Identifying and Fixing Slippery Pedestrian Surfaces

  • Every working day in Ireland more than three people are hurt in work-related slips alone
  • 23% of those who slip are off work for over one month
  • People generally slip because of contaminated surfaces or contaminated footwear

People generally slip on wet surfaces or wet shoes, not clean dry surfaces.

A slip-resistant surface need not be rough and difficult to clean. “The ability to clean a … floor to a hygienic standard is not influenced by the slip resistance” and “cleanability ... should not be a barrier to the use of slip resistant flooring in foreseeably wet or contaminated work areas” (HSL UK RR889)

The Law on Slippery Surfaces

The Safety, Health and Welfare at Work Act requires safe access, safe systems of work, risk assessment, and a safety statement. The General Application Regulations require pedestrian surfaces not to be slippery. For construction, the Construction Safety Regulations require that the floor of all indoor workstations is fixed, stable and not slippery.

Slip Risk Factors

Slips generally involve 3 risk factors.

Slip factors

1. Slippery Surface

Slips on a level typically occur on contaminated harder surfaces (such as walk-on vehicle surfaces) and not on soft surfaces such as carpets. People also slip on footwear with contaminated soles.

Slippery Surface locations include wet slippery surfaces, walkways, entrances/ exits and bathrooms. Slippery surface locations may vary from sector to sector, for example, kitchens and bathrooms in the hospitality sector and entrances/exits in the retail sector.

2. Contamination

Contamination involved in slips includes liquids like rain, other slippery contaminants like granular material/ semi-solid material and ice. On decking, mildew, algae and fine mosses can be an issue. Ice can cause slips on “non-slip” surfaces. Activities leading to surface contamination included cleaning.

Areas prone to constant or intermittent contamination could include external areas, wet-cleaned surfaces, areas at boot-cleaning machines, wash-up areas, bathrooms, areas with solid/ semi-solid or granular materials, rain and wet footwear around entrances and areas exposed to rain or icy conditionsIce can cause slips on “non-slip” surfaces.

Wet footprints at entrance

3. Pedestrian

Slips generally occur when a pedestrian has access to a contaminated slippery surface or access to a slippery surface with contaminated footwear.

Check for areas where pedestrians access surfaces exposed to ice or rain like external entrances or areas that are not cordoned off for wet cleaning.

Cleaning corden system

Assess Slip Risks

A slip "risk" is the likelihood that a slip will occur and cause harm. A slip risk assessment should include...

1. Slips - Reported & Unreported Slips

The history of incidents and near-slips may indicate that a surface is slippery. Check for a history of slips or near-slips, or other evidence that pedestrians slip on the surface. Check with workers if the surface is slippery, not just when dry but also when contaminated. Pedestrians should be actively asked for their views – "does the surface feel slippery underfoot when dry or wet/ contaminated?"

2. Intentionally Slippery Surfaces

Regulations 9, 23, 99 and 105 of the General Application Regulations outline that pedestrian surfaces should be not slippery. In limited cases, there may be a justifiable reason for a slippery surface, for example, on a van loaded by sliding the load. In these cases, contamination and pedestrian risk factors must be very carefully risk assessed and warning signs and slip-resistant footwear are likely to be required.

3. Technical Information on Pedestrian Surfaces

The slip-resistance of a pedestrian surface is likely to change because of traffic, wear and tear, contamination and cleaning. Information on claimed and actual slip-resistance may be available from Supplier Technical Data. This information may be in the Construction Regs Safety File. The Safety, Health and Welfare at Work Act requires designers, manufacturers, importers or suppliers of articles to provide or arrange for adequate information to ensure safe use.

Some independent reports also rate various floor types as high, medium or low slip-risk. Helpful reports include*:

  • CIRIA C652* (239 pages at provides detailed advice on slip resistance of various pedestrian surfaces, for example, “metal chequerplate can be particularly slippery when wet”,
  • A1 Test data from HSL research” in Safer surfaces to walk on - 2010 Update* (CIRIA C652 2010 Update) rates the slip risk of several pedestrian surfaces as high, medium or low,
  • The Slip characteristics of metal flooring material* (HSE UK RR534), for example, says “there is considerable anecdotal evidence that some in-service profiled surfaces pose a significant slip risk”,
  • Stop Slips in Kitchens – A Good Practice Guide* (HSE UK) rates the slip risk of various pedestrian surfaces as high, medium or low,
  • Ramp testing pre-engineered wood floors* (HSE UK - RR533) rates the slip risk of pre-engineered wooden flooring materials.

