Page 1 of 5 Pages SUMMARY The characteristics of flooring materials and the presence of contamination will affect the risk of pedestrian slip and trip accidents. Advice is provided on risk assessment and control, and the measurement of slip resistance. BACKGROUND 1. The Health and Safety Executive is concerned about the number of slip and trip accidents in the NHS (costing around 133M per annum) and is working towards reducing these by education and enforcement. 2. The slip resistance of smooth or lightly textured flooring materials may be reduced significantly if contaminated with liquids or dust. A very low level of contamination (i.e. a small amount of water, or the dampness left behind after mopping) will generate a risk of pedestrian slip accidents, and thicker liquids such as soap, detergent, oil or grease will further increase the risk. Dry contaminants such as talcum powder in ward areas pose a significant risk; even more so when wet. 3. Since slip resistance (friction) is a product of the two surfaces (floor and shoe) in contact, if either surface becomes contaminated there will be a reduction in slip resistance. The application of polishes or sealants will normally reduce the slip resistance of floor surfaces, especially under wet conditions. Specialist antislip polishes might increase slip resistance with some shoe types in dry, clean conditions but may actually reduce slip resistance when contaminated. 4. Pedestrians may also be at risk of slip (and trip) accidents when moving from flooring with a high slip resistance to one with a low slip resistance (and vice versa). 5. At present, there is no single European Standard for the assessment of floor surface slip resistance and manufacturers or specifiers of flooring use a variety of test methods, including ramp tests and drag-sled tests. As each method uses a different test speed, interacting material or contaminant, the results often vary and may be misleading in some cases. 6. The Health & Safety Executive (HSE), the Health & Safety Laboratory (HSL) and the members of the United Kingdom Slip Resistance Group (UKSRG) endorse the use of a combination of two specific test methods during formal slip resistance assessment: a) The Pendulum test, as described in BS 7976 (1), which is the method preferred by HSE, b) Surface micro-roughness measurements (specifically the Rz parameter). 7. The system for slip risk classification used by HSE (2) and the UKSRG (3) is shown in the Appendix (Tables 1, 2 and 3) and is based on the results of Pendulum tests and micro-roughness (Rz) measurements. Suggested Distribution Ambulance Services Accommodation Officers Care for the Elderly Catering Domestic Services /Facilities Health & Safety Infection Control Staff Portering Services Risk Management
Page 2 of 5 Pages 8. Installation processes (laying, preparing and initial cleaning) can change the slip resistance properties of flooring materials. Except for enhanced flooring materials (e.g. with embedded hard sharp particles) where the slip resistance may increase, the slip resistance after installation may be significantly below that declared by the manufacturer. 9. Research by HSE suggests that profiled flooring surfaces might not reduce the risk of slipping when used in normal pedestrian areas, but it may reduce the risk of slipping in barefoot situations. The anti-slip properties of profiled metal floors (e.g. in plant areas, cat walks, chills and ambulances) are also considered to be poor in wet conditions. 10. Other factors relating to the specification of flooring materials are given in Health Technical Memorandum HTM61 Building Components Flooring (4). This HTM is not endorsed for use in Scotland but may be used with caution. The revision of HTM61 is to be published by NHS later this year. 11. HSE and HSL have developed a Slips Assessment Tool (SAT), a PC based software package that allows non-experts to assess the slip risk potential presented by level pedestrian walkway surfaces. It uses microroughness data from a hand-held meter and other information (such as floor surface type, the cleaning regime used, the condition of the floor, type of footwear and human factors relating to pedestrian use) to arrive at a slip-risk classification. This is available as freeware on the Internet (5) together with information on suitable micro-roughness meters. Note: the information generated by the tool is subjective, and therefore should not be used within the floor specification process or during legal proceedings. ACTION 12. This notice should be brought to the attention of all appropriate managers and staff, particularly those involved in the cleaning, maintenance, specification or purchase of flooring materials, including capital project teams. 13. A risk assessment should be carried out for all floor surfaces, taking into account: location, traffic, wear and slip resistance properties of the flooring, likely contamination, cleaning regimes, footwear and accident history. The more obvious risk areas include: kitchens, food and drink areas, wash areas, workshops, inpatient wards, patient treatment areas (especially those involving liquids), and main entrances exposed to rain, snow and prevailing winds. These factors should be documented according to risk. 14. Risk assessment should take account of the volume and type of traffic including disabled pedestrians / patients, wheeled traffic and goods / equipment. It should also consider the risks due to interfaces with different floor surfaces e.g. carpets, slopes and stairs. 15. The slip resistance properties of existing flooring should be assessed, starting with the highest risk areas. It is recommended that the Slips Assessment Tool (5) be used in the first instance as the equipment is readily available and relatively inexpensive.
