The Science Behind Slip Resistance in Work Footwear
Slip, trip, and fall incidents represent over 30% of all workplace injuries worldwide, according to occupational health and safety data. In demanding sectors such as heavy chemical manufacturing, offshore drilling, food processing, and logistics warehouses, worker footing is the single barrier preventing devastating falls.
As a vertically integrated safety shoes manufacturer with 25 years of tannery and footwear engineering heritage in Kanpur, New Era Group builds lasted uppers and outsole combinations tested rigorously against European standards. In this guide, we demystify how slip resistance is measured, what SRA, SRB, and SRC mean, and the crucial changes introduced in the recent EN ISO 20345:2022 harmonized standards.
Decoding SRA, SRB, and SRC Ratings (EN ISO 20345:2011)
Under the widely recognized EN ISO 20345:2011 standard, slip resistance was evaluated across three distinct categories using mechanical coefficient of friction (CoF) testing rigs:
| Rating Code | Test Surface & Contaminant | Minimum Flat Friction | Minimum Heel Friction |
|---|---|---|---|
| SRA | Ceramic tile lubricated with Sodium Lauryl Sulfate (detergent solution) | ≥ 0.32 | ≥ 0.28 (at 7° angle) |
| SRB | Smooth steel plate lubricated with Glycerol (industrial oil substitute) | ≥ 0.18 | ≥ 0.13 (at 7° angle) |
| SRC | Passes BOTH SRA + SRB requirements under all conditions | ≥ 0.32 (Ceramic) / ≥ 0.18 (Steel) | ≥ 0.28 (Ceramic) / ≥ 0.13 (Steel) |
Achieving an SRC certification signifies that footwear provides elite slip prevention against both aqueous detergents (wet shop floors) and viscous hydrocarbons (automotive, machinery, and petroleum oils).
What Changed in EN ISO 20345:2022? (The New 'SR' Rating)
The updated 2022 standard refined slip testing to ensure more realistic workplace conditions:
- Mandatory Basic Requirement: Testing on ceramic tile with NaLS detergent (the former SRA) is now a mandatory baseline for all safety footwear—it no longer carries a separate suffix label because every certified shoe must pass it.
- The New 'SR' Marking: Footwear that successfully passes additional rigorous testing on ceramic tile with glycerol receives the prestigious SR marking, superseding the old SRC designation.
- Ø Marking: If a safety boot is specifically built for special environments (such as spiked footwear for forestry or logger boots) where flat surface testing is inappropriate, it receives the Ø designation.
Outsole Tread Engineering: How Traction is Achieved
Slip resistance is never an accident—it is the result of precision compound chemistry and tread architecture:
- Cleat Geometry & Spacing: Cleats must be angled to channel liquids away from the contact patch, preventing the dreaded "aquaplaning" effect where fluid gets trapped beneath the sole.
- Micro-Siping: Narrow slits engineered into tread lugs act like windshield wiper blades, slicing through lubricant films to make direct dry contact with the subfloor.
- Dual-Density Polyurethane (PU/PU): A softer PU midsole absorbs shock and allows the tread to deform slightly around micro-textures of the floor, while an ultra-durable PU or Nitrile Rubber outsole provides fuel oil resistance (FO) and abrasion resistance.
- Beveled Heel: A 7° to 10° beveled heel ensures maximum initial contact area the instant a worker takes a stride, preventing backward slips.
Need Custom SRC-Certified OEM Safety Footwear?
New Era Group produces over 50,000 pairs monthly of custom lasted uppers and stuck-on slip-resistant footwear for global brand partners across Europe, the Americas, and GCC.
Request an OEM QuoteHow Upper Construction Affects Foot Stability
An outsole can only perform if the worker's foot is securely anchored above it. Poorly constructed uppers allow the foot to slide internally during rapid directional changes, causing workers to roll their ankles even if the sole has gripped the floor.
Our precision-lasted uppers, crafted using DIN-certified full-grain and Barton leathers from the New Era Tanning Centre, hold the heel counter rigid and mold ergonomically around the instep. This guarantees that downward force is transferred directly into the outsole cleats for maximum grip.
Conclusion & Buyer Recommendations
When drafting technical tenders or purchasing OEM collections, always specify the required friction rating based on your end-users' daily hazard matrix. For oily environments, insist on SRC / SR ratings paired with high-tensile lasted leather uppers.
Kanpur, U.P. (India) • Specialist in Industrial Safety Footwear & Tannery