How to Test Floor Slipperiness
Manufacturers, designers, contractors and testing bodies who are required to test surface slipperiness of floor products need to ascertain that the floor surfaces designed and created do not put people’s safety at risk. However, it may also be that case that an employer needs to assess slip risks in the workplace. To do this they will need to understand the manufacturer’s slip risk data.
The Workplace (Health, Safety and Welfare) Regulations 1992 (Regulation 12) states that:
“Every floor in a workplace and the surface of every traffic route in a workplace shall be of a construction such that the floor or surface of the traffic route is suitable for the purpose for which it is used.”
The HSE recommended approach can be undertaken by two tests – a pendulum instrument and a surface microroughness meter.
Pendulum Test – BS 7976: 1-3 2002
The pendulum CoF (coefficient of friction) test is also known as a Portable Skid Resistance Tester and is in accordance with British Standards BS 7976: 1- 3 2002.
The instrument itself is a swinging, replica heel made of a standard rubber sole. This swings over a sample area of flooring in both a dry and contaminated state, and in different directions for profiled flooring.
The pendulum test values (PTVs) then gives the tester a slip potential classification of:
|High slip potential||0-24|
|Moderate slip potential||25-35|
|Low slip potential||36+|
Surface Microroughness Test
To supplement the pendulum test data, a surface microroughness test can be undertaken to indicate slip levels in contaminated conditions, this is done by measuring the surface roughness of the flooring materials used. The instrument measures the total surface roughness (Rz) of the flooring and can also indicate wear. However if testing with contaminants other than water, different levels of roughness will be required. Generally a high level of surface roughness is needed to minimise the risk of slips.If a pendulum test has not been completed, the data should be used together with results from the Slips Assessment Tool (SAT).
The slip potential classification can then be interpreted as follows:
|Rz surface roughness||Slip potential|
|Below 10 µm||High|
|20 + µm||Low|
Slips Assessment Tool (SAT)
The SAT tool is a PC based software produced by HSE and HSL to undertake slip risk assessment of walkway surfaces (can be downloaded here). This additional relevant information is collected to supplement the Rz data, and looks at the causes of floor surface contamination (e.g. cleaning processes), footwear used in the area, human and other environmental factors.
HSL Ramp Test
The HSL (Health and Safety Laboratory) ramp test was designed to recreate the conditions encountered in workplace slips. A ramp is contaminated with water and is gradually inclined with a subject walking back and forth in standard rubber sole shoes and barefoot. Once the subject slips the test ends. The average inclination angle is then used to work out the coefficient of friction of the floor materials. This approach allows for testing of various different circumstances with different shoe types, floor types and types of contamination.