Harness Hazard Alert No. 2

Summary

Thigh straps (aka leg straps) of all harnesses should be worn by males high on their thighs, almost in the crotch area, and should be prevented from loosening up and subsequently sliding down.

The reason for the above is that during the arrest of an accidental fall all straps of the harness move upwards and tighten. If the thigh straps were to hang loosely and then suddenly go up, male genitals may get caught in between one of the loose straps and the thigh, and may be injured.

The Hazard

What is it? The thigh straps of a harness will be tensioned when the fall arrest forces act on the back D-ring of the fall victim’s harness. This tension will attempt to pull the thigh straps towards the crotch area. If, immediately before the fall, these straps were being worn loosely and were hanging along the thighs, at the instant of the fall arrest they will be suddenly pulled upwards and may squeeze male’s genitals. This may result in an injury.

Why does it exist? This hazard exists primarily because the users, unaware of this hazard, prefer to have the thigh straps hanging loose in order to allow for easy climbing. The buckles on the thigh straps may be of a free-sliding-bar design (see Figure 1 on Page 2) which allows for loosening up of these straps. The centre bar slides freely along the buckle’s frame as there is no flat spring in the buckle. Such buckles hold straps firmly only when tensioned, but when worn on the thigh - the muscles’ contractions and expansions, particularly during climbing, cause cyclical tensioning-loosening of the thigh straps. These cycles ultimately lead to the free-ends of straps moving through the buckles, thus loosening the initial grip over thighs and subsequently causing the thigh straps to slide down. Different buckles, of the type which do not rely on constant tension between the straps are safer. These include those with a sliding bar which is spring loaded and not free sliding. In general, the male anatomy makes this hazard difficult to eliminate completely.

Where can you experience it? This hazard exists in Fall Arrest Systems (FASs) with harnesses which are worn with loose thigh straps. Since in many harnesses their user friendliness during climbing improves either when the thigh straps are worn as high as possible (the preferred, recommended way) or when they are quite loose - the poorly trained users often opt for the latter solution.

Who is affected by it and when? Users who climb frequently (electric utility linemen, tower erectors, telecommunication technicians, scaffolders etc.) are particularly exposed to this hazard. Users of harnesses with free-sliding-bar buckles on the thigh straps are also in this high risk category. Workers who have to wear a harness underneath their coveralls or special purpose suits (e.g: radiation protection suits worn by maintenance personnel around the nuclear reactors) are unable to visually check and re-adjust their harnesses, and therefore are also exposed to this hazard.

How to Eliminate It Or Minimize Its Consequences?

1. Train users in how to minimize this hazard by wearing the thigh straps high on the thighs at all times.
2. Do not use harnesses with free-sliding-bar buckles on the thigh straps.
3. If you climb frequently and at a quick pace, wear a special protective cup (for genitals) of the type which is commonly used in several male sport disciplines in which there exists a risk of injury to this part of the body (e.g.: ice hockey, baseball, football).
4. Provide proper training in fall protection to all users of Fall Arrest Systems (FASs).
5. Follow User’s Instructions supplied with each harness by the manufacturers.

Additional Information and Comments

The thigh/leg straps of many models of harnesses are often perceived to be uncomfortable when worn snugly around the thighs, particularly, when climbing is a major part of the harness user’s workday. On some harnesses, according to their users, having these straps hang loosely on the thighs may actually be the simplest way of feeling less constrained by the harness when climbing. These practices are not recommended but must be recognized as common practice.

On some harnesses with tongue-and-grommet buckles on the thigh straps, the spacing between the grommets makes the straps too loose when buckled.

While no major permanent disability has been reported due to this hazard, minor injuries have been documented. Although unconventional, but very likely the most effective protection in the form of sports-style protective cups. This may be the best solution for frequent climbers.

References

1. Lost time fall accident injury. Transmission lineman. Confidential medical records.
2. Sulowski, A.C., “Fall Arrest Systems - Practical Essentials”, Published by the CSA International, January 2000, Toronto, Ontario, Canada.
3. ANSI Z359.1-1992 (R1999) American National Standard safety requirements for personal fall arrest systems, subsystems and components. American National Standards Institute Inc., New York, NY, and American Society of Safety Engineers, Des Plaines, IL.
4. “Qualified Inspector of Fall Protection Equipment” Seminar Manual, Sulowski Fall Protection Inc., Toronto, ON, 1997.
5. “The Fundamentals of Fall Protection” Seminar, CSA International, Toronto, ON, 1999.

Figures

Figure 1 - Free-Sliding Bar Buckle