CPSI Entrapment and Protrusion Hazard Testing Questions and Answers 2 — Questions and Answers
Question 1: Which ASTM F1487 dimension defines the lower boundary of the head entrapment zone?
- 2.5 inches
- 3.5 inches (Correct answer)
- 4.5 inches
- 5.5 inches
Correct answer: 3.5 inches
The head entrapment zone begins at 3.5 inches — openings larger than 3.5 inches can admit a child's head.
ASTM F1487 establishes the head entrapment zone as openings between 3.5 inches and 9 inches. The 3.5-inch lower boundary reflects the minimum head dimension of the age group — a child's head can pass through an opening that is 3.5 inches or larger. The 9-inch upper boundary represents the point at which the head can pass through freely in both directions. Openings within the 3.5-to-9-inch range are prohibited because a child's head can enter but cannot exit, creating entrapment and strangulation risk.
Question 2: How many thread pitches beyond the nut is the maximum allowable protrusion for fasteners on playground equipment?
- 1 thread pitch
- 2 thread pitches (Correct answer)
- 3 thread pitches
- 5 thread pitches
Correct answer: 2 thread pitches
ASTM F1487 limits fastener protrusion to a maximum of 2 thread pitches beyond the nut.
ASTM F1487 specifies that bolts and other fasteners must not extend more than 2 thread pitches (2 times the pitch distance between threads) beyond the nut or attachment surface. This small protrusion is considered the acceptable manufacturing tolerance. Greater protrusion creates a snag hazard for drawstrings and clothing and a laceration hazard if the exposed threads are sharp. CPSIs use thread-pitch gauges or visual inspection to identify non-compliant fastener protrusions.
Question 3: What testing device is used to check for head entrapment openings on playground equipment?
- A 3.5-inch and 9-inch probe or go/no-go gauge (Correct answer)
- A standard 12-inch ruler
- A digital caliper measuring to 0.001 inches
- A tape measure
Correct answer: A 3.5-inch and 9-inch probe or go/no-go gauge
CPSIs use go/no-go probes or gauges with critical dimensions of 3.5 inches and 9 inches to test for head entrapment openings on playground equipment.
CPSIs use specialized probes or go/no-go gauges calibrated to 3.5 inches and 9 inches to test openings in playground equipment for head entrapment potential. The test involves attempting to pass the 3.5-inch probe through each opening — if the probe passes through, the opening is large enough for a child's head to enter. The 9-inch probe is then used to verify the opening is also large enough for the head to exit. An opening that admits the 3.5-inch probe but not the 9-inch probe is in the prohibited entrapment zone.
Question 4: What is the finger entrapment zone for playground equipment openings?
- Less than 1/4 inch
- Between 3/8 inch and 1 inch (Correct answer)
- Between 1 inch and 2 inches
- Greater than 2 inches
Correct answer: Between 3/8 inch and 1 inch
The finger entrapment zone is openings between 3/8 inch (0.375 inches) and 1 inch in diameter — fingers can enter but cannot be withdrawn.
ASTM F1487 identifies finger entrapment as a hazard when openings are between 3/8 inch (0.375 inches) and 1 inch. In this size range, a child's finger can enter an opening and become entrapped — the finger may be inserted while straight, then bend or swell, making withdrawal painful or impossible. Equipment must be designed so that openings are either less than 3/8 inch (too small for a finger to enter) or greater than 1 inch (large enough for free withdrawal). CPSIs check areas around fasteners, rungs, and holes for this hazard.
Question 5: What is the torso entrapment zone as defined in ASTM F1487?
- 3.5 to 9 inches
- 9 to 18 inches (Correct answer)
- 18 to 24 inches
- 24 to 36 inches
Correct answer: 9 to 18 inches
The torso entrapment zone is openings between 9 and 18 inches — these can admit a child's torso but not allow it to exit.
ASTM F1487 identifies three entrapment zones: finger (3/8 to 1 inch), head (3.5 to 9 inches), and torso (9 to 18 inches). The torso entrapment zone covers openings between 9 and 18 inches — large enough for a child's torso to enter but potentially too small for it to exit, particularly if the child is wearing a coat or if the child's torso tapers (shoulders wider than waist) after entering feet-first. Equipment must avoid creating openings in any of these three ranges wherever a child could be expected to insert a body part.
Question 6: In playground entrapment hazard testing, what does it mean if a 3.5-inch probe passes through an opening but a 9-inch probe does not?
- The opening is safe because it is between 3.5 and 9 inches
- The opening is in the prohibited head entrapment zone and is a hazardous condition (Correct answer)
- Additional testing with a 6-inch probe is required
- The opening only needs to be checked for torso entrapment
Correct answer: The opening is in the prohibited head entrapment zone and is a hazardous condition
An opening that admits the 3.5-inch probe but not the 9-inch probe is in the prohibited head entrapment zone — a child's head can enter but cannot exit.
The go/no-go testing method determines if an opening falls in the prohibited head entrapment zone (3.5 to 9 inches). If the 3.5-inch probe passes through the opening, the opening is large enough for a child's head to enter. If the 9-inch probe does NOT pass through, the opening is too small for the head to exit once entered. This combination — 3.5-inch passes, 9-inch fails — definitively identifies a head entrapment hazard. The CPSI should document this finding with photos, note the specific location, and recommend immediate correction or closure.
