Choose anti-slip sandals by the outsole material, tread depth, and heel security — rubber soles with defined tread generally grip wet floors and uneven terrain best.
Most “non-slip” marketing promises less than the label suggests, and the real mistake shoppers make is picking a pair before naming the surfaces they’ll actually walk on. The right sandal for a slick restaurant kitchen is a different shoe from one built for a damp pool deck or a gravel path. Once you match the outsole and tread to the environment, the rest of the decision gets simple.
What Makes A Sandal Actually Slip-Resistant?
Slip resistance starts with the outsole compound and the tread pattern, not the brand name. The Health and Safety Executive (HSE) points to rubber soles as providing generally better grip on wet floors than polyurethane alternatives, so that alone narrows the field.
The tread geometry matters just as much as the material. Look for a sole with a well-defined pattern and plenty of edges — those edges create friction and channel water or oil away from the foot. Deep, blocky lugs suit rough outdoor ground, snow, mud, or loose dust. A finer, denser tread with more contact points often works better on smooth indoor floors with thin liquid film, where larger lugs can actually reduce contact and hydroplane.
The Materials That Grip:
- Rubber: Best all-around grip on wet and oily surfaces; durable on rough terrain.
- Polyurethane: Common in budget sandals; can be harder and more slippery on wet film.
- Tread edges: More edges and siping (small slits) increase surface contact and fluid dispersion.
How Should The Sandal Fit And Hold Your Heel?
A slip-resistant sole won’t save you if your foot slides out of the shoe. Heel security is the second critical factor — a secure heel strap or a fully enclosed back keeps your foot planted and your center of gravity over the sole. Thong-style flip-flops let the foot drift forward and sideways, which is exactly when instabilities happen, especially near water.
Fit at multiple points is non-negotiable. The sandal should hold your heel snugly, your arch should sit on the footbed’s support, and your toes shouldn’t overhang the front. If the foot can slide forward even slightly, you’re already at risk on a wet surface. This guidance aligns with OSHwiki’s emphasis on footwear retention — a shoe that doesn’t stay put on your foot can’t do its job.
Do You Need Certified Slip Resistance?
For retail and home use, a rubber sole with good tread is usually enough. For workplace or occupational use, the rules are stricter, and you need to verify claims, not trust them.
In U.S. occupational settings, the main whole-shoe slip-resistance test method is ASTM F2913. While OSHA doesn’t issue a slip-resistance rating standard, some footwear is certified under the ASTM F3445-21 performance specification — a scheme tied to the F2913-19 test method. Shoes certified under that scheme may carry an “F3445-21 SR” label.
Industry guidance from Occupational Health & Safety is blunt: in this class of footwear, look for test data, not brochure adjectives. When you’re buying for a business, ask the supplier for the specific standard the shoe was tested against, the coefficient of friction (CoF) score, and a trial pair for real-world testing on your own floor — something HSE officially recommends before a large purchase.
| Setting | Recommended Tread | Key Consideration |
|---|---|---|
| Wet indoor floors (kitchens, hospitals) | Finer, dense tread | Channels thin liquid; prioritizes contact area |
| Oily or greasy surfaces | Soft rubber, siped edges | Edges needed to break oil film |
| Pool decks / rain | Deep, open lugs & secure heel | Drainage prevents hydroplaning |
| Outdoor uneven terrain | Aggressive, deep lugs | Stability on gravel and dirt |
| Mud or loose dust | Self-cleaning, wide-spaced tread | Prevents clogging and loss of grip |
Beyond The Sole: Other Safety Hazards
Slip resistance is one layer of protection and never the entire story. In many workplaces where slip hazards exist, slip-resistant footwear is required PPE, but the hazard assessment may demand additional protection — impact, puncture, electrical, or metatarsal — depending on the job.
Verify whether a certification like ASTM F3445-21 SR covers only slip testing or if it includes other protections; it generally does not. For most home and casual use, a rubber outsole, proper tread depth for the terrain, and a heel that locks your foot in place will cover you. For work, demand test data and a trial pair.
If your decision comes down to a specific model, HSE’s footwear procurement guidance outlines the full selection criteria and testing advice.
References & Sources
- Health and Safety Executive (HSE). “Slips and trips: Footwear procurement.” Official guidance on sole materials, tread, fit, and trial pair testing.
- OSHAWiki. “Measuring slip resistance of floorings and footwear.” Technical overview of slip-resistance testing and foot retention.
- Occupational Health & Safety. “Decoding Safety Footwear Standards.” Industry article on ASTM F3445-21 SR certification and its link to F2913-19 testing.