Combined 3D Services
FST Testing and Compliance: 3D Printed Parts for Aircraft, Rail, and Marine Interiors
By Mike Moussa, PE — If your parts go inside aircraft, trains, buses, or ships, they need to meet flame, smoke, and toxicity (FST) requirements. Here’s what you need to know about 3D printing FST-compliant components.
What Is FST Compliance?
FST stands for Flame, Smoke, and Toxicity — a set of performance requirements for materials used in enclosed passenger spaces. The concern is straightforward: in a fire, materials shouldn’t burn easily, shouldn’t produce dense smoke that prevents evacuation, and shouldn’t release toxic gases that incapacitate people.
Standards by Industry
Aviation (FAR/CS 25.853)
The most stringent FST requirements in any industry:
- Vertical burn (60 second) — burn length ≤6″ for cabin materials, ≤8″ for cargo
- Smoke density (NBS) — Ds at 4 minutes ≤200 for most applications
- Heat release (OSU 65/65) — peak ≤65 kW/m² and total ≤65 kW-min/m² for large panels
- Toxic gas emission — HCN, HCl, HF, SO₂, CO, NOₓ below specified limits
The FAA doesn’t care that your part is small or non-structural. If it’s in the cabin, it has to pass.
Rail and Transit (NFPA 130 / EN 45545)
Similar concepts, different standards:
- NFPA 130 — US standard for fixed guideway transit and rail
- EN 45545 — European standard for railway vehicles (often more stringent)
- Requirements vary by hazard level (HL1-HL3) and application
Marine (IMO FTP Code / SOLAS)
- IMO Resolution MSC.307(88) — fire test procedures for marine materials
- SOLAS Chapter II-2 — fire protection, detection, and extinction
- Applies to passenger vessels, offshore platforms, naval vessels
3D Printable FST Materials
Not many 3D printing materials pass FST testing. The proven options:
| Material | Process | FAR 25.853 | Strength | Max Temp |
|---|---|---|---|---|
| ULTEM 9085 | FDM | ✅ Certified | High | 170°C |
| PEKK-A (Antero 800NA) | FDM | ✅ Certified | Very High | 240°C |
| PPSU | FDM/SLS | ✅ Passes | High | 190°C |
| Nylon PA12 FR | SLS | ⚠️ Some tests | Medium | 80°C |
ULTEM 9085 is the workhorse for FST-compliant 3D printing. It’s been flying on commercial aircraft since the mid-2010s and has the most extensive certification data available.
Our FST Capabilities
- 3D printing in ULTEM 9085 — the most proven FST material for additive manufacturing
- Design guidance for FST compliance — wall thickness, geometry, and orientation affect test results
- Material traceability and lot documentation
- Coordination with test labs for formal FST certification testing
- Production parts for aircraft, rail, and marine applications
Important Caveats
A few things to understand about FST compliance and 3D printing:
- Material certification ≠ part certification. The material passing FST tests doesn’t automatically mean your specific part passes. Part geometry, thickness, and orientation affect results. Testing may be required for your specific application.
- Print parameters matter. Infill, layer height, and print orientation affect FST performance. We use validated print parameters for FST applications.
- Documentation requirements vary. Airlines and OEMs have their own approval processes beyond the FAA minimums. We help navigate this but it’s not simple.
Get Started
If you need FST-compliant 3D printed parts — whether for aircraft, rail, marine, or any enclosed space — let’s talk. We’ll help you select the right material, design for compliance, and navigate the testing requirements.
📧 info@partsnap.com | 📞 (214) 449-1455 | Discuss FST Requirements