In June’s post we discussed situation-specific slip resistance safety standards, which reflect the use or function of a floor and the friction (coefficient of friction) demands placed on it. Many U.S. floor friction standards are “one size fits all” — for instance, a wet dynamic coefficient of friction (DCOF) of 0.43 is considered adequate for any situation where the (level) floor gets wet. Traditionally, using the ASTM C 1028 method of assessing a floor’s slip risk, a 0.60 static coefficient of friction (SCOF) was considered adequate. (However, ASTM has officially withdrawn that test method, and so the 0.60 safety criterion is now a thing of the past. It no longer has any relevance whatsoever.)
Would you expect a posh hotel lobby to have the same demand for traction as a basketball court? The higher speeds and rapid acceleration and stopping demands of basketball call for a much higher, but still limited, amount of friction. This comparison is just one example of why different slip test safety standards are appropriate for different floor areas.
After 15 years of experience with the sophisticated safety standards mentioned above, Standards Australia on June 16, 2014 issued an improved version (preview: HB_198-2014). Wet slip resistance (or the dynamic coefficient of friction), as before, is tested using the British pendulum instrument. Either soft or hard rubber sliders can be used to simulate dress shoes (“Four S” hard rubber) or athletic shoes and bare feet (“TRL” soft rubber). Only one of the safety criteria (either hard or soft rubber) need be satisfied to comply with the slip test safety standard.
The new safety standards are summarized in Table 1 below. For example, Line 1 shows that steep outdoor ramps should have a wet Pendulum Test Value (PTV, which is also sometimes called BPN for Brithish Pendulum Number), tested with soft rubber, of at least 45. On the other hand, for normally dry areas in hotels, elevator lobbies and kindergartens, a wet PTV of 12 (hard rubber) is adequate. (Remember that dry areas can get contaminated with dust and with tracked-in grease from a parking area or kitchen. Wet slip resistance can help prevent slips in these cases.)
Table 1. Standards Australia slip resistance minimums
Swimming pool decks, preferably tested with soft rubber (to simulate bare feet), should have a minimum PTV of 40, but for hospital and aged care facility bathrooms a PTV of 35 is considered adequate.
The Australian standards also quote requirements for dry and wet stairs and landings, which were already specified in the National Construction Code there. Dry stairs need a wet PTV of 35 or higher, while even more stringent standards apply to wet stairs.
We at Safety Direct America conduct both laboratory British pendulum skid tests, and testing at your location on your existing floors. We also test using the ANSI A137.1 ceramic tile slip resistance test procedure and safety standards specified by the 2012 International Building Code (IBC), using the BOT-3000E digital tribometer. In many cases the IBC safety standard will be easier to meet than the Australian standard. The IBC standard is very permissive in some circumstances, making it easier to sell slippery flooring. The Australian standards are not as vendor-friendly and so are a much more reliable method of preventing accidents, injuries, and litigation.
Regarding the basketball court mentioned above, it’s not included in the Australian standards. An ASTM standard and a European standard specify a PTV between 80 and 110, with no part of the court deviating from the mean by more than 4 units. This applies to dry testing if the court is kept dry in use. For safety, most indoor basketball courts (being very smooth and glossy) must be kept dry by assiduously wiping up sweat deposited when players fall (or get knocked down), which they very frequently do.