* This list is non-exhaustive and in no particular order

4. Slip-resistance Measurements

Slip-resistance can be measured and quantified. Several types of measurement and rating systems are available.

A wet Pendulum Test Value (PTV) of 36+ (or equivalent) in final use conditions could be considered low-slip-risk. A PTV of 0 to 24 would be high-slip-risk.

Slip Alert Tester

Slip resistance tests are available from private companies. Workplaces can hire machines to take their own slip resistance measurements.

Map Slip-risk Areas

The Mapping tool has four simple steps to identify where slips, trips and falls have happened and identify slip-risk areas.

Slip risk map

Fix Slippery Pedestrian Surfaces

Where a surface originally had good slip-resistance, it may be possible to restore that slip-resistance, otherwise resurfacing may be needed.

1. Deep Clean

Where a surface originally had good slip-resistance, it may be possible to restore that slip-resistance with a thorough deep clean. The UK Timber Decking and Cladding Association (TDCA) advise "The key factor in preventing slippery decking is to ensure that the deck surface is kept clean and surface deposits such as mildew, algae and fine mosses are kept at bay."

2. Chemical or Physical Treatment

Chemical or physical treatments to improve slip-resistance include*:

Nano blasting Floor

  • Abrasive techniques* (such as nano blasting) must comply with the regulations for blasting where relevant
  • Acid etching* must use the proper safeguards for handling chemicals such as hydrofluoric acid

* This list is non-exhaustive and in no particular order

3. Contain, Divert or Remove Contamination

Physical changes may be required to the surface to contain, divert or remove contamination, for example, bunds, thresholds or drains. Adequate drainage can be provided where needed, especially for areas where contaminants may pool. Contaminants may be contained or channeled away from pedestrian areas, e.g. at thresholds. The materials used should be non-slip.

4. Resurface

Resurface the pedestrian surface with a material that provides a low slip-risk. Methods of resurfacing a slippery surface include*:

  • Anti-slip coating*, for example, the UK TDCA advise about "anti-slip decking products that can be fitted retrospectively [and] generally fix into the grooves or ...the surface."
  • Anti-slip strips/ patches* need to be monitored and replaced when worn*,
  • Anti-slip film on glass floors*
  • Mats* are only appropriate in limited situations. Mats may be a source of contamination and can also present a trip hazard if the edges are raised and/or not properly secured in place

* This list is non-exhaustive and in no particular order

Verify and Maintain Slip-resistance

To check the improvement, it is recommended to assess slip-resistance before and after treatment, and monitor periodically thereafter to ensure continued slip-resistance. New cleaning regimes may be required.

Review the risk assessment and take corrective action if required

Operational Controls for Slippery Floors

Noting the legal requirement that pedestrian surfaces not be slippery, operational controls identified in the risk assessment for high slip-risk floors could include, in no particular order

  • slip-resistant footwear, including slip-resistant overshoes for visitors
  • warning signs, noting signs should only be used where hazards cannot be avoided or adequately reduced. Part E of the General Application Regulations specifies places with a risk of falling shall be marked with alternating yellow and black, or red and white 45° stripes with dimensions commensurate with the dangerous location

Warning stripes

Slippery Surface Case Studies

HSL advise about an abattoir that reduced slips costs from £207,800 to £136,000 over three years by “clear” floor specifications, “matched” footwear, monitoring and removal of chequer plate.

The HSE UK provides useful advice on improving slip resistance on their website. The advice on acid-etching (and hydrofluoric acid) is important. HSE UK has a wide range of case studies including

  • Housekeeping and cleaning regimes
  • Effective matting systems
  • Design of workplace and work activities
  • Maintenance of plant and the work environment
  • Effective training and supervision
  • Working together to solve the problem

The Napo animated video "Shining example" (1 minute, 8 seconds) shows the problem with choosing a floor surface based solely on how it looks