ASTM F 1487 requires that all surfacing used in play areas must comply with the requirements of ASTM F 1292 Standard Specification for Impact Attenuation of Surface Systems under and around Playground Equipment. Manmade surfacing materials like Engineered Wood Fiber, Poured in Place surfacing, rubber tiles and loose fill rubber products are be lab tested for Impact Attenuation. The lab test will indicate the "critical height" that the product protects. Specific thicknesses or depth of material will be listed for specific "critical heights". When purchasing these products you should always make sure that the product you select will protect children from a fall equal to or exceeding the "fall height" of the equipment and require that the supplier provide you with copies of the certification. It is a good idea to specify a product that exceeds the requirement for the "fall height" because all materials will lose some Impact Attenuation value over time.
If you use natural materials such as sand or wood mulch, Table 2 on page 11 of the Consumer Product Safety Commission Public Playground Safety (Publication #325) provides a chart that indicates average Impact Attenuation Values for some typical surfacing materials but the actual values can vary significantly.
"Critical Height" is a property of the surfacing material. It is the fall from below which a life threatening head injury would not be expected to occur on the surfacing system.
"Fall Height" is a property of the play equipment. It is the vertical distance between the highest accessible designated play surface of the play equipment and the protective surface beneath it.
Impact testing is not required by law. Purchasing a product that is certified to comply with the requirements of ASTM F 1292 and has a "Critical Height" that exceeds the "Fall Height of your equipment is the minimum requirement. Surfacing materials can match or exceed the cost of the play equipment so field testing can be a good way to protect your investment. Visual Playground Safety Inspections as required by the California Playground Safety Regulations cannot certify that the Surface materials are compliant. The depth of product can be probed and compared with the charts provided by the manufacturers but Impact testing is the only way to be sure that the product you have installed meets or exceeds the requirements.
ASTM F 1292 requires that at least three impact sites be tested in each play area. The test requires that a head form be dropped from the fall height of the play equipment three times at each impact test site. The test results of the second and third drop from each site to be averaged and recorded. The head form is attached to a hand held device that records the G-max and HIC values of each drop. The G-max is the maximum deceleration of gravity. The HIC is Head Impact Criteria or the measure of impact severity and duration. A full understanding is not necessary but if you would like the full explanation please read ASTM F 1292. The important thing to remember is that the G-max reading must be less than 200 and the HIC reading must be less than 1000.
Impact testing requires the use of a piece of equipment known as the Triax 2000 which is a tripod that holds the head form at the proper fall height. The head form is held with an electromagnet and released for a free fall to the surface. The test normally takes about 1 1/2 hours per play area.
There are only a few companies in California that provide Impact Testing. There is no set fee for the test and the cost will vary depending on the company doing the test, the travel time and the number of sites to be tested. The low price can run as low as $400 to $500 and range to as high as $1000 - $1200 per site. Please call or email if you are interested in a quote for impact testing. Your first priority should be having the playground equipment certified.