Dynamic Coefficient of Friction, or DCOF, measures how slip resistant a floor is while someone is actually walking on it, using a wet testing method that has replaced older static friction standards.
Understanding Dynamic Coefficient of Friction
Dynamic Coefficient of Friction, or DCOF, measures the slip resistance of a floor surface while it is in motion, simulating an actual footstep rather than a foot resting still. It has become the industry standard for rating slip resistance because it more closely reflects how people actually slip and fall.
DCOF vs. Static Coefficient of Friction
Older slip resistance standards relied on Static Coefficient of Friction, which measures resistance to a stationary foot and was long associated with a 0.5 benchmark, mistakenly attributed to OSHA for years before being formally retracted. DCOF testing, defined under ANSI A326.3, measures resistance under a wet, moving load and is now the accepted method for rating tile and resinous flooring.
The 0.42 Benchmark
ANSI A326.3 sets a minimum wet DCOF of 0.42 for flooring in areas expected to be walked on when wet, a threshold also adopted by ANSI A137.1 for ceramic tile and referenced in the International Building Code. Coatings and non-slip additives are chosen and tested against this number for high risk areas like pool decks, commercial kitchens, and locker rooms.
Why This Matters for Coating Selection
A smooth, glossy epoxy or polyaspartic topcoat alone will not meet a 0.42 wet DCOF rating in most cases. Non-slip additives such as aluminum oxide or polymer grit need to be broadcast into the finish coat at the right rate to hit code required slip resistance, especially in areas covered by ADA guidance or the International Building Code.
Also Called
DCOF, Wet Dynamic Coefficient of Friction
