Winter 2000-2001
The ASTM Board of Directors (BoD) appointed a Slip Resistance Task Group (TG) to develop a plan of action to assist with issues surrounding slip resistance. In essence, the documents being considered present a relative ranking. The standards may call for the identification of a set of external calibration material sets (footwear- and walkway-reference materials or surrogates) that represent the range (low-to-high) of pedestrian slip resistance situations. Following a detailed procedure, a valid tribometer would be required to rank these material sets in their proper order, and in doing so would develop a calibration curve. Once generated for any apparatus, this curve is under consideration to be used to then verify the instrument or qualify/measure the slip resistance of surfaces with it, using the reference set of surrogates. It is also under consideration that various surfaces or footwear materials tested may be ranked against this calibration set.
If this approach is technically feasible, ranking results may eliminate the need to reconcile the differences in numeric results of the various tribometers.
The Task Group is proposing these concepts for F-13's development of tribometric testing standards. The ultimate responsibility for determining the approach's feasibility and subsequent document development lies with Committee F13.
REPORT FROM THE ASTM BOARD TASK GROUP ON SLIP RESISTANCE
Background
The Board desires to bring together involved parties and stakeholders to resolve the issues and craft a set of action steps providing a speedy resolution consistent with the complexity of the technical issues involved. To accomplish this, the Board formed a task group composed of slip and fall industry experts and the leadership of F13 on Safety and Traction for Footwear. There is representation from OSHA, the Ironworkers District Council, insurance companies, footwear trade associations (FIA), the Tile Council of America (TCA), and the Resilient Floor Covering Institute (RFCI). Don Marlowe, Vice-Chairman of the Board of Directors, was appointed chairman of the task group.
Meeting 1 of the Task Group
The task group agreed to develop a base test method which would include the identification of several matching floor and shoe materials that would represent a scale of values from slippery to non-slippery. It would also include parameters that are generic in nature such as test environment, preparation of materials, reporting etc.
Meeting 2 of the Task Group
The task group met again on September 8, 2000 at which time a new model for addressing slip resistance was agreed upon. The model includes the development of three interrelated documents as follows:
Document 1 (D1) is a Standard Practice Establishing Sets of Reference Shoe and loor Materials and a System to Plot a Curve of Slip Measurements.
Summary: The task group decided to initially fix the shoe material and measure against 3 - 5 different floor materials ranging from low to high slip/roughness. This reduces the complexity of the testing program. A universal, numerical value for slip will not be defined.
Document 2 (D2) is a Standard Practice for Selection of Tribometers and Verification of Tribometer Slip Resistance.
Summary: Using D1, this would provide a curve for specific slip resistant testing machines.
Document 3 (D3) is a Standard Practice for Making Slip Resistance Measurements in the Field Using the Verified Testing Machine.
Summary: The practice would provide a measurement of slip resistance in the field with a testing machine verified using D1 & D2.
The task group intends the documents to have the following characteristics as well:
Address
the issue of biofidelity as it correlates to the roughness.
They
will not identify proprietary apparatus.
They
may specify shared, desirable attributes of all tribometers.
They
leave apparatus manufacturers responsible for qualifying their equipment.
Meeting 3 of the Task Group
The task group met on November 9, 2000 and analyzed information on possible surrogate surfaces which included several combinations.
The result of the testing indicated the following:
Preliminary tests indicated that a monotonic curve which provided initial indications that the concept of Document D1 is viable.
Sensor preparation is an issue that needs careful consideration.
The task group discussed materials for use in developing the surrogate floor materials.
The task group discussed options for surrogate foot materials, and their viability in terms of consistent material manufacture and their ability to maintain properties over time.
The group reduced the number of documents from 3 to 2. This was a result of combining the material in previously in D1 and D2 into a single document D1. D3 then becomes D2, as follows:
Document D1 - Standard Practice for the Verification of Slip Resistance Testing Machines by Plotting a System Curve Using Established Sets of Reference Shoe and Floor Materials
Summary: Fix the shoe material and measure against 3 - 5 different floor materials ranging from low to high slip/roughness. This reduces the complexity of the testing program. A universal, numerical value for slip will not be defined. Using the surrogate surfaces, a graphed, monotonic verification curve will be generated by the users for specific slip resistant testing machines. This can then be correlated to obtain field values in D2.
Document D2 - Standard Practice for Making Slip Resistance Measurements in the Field Using the Verified Testing Machine
Summary: The practice would provide a measurement of slip resistance in the field with a testing machine verified using D1.
Future Action
The task group is continuing to test prospective materials and will continue developing documents D1 and D2. Their next meeting is in March at ASTM Headquarters.
Edited from ASTM Release, December 2000
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