CPSI Surfacing Requirements and Impact Attenuation Testing 5 — Questions and Answers
Question 1: A newly installed loose-fill rubber surface passes Gmax testing but fails the HIC threshold of 1000. What does this indicate?
- The surface depth is too shallow causing rotational head injury risk
- The surface is too soft and needs compaction
- Gmax alone is not sufficient to certify safety; HIC must also pass (Correct answer)
- The rubber material must be replaced with wood fiber
Correct answer: Gmax alone is not sufficient to certify safety; HIC must also pass
Both Gmax (≤200 g) and HIC (≤1000) must be within acceptable limits under ASTM F1292 for surfacing to be considered safe.
Question 2: What is the primary purpose of containment borders around loose-fill playground surfacing?
- To improve the aesthetic appearance of the playground
- To prevent surfacing migration and maintain required depth (Correct answer)
- To reduce installation costs by limiting material spread
- To mark the boundary of the use zone for supervisors
Correct answer: To prevent surfacing migration and maintain required depth
Containment borders keep loose-fill surfacing within the use zone, ensuring the material maintains adequate depth for effective impact attenuation.
Question 3: Under CPSC guidelines, what is the required use zone overlap when two swings are placed back-to-back (rear use zones meet)?
- Use zones may not overlap under any circumstances
- Overlap is permitted only if both swings are bucket seat type
- Overlap is acceptable only for toddler swings, not standard belt swings
- No overlap is permitted for swings; use zones must be separate (Correct answer)
Correct answer: No overlap is permitted for swings; use zones must be separate
CPSC guidelines prohibit the overlap of swing use zones because simultaneous use creates a high-risk collision hazard.
Question 4: Which environmental condition most rapidly degrades the impact attenuation performance of pea gravel surfacing?
- Freezing temperatures causing gravel to compact
- Displacement through heavy use creating thin spots (Correct answer)
- Ultraviolet light breaking down the gravel surface
- Rain washing fine particles into the gravel voids
Correct answer: Displacement through heavy use creating thin spots
Heavy foot traffic and play activity displace pea gravel from high-use areas, creating dangerously thin spots directly beneath equipment.
Question 5: An inspector tests surfacing beneath a slide exit using a triaxial accelerometer and records a Gmax of 185 and HIC of 950. What should the inspector conclude?
- Surfacing passes both criteria and no action is required (Correct answer)
- Surfacing fails HIC only; the area must be closed
- Surfacing fails Gmax only; add 2 inches of material
- Both values exceed limits; immediate closure is required
Correct answer: Surfacing passes both criteria and no action is required
Both 185 g (below 200 g limit) and 950 (below 1000 HIC limit) are within acceptable ASTM F1292 thresholds, so no corrective action is needed.
Question 6: When testing unitary surfacing (e.g., rubber tiles or poured-in-place rubber) in a laboratory per ASTM F1292, from what drop height is the test performed to represent a 12-foot critical fall height?
- 12 feet
- The actual critical fall height of the equipment being covered (Correct answer)
- A standardized 3.15-foot (960 mm) drop height
- 6 feet, as a 50% safety factor is applied
Correct answer: The actual critical fall height of the equipment being covered
Under ASTM F1292, laboratory testing drops the impactor from a height equal to the critical fall height of the specific equipment the surfacing is intended to serve.
Question 7: Which of the following is a documented disadvantage of shredded/recycled rubber as playground surfacing compared to engineered wood fiber?
- Lower impact attenuation performance at equivalent depths
- Potential for chemical leaching and higher surface temperatures in sunlight (Correct answer)
- Greater displacement from use zones during normal play
- Inability to pass ASTM F1292 testing requirements
Correct answer: Potential for chemical leaching and higher surface temperatures in sunlight
Shredded rubber can leach chemicals from recycled tire compounds and absorbs solar heat, reaching surface temperatures that can burn children's skin.
CPSI Surfacing Requirements and Impact Attenuation Testing 5
A newly installed loose-fill rubber surface passes Gmax testing but fails the HIC threshold of 1000.
What does this indicate?