DIN 51097 Areas where walking barefoot on wet surfaces is permitted - Walking Method - Slope Test

The "DIN 51097 Testing of floor coverings - Determination of slip resistance properties - Areas where barefoot walking is possible on wet surfaces - Walking method - Slope test" standard, published by the German Institute for Standardization (DIN), is used to measure slip resistance. It is a critical angle at which two testers, either wearing standard shoes or walking barefoot, reach the safe walking limit on an inclined plane consisting of the tested surface and a contaminant. The slip angle determines the coefficient of friction. This standard assigns A, B, and C ratings (barefoot).

DIN 51097 is a German standard developed to test the slip resistance properties of floor coverings in areas where people walk barefoot and surfaces are likely to be wet. This standard has undergone several updates over the years.

Although partially superseded by the European standard “EN 16165 Determination of slip resistance of pedestrian surfaces - Evaluation methods”, the DIN 51097 standard continues to be widely referenced in the flooring industry, particularly in specifying tiles, mats and coverings in entertainment and hygiene facilities.

This standard is particularly important for environments where slips pose a significant safety risk due to water, soap, or other contaminants reducing friction, such as swimming pools, showers, saunas, changing rooms, and spa areas.

The DIN 51097 test uses a ramp test (inclined plane method) to measure slip resistance under realistic barefoot conditions. This test generally follows these steps:

• A sample of the flooring material is attached to an adjustable ramp.
• To simulate slippery, soapy conditions, the ramp is moistened with a soap solution (water + neutral wetting agent).
• A trained tester walks back and forth barefoot on the ramp as it gradually slopes.
• The critical angle at which the tester slides (acceptance angle) determines the material's performance.

This test is repeated multiple times, and the average angle classifies the floor covering. This method differs from the DIN 51130 standard, which tests under shoe-wearing (while wearing shoes) conditions using oil as a contaminant and assigns R ratings (R9 to R13).

Floor coverings are classified into A, B, and C groups according to the minimum slope angle at which safe walking is possible:

• Group A: Minimum angle of at least 12 degrees. Typical applications are dry, walkable areas with minimal water exposure, such as locker rooms or lockers. Essential slip resistance.
• Group B: Minimum angle of at least 18 degrees. Typical applications are moderately wet areas such as poolside walkways, showers, or areas around pools where water splashes are expected.
• Group: Minimum angle of at least 24 degrees. Typical applications include highly challenging wet or submerged areas such as swimming pool floors, sloping pool entrances, or busy shower areas. Maximum slip resistance is required.

Higher ratings mean better grip and safety in wet conditions. For example, a rating of C is usually mandatory in public swimming pools to minimize the risk of accidents.

Slips and falls in wet areas are a leading cause of injury in public and commercial spaces. DIN 51097 and similar standards help manufacturers, architects, and facility managers select appropriate materials to reduce liability and ensure compliance with health and safety regulations.

Many modern flooring products, particularly porcelain tiles and non-slip mats, are labeled with DIN 51097 standard ratings, along with pendulum tests or other methods for broader verification.

In recent years, the EN 16165 standard has effectively updated the DIN 51097 standard for barefoot areas by incorporating similar ramp testing methods. However, the A, B, and C classification system defined in the DIN 51097 standard remains a practical benchmark in the industry.

For areas where shoes are worn, the DIN 51130 standard applies. Combining both standards provides comprehensive safety in various usage scenarios.

The DIN 51097 standard is considered important for the following reasons:

• The risk of accidents is high in wet and barefoot areas: Slips and falls are among the most common accidents around pools and wet facilities. Wet surfaces and bare feet create dangerous conditions that lead to injuries ranging from bruises and fractures to head trauma and, in the case of near-water or falling into water, drowning. Experts believe that the most critical factor in preventing such slips is the surface characteristics, as properly selected non-slip surfaces maintain grip even when wet or soiled.
• Standardized tests for realistic conditions: Unlike general slip tests (e.g., DIN 51130 for areas with oily shoes), the DIN 51097 standard simulates walking barefoot on soapy, wet ramps. This provides a reliable and repeatable way to classify materials according to their performance under conditions suitable for real-world use.
• Compliance with safety regulations and reduced liability: Many health and safety guidelines refer to DIN 51097 or similar standards for wet barefoot areas. Public and commercial facilities often require minimum ratings to comply with building codes and reduce the risk/liability of injury. Appropriate non-slip flooring demonstrates due diligence in preventing foreseeable accidents.
• Encouraging safer designs with non-slip materials: This standard promotes the use of textured, high-grip tiles or mats that maintain traction in wet conditions and significantly reduce accident rates.

Consequently, the DIN 51097 standard provides a reliable and standardized way to measure barefoot slip resistance in wet environments, promoting safer designs in swimming pools, baths, and healthcare facilities worldwide.

For many years, our organization, with its competent and experienced staff, has been understanding the needs of its clients, providing the advanced testing services they require, and assisting in the establishment, implementation, and improvement of management systems. Within this framework, we also provide testing services in accordance with the "DIN 51097 Testing of floor coverings - Determination of slip resistance properties - Areas where barefoot walking is possible on wet surfaces - Walking method - Slope test" standard.