December 22, 2022
According to the National Safety Council, slips, trips, and falls remain one of the leading causes for work related injuries in the Unites States. Knowing this, it may be surprising to learn that currently there is not a federal standard or mandate in place regarding slip resistance for flooring.
The standards established by the American National Standard Institute and Tile Council of North America are typically used as guidelines for hard surfaces (ceramic tiles and stone), and can be applied to other hard surfaces such as resinous flooring. Despite these being periodically modified and updated, there is still debate regarding a globally recognized standard and / or test method.
This guide was created to help give a broader understanding to slip resistance and how it applies to resinous flooring. It gives a brief history on past and current American standards. It also explores the concern behind why a universal standard has not been reached, and how one can ensure their flooring will provide adequate slip resistance.
Sections
- Background
- Historical Standards for Slip Resistance
- Current Standards for Slip Resistance
- Debate on Test Methods
- Specifying Slip Resistance- Dur-A-Flex
Background
The Coefficient of Friction (COF) is a metric used to gauge the slip resistance of flooring. Coefficient of Friction is defined as the ratio between the force necessary to move one surface horizontally over another and the pressure between the two surfaces. In the case of flooring, the COF represents the resistance between a human foot (shoed or shod) and a flooring material.
It is widely believed that the American Disabilities Act (ADA) and Occupational Safety and Health Administration (OSHA) have standards for slip resistance for working / walking surfaces. However, currently there are not definitive standards from either OSHA or the ADA.
In the late 1970s, OSHA spent years researching the topic of slip resistance. It seems that a study by the University of Michigan and reported in the Work Surface Friction: Definitions, Laboratory and Field Measurements, and a Comprehensive Bibliography was recommended as a guide on proper slip resistance. This report is thought to be the source of the minimum of COF 0.5 standard that began circulating as a non-mandatory guideline. It states, “A COF of 0.5 is not intended to be an absolute standard value. A higher COF may be necessary for certain work tasks, such as carrying objects, pushing or pulling objects, or walking up or down ramps.”
In 1990, an ADA appendix, incorrectly attributed the 0.5 Static Coefficient of Friction value to OSHA. In 2006, any reference to that was retracted. Presently, the ADA states that flooring must be “slip resistant to minimize hazards to people with disabilities.” However, it doesn’t specify a minimum of slip resistance, “because a consensus method for rating slip resistance remains elusive.” It seems OSHA continues its attempt to define a quantitative specification, but has yet to do so. In the meantime, the standards set by the American National Standard Institute are what are most widely specified.
Historical Standards for Slip Resistance
The American National Standard Institute (ANSI) created standards regarding slip resistance of hard surface materials (mainly ceramic tile and stone). It should be noted that these standards are applicable to resinous flooring however they are only “intended to serve as a guide to the general public, manufacturers, distributors, specifiers, architects, contractors, testing laboratories, building owners, and other businesses and professionals.”
ANSI specified that an automated drag-sled type tribometer device should be used for testing. ANSI found the BOT 3000E or the equivalent to be satisfactory. All threshold limit values provided below apply to the BOT 3000E device.
Historically slip resistance was measured using the Static Coefficient of Friction (ANSI B101.1).This standard provided the measurement of non-moving friction (a person standing still) on a wet (water) flooring sample. It determined a Static Coefficient of Friction (SCOF) minimum of 0.60 was sufficient. This has since been discredited by safety experts and has been expired as the preferred method for testing slip resistance.
The standard was updated to the more accurate, and more detailed testing method of Dynamic Coefficient of Friction (ANSI B101.3). This method measured moving friction (a person walking) on a wet (water and a cleaning agent) surface. The standard establishes a minimum Dynamic Coefficient of Friction (DCOF) of greater than 0.42 for level floors.
A third standard, ANSI A137.1, was written by Tile Council of North America. This standard modified the criteria for the test method and determined the safety standard for ceramic tile on a level surface is a dynamic coefficient of friction of 0.42 or higher. This standard was added to the 2012 International Building Code requirement.
The American National Standard Test Method for Measuring Dynamic Coefficient of Friction of Hard Surface Flooring Materials (ANSI A326.3-2017) was released in January of 2018. It was also created with collaboration from the Tile Council of North America (TCNA). ANSI A326.3-2017 set the parameters for testing interior floors and set limits for both wet and dry DCOF.
“Surfaces not intended to be walked upon when wet shall have a dry DCOF of 0.42 or greater.”
“Hard surface flooring materials suitable for level interior spaces expected to be walked upon when wet with water shall have a wet DCOF of 0.42 or greater.”
