Coefficient Of Friction Testing
Coefficient of Friction (COF) testing measures the static or dynamic friction ratio between two surfaces, typically footwear versus flooring, to evaluate slip resistance and fall risk. It is a dimensionless ratio (μ = F/N) where F is frictional force and N is normal force. Static COF resists initial motion, while dynamic COF (DCOF) measures sliding friction. Standards like ASTM F2913-24 and ISO 24267 guide testing for workplace safety.
On a shop floor, COF testing is used to assess slip hazards on walkways, stairs, and work platforms under realistic contaminants like water, oil, or dust. Safety teams use tribometers or whole-shoe testers per ASTM F2913-24 to measure DCOF, comparing flooring finishes or footwear for high-risk areas. Results inform risk assessments, footwear selection, and corrective actions like floor recoating or mat replacement. In a SafeDesk system, COF data documents due diligence for WorkSafeBC compliance, triggering alerts when values fall below internal thresholds to prevent slips and falls.
- Using non-standard test methods (e.g., ASTM D1894 for plastic films) instead of footwear/flooring standards like ASTM F2913-24, leading to false confidence in traction.
- Testing only dry, clean surfaces while real hazards involve wet, oily, or dusty conditions, ignoring contaminant effects on COF values.
- Failing to control or document test parameters (load, speed, contaminant type, footwear), making results non-repeatable and indefensible for compliance.
How do static and dynamic COF relate to slip risk?
Static COF (SCOF) is relevant to initial foot contact, resisting start of motion. Dynamic COF (DCOF) is more critical for ongoing gait, as slips typically occur during heel strike or mid-stance. Standards like ASTM F2913-24 focus on DCOF under realistic contaminants to predict slip risk on shop floors.
What does ASTM F2913-24 specifically measure, and why is it important?
ASTM F2913-24 measures dynamic COF between complete footwear and flooring using a whole-shoe tester, allowing testing with contaminants like water, oil, or grease. It supports comparison of safety shoe models under workplace conditions, providing quantitative DCOF data for internal specifications and due diligence evidence.
How do NFSI wet DCOF methods apply to industrial environments?
NFSI wet DCOF methods test wet dynamic COF for hard surfaces using approved tribometers with SBR sensors, originally for barefoot areas like pools. In industrial settings, they evaluate washroom or locker room floors, offering structured wet testing protocols that can be adapted for wet zones, broadening traction management.