, buildings and structures appertaining thereto”
- “includes a trustee, receiver, mortgagee in possession, tenant, lessee, or occupier of any lands or premises used or to be used as a workplace, and a person who acts for or on behalf of an owner as an agent or delegate”
- “a construction project, whether public or private, including, (a) the construction of a building, bridge, structure…”
- “a person who has charge of a workplace or authority over a worker”
- “a person who performs work or supplies services for monetary compensation…”
Note: Refer also to OHSA Part III – Duties of Employers and Other Persons.
Live Performance Definitions
Note: These additional definitions are provided for clarity and guidance for this guideline only and, unless otherwise noted, are not definitions found under the OHSA or its regulations.
- Temporary Performance/Event Structure (“structure”)
- A temporary structure dedicated to house the technical production of entertainment events, including custom temporary structures, for either indoor or outdoor use.
- “’practice of professional engineering’ means any act of planning, designing, composing, evaluating, advising, reporting, directing or supervising that requires the application of engineering principles and concerns the safeguarding of life, health, property, economic interests, the public welfare or the environment, or the managing of any such act” [Professional Engineers Act, R.S.O. 1990, CHAPTER P.28]
- Lighting hang
- The placement of luminaires and/or cables for a performance/event.
- Load-in or Take-in (Fit-up, Set-up)
- The initial delivery and installation of production elements including rigging, automation, scenery, electrics, audio, etc. at the rehearsal space or performance/event venue.
- Load-out or Take-out (Strike, Tear-down)
- The dismantling and removal of production elements including rigging, automation, scenery, electrics, audio, etc. from the rehearsal space or performance/event venue.
- Professional Engineer, P.Eng. (“professional engineer”)
- An engineer licenced in the province of Ontario, as defined in the Professional Engineers Act.
- Risk Assessment
- Careful evaluation of all equipment, machinery, work areas and processes to identify potential hazards that workers may be exposed to and assessment of the impact of the identified hazards on those that work in the area. Assessing the risk means determining the likelihood that the hazard may lead to injury or illness and the severity of that potential injury or illness.
The Construction Projects Regulation (O. Reg. 213/91) applies to all projects as defined by the OHSA which may include the erection, installation, alteration, repair, structural maintenance and dismantling of these structures. The regulation for Industrial Establishments (R.R.O. 1990, Reg. 851) applies to all industrial establishments as defined by the OHSA which may include these structures after they have been constructed.
Depending on the nature of the installation of the structure and the performance/event, additional legislation may apply, e.g. the Ontario Building Code (OBC). Workplace parties should familiarize themselves with all legislative and regulatory requirements that may apply to their workplace.
Types of structures
These structures are infinitely variable in design, type, size, and materials (wood, metal etc.) - from simple to very complex. They may be assembled and configured with pre-engineered component(s) such as scaffolding, trusses, platforms etc. or any combination thereof, and may or may not have a roof, wall elements or bleacher seating. Examples of structures include:
- Elevated platforms (stages)
- Pre-engineered multi-use units such as a fabric tents
- Mobile stages, on transport carriers
- Portable or semi portable single or multi-function structures
- Custom temporary structures
- Structures used to hang equipment
- The structure shall be designed to suit the intended purpose and support all loads applied to it (rigging, automation, lighting, sound, video, scenery, wind, snow, construction, live loads etc.) (section 31(1) of O. Reg. 213/91).
- The structure should be designed in accordance with good engineering practice and must be approved by a professional engineer with experience in structural engineering and an understanding of:
- The different types and configurations of these structures;
- Dynamic loads that these structures may be subjected to;
- Ground conditions or floor construction at the site(s) where the structure will be used;
- The materials (including proprietary structural elements) normally used for these structures and their structural properties;
- The skills and capabilities of the people normally employed to erect these structures; and
- The equipment and materials likely to be hung on, around and under these structures in a live performance/event setting.
- When used outdoors:
- The design should account for wind, rain and snow loads in accordance with part 4 of the OBC, including severe weather conditions that may develop and should be site specific.
