ASTM C 1028 - an unreliable safety test
ASTM C 1028 has been officially withdrawn, with no replacement, in 2014 by the ASTM. There are no plans to resurrect this poor
test method for measuring wet static coefficient of friction (SCOF). The days of looking to achieve a 0.60 for level floors and a 0.80 for ramps is now officially over. Here is some information on
currently valid slip test methods. The latest (2012) building code requires a 0.42 DCOF rating according to the ANSI A137.1 slip test method.
The ASTM C 1028-07
static coefficient of friction test is widely recognized to be inappropriate for assessing pedestrian safety. It can give "safe" ratings to very slippery materials. This weakness is recognized in writing by Ceramic Tile Institute of America, Tile Council of North America, and the University of Southern California Medical Center Biomechanics Department, as well as being known by forensic experts worldwide:
1. Ceramic Tile Institute of America (CTIOA.org
) in 2001 explained the weaknesses of the ASTM C 1028 method
and endorsed the pendulum as a primary standard, with the Tortus secondary. The endorsement from ctioa.org states, "These portable tests are intended to replace the horizontal pull-meter test, American Society for Testing and Materials Method C 1028-96, that U.S. ceramic tile manufacturers currently use for field testing of their products."
2. Eric Astrachan, Executive Director of Tile Council of North America, stated in his article "Updates to an American Method for Measuring Coefficient of Friction
" that dynamic friction is important in assessing safety. Static coefficient of friction (measured by the ASTM C 1028) does not properly measure slip potential for flooring.
3. A published human traction study by the University of Southern California Medical Center proved that the static friction test (ASTM C 1028) had no relationship to human traction.
4. The Access Board of the U.S. Department of Justice is responsible for establishing guidelines for accessibility to disabled persons (in other words, they set the guidelines for the "required" slip resistance of flooring for the ADA, or Americans with Disabilities Act). The Board is often quoted as having in 1991 recommended a minimum static coefficient of friction of 0.60 for level floors and 0.80 for ramps. In fact the Access Board states in a May 17, 2011 letter
that they never recommended that, but had quoted the recommendation from a research project they funded. Further, the Access Board is not authorized to establish guidelines for public safety, they state. In 2004 they "rescinded the advisory material" and in May 2011 removed from their website "the technical assistance bulletin … that references the 1991 guidelines and its advisory note."
Eric Astrachan also stated in his article (above) that there are "common requests for tile with a static COF [using ASTM C 1028] of 0.6 or better (which) stems from a now outdated ADA Access Board
document in which a 0.6 static COF recommendation was made. Commonly misunderstood, this document never set a requirement and has now been withdrawn. The United States Access Board subsequently
published a document called "Bulletin #4: Ground and Floor Surfaces" that clears up much of the confusion about this issue and which has no [static] COF recommendation or requirement."
Other devices such as the American Slip Meter ASM 825A and the "James Machine" also assess static coefficient of friction and they are subject to the same risks and drawbacks as ASTM C 1028. These
should NEVER be used to assess pedestrian safety in the wet or otherwise lubricated condition.
Another common misunderstanding is that OSHA recommends a minimum coefficient of friction (COF) of 0.50 for workplace flooring surfaces. They have, but without specifying how the COF is to be determined. Different slip resistance test methods give completely different results, particularly under wet conditions. So the same floor could have coefficients of friction of 0.3, 0.4, 0.5, or 0.6 (or anywhere in between) depending entirely on what test method was used. The OSHA recommendation is therefore meaningless, and has been causing confusion for many years.
(This webpage was last updated in January of 2018...be careful of old information!)
This video helps explain one of the major problems with the C1028 slip resistance test and shows reliable coefficient of friction testing methods...
Valid professional, certified, engineer-stamped floor slip resistance testing services and information on
making floors anti-slip are available at SafetyDirectAmerica.com