Anti-Slip Standards for Walkways: Coefficient of Friction, DIN 51130 and OSHA
Slip resistance is specified three ways depending on jurisdiction — and gritted FRP grating clears all three.
Coefficient of friction (COF)
The most portable number. Most industrial specifications set a minimum COF of 0.5 (wet) for walkway surfaces. Typical gritted FRP data: 0.9+ dry, 0.7–0.8 wet. Meniscus surface: ~0.5–0.6 dry, lower wet — the reason grit is specified wherever wet service exists.
DIN 51130 (R-classes) — German/EU practice
A ramp test with an operator walking a controlled oil-wet incline; the angle sets the class:
| Class | Angle | Typical application |
|---|---|---|
| R9–R10 | 6–17° | Indoor general areas |
| R11 | 10–19° | Wet industrial work areas |
| R12–R13 | 18–35° | Oily processing, ramps, food industry |
Gritted FRP grating is commonly tested at R12–R13; ask for the report with your order if your spec cites DIN.
OSHA — US practice
OSHA 1910/1926 rules require walking-working surfaces free of hazards, with slip-resistant surfaces where tools, machinery or processes create slip risk (and specific slip-resistance language for fixed ladders). There is no numeric COF in the rule — the requirement is performance-based, which is why US specifications typically import the 0.5 COF or R-class numbers anyway.
Practical specification line
“Walkway surface: integral bonded quartz grit, COF ≥ 0.7 wet per [test report], R-class ≥ R11 per DIN 51130.” Short, testable, and answered by the standard gritted product.