You’re building a wall, decking the second floor of a building, or sheeting a roof. How do you protect employees from falling when they create the structure and there is nowhere to tie it off? What about other employees not involved in the work? How do you protect them from the created fall and falling object exposure?
Suppose other means of fall protection create a greater hazard or are not feasible. In that case, you may implement a controlled access zone. Controlled access zones are designated areas where leading-edge work may occur without guardrails, safety nets, or personal fall arrest systems protecting employees. A controlled access zone must be part of an alternative fall protection plan complying with the appropriate OSHA standard.
When implementing a controlled access zone as an alternative fall protection plan, specific requirements are needed. Let’s explore some of those requirements in more detail.
Control Access Zone Systems Basic Requirements
Control Access Zone systems shall comply with the following provisions:
- Controlled access zones are defined by control lines or other means of restricting access to areas where leading-edge operations occur.
- The control lines should be erected not less than 6 feet (1.8 m) nor more than 60 feet (18 m) from the leading edge of the member, whichever is less.
- The control line shall extend along the unprotected or leading-edge length. It shall be approximately parallel to the unprotected or leading edge.
- The control line shall be connected to a guardrail system or wall on each side.
- Control lines shall consist of ropes, wires, tapes, or equivalent materials, and supporting stanchions as follows:
- Each line shall be flagged or marked at no more than 6-foot (1.8 m) intervals with high-visibility material.
- Each line shall be rigged and supported so that its lowest point (including sag) is not less than 39 inches (1 m) from the walking/working surface. Its highest point is not more than 45 inches (1.3 m) from the walking/working surface.
- Each line shall have a minimum breaking strength of 200 pounds (.88 kN).
Employees must be protected through limited access to high-hazard locations when using this plan to implement the fall protection options available. A competent person’s-controlled access zone (CAZ) shall be established in an area where a recognized hazard exists. The boundary of the CAZ shall be communicated by the competent person in a recognized manner, either through signs, wires, tapes, ropes, or chains.
Controlled Access Zone Competent Person
Take the following steps to ensure that the CAZ is marked or controlled by the competent person:
- All-access to the CAZ must be restricted to authorized entrants.
- Before starting work, employees permitted in the CAZ should read and sign this plan.
- The competent person shall ensure that all protective elements of the CAZ be implemented before the beginning of work.
These examples must be tailored to fit your project’s specific needs. It’s an excellent start to help get your creative juices flowing. Performing a hazard analysis is recommended to determine all control points where conventional fall protection systems are infeasible and would create a greater risk.
Precast CAZ Plan
During precast operations, conventional fall protection systems may present a more significant hazard to employees. Safety nets, guardrails, and personal fall arrest systems will not provide adequate fall protection because the structure during construction will not support nets. If a fall occurs, nets will most likely cause the walls to collapse. At the same time, there are no suitable attachment or anchorage points for guardrails as the leading edge is being created. Erecting and moving temporary guardrails creates an added level of fatigue which may lead to falls. While temporary anchorage points may be installed, the location and amount are limited due to the structural integrity of the precast structure. Personal fall arrest systems may cause a more significant hazard. Employees must also be able to move freely to avoid underneath overhead loads. Precast is set in place with the use of cranes. The intricacy of the process creates a more significant hazard to employees involved in setting and unhooking precast members. A minimum of three vertical sections from the leading edge is required to maintain a controlled access zone. A movable barricade shall be installed to restrict the controlled access zone.
Roof Truss and Rafter Erection CAZ Plan
Conventional fall protection may present a more significant hazard to employees during the erection and bracing of roof trusses/rafters. Safety nets, guardrails, and personal fall arrest systems will not provide adequate fall protection because the nets will cause the walls to collapse. At the same time, there are no suitable attachment or anchorage points for guardrails or personal fall arrest systems.
Requiring employees to use a ladder for the installation process will cause a more significant hazard because they must stand on the ladder with their back or side to the front. While erecting the truss or rafter, the employee will need both hands to maneuver the truss and therefore cannot hold onto the ladder. In addition, ladders cannot be adequately protected from movement while trusses are being maneuvered into place. Many employees may experience additional fatigue because of the increased overhead work with heavy materials, leading to a more significant hazard.
Exterior scaffolds cannot be utilized because the ground, after recent backfilling, cannot support the scaffolding. In most cases, the erection and dismantling of the scaffold would expose employees to a more significant fall hazard than the erection of the trusses/rafters.
Employees will install interior scaffolds along the interior wall below the location where the trusses/rafters will be erected on all walls eight feet or less. “Sawhorse” scaffolds constructed of 46-inch sawhorses and 2×10 planks will often allow employees to be elevated high enough to allow for the erection of trusses and rafters without working on the top plate of the wall. Alternatively, a carpenter bracket scaffold may also be used in the wall’s interior. This method will use 2 x 6″ lumber with a minimum of two 1 x 6″ braces every 3′ 6″.
A crew supervisor will oversee safe working procedures when scaffolds and ladders pose a greater risk on the top plate of structures with walls higher than eight feet. During all stages of truss/rafter erection, the stability of the trusses/rafters will be ensured.
Controlled access zones present varying degrees of risk, depending on the surrounding environment and nature of the work. Therefore, employers and employees must be well-versed in best practices when using a controlled access zone as a fall protection measure.
A controlled access zone (CAZ) means an area where specific work (e.g., overhand bricklaying) may occur without using guardrail systems, personal fall arrest systems, or safety net systems, and access to the zone is controlled.
Infeasible means that it is impossible to perform the construction work using a conventional fall protection system (i.e., guardrail system, safety net system, or personal fall arrest system) or that it is technologically impossible to use any of these systems to provide fall protection.
Leading-edge means the edge of a floor, roof, or formwork for a floor or other walking/working surface (such as the deck), which changes location as additional floor, roof, decking, or formwork sections are placed formed or constructed. A leading edge is considered an “unprotected side and edge” during periods when it is not actively and continuously under construction.
Safety-monitoring system means a safety system in which a competent person is responsible for recognizing and warning employees of fall hazards.
Unprotected sides and edges mean any side or edge (except at entrances to points of access) of a walking/working surface, e.g., floor, roof, ramp, or runway where there are no wall or guardrail system at least 39 inches (1.0 m) high.
A warning line system means a barrier erected on a roof to warn employees that they are approaching an unprotected roof side or edge and which designates an area in which roofing work may take place without the use of guardrail, body belt, or safety net systems to protect employees in the area.
Related OSHA Standards