- The structure must possess adequate strength and stability in erection, use and dismantling. The load calculations for the structure should determine the load capabilities of the components (section 25(1)(e) of the OHSA and subsections 31, 125-136 of O. Reg. 213/91). Ensure:
- All structural components are designed with appropriate factors of safety.
- Hardware and other technology are appropriate and adequate for the intended use.
- All key components are easily accessible for inspection and maintenance.
- The design and engineering process should address:
- The weight, balance, size and shape of each component of the structure to ensure the structure is appropriate for:
- The intended use
- The anticipated load
- Restrictions imposed by its location.
- The methods used to move components during erection and dismantling.
- Safe handling by workers when moving, erecting and dismantling the structure.
- All connections between guy wires, if used, and structural members. Localized stresses on structural members such as slings wrapped around truss members or any other structural members shall be considered (section 31 of O. Reg. 213/91).
- Connection points to existing structures and/or other temporary structures.
- The effects of stresses imposed by live loads.
- Any limitation for the design (max. number of occupant, max. wind velocity etc.).
Constructor/ Employer responsibilities
- Every project that is governed by the OHSA has both an owner and a constructor. Under the OHSA, a constructor is a party (an individual or company) who oversees the project. The constructor will either be the owner of the project or a party contracted by the owner to undertake the project for the owner. The constructor can also have duties under OHSA as an employer.
- The constructor is the person with overall authority for health and safety matters on a project. The constructor is the party with the greatest degree of control over health and safety at the entire project and is ultimately responsible for the health and safety of all workers (section 23(1)(b) of the OHSA). The constructor must ensure that all the employers and workers on the project comply with the OHSA and its regulations (section 23(1)(b) of the OHSA). For additional information refer to Constructor Guideline posted on the MOL website.
- The constructor shall appoint a competent person (example: Production Manager or Technical Director) as a supervisor to have overall supervisory responsibility on site for the work on the project including work on the structure (section 14(2) of O. Reg. 213/91).
- The constructor or supervisor should establish a communication process and a chain of command for the erection and dismantling of the structure, and for unexpected situations and emergencies. The constructor shall establish a written procedure to be followed in the event of an emergency and the procedure shall be posted in a conspicuous place at the project (section 17 of O. Reg. 213/91). The constructor also has the duty to ensure that every worker at the project has ready access to a telephone, two-way radio or other system of two-way communication in the event of an emergency (section 18 of O. Reg. 213/91). These emergency procedures should also apply when the structure is in use (section 25(2)(h) of the OHSA). Refer to the Operations Management Plan (OMP) in the Documentation section of this guideline.
- As part of the chain of command, the supervisor should be onsite at all times during erection, use and dismantling of the structure. This person should be authorized to make and implement decisions about event cancellation and site evacuation. The name of the supervisor should be communicated to ensure that everyone (including contractors, vendors, performers etc.) knows who is responsible. Further details about the role of the supervisor during use of the structure can be found in Managing the Completed Structure section of this guideline.
- At least once a week, or more frequently as the supervisor determines is necessary, the supervisor or another competent person appointed by the supervisor shall inspect all equipment and structures to ensure that they do not endanger any worker (section 14(4) of O. Reg. 213/91).
- The supervisor/other competent person should understand (or hire someone who understands) the engineering documentation for the structure’s components and design including expected loading for the configuration of the structure when in use. Any deviation from the original intended construction or use should be reported to the professional engineer and revised signed and sealed drawings should be prepared and be available at site.
- The constructor of the structure should ensure adequate organization, coordination and oversight of all contractors and workers and their related activities, recognizing that:
- Relationships among the workplace parties are complex and vary for each event.
- Contractors and workers may come from other provinces or countries.
- Before work on a project is begun, the constructor and each employer involved in the project shall complete a Ministry of Labour approved registration form (section 5 of O. Reg. 213/91). A Notice of Project is also required if the total cost of the labour and materials for a project is expected to exceed $50,000 (section 6 of O. Reg. 213/91). For clarification and further details, refer to Appendix A of this guideline. If in doubt, contact the Ministry of Labour at 1-877-202-0008.
