2.1 Federal Specification KK-165C Leather, Cattlehide, Vegetable Tanned and Chrome Retanned, Impregnated and Soles (Type 1 Factory (shoemaking) Class 6 Strips). (Appendix Ref. 2)

2.2 OSHA-"Walking and Working Surfaces Compliance Guidelines", Federal Register 4/10/90, 29CFR Part 1910, Appendix A to subpart D.

2.3 BOCA National Building code/1990, Commentary Booklet on Sect. 803.5 / "Floor Surfaces"

2.4 Ceramic Tile Institute Field Report CTI82-1-1 (R85) "Coefficient of Friction between Footwear and Ceramic Tile", (Appendix Ref. 13) (dry) and ISO TC/189 (wet)

2.5 ASTM D2047, "Standard Test Method for Polish Coated Flooring as Measured by the James Machine".

2.6 ASTM D4101, "Standard Specification for Polypropylene Plastic Injection and Extrusion Materials".

2.7 ASTM C1028, "Standard Test Method for Evaluating the SCOF of Ceramic Tile and Other Like Surfaces by the Horizontal Dynamometer Pull Meter Method".(Appendix Ref. 16)

2.8 VOSI V.41.21 "Universal Specification / Test Method For Slip Resistant (*) Walkways, in the Field & Laboratory, As Measured By a Drag Type Friction Tester"

2.9 VOSI V41.24 "Standard for Standards Terminology".

2.10 VOSI V41.23Y "Standard for Slip Resistant Footwear, etc."

2.11 VOSI V41.23Z "Standard for Forensic Engineers who Investigate Slip and Fall Accidents".

3.1 Definitions

3.1.1 Friction - The resisting force that arises when a surface of one substance slides, or tends to slide, over an adjoining surface of itself or another substance.

3.1.2 Static Coefficient of Friction (SCOF) - The ratio of the horizontal component of force (parallel to the walkway surface, passing through the tester center of gravity and aligned with the tester's major axis) required to overcome the resistance to begin movement to the normal component of the vertical force (weight) of the object. Sensor contact time is 3 seconds maximum. See 5.7.5 for Kinetic Coefficient of Friction (KCOF) measurement.

3.1.3 Kinetic (Dynamic) coefficient of friction (KCOF) - The COF under conditions of macroscopic relative motion between two bodies. (Ref 2.9)

3.1.4 Pedestrian Slip Resistance (Appendix Ref. 12) - The properties of a walkway surface that significantly reduces the probability of a person slipping thereon when wearing Slip Resistant footwear. (See. "Slip Resistant Walkway" & "Slip Resistant Footwear").

3.1.5 Slip Resistant Walkway (Appendix Ref. 12) (Primary Criteria) - A walkway surface wherein the SCOF between standardized leather and a clean, dry, level surface is 0.50 minimum when using a sensor pressure similar to walking sole pressure [(69 - 173 KPa (l0 - 25 PSI)]. (Ref: 2.8)

3.1.6 Slip Resistant Walkway (Outdoors or Indoors with Walkways Normally Subjected to Water Contamination) - A walkway surface wherein the SCOF between Standardized Monarch EVA and a level, dry or wet (water) surface is 0.50 and 0.35 minimum respectively, when using a sensor pressure similar to walking sole pressure [(69 - 173 KPa (l0-25 PSI)]. (Ref. 2.4). The wet kinetic (Dynamic) coefficient of friction (KCOF) shall be 0.30 minimum at 5 cm/sec (2"/sec) (Appendix Ref. 14,15), (Ref: 2.7) Dry SCOF / Wet SCOF = 1.50 max.

3.1.7 Slip Resistant Footwear12 (Primary Criteria)- Any smooth shoe sole and heel material having a 0.35 minimum dry SCOF against the "Primary Standard Polypropylene (leather) Test Panel" (Definition of "Standard Leather") when using a sensor pressure similar to walking sole pressure [(69 - 173 Kpa (l0 - 25 PSI)]. Smooth running sports footwear and work boot materials should have a 0.60 minimum SCOF when tested as previously stated (Appendix Ref. 12). See NOTE 3.

3.1.8 Slip Resistant Footwear (Footwear normally subjected to water contamination). Any smooth shoe sole or heel material having a minimum SCOF of 0.50 dry and 0.35 wet on the "Primary Standard Florida Ceramic Tile"(Appendix Ref. 16) (Definition of "Standard Rubber") (Appendix Ref. 17) when using a sensor pressure similar to walking sole pressure. The wet kinetic (dynamic) coefficient of friction (KCOF or DCOF) shall be 0.30 minimum at 5cm/sec (2"/sec) see NOTE 3. (ref: 2.8) Dry SCOF / Wet SCOF = 2.0 max.

