Certified vs. Non-Certified Anchorages
Many factors are involved in making the choice. It is important to truly evaluate the best anchorage type and methodology for each given situation.
WHILE many new topics are addressed in the ANSI Z359 family of fall protection standards--which was available for purchase in late August and takes effect Oct. 15--one of the critical concepts presented is certified and non-certified anchorages for fall protection systems. Because the consequences of anchorage failure can be catastrophic, it is critical that anyone involved in the selection and design of anchorages understand the limitations and risks involved with using both certified and non-certified anchorages.
But it is important to note that certified versus non-certified is not comparing good against bad, as the language might suggest. Non-certified anchorages are not necessarily bad. They adhere to a different set of criterion, require a significant amount of judgment from competent persons, and should be properly evaluated.
Regulations and Standards
The safety requirements set forth by OSHA represent the regulations that must be followed by law. Consensus standards such as ANSI's represent the best practices in the industry and many times become the precursor for the direction in which the regulations are headed.
For the past several years, the ANSI Z359 committee has been working on a new family of standards to reflect the changes in the industry and provide a more comprehensive and informative document. Full understanding of certified and non-certified anchorages is best achieved within the context of the Z359.2-2007 standard, Minimum Requirements for a
Comprehensive Managed Fall Protection Program. The standard describes this comprehensive program and includes:
• Policies, duties, and training
• Fall protection procedures
• Eliminating and controlling fall hazards
• Rescue procedures
• Incident investigation
• Evaluating program effectiveness
Included in the fall protection procedures section is the need to first identify fall hazards within a facility. Once the hazards have been identified and prioritized, they can be systematically abated following the Hierarchy of Controls. If a solution with anchorages and personal protective equipment is chosen, it is critical to understand the different types of anchorages, the issues associated with selecting anchorages, design loading requirements, and other important design considerations.
Types of Anchorages
When considering how to protect an employee from a fall, it is important to understand the differences in the types of anchorages. Five unique types of anchorages are:
• Fall arrest
• Work positioning
• Travel restraint
• Horizontal lifeline
The ANSI Z359 standard defines all of these anchorage types and provides distinct loading requirements for each. Every anchorage type serves a different purpose, but some anchorages can be designed to fulfill multiple needs.
Fall Arrest. Used to support a worker wearing the proper personal protective equipment going through a free fall with a maximum arresting force of 1,800 pounds to the body.
Work Positioning. Used to assist a worker so he may work "hands free." This anchorage will prevent the worker from falling more than 2 feet with the work positioning equipment but may, in some cases, also require the use of a back-up fall arrest anchorage in the event of a fall.
Travel Restraint. Sometimes referred to as a "dog leash," used to prevent an employee wearing the personal protective equipment from ever reaching the edge of the work surface where a fall could occur.
Horizontal Lifeline. The loading this system experiences is dependent on multiple factors, including the sag of the horizontal lifeline, the number of spans, the number of workers attached, as well as the type and size of the material for the lifeline and more.
Rescue. The anchorage that is used in the event of a rescue is many times overlooked, which can be very dangerous in the time of a crisis requiring a rescue situation.
While it is crucial to understand the distinctions among the different types of anchorages, it is also important to evaluate how the solution falls within the Hierarchy of Controls. The Hierarchy of Controls assists in the evaluation of abatement solutions to determine the most effective and least "defeatable" means to protect workers.
It should be noted that the frequency of the task should be considered when evaluating the best solution. OSHA regulations provide guidelines as to which abatement solutions are appropriate depending on the frequency of tasks. Other items to consider include productivity of workers, accessibility to the work area, short-term and long-term costs, and overall safety of the situation.
As the design loads are reviewed for each type of anchorage, it should be made clear when anchorages can serve more than one purpose, because serving multiple purposes can significantly change the required load capacity of the anchorage. The following are the design loads specified in the ANSI Z359.2-2007 standard:
• Fall Arrest
» Non-Certified: 5,000 pounds
& » Certified: 2 x maximum arresting force
• Work Positioning
& » Non-Certified: 3,000 pounds
» Certified: 2 x foreseeable force
• Travel Restraint
» Non-Certified: 1,000 pounds
» Certified: 2 x foreseeable force
• Horizontal Lifeline
» Certified ONLY: 2 x maximum tension
» Non-Certified: 3,000 pounds
» Certified: 5 x applied load
The critical question to consider is: When and why would someone use a non-certified anchorage instead of a certified anchorage?
