ANSI A326.3 Acutest Does Not Predict Likelihood of Slip

A widely used floor friction test, American National Standards Institute A326.3, states in its introduction that “it can provide a useful comparison of surfaces, but it does not predict the likelihood a person will or will not slip on a hard surface flooring material.” The test assesses wet dynamic coefficient of friction (DCOF) using the BOT-3000E digital tribometer. Higher DCOF is normally expected to correspond to greater slip resistance. (An earlier ANSI standard, A137.1, specifies essentially the same test method as ANSI A326.3.) Strangely, the newer standard also says that “for the elderly and disabled who slide their feet on the floor … smooth and dry flooring is needed, specifically flooring with a low wet COF that is kept dry when in use.” Apparently these people  — about 65 million Americans — are not expected to be outdoors when sidewalks, streets, outdoor malls, and plazas are wet with rain or dew.

The manufacturer of the BOT-3000E states that “The ANSI A326.3 standard calls for a specific SBR rubber sensor which simply is not suited for rough, exterior surfaces … a method which uses the BOT to test rougher surfaces would have to prescribe a more robust sensor material.” Most outdoor surfaces that are safe for pedestrians, such as typical sidewalks, roads and crosswalks, have surfaces that are much rougher than typical indoor surfaces.

The BOT-3000E, in our vast experience testing with it, should never be used to assess the slip resistance of polished concrete floors. Using the BOT-3000E to test a polished concrete pool deck would be incredibly dangerous. ANSI A326.3 was published by a “tile council” that works for tile manufacturers and polishing associations. It’s like trusting a candy salesman when he says that their sugary candy doesn’t cause cavities in teeth.

A number of expert witnesses in slip and fall litigation — some of them unabashedly crooked — use test devices and methods that were withdrawn with no replacement years ago by the American Society for Testing and Materials (ASTM), for reasons that included poor precision. These include the English XL and its withdrawn standard ASTM F 1679, and the Brungraber Mark II with ASTM F1677. The users of these instruments are now using a round-about way of trying to give their instruments with poor precision some sort of “validity” by “passing” ASTM F2508, but “passing” this standard does not validate these instruments at all. But with the notorious precision problems associated with the XL, Mark II and Mark III slip test devices, their users are always trying to find some way of unscrupulously fooling juries.

Selection of flooring for areas that get wet in use (restrooms, plazas, commercial kitchens, flower shops, etc.) is often based solely on initial slip resistance — that is, when the flooring comes out of the box before being installed. Unfortunately wet slip resistance is not an immutable property that remains constant forever. Some flooring in areas with high foot traffic loses its good wet slip resistance in a matter of a few weeks, creating a dangerous condition. That is why McDonalds Restaurants spent years developing the test for Sustainable Slip Resistance. The flooring is first tested wet with the pendulum (using a hard or soft rubber slider, or both, as appropriate), abraded using a standard technique, then tested again with the pendulum DCOF tester. Flooring that scores a wet Pendulum Test Value of 35 or higher after abrasion is said to have Sustainable Slip Resistance.

The pendulum test has more than 40 safety standards for specific situations such as external ramps; bathrooms, wards and corridors in hospital and ages care facilities; supermarket aisles; communal shower rooms; wet stairs; and swimming pool decks, ramps and stairs leading into the water. These standards have been in effect essentially unchanged (though reaffirmed) since 1999.

Two ceramic tile and porcelain manufacturers, Daltile and Marazzi, state that “ceramic and porcelain tiles shouldn’t be used in areas where oil, grease, or water is expected on the floor both indoors or out.” [emphasis added] Then they proceed to recommend guidelines for wet DCOF minimums in wet, oily or greasy areas. One might question how useful these contradictory statements would be when a property owner is defending against a large personal injury lawsuit. It appears that the manufacturers will not turn down sales for the forbidden areas, but they appear to have ducked any responsibility with their caveat.

Neither manufacturer acknowledges that the slip resistance of their product is likely to change with wear.

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