NOTE 1 - These definitions were approved by a majority of the respondents to an international survey of " Proposed Uniform Definitions" by the Slip Resistance Coordinating Committee of the National Association of Safety and Health Professionals (NASHP). Testing in accordance with this specification/test method correlates with slip and fall accident rate. (Appendix Ref. 12)

3.2 Test Method Terms

3.2.1. "Standardized Leather" - Leather which has been tested against the "Primary Standard Polypropylene Test Panel" per paragraph 5.5. The average SCOF obtained has been shown to maintain its original 0.35 value over time.

3.2.2. "Secondary Standard Polypropylene Test Panel"(Appendix Ref. 8) - A test panel which is marked with a "Standard SCOF", based on simultaneously testing with the "Primary Standard Polypropylene Test Panel," and used when standardizing the leather sensor prior to SCOF testing (see 5.3.3.5 and 5.5.3, used only for dry testing).

3.2.3. "Secondary Standard Florida Ceramic Tile" - Used for dry and wet testing. A test panel which is marked with a "Standard dry and wet SCOF" based on simultaneously testing of Monarch EVA with the "Primary Standard Florida Ceramic Tile".

3.2.4. Sensor - The "Standardized Leather", "Standard Monarch EVA" or smooth footwear material affixed to the bottom of the tester that contacts the walkway surface when measuring SCOF.

3.2.5 Footwear - Shoes, rubbers, or boots used under both dry and wet (water) conditions.

3.2.6 Footwear (Leather / Rubber) Traction Index - The ratio of the SCOF of leather type materials to the standard SCOF of leather on the standard polypropylene test surface. The ratio of the SCOF of rubber materials, dry and wet, to the standard SCOF of Monarch EVA marked on the Florida Ceramic Tile Secondary Standard.

4.1 In order to be termed "Slip-Resistant Footwear" per the dry primary criteria, (ref 3.1.6) footwear materials tested per par. 5 must conform to the SCOF requirements specified herein. Average SCOF values obtained may be compared directly to the generally recognized limiting value of > or = to the standard SCOF marked on the Secondary Standard Polypropylene Leather Test Panel. (0.35 dry on the primary standard polypropylene leather test surface).

4.2 Dry and wet (water) testing, (ref 3.1.8) using smooth footwear materials, requires a minimum SCOF of 0.50 dry and 0.35 wet (water) on the primary Standard Florida Tile. If tested the minimum wet dynamic COF (KCOF or DCOF) shall be 0.30 minimum at 5 cm/sec (2 "/sec).

4.3 Heel top pieces must have a hardness less than 93 Shore A (IRHD) to be classified as "slip resistant"(Appendix Ref. 15).

4.4 Due to the relative humidity and temperature dependence of the dry SCOF of footwear materials, and since these parameters are not controlled in the test method within this specification (many tests are performed on site or in situ), the humidity and temperature at which slip resistance is determined must also be reported.

5.1 Scope

5.1.1 This test method covers the measurement of the static coefficient of friction (SCOF) of clean, level dry and wet footwear materials in the field and laboratory by a horizontal pull (drag type) slip tester. This test method is not suitable for surfaces with contaminants other than water.

5.1.2 This standard does not purport to address all of the safety problems, if any associated with its use. It is the responsibility of the user of this standard to establish appropriate safety practices and determine the applicability of regulatory limitations prior to use.

NOTE 2 - There is no similar or equivalent ISO or CEN standard. This Specification / Test Method is being proposed to the walkway and footwear materials committees of ISO (International Standards Organization) and ANSI Z41. Standard V41.23Y references conflicting ASTM test methods for measuring the SCOF of footwear materials.

5.2 Significance and Use

5.2.1 This test method may be used for measuring SCOF between walkway surfaces and user contact materials such as shoe sole and heel material. The measurements made by this type of apparatus are related to the slip resistance of clean dry surfaces to standardized leather and wet surfaces to Monarch EVA type (rubber) shoe materials.

5.2.2 The test results using this test method for SCOF are comparable to this type of equipment only.

5.2.3 BOCA recommends a 0.50 minimum SCOF between leather and the walkway surface. An OSHA proposed guideline states that 0.50 minimum SCOF is recommended as a guide to achieve proper slip resistance. This is the same value as the ASTM D2047 definition of a "slip resistant" polish; which is the same approximate SCOF required by a fast walking young male (Appendix Ref. 12). Official publications (building codes, consensus standards, ASTM Standard Practice Guidelines, government publications etc.) should reference VOSI V 41.21 and V 41.22 for slip resistant walkway and footwear requirements.