Certified vs. Non-certified Anchorages
The ANSI standard's approach to these two methods of anchorage evaluation and the associated design loading requirements further explains the distinction between the types. A certified anchorage is one where there is documentation that the system meets the requirements of the standard and where a qualified person identifies the anchorage and designs the system. In contrast, a non-certified anchorage is one that a competent person can judge to be capable of supporting the predetermined anchorage forces and incorporates an energy-absorbing device.
But who is a competent person? According to the ANSI standard, a competent person is one who identifies existing, foreseeable, and predictable hazards and has the authority to take prompt corrective measures to eliminate such hazards. Typical responsibilities of a competent person also include supervision of work at heights, inspection of equipment, and training of authorized persons.
With this definition of non-certified anchorages, competent persons are now asked to take on the additional responsibility of "judging" what is capable of supporting specific loading criteria. This is an exception to the requirement that anchorages are designed, installed, and used under the supervision of a qualified person.
The ANSI standard refers to competent persons selecting anchorages consisting of "unquestionably" strong elements of a structure. But it seems that this situation fits the 80/20 rule in life. That is, there may be 10 percent that are truly unquestionably strong, as in the case of a large bridge girder or other major structure. Another 10 percent certainly will not hold any additional loading, such as conduit, sprinkler line, or other smaller elements. That leaves 80 percent that are likely to require more investigation than a visual judgment to determine whether they can safely support the loading criteria. (It should also be noted that, in many cases, the addition or modification of the structure as part of the fall protection system loading will invoke the involvement of the building code for a local or state jurisdiction regarding the need for a professional engineer being involved in the change-in-use to the structure.)
As this discussion illustrates, there is no definitive answer to when and why someone would use a non-certified anchorage. Many factors are involved in determining appropriate anchorages, so it is important to truly evaluate the best anchorage type and methodology for each given situation.
When evaluating a structure for anchorage loading, there are multiple factors to consider beyond the type of anchorage and whether you are using a certified or non-certified anchorage approach. In most cases, there are not only vertical loads imposed to the supporting structure, but also a horizontal loading component. Predetermined fixed loads, such as the dead load or self-weight of the structure and its components, also must be considered in the load analysis. In addition, for variable loads such as wind load, snow load, and seismic loads, building codes guide the structural engineer on how to combine these loads to create a safe structure. Loading from anchorages can be added to these other loads directly to evaluate the capacity of the structure.
Another approach to consider is the conditional use method. If needed, this allows the conditional use of the anchorage if it can be controlled such that certain other loads are not present when the anchorage is being used. This approach requires strict control by the qualified person to be sure the proper procedures are being followed so the structure is not overloaded.
When considering the use of certified versus non-certified anchorages, there are a number of other things to consider. One must consider the "bad day" scenario of, what would happen if my competent person selected a non-certified anchorage that could not support the required load?
Some questions to consider include:
• What is the mode of failure of the structure?
• Is it a steel structure that might show some yielding first before complete collapse?
• What might be hit in the path of the fall that could cause additional injury to the worker?
• What about a failure where there is the release of hazardous materials, in the case of an attachment to a filled pipe?
• What kind of downtime would be involved to repair the structure, and how would that affect production or deadlines?
Whether the failure would result in an injury or worse, there must be serious consideration of the training, tools, and responsibilities given to the competent person in the use of a non-certified anchorage.
Fall protection is a complex subject. It involves multiple regulations and standards for both general industry and construction. When the abatement includes anchorages and personal protective equipment, a full understanding of the requirements is critical. These requirements are not only about structural capacity of the anchorages and their supports, but also include other important issues such as total fall distance, equipment inspection and compatibility, training, and procedures.
While it may not be possible to have all anchorages certified by a qualified person, it is still important to enlist a qualified person to prepare documentation and provide guidance to competent persons. This will enhance the competent persons' ability to make informed decisions. When considering the new ANSI standard, it is important to clearly understand the decisions you are making when choosing to use the non-certified anchorage method, as well as the requirements and responsibilities you are asking of your competent person.
This article originally appeared in the October 2007 issue of Occupational Health & Safety.