Abandoned, Withdrawn and Flawed Floor Slip Resistance Test Methods Continue to Plague the USA

Slip and fall accidents can have serious consequences, leading to injuries and even fatalities. That’s why it’s crucial to ensure the safety of floors, particularly in public areas such as shopping centers, hotels, and hospitals. However, not all floor slip resistance testing techniques are created equal, and some American tests have even been withdrawn or abandoned over the years for being bogus. It’s really just in the ultra-litigious USA that these flawed and bogus test methods appear. The rest of the world has mostly been using the pendulum tester for over 50 years now to aid in reliable slip and fall accident prevention.

One such bogus technique is the James Machine, which was developed in the 1940s and became popular in the 1970s. The machine measures the static coefficient of friction (SCOF) of a flooring material, which measures how slippery a floor is to someone who is standing still (static) on a clean and dry floor (the test is done dry). The James Machine has been criticized for being unreliable and not reflecting real-world conditions. In fact, ASTM F489, the “Standard Test Method for Using a James Machine”, was withdrawn in 2005 since it was likely the cause of countless slip and fall accidents by giving high SCOF readings to very slippery floors.

James Machine slip test

Older James Machine SCOF Tester

Somehow, ASTM D2047 is still an active ASTM standard (and used in UL 410), but says it’s only for measuring the SCOF of “Polish-Coated Flooring Surfaces”. Flooring salespeople and manufacturers like to ignore that fact and use results from this highly flawed and irrelevant test to help them sell slippery flooring. Again, no matter what type of flooring you’re testing (polish-coated or not), figuring out if someone will slip on a clean and dry floor while standing still on it will always be irrelevant. To use this test to say your floor is slip resistant under wet or otherwise contaminated conditions (dust, etc.) is nothing short of fraud.

Another largely bogus slip resistance testing technique in America is the ANSI A326.3 DCOF AcuTest, which measures the dynamic coefficient of friction of a flooring material using an SBR rubber foot which is dragged across the floor using the BOT-3000E digital tribometer. This tile manufacturer-created test has been criticized for producing erroneous and misleading results and not being representative of real-world slip resistance in many cases, especially on many polished concrete, epoxy, polish-coated, and polished stone floors.

BOT-3000E Slip Resistance (COF) Tester

The BOT-3000E used in the DCOF AcuTest

The ANSI A326.3 test method is full of disclaimers and warnings due to the inconsistencies with this test method. Some of the most glaring warnings in ANSI A326.2 are, “it can provide a useful comparison of surfaces, but does not predict the likelihood a person will or will not slip on a hard surface flooring material”, “No claim of correlation to actual footwear or human ambulation is made”, and “Because many variables affect the risk of a slip occurring, the measured DCOF value shall not be the only factor in determining the appropriateness of a hard surface flooring material for a particular application.” To use this test to say your floor isn’t slippery when wet would be to ignore what the test method itself says.

Some of the most notorious bogus slip resistance testing techniques created in the USA are the English XL Variable Incidence Tribometer (VIT), and the Brungraber Mark I/Brungraber Mark II/Brungraber Mark IIIB Slip Testers. The Brungraber Slip Testers and English XL have been criticized for producing artificially high results that do not reflect real-world slip resistance. These instruments have proven to be very popular mostly amongst expert “liars for hire” who usually work for defense attorneys in high-dollar slip and fall lawsuits. In fact, the National Floor Safety Institute, a non-profit organization dedicated to preventing slip and fall accidents, has called the machines “unreliable and invalid.” As a result, the ASTM International withdrew its support for the Brungraber Mark II and English XL in 2006. So did OSHA.

See the pendulum in use doing ASTM E303 in this video


In conclusion, it’s essential to choose a reliable and valid floor slip resistance testing technique to ensure the safety of floors. The pendulum floor slip resistance tester has been in use for over 50 years and has a peer-reviewed published test method in at least 50 nations. None have been withdrawn or abandoned. In the USA, ASTM E303 was updated in 2022 to include better instructions for getting more precise readings when testing the slip resistance of floors. Originally published in 1993, ASTM E303 was updated to make it more like the European/United Kingdom (EN 16165) and Australian/New Zealand (AS 4586) versions of the pendulum DCOF floor tests.

The use of bogus or withdrawn floor slip testing techniques such as the James Machine, BOT-3000E, English XL and Brungraber Mark IIIB Slip Testers underscores the need for accuracy and consistency in floor slip resistance testing in the USA. By using a valid and reliable slip resistance testing technique, you can help prevent slip and fall accidents, keep your property safe, and avoid costly slip and fall lawsuits.

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