The Future of Fall Protection Equipment Testing
Before the ANSI/ASSE Z359.7 standard, there was no person or entity an end user could turn to for compliance testing information on any piece of fall protection equipment.
- By W. David Lough
- Jul 01, 2010
There have always been a multitude of questions surrounding the testing of fall protection equipment. How does a company ensure compliance with industry standards? Is there traceability for testing of fall protection equipment? Can end users be sure that the fall protection equipment they are using passed the applicable American National Standards Institute (ANSI) test requirements in their entirety? Is the test laboratory compliant with a specific laboratory standard? Is it possible to compare results of testing with a laboratory in different geographic locations? Does every test laboratory understand the product it is testing? This list of questions can go on and on, and in the past, there have been no comforting answers for the people who depend on this equipment to protect their lives. The answer to all of the above-mentioned questions is "no," creating a "buyer beware" market for many years. Thankfully, change is in the very near future.
The addition of a number of new ANSI standards for fall protection, along with a need to better understand the science of a fall, has prompted the fall protection industry to review some of its traditional testing conventions and practices in recent years. This, in turn, has brought into question the validity of current testing on fall protection equipment and the results.
Everything from how data is collected to sampling rates and test weights is being reviewed to ensure testing incorporates adequate factors of safety into the design of fall protection products. It was only three years ago that ANSI increased its test weight requirements from a 220-pound test weight to a 282-pound test weight for energy-absorbing lanyard testing. This change was based on a research project conducted by Gravitec Systems, Inc. The project compared rigid test weights to human test subjects.
Prior to this research and the subsequent report, it was commonly believed a conversion factor of 1.4 would accurately model the differences between how a rigid weight dissipated energy compared to a human body in a full-body harness. For example, by using a 220-pound rigid test weight, it was believed by the scientific community in the fall protection industry that this would be comparable to results found when a 310-pound person fell the same distance. The research project testing results indicated this was not the case, and the conversion factor should be closer to 1.1 rather than 1.4. In other words, the rigid test weight increases the impact forces seen during a fall only slightly.
This, in turn, means many of the energy-absorbing lanyards on the market up until a few years ago had an actual capacity of 242 pounds (220 pounds x 1.1), rather than 310 pounds. Needless to say, this was of great concern to many manufacturers and users of fall protection products. (For further information about this report, visit www.gravitec.com/testing and click on "Rigid Weight vs. Human Weight: 1.4 Multiplier Test.")
The Z359.7 Standard
The concerns about proper testing procedures and documentation have encouraged ANSI to create a new standard for fall protection equipment testing. The ANSI/ASSE Z359.7 (Certification Testing of Fall Protection Products) standard is a giant step forward because past requirements for fall protection equipment testing laboratories did not exist. It was left up to the ethics of the manufacturer. Some are very competent and thorough, and some are not.
The ANSI/ASSE Z359.7 standard will require accreditation as an ISO 17025 laboratory for every laboratory where testing of fall protection equipment is conducted. The requirements of the ISO 17025 standard mandate a level of consistency among testing laboratories that was sorely lacking in the past. Laboratories will now have requirements for calibration of equipment, uncertainty measurements, testing procedures, reporting procedures, and report generation. Hopefully, this new standard will allow laboratories in different parts of the country to generate similar results for the same specimens.
What else does the implementation of this testing standard do? It provided the manufacturer with more direction about how to test. It also provides the end user with an action plan to question the quality of fall protection equipment that is alleged to meet ANSI requirements if there is uncertainty. Before this standard, there was no person or entity an end user could turn to for compliance testing information on any piece of fall protection equipment. ANSI is not an enforcement body, nor can it police misrepresentation of equipment that falsely uses the ANSI standard mark. Manufacturers did not always volunteer testing information and had no requirement to do so.
The ANSI/ASSE Z359.7 standard will require the manufacturer to provide testing information to the end user upon request if the manufacturer claims their equipment is ANSI compliant and uses the ANSI standard mark. If the manufacturer does not or cannot provide the testing information, there are a number of courses of action the end user can take to get the information or question the validity of the testing that was performed. None of these alternatives were available to the end user in the past. These actions can range from addressing the accrediting body that accredited the testing laboratory as ISO compliant to addressing the professional engineer who stamped the test results and his/her associated professional organization. Laboratories will risk losing their accreditation if testing is not performed according to the appropriate standards and test procedures.
Manufacturers that want to provide their customers with the added security of independent third-party testing will have an avenue to do so. Testing laboratories must become accredited to perform fall protection equipment testing. Manufacturers will benefit from the added value by the end user when testing is performed by an independent, third-party testing laboratory.
Concern for Overweight Workers Who Fall
Another issue that is presently causing some heated conversation in the fall protection testing world is the problem of our growing workforce. Currently, all fall protection equipment that meets an ANSI standard has a capacity range of 130 pounds to 310 pounds. Testing to determine whether fall protection equipment is ANSI compliant is conducted only to this maximum capacity.
In North America, we are seeing larger workers whose body weights surpass the ANSI standard capacity of 310 pounds. The maximum capacity of 310 pounds is intended to apply to fully clothed and tooled worker, which means workers over 310 pounds do not have ANSI-conforming equipment at their disposal. To make matters worse, there are manufacturers that are producing harnesses for workers over 310 pounds; in some cases, manufacturers are claiming their harness(es) can accommodate up to a 440-pound worker. That is fine if the only criterion for safety is that the harness webbing doesn't break or allow the worker to fall out of the harness.
However, this does not take into consideration the connecting means (lanyard, self-retracting lifeline, etc.), the anchor point, or any rescue gear, all of which are most likely designed for a maximum capacity of 310 pounds. In addition, suspended workers who are out of shape, overweight, obese, or morbidly obese experience the physical effects of suspension sooner than lighter workers.
This should be of great concern because we cannot predict the maximum arrest force to which a worker over 310 pounds will be subjected in a 6-foot fall. Therefore, we cannot make assumptions about the physical damage that may occur during a fall or during suspension. Imagine a worker who has fallen 6 feet in a harness, sustained broken bones, or suffered internal damage and must then wait until a rescue can be safely performed. Add blood pressure fluctuations, limited mobility, increased heart rate, and labored breathing likely experienced by an overweight person, and we begin to understand this recipe for disaster.
Testing to create a benchmark that will help to determine the effects of a 6-foot free fall on a worker weighing more than 310 pounds does not exist. It is just too dangerous, and there is no safe way to determine the effects of such tests. Providing a harness for workers weighing more than 310 pounds without understanding the effects may protect the worker's right to work at height, but it does little to protect the worker.
By the end of next year, when the ANSI/ASSE Z359.7 standard is effective, end users of fall protection equipment will be able to sleep a little better at night. They will know the testing of their fall protection equipment that bears the ANSI standard mark was performed in an accredited laboratory with acceptable, calibrated equipment. Test reports will be available to end users. And they will also be assured the appropriate compliance testing was performed and the equipment passed those tests.
This article originally appeared in the July 2010 issue of Occupational Health & Safety.