Most people recognize the name Leonardo da Vinci – the Renaissance painter behind hugely famous works like the Mona Lisa and The Last Supper. But few people know he was also one of the first people to understand the importance of friction and the role it plays in the interaction of materials.
He observed that different materials move across different surfaces with varying degrees of difficulty. Although da Vinci made the discovery, he never officially published any of his observations – typical absentminded creative type – so all the credit went to Guillaume Amontons, who rediscovered the laws over a century later. In honor of da Vinci’s work, though, scientists and engineers who study and measure the resistance of walking surfaces now recognize da Vinci as the father of tribometry – the measurement of friction on a surface.
Today, tribometry figures heavily into floor safety. Having the right amount of friction between the floor and the soles of the shoes of the person walking on it is essential. Slips and falls happen when the coefficient of friction (COF) between the two surfaces is insufficient.
Typically, rough surfaces like brushed concrete or carpet have a higher COF than smooth surfaces like polished marble, tile or wood. Dry surfaces also generally have a higher COF than wet ones. When you’re trying to decrease the likelihood of slips and falls in your workplace, increasing the COF of walking surfaces is often part of the solution.
A surface’s COF can be measured with a machine called a tribometer. This tool simulates the action of a foot on the walking surface. The higher the measurement, the better the friction is between the two surfaces. When measuring COF, it is important to note that the measurement reflects the condition of the floor when the measurement is taken. The floor may have a high COF when it’s dry, but be very slippery when it’s wet.
OSHA recommends a COF of 0.50 on dry surfaces, but does not specify the method to be used for testing it. The ADA recommends a COF of 0.60, but like OSHA, no test method is specified.
Because it was difficult to determine how to achieve the recommended COF, the National Floor Safety Institute (NFSI) and the American National Standards Institute (ANSI) jointly published a set of standards to provide guidance for facilities that want to quantify the safety of their walking surfaces.
The standards also provide guidance for using a binary output tribometer (BOT) on both wet and dry surfaces. The readings from these machines can be used to help facilities determine where they may need to focus on improving COF to help prevent slips and falls.
There are a lot of different ways to increase the COF of different walking surfaces – and prices range from inexpensive to major investment. Some of the quicker, less expensive solutions for different areas throughout the facility include:
Foyers and Entrances
Receiving and Shipping Docks
- Replacing smooth metal walking surfaces with diamond plate
- Using squeegees or absorbents to manage rain or snow that enters when dock doors are open
Cafeterias, Break Rooms and Coffee Islands
- Placing adhesive-backed floor mats in front of ice machines, sinks and microwaves
- Ensuring that there are adequate supplies of paper towels or napkins to quickly clean up messes as well as sufficient trash cans to collect wastes
Da Vinci once said, “Knowing is not enough, we must apply.” So you understand the role that friction plays in floor safety and that areas with slippery surfaces are prone to contribute to slip and fall injuries. Now it’s time to do something about it. The first steps toward improving floor safety are to identify potentially dangerous areas in your facility and implement solutions to decrease the likelihood of injuries.