Slip Resistance Coefficient
How does Slip Resistance Coefficient relate to OSHA requirements?
OSHA does not codify a single numeric CoF for all walking surfaces but recognizes static CoF as a reasonable measure, recommending 0.5 as a guide. This is not an absolute standard; higher CoF may be necessary for tasks involving load handling or ramps. Employers must perform hazard assessments and may adopt higher thresholds (e.g., 0.6-0.8) for elevated-risk areas.
Is there a specific CSA or WorkSafeBC numeric standard for floor slip resistance?
WorkSafeBC emphasizes risk-based controls rather than a single numeric CoF. Canadian guidance commonly uses benchmarks: flat floors should measure at least 0.6 CoF, and ramps at least 0.8. CSA references ISO 13287 for footwear slip resistance testing, while structural standards (CSA S16) define slip coefficients for bolted connections (class A μ≈0.30, class B μ≈0.50).
How do static and dynamic CoF influence slip risk differently?
Static CoF (SCOF) describes friction just before sliding begins, relevant to initial foot contact. Dynamic CoF (DCOF) describes friction during motion, more predictive of slip risk at heel strike and push-off. Footwear standards (ISO 13287) focus on dynamic CoF, while many floor standards reference static CoF. Slip events often occur at heel strike, making dynamic CoF under realistic gait conditions more relevant.
The Slip Resistance Coefficient, or coefficient of friction (CoF), is a dimensionless ratio quantifying frictional force opposing movement between footwear and a walking surface, divided by the force pressing them together. It serves as a quantitative index of slip resistance, with static CoF measuring force to start sliding and dynamic CoF measuring force to maintain sliding. Safety thresholds typically recommend CoF ≥ 0.5 for flat surfaces and ≥ 0.8 for ramps.
On a manufacturing shop floor, the Slip Resistance Coefficient is applied in three main ways. First, during floor surface selection and specification, EHS teams set minimum CoF values (e.g., ≥ 0.5 for flat dry areas, ≥ 0.8 for ramps or wet zones) and verify compliance via tribometer or pendulum tests. Second, in footwear procurement, safety shoes are selected based on ISO 13287 dynamic CoF tests to ensure compatibility with floor finishes and contaminants like water or oil. Third, in risk assessment and incident investigation, measured CoF values are compared to thresholds to identify degradation, guide maintenance, and implement controls such as guardrails or cleaning protocols. This quantitative metric is recorded per location in compliance systems to flag zones below acceptable levels.
Assuming any 'non-slip' or textured floor is compliant without verifying its actual slip resistance coefficient under realistic wet or oily conditions, leading to false security and slips.
Using CoF values obtained in dry laboratory conditions as the sole safety criterion for wet or oily work, ignoring that effective CoF can drop below 0.3-0.4 when contaminated.
Misinterpreting OSHA's 0.5 static CoF guidance as a universal, task-independent standard, without accounting for higher friction needs on ramps or during load handling.