Current Standards for Slip Resistance
The American National Standard Test Method for Measuring Dynamic Coefficient of Friction of Hard Surface Flooring Materials was updated and released in February of 2022 (ANSI A326.3-2021). The new version includes criteria for exterior areas, barefoot traffic, and areas commonly exposed to oils and grease. The standard also includes a Product Use Classification.
ANSI A326.3-2021 sets the specifications for slip resistance for hard surface flooring products as follows:
3.1 DCOF ≥ 0.42: Unless otherwise declared by the manufacturer, hard surface flooring materials suitable for level interior spaces expected to be walked on when wet with water shall have a measured wet DCOF value of 0.42 or greater when tested using SBR testfoot material and SLS solution as per this standard. However, hard surface flooring materials with a measured wet DCOF value of 0.42 or greater are not necessarily suitable for all projects. The specifier shall determine materials appropriate for specific project conditions, considering by way of example, but not in limitation, type of use, traffic, expected contaminants, expected maintenance, expected wear, and manufacturers’ guidelines and recommendations.
3.2 DCOF < 0.42: When tested using SBR testfoot material and SLS solution as per the procedure in this standard, hard surface flooring materials with a measured wet DCOF value of less than 0.42 (including by way of example, but not in limitation, polished surfaces), unless otherwise declared by the manufacturer, shall only be installed when the surface will be kept dry when walked upon and proper safety procedures will be followed when cleaning the hard surface flooring materials. Hard surface flooring not intended to be walked upon when wet shall have a dry DCOF value of 0.42 or greater when tested per Section 10.0 of this standard.
ANSI A326.3-2021 also categorizes the standards into the following product use classifications:
Product Use Classification
| Classification | Reference Category | Criteria |
|---|---|---|
| Interior, Dry | ID | ≥ 0.42 dry DCOF (per Section 10.1) |
| Interior, Wet | IW | ≥ 0.42 wet DCOF (per Section 9.1) or Manufacturer-Declared |
| Interior, Wet Plus | IW+ | Manufacturer-Declared |
| Exterior, Wet | EW | Manufacturer-Declared |
| Oils / Greases | O/G | Manufacturer-Declared |
Interior, Dry: Product shall be kept dry, level, and free of contaminants when in use. Hard surface flooring not intended to be walked upon when wet shall have a dry DCOF value of 0.42 or greater.
Possible Areas of Use:
- Indoor shopping malls
- Hotel lobbies
- Office buildings
- Showrooms
- Home interiors without water sources
- Other level areas where surface where surface will be kept dry and contaminant free
Interior, Wet: Product shall have a minimum measured wet DCOF value of 0.42 or greater.
Possible Areas of Use:
- Entry foyers
- Public restrooms (without showers)
- Grocery stores
- “Front of the house” in restaurants
- Home interiors including bathrooms and kitchens
Interior, Wet Plus: Product shall be manufacturer-declared for this category based on manufacturing parameters, internal quality control criteria, and manufacturer experience with similar surfaces. (In the absence of such declaration, it is generally accepted that hard surface flooring in this category should have at least a minimum wet DCOF value of 0.50.)
Possible Areas of Use:
- Public showers
- Interior pool decks
- Locker rooms
- Covered exterior areas
- Steam rooms
- “Front of the house” applications in restaurants with an open kitchen, and in “front of the house” applications in quick service, fast-casual, and self-service restaurants
- Food areas in gas stations
Exterior, Wet: Product shall be manufacturer-declared for this category based on manufacturing parameters, internal quality control criteria, and manufacturer experience with similar surfaces. (In the absence of such declaration, it is generally accepted that hard surface flooring in this category should have at least a minimum wet DCOF value of 0.55.)
Possible Areas of Use:
- Level outdoor living spaces
- Pool decks
- Walkways
- Patios
- Sidewalks
Oils/Greases: Product shall be manufacturer-declared for this category where oil, grease, and/or fats may be present, based on manufacturing parameters, internal quality control criteria, and manufacturer experience with similar surfaces. (In the absence of such declaration, it is generally accepted that hard surface flooring in this category should have at least a minimum wet DCOF value of 0.55.)
Possible Areas of Use:
- Level areas regularly exposed to automotive fluids
- “Back of the house” fast food or family style restaurants
- Food preparation areas with grills or deep-fry equipment
- Any area where oil, grease, and / or fats may be present so long as such floors are level, regularly cleaned, maintained, and free of standing water and contaminant build-up
Disclaimer: The above is a synopsis of information contained in A326.3-2021. For full details on slip resistance and other factors that must be taken into consideration such as proper drainage, cleaning, maintenance, and any other ideal conditions, a specifier should do their own due diligence and read the full standard. TCNA has made a free digital copy of the standard available to the public at TCNAtile.com.
