Why You Should Require 50% of the Maximum Impact Allowance OR LESS
When selecting a playground surface, not all materials provide the same level of protection. Many playground owners unknowingly accept surfacing that barely meets industry safety standards, leaving children at greater risk of injury.
The solution? Ensure that your playground surface is tested and installed to meet 50% or less of the maximum allowable impact thresholds for g-max and HIC.
Understanding g-max and HIC—And Why They Matter
When a child falls, the surface they land on determines how much force their body absorbs. This is measured in two key ways:
G-max: Measures the peak force of an impact. Lower numbers mean better shock absorption.
HIC (Head Injury Criterion): Assesses the potential severity of a head injury from impact acceleration and duration. Lower scores indicate lower risk.
Industry standards, such as ASTM F1292/3313, establish maximum impact limits for playground surfacing to reduce serious injury risk. The commonly referenced limits are:
✔ 200 g-max (force of impact)
✔ 1000 HIC (the threshold where life-threatening brain injuries become more likely)
However, choosing surfacing that merely meets these limits is not enough. To improve safety, we recommend 50% or less of these maximum values (100 g-max / 570 HIC or lower).
Why You Shouldn’t Settle for the Maximum Allowance
To understand why exceeding 100 g-max is risky, consider this:
🏈 Football players are pulled from a game when they sustain hits around 80-90 g-max due to concussion concerns.🤕 At 200 g-max, the human body experiences an impact twice as severe—yet some playground surfaces still meet only this minimum requirement.
💡 Just because a surface is technically compliant doesn’t mean it provides the best protection. Lower g-max and HIC values significantly reduce severe injury risks.
How to Ensure Your Playground Surfacing Meets 50% or Less of the Maximum Allowance
1. Request Impact Test Results from the Manufacturer
Ask for certified impact attenuation test results (in accordance with industry standards like ASTM F1292/3313).
Require proof that g-max does not exceed 100 and HIC does not exceed 570 at the maximum fall height (the maximum fall height a child could reasonably reach, not just the tallest platform)
2. Specify the Requirement in Your Contract
Before ordering, include written specifications requiring the installed surface to perform at or below 50% of the maximum ASTM thresholds.
Avoid vague language like “meets ASTM F1292/3313,” since this only ensures compliance at the maximum limits.
3. Require Post-Installation Third Party Testing
The performance of surfacing can change after installation due to compaction, wear, or improper installation.
Ensure your contract includes a third-party impact test after installation to confirm compliance with your specified safety thresholds.
4. Choose Materials That Consistently Test Below 50% of the Maximum Allowance
Not all surfacing materials maintain their impact attenuation over time. Consider:
✔ Poured-in-place rubber (Ensure adequate thickness and binder quality)
✔ Rubber tiles (Check seams to prevent degradation)
✔ Engineered wood fiber (Requires regular maintenance to maintain impact performance)
✔ Synthetic turf with shock pads (Ensure the padding layer meets 50% impact thresholds)
The Bottom Line: Require Better Than the Minimum
For public playgrounds, selecting the right surface is one of the most critical safety decisions you’ll make.
✔ Require that g-max is 100 or lower and HIC is 570 or lower.
✔ Put it in writing before purchasing the material.
✔ Verify with post-installation testing to confirm compliance.
By requiring better than the minimum, you’re actively reducing the risk of severe injuries and ensuring that your playground surfacing provides the highest level of protection possible.
More Information for clarity beyond the blog
Explanation of Fall Height
Fall height is the distance from the highest point a child can stand or place their feet on a piece of equipment down to the protective surfacing below. This measurement helps determine whether the surfacing under and around that equipment can adequately cushion a fall and reduce the severity of head injuries.
Some equipment manufacturers may rate their product according to the tallest platform height. However, in practice, a child’s feet might be higher than that platform as they climb or maneuver in ways not always anticipated in the equipment design. That is why we test based on the highest height a child’s feet can reasonably reach, rather than just the manufacturer’s platform height. By doing so, we account for children’s natural play behaviors and help ensure the chosen surfacing can lessen the chance of severe injury during everyday use. This method acknowledges that no playground can be entirely free of risk, yet aims to limit hazards and provide a space for safer, developmentally appropriate play experiences.
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