5.3 Apparatus

5.3.1 This test method covers a variety of apparatus designed for the purpose of measuring the SCOF by the horizontal pull slip tester. A typical apparatus consists of a) a force gauge or load cell/sled assembly b) a standard calibration weight c) three mounting locations for attaching "sensor" material (See 5.3.2) and d) a means to pull the apparatus across the surface being tested. The horizontal force may be applied manually, by attaching the hook on the force gage to the hook on the sled, and pulling (Figure 1) (Appendix Ref.3). A power actuated device uses a tension cord to "reel" in the sled across the surface being tested (Appendix Ref. 4). The vertical loads shall result in a contact pressure of not less than 69 KPa (l0 PSI) and not more than l73 KPa (25-PSI).

5.3.1.1 The standard calibration weight has a mass equal to one half the weight of the sled assembly (2.2 +/- 0.00454 Kg (5.0 + / - 0.01 lb.) for the Technical Products tester (Appendix Ref. 3)

5.3.2 Sensor Material5 The sensor material shall be smooth footwear heel and sole materials. Cut the sensors to the size required by the specific apparatus.

NOTE 3 - Where leather type materials are used as footwear material, dry testing should be done to establish the relationship between those materials and the readings obtained using "standardized leather" pads. All smooth heel and sole materials should have a SCOF > or = "standardized leather"(Ref. 3.1.7). Were rubber materials are used dry and wet testing should be done to establish the relationship between these materials and the readings obtained using standardized Monarch EVA against the Florida Ceramic Tile (Ref 3.1.8). The maximum hardness of heel (top piece) materials is 93 Shore A (IRHD) or 45 Shore D (Appendix Ref.15). Tests on patterned solings, made in the walking direction, must meet paragraph 3.1.6 and 3.1.7 requirements when using a ten-pound weight alternately on the heel and sole.

5.3.3 Secondary Standard Polypropylene Test Panel

5.3.3.1 Aluminum backing square, 5052H32 alloy, 2.4mm (3/32 in.) thick and 203 mm (8 in.) square. (Available from most aluminum companies.)

5.3.3.2 Polypropylene pane (Appendix Ref. l6) 0.79 mm (l/32 in.) thick cut to fit aluminum square. Material per ASTM D4101-PP011X Extruded Polypropylene ; Shore D hardness 60-70. Mount polypropylene with the reflective side outward.

5.3.3.3 Polypropylene Adhesive (Appendix Ref. 7).

5.3.3.4 Secondary Standard Test Panel Assembly

5.3.3.4.1 Assemble polypropylene panel by applying adhesive to both the non-reflective polypropylene and aluminum surfaces and cementing polypropylene panel to aluminum.

5.3.3.5 Commercial polypropylene test pane (Appendix Ref. l8) - Secondary standard polypropylene test panels, equivalent to the primary standard, are standardized against a primary SCOF standard of 0.35 ("standardized leather" against a primary standard polypropylene test panel) when purchased from the manufacturer. Self prepared test panels sent to the manufacturer for standardization will be marked with the SCOF obtained using standardized leather ( see par. 5.5.3 regarding leather correction factor). The SCOF marked on the back of the secondary standard panel shall be 0.35 +/- 0.l0.

5.3.4  Secondary Standard Florida Ceramic Tile (Appendix Ref. 16, 8).
          Dry and wet SCOF marked on panel is for Standard Monarch EVA only

NOTE 4 - Primary standard polypropylene is the same as 5.3.3.2.

5.4 Test Surfaces

5.4.1 Test surfaces shall be the Secondary Standard polypropylene leather test panel8 and Secondary Standard Florida Ceramic Tile16. The area adjacent to the test surface must be sufficiently continuous to accommodate the tester and traveling limits of the apparatus.

5.4.2 When determining the SCOF of footwear soles and heels in their "as found" condition, the test shall be preformed per the following procedure.

5.4.2.1 Identify the footwear to be tested by manufacturer, trade name, style, color, heel height etc. Record the temperature and humidity.

5.4.2.2 Surface Preparation - Prior to starting the tests, remove surface dirt from the footwear soling and test surfaces by brushing with a paper towel. Be careful not to alter the test surface during the process of removing the loose surface dirt. The footwear is now ready for testing.

5.4.3 InSitu Actual Footwear

5.4.3.1 Place the heel or sole of the actual footwear on either the polypropylene (dry test) or Secondary standard Florida Ceramic Tile test panels (dry and wet test). Place a 4.54 kg (10 lb.) weight (Model 80 Test Block) alternately on the heel or sole making sure that the remainder of the soling material is not resting on any surface.