Page 3 of 5 Pages 16. The overall risk of slip and trip accidents in each area should be assessed using the above factors and used to prioritise the actions required to reduce / remove the risks. 17. Smooth or lightly textured flooring surfaces should be maintained in a clean, dry state and cleaning should preferably be carried out when traffic is nil/low. If contamination occurs, even in small amounts, there should be robust procedures in place to control the risk as soon as possible, including the use of: a) barrier matting at entrances, b) spot cleaning methods to remove small amounts of contamination quickly, e.g. absorbent paper towel, c) dry-mopping processes, after traditional wet-mopping, to reduce wetness and drying time, d) cordons to restrict access to wet floors, in conjunction with warning signs, until the floor is dry. 18. Barrier matting should be of sufficient quality and quantity to ensure, as far as reasonably practicable, the removal of dirt and water from footwear. Typically, it should require each foot to contact it at least three times while crossing (i.e. at least 6 metres). The use of temporary matting is not recommended as it may introduce more hazards that it prevents. If temporary matting is used pending a permanent solution, precautions will be required to guard against creepage and trip hazards. The matting should be maintained in a clean and dry state as far as possible. The flooring beyond the matting should have good water-wet slip resistance to cope with water migration and drips from coats and umbrellas etc. 19. In situations where contamination of flooring surfaces is expected (even occasionally), it is recommended that specialist anti-slip flooring is used, such as materials incorporating a high concentration of embedded carborundum grit or similar. Such flooring will require appropriate cleaning techniques to retain its antislip properties and its use should be taken in consultation with infection control specialists. The use of flooring surfaces with profiled patterns for normal pedestrian areas is not recommended. 20. When specifying new floor surface materials for existing areas and especially for new premises, the slip resistance properties should be specified and assessed carefully. Care should be taken in the interpretation of manufacturer s information which may be based on inappropriate test methods and which may relate to slip resistance before, rather than after, installation and use. 21. It is recommended that the assessment of flooring material should be based on a combination of Coefficient of Friction data produced by Pendulum tests to BS 7976-2 and Rz micro-roughness measurements as appropriate. These data should be confirmed in the installed condition (see Background paragraph 8). 22. It is essential that all flooring should be maintained from new by appropriate cleaning techniques (e.g. as specified by the manufacturer and approved by Infection Control staff) and the avoidance of inappropriate polishes or sealants. It is recommended that slip resistance be re-assessed at regular intervals to determine any changes due to wear, type of activity, environment etc.
Page 4 of 5 Pages REFERENCES (1) British Standard BS 7976-2, Pendulum Testers Method of Operation, BSI, 2002 (2) The assessment of pedestrian slip risk: The HSE approach, Health & Safety Executive, (code S&T1) Oct 2004 (3) The Measurement of Floor Slip Resistance: Guidelines Recommended by the UK Slip Resistance Group, Issue 2, June 2000 (contact slips@hsl.gov.uk for details). Note: this document is currently under revision. (4) Health Technical Memorandum HTM61, Building Components Flooring, 2 nd ed., NHS, 1995 - not endorsed for use in Scotland (may be used with caution). Note: this HTM is currently under revision. (5) HSE Slips Assessment Tool (SAT) www.hsesat.info/. BIBLIOGRAPHY 1. Slips and trips: Guidance for employers on identifying hazards and controlling risks, HS(G)155, HSE Books, 1996, ISBN 0 7176 1145 0 2. Slips and trips: Guidance for the food processing industry, HS(G)156, HSE Books, 1996, ISBN 0 7176 0832 8 3. Preventing slips and trips at work, Leaflet INDG225(rev1), HSE Books Nov 2003 (single copy free or priced packs of 15), ISBN 0717627608 4. Preventing slips in the food and drink industries - technical update on floor specifications, Food Information Sheet FIS22, HSE Books, May 1999 5. Slips and trips: Summary guidance for the catering industry, Catering Information Sheet CAIS6, HSE Books, June 1996 Note: this document is currently under revision. 6. Slips and trips: Summary guidance for the food industry, Food Information Sheet FIS6, HSE Books, Sept 1998 7. Slips and trips in the health services, Health Services Information Sheet HSIS2, HSE Books, Sept 2003 The above HSE documents may be viewed on the website http://www.hse.gov.uk/slips/information.htm or obtained from HSE Books, PO Box 1999, Sudbury, Suffolk CO10 6FS Tel: 01787 881165 Fax: 01787 313995
APPENDIX Page 5 of 5 Pages Table 1 Slip risk classification, based on pendulum test values Pendulum value Slip Risk 0-24 High 25-35 Moderate 36-64 Low 65 + Extremely low Table 2 Potential for slip classification, based on Rz microroughness values (applicable for water-wet, low activity pedestrian areas) Rz surface roughness (microns, µm) Below 10 Potential for slip High 10 or above (but below 20) Moderate 20 or above Low Table 3 Minimum floor roughness levels required for typical workplace contaminants Minimum Roughness (microns, µm) Contaminant 20 Clean water, coffee, soft drinks 45 Soap solution, milk 60 Cooking stock 70 Motor oil, olive oil above 70 Gear oil, margarine The above risk classification tables are based on The assessment of pedestrian slip risk: The HSE approach, Health & Safety Executive, (code S&T1) Oct 2004. Interpretation of results Ideally, both pendulum coefficient of friction and surface roughness measurements should be used to give an accurate indication of floor surface slipperiness. Results should be interpreted using the information in Tables 1 and 2 above, taking account of any directional effects (grain), as well as Table 3 which extends the microroughness results for a variety of contaminants. Pendulum classifications given in Table 1 are based on the use of a standardised soling material known as Four-S rubber (standard simulated shoe sole), developed by HSL and the UKSRG. This material was designed to represent footwear materials of average slip resistance; use of more or less slippery soling materials may affect the overall potential for slip. In barefoot environments, it is recommended that further testing is undertaken using an alternative standardised material known as Five-S rubber (standard simulated soft shoe sole). This material, which is also known as TRRL Rubber, replicates a bare foot sole.