We are committed to protecting your personal data and providing you with access to your personal data in accordance with the personal data protection laws in force in the European Union.
By clicking "Accept All", you are giving us permission to place cookies to enhance your experience on this website, to help us analyze site performance and usage, and to allow us to deliver relevant marketing content. You can manage your cookie settings below. By clicking "Confirm" you agree to the current settings.
2026-09-17
Blog
EN 469 vs. NFPA TPP: Two Ways to Measure Thermal Protection
Firefighting protective clothing needs to answer one basic question: how well does it protect the wearer from heat?
EN 469 and NFPA's TPP test both try to answer this — just in very different ways.
EN 469: Two Separate Tests
EN 469 splits thermal protection into two independent tests:
ISO 9151 measures flame exposure, reported as HTI₂₄
ISO 6942 measures radiant heat exposure, reported as RHTI₂₄
Each test isolates one type of heat and reports it on its own.
NFPA TPP: One Combined Test
NFPA's TPP test takes a different approach. It exposes a multi-layer clothing composite to flame and radiant heat at the same time, at a fixed intensity of 84 kW/m² (2.0 cal/cm²·s).
The result is a single TPP rating, in cal/cm². It's calculated by multiplying the exposure time (until a predicted second-degree burn) by the heat flux. NFPA 1971 sets a minimum TPP rating of 35 for structural firefighting garments.
Can the Two Be Converted?
No. The heat sources, test setups, and evaluation methods are fundamentally different. An EN 469 HTI/RHTI result cannot be mathematically converted into an NFPA TPP rating — and vice versa.
What This Means in Practice?
EN 469 gives you two separate numbers — one for flame resistance, one for radiant heat resistance. This lets you see exactly where a garment's strengths lie.
TPP gives you one combined number. It's convenient for a quick comparison, but it doesn't tell you whether the protection comes mainly from flame resistance or radiant heat resistance.
The Takeaway
EN 469 and NFPA TPP measure similar things for similar reasons — but they're not interchangeable. Use each standard's results to understand a garment's thermal protection characteristics on its own terms, rather than trying to convert one into the other.t directly into the other.