Like what you’re reading?
Keep this information at your fingertips by downloading a complimentary copy of “A Guide to Slip Resistance for Resinous Flooring.”
Debate Regarding Slip Resistance
There are multiple test methods that have been approved around the globe for measuring slip resistance. Each test method uses different instruments, test parameters and environments. The more popular instruments used for testing slip resistance include:
- British Pendulum
- Ramp Testing
- Tribometer
The British Pendulum Test is one of the most accepted pedestrian slip resistance test method worldwide. The test is well-proven and also backed by an American Society for Testing and Materials (ASTM) standard. It is used by over 50 countries around the world, however, the criteria for the test methods can vary from country to country. Slip resistance is classified by its Pendulum Test Value (PTV). The higher the number the better the slip resistance. On a horizontal surface, 11-18 PTV would be considered very poor while 51-70 PTV would be considered good and 70+ PTV would be considered best.
The ramp test method is also widely accepted in Europe. It is recommended by the German Institute for Normalization (DIN) standard DIN 51130. As the name suggest the tests are conducted with the flooring angled as a ramp. The test results are classified as R9 thru R13, with R9 being the least amount of slip resistance and R13 being the highest slip resistance (steepest ramp angle without slipping). Depending on an area’s environmental conditions, a range of R11- R13 would typically be specified.
The tribometer as mentioned previously, has been in use since 1971 and also used for measuring floor slip resistance testing in approximately 50 countries. Slip resistance values are provided at DCOF up to 1. Depending on an area’s environmental conditions, an DCOF range of 0.42 – 0.6 would typically be considered adequate to best.
Although there is substantial testing and data to support the validity of all of these test instruments, there is not a consensus on which test method is best or most accurate. Since the environmental conditions for each test is not the same, there isn’t a direct correlation between results, and this is why, as the ADA declares, a consensus method for rating slip resistance remains elusive.
Specifying Slip Resistance with Dur-A-Flex
Dur-A-Flex resinous flooring systems can be made to meet or exceed the minimum DCOF rating of 0.42. Through broadcast aggregate choices and textured additives, these ratings can be increased to meet the safety and slip resistance needs specified for any area.
Broadcast Aggregates / Finishes
- Smooth Finish
- Orange Peel Texture
- Decorative Vinyl Chip (Macro/Micro)
- Decorative Quartz (Q28/Q11)
- Solid Topcoat Quartz (Flintshot/Q-ROK)
Texture Additives
- Dur-A-Grit (Aluminum Oxide #54, #36, #24)
- Dur-A-Grip (Granulated Polymer)
To determine the appropriate amount of slip resistance for your project first consult the specifications from ANSI A326.3-2021*, then contact your Dur-A-Flex territory sales manager or tech representative. They will work with you to determine which textures, grit or grip additives, or smooth coatings will meet the requirements for your specific environment. The next step would be to order samples or a test patches and adjust accordingly. A sample should always be obtained and tested prior to the installation of any slip resistant flooring system.
* For projects outside of North America, please consult the slip resistance standards or regulations in that specific region, and discuss those with a Dur-A-Flex representative.
References:
Dur-A-Flex, Inc. dur-a-flex.com
Kendzior, R.J. (2011). The New B101.1 Floor Safety Standard. Occupational Health & Safety. https://ohsonline.com/Articles/2011/09/01/The-New-B101.1-Floor-Safety-Standard.aspx
Occupational Safety and Health Administration. https://www.osha.gov/laws-regs/standardinterpretations/2003-03-21
Guide to the ADA Accessibility Standards. U.S. Access Board. https://www.access-board.gov/ada/guides/chapter-3-floor-and-ground-surfaces/
American National Standard Test Method for Measuring Dynamic Coefficient of Friction of Hard Surface Flooring Materials. (2017). Tile Council of North America. https://www.tcnatile.com/images/pdfs/ANSI_A326.3_1-18.pdf
American National Standard Test Method for Measuring Dynamic Coefficient of Friction of Hard Surface Flooring Materials. (2021) Tile Council of North America. https://www.tcnatile.com/images/pdfs/ANSI_A326.3_2021_February_2022_Locked.pdf
Tile Council of North America. https://www.tcnatile.com/images/pdfs/A3263_Product_Use_Press_Release.pdf
Slip Resistance Testing Standards in 2022. Safety Direct America. https://safetydirectamerica.com/slipresistancetestingstandards/
FloorSlip. http://www.floorslip.co.uk/floor-slip-ratings.html
Author: Jes Grant
Jes Grant is the content development manager for Dur-A-Flex. She has over 15 years of experience creating content for various technical industries, and has been featured in several publications for her writing and design work.