5.4.3.2 Tape a string loop to the back of the heel and sides of the shoe upper surface. Use a force gauge to determine the shear force on both the dry and wet surfaces.

5.4.3.3 Weigh the footwear within 5.7 gm (0.2 oz.). (Postal scale or equivalent)

5.5 Calibration

5.5.1 For the manually operated device, determine the force gage correction factor at 0.50 SCOF by using a standard calibration weight that is one-half the weight of the sled apparatus (vertical force). Lift the standard test weight slowly vertically using the force gage provided with the sled apparatus (Fig. 1). The gage correction factor is determined by dividing the weight of the standard weight by the force gage reading. For power actuated devices and other types of manually operated devices, follow the manufacturer's suggested calibration procedures.

5.5.2 Allow the temperature/humidity gage to stabilize before testing.

5.5.3 Prepare the sensor pads per 5.6.1.

5.5.4 Prior to performing an on-site test, the performance of the test instrument and the operator should be verified against a secondary standard polypropylene test panel when initially received. The average of the eight successive readings taken per 5.6.2 shall be within 0.02 of the value stated in the manufacturer's log. The range of readings should be within 0.05. The manufacturer of the apparatus shown in Fig. 1 can provide "Certificates of Operator Qualification"(Appendix Ref. 8).

5.6 Procedure - Dry for Determining Whether Footwear is Slip Resistant

5.6.1 Test the proper functioning of the force gage. Verify the instrument calibration per par. 5.5 or the manufacturer's instructions. Dress the footwear sensor pads after affixing them to the tester with the wear surface outside. Place the complete assembly on a sheet of 400 grit wet/dry carborundum paper.9 Repeatedly pull the complete assembly in its normal direction of travel across the carborundum paper until a uniform bearing surface is achieved. This is accomplished by sanding the pads initially 30 times using a stroke about 102 mm (4 in.) long on 120 grit paper followed by 15 strokes on 400 grit. Sand pads five times on 400 grit wet /dry paper before each set of tests. Brush or wipe all foreign material from the tester pads using a paper towel. Use same sanding procedure for rubber type footwear materials except sand 25 times / 80 grit and 10 times / 400 grit.

5.6.2 Place the apparatus on the secondary standard polypropylene test panel (primary criteria par. 3.1.6) with sufficient distance for travel of the sled. Apply the load so as to minimize the duration of contact with the Polypropylene Test Panel (2 sec. avg.). Record the maximum horizontal axial force needed to initiate movement. When movement is observed immediately stop the test. Beginning with the normal walking direction, (A to C) repeat the operation through two revolutions in 90 degree increments for a total of eight readings by rotating the test panel. Minimize the time the apparatus is in contact with the surface by pre-loading the horizontally positioned force gage. Remove sensor pad pressure when not testing.

5.7 Procedure- Dry & Wet Testing of Footwear

5.7.1 This procedure is performed only after determining whether the footwear is "slip resistant" i.e. 0.50 minimum SCOF when tested per 5.6 or 5.4.3 and correcting average SCOF per 5.8. (ref 3.1.6)

5.7.2 Place tester on Secondary Standard Florida Ceramic Tile and repeat 5.6.

5.7.3 Spray test surface with distilled water and repeat 5.6.2. Place and slide pads on wet surface before testing.

5.7.4 Multiply the average SCOF by the gage correction factor. Corrected average SCOF must be 0.60 minimum both dry and wet in order to meet Ceramic Tile Institute of America requirements for ceramic tile and similar materials (Ref 2.4) When using a Neolite sensor. Footwear materials must meet 3.1.7 SCOF requirements.

5.7.5 Measure kinetic COF (KCOF) simultaneously with SCOF test for 0.30 minimum requirement (Ref. 3.1.7) with sensors sliding on wet (Ref. 5.7.2) Florida Ceramic Tile at an approximately constant velocity of 5 cm/sec (2"sec).

5.8 Calculations

5.8.1 Divide the force gage scale reading (kg or lbs.) by the weight of the assembly that is in contact with the surface. (On some devices the scale is calibrated directly in SCOF3) Add weight of shoe (5.4.3.3) to 4.54-kg (10-lb.) weight when testing actual footwear.

5.8.2 For each of the readings taken, estimate the SCOF to the nearest 0.01. Determine the average SCOF. Discard the initial reading if greater than all other readings and then repeat it (See NOTE 5). Example: Average horizontal axial force to start motion = 2.72 Kg (6.0 lbs.).

Test weight = 4.54 Kg (10.0 lb.)

SCOF =

2.72 kg --------- 4.54 kg

=

6.0 lb ------- 10.0 lb

=

0.60