If your mulch supplier sends you a lab report with your material and you're not sure what to look at first, you're not alone. Most contractors know they need a compliant material but haven't spent much time in the specifics of what the numbers actually mean. Here's a field-level breakdown.
Why the Report Exists
For engineered wood fiber and similar loose-fill surfacing materials, a lab report is typically a third-party confirmation that the product meets ASTM F1292 at a specific fall height. The playground equipment you're installing under determines the fall height you need, and the fall height determines how deep the material needs to be and what impact attenuation performance is required.
The report is your documentation that the material can do what the spec says it can do. Without it, you're installing on the manufacturer's claim alone.
The Numbers That Matter Most
Peak g (deceleration): This is the maximum force recorded during the test drop, expressed as a multiple of gravity. The ASTM F1292 limit is 200g. If the report shows anything above that at your specified fall height and depth, the material doesn't meet the standard for that configuration.
HIC (Head Injury Criterion): HIC is a calculation based on the shape of the deceleration curve over time, not just the peak. Limit is 1000. It's a more sensitive measure of injury potential than peak g alone because it accounts for how long the force is applied.
Both numbers must be below their limits. A material that passes peak g but fails HIC doesn't pass the test.
Test depth and fall height: The report should specify exactly what depth and fall height the test was conducted at. A material tested at 12 inches depth for an 8-foot fall height is not automatically certified for a 10-foot fall height at the same depth. If your equipment exceeds the tested configuration, you need data for that configuration -- or you need more depth.
Particle Size and Composition Data
Better lab reports also include particle size distribution data. For EWF, you're looking for a distribution that's predominantly in the 1/4 inch to 2 inch range, with minimal fines.
Why does particle size matter? Fine particles -- the powdery material that results from wood fiber degrading -- don't cushion impact the same way intact fibers do. High fines content in a fresh material is a red flag. It suggests the material is already degraded, or it's not genuine engineered wood fiber.
If the report shows more than 10-15% of material passing a #16 sieve (roughly 1mm), that's worth a conversation with your supplier.
Moisture content is usually listed too. EWF typically ships and performs best in the 30-50% moisture content range. Below that, the material can be dusty and settle more quickly. Above 60%, you may have compaction issues on install and the material may not perform as tested until it dries down.
What the Certifying Body Tells You
Look at who ran the test. IPEMA (International Play Equipment Manufacturers Association) certification means the product has been tested by an accredited third-party lab and the results are on file. Not all products carry IPEMA certification -- some suppliers rely on their own test results without third-party oversight.
The lab name should be on the report. Accredited labs include SGS, Bureau Veritas, and several university-affiliated testing programs. If you don't recognize the lab, it's worth asking your supplier whether the lab is ASTM-accredited.
Match the Report to the Job
Before you sign off on a material for a specific job, check three things:
- Fall height: Does the tested fall height match or exceed the highest equipment fall height on this job? If equipment goes to 10 feet, you need a passing test at 10 feet or a depth spec that accounts for the gap.
- Test depth: Is the tested depth achievable on this site? If the report tests at 12 inches and your contract calls for 12 inches, you need to actually install and maintain 12 inches.
- Date: How old is the test? Some agencies require lab reports within 12-24 months. An older report may not reflect current production batch consistency.
When the Numbers Don't Add Up
If a supplier gives you a lab report that doesn't show HIC and peak g separately, or doesn't specify the fall height and test depth, push back. You need enough information to confirm the material is appropriate for your specific job.
If the report shows the material passing at a fall height lower than your equipment requires, ask your supplier for data at the correct fall height. If they don't have it, that material is not certified for your job as written.
A lab report is only useful if it actually applies to the installation you're doing. Read it before the truck shows up, not after.