- The parameters of the structure’s design should be explicitly outlined in the engineering documentation.
- Documentation to determine the balance of loading and scale of forces acting on the structure should be based on calculations from the OBC.
- Documentation should include:
- A statement of the structure’s intended use.
- Drawings accompanied by a stamped engineering report detailing the load limits the structure is designed to bear. Supplementary details (example: loads from rigging, automation, lighting, sound, video, scenery etc.) may not be available until nearer to the event but should be verified and approved by the professional engineer before the structure is used.
- Operating limits of the structure including the effects of all loads (dynamic, static, environmental, etc.).
- Load plots for any structures with rigging/hanging/stacked components.
- Ground or floor loading from the structure.
- Details of the methods of transferring all horizontal forces (including wind) back to the ground, including ground pressures required for stakes of any guyed supports.
- A list of items or connections that require checking each time the structure is erected in order to enable effective physical inspection of the structure.
- A sign off report by a professional engineer stating that the temporary performance event structure is constructed and erected in accordance with the design drawings.
- All documentation should be specific to the venue, structure, equipment and loads. Load calculations should be current. Load plots should be written, graphed and/or plotted so that riggers clearly understand what maximum loading is permitted.
- An Operations Management Plan (OMP) should be prepared by the constructor/ employer and the professional engineer.
- The OMP governs the operations of the structure throughout its use period, including load-in and load-out of all supported and nearby elements.
- The OMP should consider all manufacturers’ operational guidelines.
- The OMP should define the actions to be taken for different parts of the structure during and in anticipation of changing weather conditions.
- The OMP should include appropriate environmental monitoring procedures as specified by the professional engineer. Environmental conditions may be weather-related (high winds, lightning, heavy rain, hail, snow etc.) or physical (avalanche flood, forest fire, earthquake etc.). Procedures may include:
- Maintaining real time on-site wind speed monitoring for the entire period the structure is assembled.
- Monitoring the local weather and wind forecast.
- The constructor/ employer’s supervisor should have the authority to implement the actions required by the OMP to ensure the safety of workers in relation to the structure. The supervisor should verify that such actions can be achieved as documented and that workers are adequately trained. When a warning indicating severe or unusual weather conditions is issued for the site, the supervisor will take immediate appropriate actions to make the area safe for all workers, (including performers), volunteers and patrons as described in the established OMP.
- Structure assembly drawings will normally be required for all but the simplest structures and should include a description of how to safely erect and dismantle the structure.
- The structure should be equipped with signage to identify the competent person supervising the structure and his/her contact information, as well as the availability of the OMP.
- The structure should be equipped with signage to identify load limits for the structure if applicable (e.g. max. occupancy, max. wind velocity).
- A current copy of all relevant documentation should be kept at the event site. An additional copy should be kept in a secure location off site in case of emergency or loss of site documents.
Preparation and planning
- Early in the planning process, a risk assessment should be carried out by a competent person (example: Production Manager or Technical Director) to cover the erection, use and dismantling of the structure, including any hazards it may create.
- The risk assessment should include the identification, assessment and control of hazards, including those related to access, egress and evacuation.
- The process should seek to eliminate hazards.
- Where hazards cannot be completely eliminated, controls should be designed and implemented to reduce the hazard to levels that present a minimal risk to worker health and safety.
- Such controls should include appropriate training, supervision, engineering controls, work practices, administrative controls and personal protective equipment.
- The risk assessment process should continue throughout production and monitor conditions for new or evolving hazards. As circumstances change, the risk assessment should be updated.
- Planning should include consultation with the relevant authorities having jurisdiction (AHJ), including the Fire Department, Police Department, Emergency Medical Services, Building Department and others that might be relevant depending on the location, municipality, venue, etc.
