U.S. workplace context
OSHA requires walking-working surfaces to be kept clean and, to the extent feasible, dry, and free of hazards such as leaks, spills and damaged surfaces.
No universal magic number
Different test methods, products and jurisdictions use different criteria; a single coefficient should not be treated as universal compliance.
Wet processes
Where wet processes are used, drainage and suitable standing conditions become part of workplace planning.
Maintenance matters
A floor's real-world slip behavior can change with wear, cleaning chemistry and contamination.
Commercial flooring decisions depend on the actual substrate, moisture conditions, traffic, cleaning regime, accessibility requirements, fire/building rules, manufacturer instructions and local code. This site is for planning and comparison, not installation instructions.