OSHA’s “Suggestion” for Minimum Floor Coefficient of Friction (COF)
We often hear the question, “What does OSHA require for floor slip resistance?” The answer is that OSHA doesn’t require anything, but nevertheless has caused a lot of confusion for employers and the public on this subject. There has never been an official OSHA slip test or safety standard for flooring.
In a nonmandatory appendix to a proposed rule in 1990, OSHA said, “A reasonable measure of slip-resistance is static coefficient of friction (SCOF) … is recommended as a guide to achieve proper slip resistance. A COF of 0.5 is not intended to be an absolute standard value. A higher COF may be necessary for certain work tasks, such as carrying objects, pushing or pulling objects, or walking up or down ramps.”
The 0.5 SCOF figure later seemed to achieve even more credibility when OSHA was quoted by the ADA Accessibility Guidelines (ADAAG) of the Department of Justice Access Board. OSHA opined that this is the reason the 0.5 SCOF figure is often attributed to OSHA.
The OSHA appendix didn’t specify how COF was to be measured. Different methods of measuring COF give different answers. For instance, using leather to simulate shoe bottoms will give a different COF for the flooring-shoe bottom combination than if rubber or polyurethane (the latter being common for high heels) is used. Also, different devices (e.g. ASTM C1028, BOT-3000E, pendulum, James Machine, etc.) give different answers. Thus it’s very feasible for the same flooring to have a COF of 0.4, 0.5, 0.6 and 0.7 (or anywhere in between), depending only on the test method. Therefore to say that 0.5 is a minimum — without specifying the test method — is totally meaningless.
In addition, static coefficient of friction (SCOF) measurements may apply to people standing still, but they have long been discredited for assessing safety when people are walking or running or in motion conducting various work activities on floors that may at times be wet or otherwise lubricated.
For many years there have been recurring rumors that OSHA will make a rule regarding floor slip resistance, but at this time that doesn’t look like it’s going to happen.
OSHA is correct that various activities and work tasks put different demands on floor friction. (This is correctly, though vaguely, reflected in the 2012 International Building Code.) There are standards that allow for these differences, and Safety Direct America can supply the test data and safety standards to determine whether a particular flooring is appropriate.