- Choose a competent supplier/manufacturer for the structure who will be able to:
- Demonstrate they have knowledge and understanding of the work involved including a good working knowledge of the OHSA, the Construction Projects Regulation (O. Reg. 213/91), the Industrial Establishments Regulation (R.R.O. 1990, Reg. 851), and other potentially relevant legislation (e.g. the OBC);
- Manage/eliminate the risks involved in constructing these structures;
- Demonstrate they employ only suitably trained workers;
- Have a regular and documented non-destructive testing program in place for the materials related to these structures;
- Provide a stamped engineered design drawing of the structure, including allowable loads on the structure and its components, weather design loads, ground loads on ground support members, etc.;
- Provide operating and maintenance instructions for the structure;
- Include a completion inspection and field evaluation based on design drawings; and,
- Provide a written sign-off by a person who is a professional engineer.
- When choosing the location for a structure to be used outdoors, consider:
- Adequate drainage – If the site is prone to flooding, this could reduce the load bearing capacity of the ground or cause the ground under the supports to be washed away.
- Load bearing capacity of the ground – Consider the need for geotechnical testing and ensure the ground is capable of supporting the imposed loadings in all weather conditions. The use of heavy equipment (such as cranes or lift trucks) to install sections of structures or equipment may create very high point loads.
- Ground variations – Where there is a gradient or the ground is uneven, the structure must be capable of being adjusted to safely deal with such variations.
- Distance from overhead power lines – The upper part of the structure and any cranes or other equipment that may be used in its assembly must be kept clear of power lines (section 188 of O. Reg. 213/91 and section 43 of R.R.O. 1990, Reg. 851).
- Distance from nearby structures, buildings and vegetation – Consider the risks in case of a possible spread of fire.
- Access and egress methods/routes – Consider these for both vehicles for setup and tear down, as well as for the general public. Separate access for emergency vehicles should be provided to ensure appropriate access in an emergency or evacuation.
- Assess each phase of the job and ensure that adequate time, the necessary equipment and an appropriate number of workers are provided to do the job safely.
- Ensure each worker working on the structure shall be:
- Trained and competent in all skills that may be needed in their work and carrying relevant documentation of training;
- Provided with an orientation to the site and structure; and
- Informed of all potential or actual hazards by the supervisor (section 25(2)(a) of the OHSA).
- Ensure that emergency responders (Fire Department, Police Department, and Emergency Medical Services) are adequately prepared to respond appropriately. Emergency responders should be provided an opportunity to tour the site and to be oriented to the site and structure.
- In consultation with the AHJ, ensure adequate access and egress routes for the site.
- Ensure provision of qualified first aid personnel and first aid kits whenever workers are on site, as well as when there is an audience.
- Ensure provision of fire extinguishers on and around the structure prior to first use (for rehearsal, technical work, etc.) and during erection and dismantling operations (subsections 52-55 of O. Reg. 213/91).
When the work activity includes Load-in or Take-in (Fit-up, Set-up) and Lighting Hang (collectively, “construction activities”), the requirements of the Construction Projects Regulation (O. Reg. 213/91) apply to the project.
- It is recommended that a professional engineer be present through the construction activities to ensure the structure is assembled in accordance with its design documentation.
- All construction activities at the venue should be monitored to ensure that the structure is erected properly. Attention should be paid to the following:
- The construction of the structure should be carried out in accordance with plans and specifications drawn up by a professional engineer, as well as manufacturer’s instructions.
- Apparent similarities between proprietary systems used for structures may only be cosmetic. It is important not to mix products from different manufacturers unless approved by the professional engineer.
- Equipment should be checked to ensure that it is fit for its purpose and fully meets any specification that has been laid down.
- All components should be examined during assembly (and dismantling) for signs of wear, deformation or other damage, and replaced where necessary. Replacement components should be available on site. Damaged materials should be marked and removed from service immediately.
- Correct alignment of components is important - they should not be bent, distorted or otherwise altered to force them to fit.
- Particular attention should be given to fastenings and connections. It is essential to provide suitable covering for bolts and fittings that project into or adjoin audience, backstage or performance areas.
- Erection should take place in a way that ensures structural stability at all times.
- Ensure that other work carried out close to the structure does not affect its structural stability.
- Ensure appropriate structure grounding for electrical safety, including for lightning protection when used outdoors.
- Ensure appropriate ballasting and/or anchoring of the structure. If ballast is not anchored/fixed, the lateral loads that could cause it to slide must be factored into calculations.
- Where guying is used, care should be taken to ensure that the guys and their anchors are properly installed and do not cause an obstruction. All stakes or anchors should be located, covered or identified using barriers, fencings, hoarding or flagging, so that they do not create a tripping hazard.
- Where scaffolding or work platforms are being used or assembled, compliance with subsections 125-136 of O. Reg. 213/91 is required.
- The professional engineer should check the structure after it has been erected and before it is used for the first time to make sure that it complies fully with the drawings and design documentation. Verify that the checks have been carried out effectively and have been recorded. The AHJ also may wish to do a final inspection.
- The design, construction and installation of the structure should enable an efficient response to an emergency:
- Unimpeded operation of emergency equipment; and
- Easy exit from the venue in emergencies.
Managing the completed structure
- For each event, a supervisor should be appointed to be responsible for the oversight of contractors and workers. The supervisor shall be a competent person (section 25(2)(c) of the OHSA).
- A supervisor (example: Technical Director or Rigger) should monitor the structure at all times during use (section 25(1)(e) of the OHSA) for the effects of weather and/or misuse (example: the overloading the roof of the structure). In practice this means that a representative of the supplier, or other suitably qualified person, should be on-site at all times while the structure is in use.
- The structure should be inspected throughout use and maintained regularly by the supervisor (example: Technical Director or Rigger). Daily inspection is recommended.
- In consultation with the professional engineer, and the supplier/manufacturer, develop a checklist of items and connections to be inspected. These items to be checked should include:
- The ground to confirm that no deterioration in its load bearing capacity, such as excessive settlement, has occurred.
- Ballasts and anchorage systems to ensure guy wires are tight and ballasts have not shifted.
- Establish a maintenance schedule with a method of logging the maintenance work done and keeping written records. Conduct maintenance according to the schedule and more frequently when any observed behaviour of the structure warrants it.
- Pay particular attention to components that might be subject to wear or damage from outside sources, especially due to frequent assembly and disassembly. Damaged components must be repaired or replaced. Those that cannot be repaired should be marked and removed from service immediately.
- During ongoing use of the completed structure, loads can be applied in various ways. It is important that design loads are not exceeded. Measures must be taken to prevent overload by:
- People - due to overcrowding any part of a structure
- Equipment loads - rigging, lighting, special effects, sound systems, video and TV screens, etc.
Dismantling and load out
The requirements of the Construction Projects Regulation (O. Reg. 213/91) also apply to the structure when the activity related to the structure includes a Load-out or Take-out (Strike, Tear-down) (collectively, “dismantling activities”).
- Dismantling activities are subject to the same risks as the construction activities. Dismantling activities should be carried out methodically by workers who are appropriately trained, and strictly in accordance with the design documentation.
- It is recommended that a professional engineer be present to ensure that the structure is dismantled in accordance with its design documentation.
Alterations and change of use
Any modifications to the structure should be made in consultation with the professional engineer, who should document, approve and sign off on any and all alterations/modifications.
- Structural components should not be removed (except as part of the dismantling protocol) without first consulting the professional engineer.
- If cladding, tarps or enclosures are added to a structure used outdoors that were not included in the structure’s design drawings, the structure will become more vulnerable to wind and may also allow other forces to be transmitted to the structure. Never add banners or other types of hoarding to a structure without first consulting the professional engineer as above.
- Before changing the use of a structure, the professional engineer should be consulted to ensure that such changes will not result in loads or operational requirements exceeding those originally anticipated and allowed for at the time of initial construction.
Call 1-877-202-0008 anytime to report critical injuries, fatalities or work refusals. For general inquiries about workplace health and safety and to report potentially unsafe work conditions, call 8:30 a.m. – 5 p.m., Monday to Friday. In an emergency, always call 911 immediately.