You’ve seen the numbers on every fire suit. SFI 3.2A/1. SFI 3.2A/5. SFI 3.2A/15. They show up on hang tags, product listings, and tech inspection sheets at every track in Canada. Most racers can read the number. Far fewer know what it actually means.
What protection are you getting? Does the number refer to layers? Does certification expire? And which rating does your class require?
This guide covers all of it. By the end, you’ll know exactly what you need before you buy.
What Is the SFI Foundation?
These safety standards don’t come from the tracks or the race series. They come from the SFI Foundation — a non-profit organization that has been setting and enforcing safety standards for motorsport equipment since 1978.
Here’s how the process works. A manufacturer builds a suit and submits it to an SFI-approved testing lab. The lab runs fire and heat tests on the fabric, the stitching, the zippers, and the cuffs. If everything passes, the manufacturer earns the right to put an SFI-certified patch on the left shoulder of that suit.
That patch is your proof. It means the suit has been independently tested to a published standard — not just measured against the manufacturer’s own claims. A suit without that patch is unverified, no matter what the price tag says.
In Canada, SFI certification is recognized across drag racing, oval racing, and dirt track. The NHRA rulebook references SFI specs for every class from bracket racing to nitro. So does ASN Canada FIA, which governs national-level sanctioned motorsport across the country. If you race in Canada, you almost certainly need a certified suit.
How SFI Ratings Are Measured
The SFI spec number for driver suits is 3.2A. The digit at the end — the /1, /5, /15, or /20 — is the protection level. It’s based on a measurement called Thermal Protective Performance, or TPP.
TPP tells you how long a suit can hold back a second-degree burn in a simulated fire. To get the time in seconds, divide the TPP value by two. Here’s how each rating compares:
| SFI Rating | TPP Value | Time Before 2nd Degree Burn |
|---|---|---|
| SFI 3.2A/1 | 6 | ~3 seconds |
| SFI 3.2A/5 | 19–24 | ~10 seconds |
| SFI 3.2A/15 | 60+ | ~30 seconds |
| SFI 3.2A/20 | 80+ | ~40 seconds |
The most common misconception is that the rating number is the layer count. SFI-5 does not mean five layers. A suit earns its rating based on how its materials and construction perform in testing. Higher-rated suits do tend to use more layers — extra layers create air gaps that slow heat transfer to your skin — but the rating is a test result, not a layer count.
Those extra seconds matter more than most people appreciate. The gap between a 3.2A/1 and a 3.2A/5 is seven more seconds to escape a burning car. That’s a meaningful difference.
SFI 3.2A/1 — The Entry-Level Rating
A single-layer 3.2A/1 suit gives you about 3 seconds of protection before a second-degree burn. It’s typically built from fire-resistant cotton or a treated fabric like Pyrovatex.
The NHRA rulebook requires 3.2A/1 for naturally aspirated cars running between 10.00 and 13.99 in the quarter mile. Most Canadian tracks follow the same threshold. That makes it the legal minimum for everyday bracket racing and slower street-legal drag events.
Three seconds is the legal floor. It’s not a lot. Many experienced racers choose to run a higher-rated suit even when the rulebook doesn’t require it. The cost difference is small. What you get in return is real.
At EPIC Racewear, our 1-layer 3.2A/1 suits are built to your exact measurements in your team colours — not pulled from a rack and hoping they fit.
SFI 3.2A/5 — The Most Common Standard in Canada
The 2-layer 3.2A/5 rating is the most widely required spec in Canadian motorsport. You get about 10 seconds of protection — more than three times what a 3.2A/1 provides. Most 3.2A/5 suits use two or more layers of Nomex, which is an inherently fire-resistant aramid fibre made by DuPont.
The NHRA rulebook requires 3.2A/5 for any car running 9.99 or quicker, and for any car using forced induction or nitrous below 10.00. Most oval and road racing series in Canada reference the same standard for their competitive classes.
If you’re buying one suit that covers you across different tracks and classes, 3.2A/5 is the right choice. It meets virtually every Canadian requirement outside of extreme fuel categories. The jump in protection over 3.2A/1 is real, and the price difference is less than most racers expect.
Our 2-layer 3.2A/5 suits are built from multi-layer Nomex construction, cut to your measurements, and finished in your colours and sponsor layout. No generic fit, no stock design.
SFI 3.2A/15 — For the Quicker Classes
Move into quicker and more dangerous territory and the rules reflect it. SFI 3.2A/15 provides about 30 seconds of protection. It’s required by the NHRA rulebook for cars running 7.50 to 9.99 in the quarter, open-bodied cars with forced induction, and most Pro Modified and Advanced E.T. classes.
These suits use multiple layers of Nomex or similar high-performance aramid fabrics. They’re heavier than a 3.2A/5 and more expensive to build. The protection they provide is dramatically higher, and for the classes that need them, there’s no substitute.
One important detail: the SFI Foundation sets a 5-year certification life on 3.2A/15 suits. After five years, the suit must be recertified by the original manufacturer or replaced. Track that date from the moment you buy.
SFI 3.2A/20 — Nitro and Top Alcohol
SFI 3.2A/20 is the highest rating in common use. It’s required for Top Fuel, Funny Car, Top Alcohol Dragster, and front-engine, open-bodied cars running 7.49 or quicker with forced induction.
Nitromethane and alcohol fuels burn very differently from gasoline. They push far more volume through the engine, which means a bigger, faster fire if something goes wrong. A 3.2A/20 suit is built specifically for that environment.
Most grassroots Canadian racers won’t need one. But if you run a nitro or alcohol class, it’s non-negotiable. Your tech inspector will check.
Don’t Forget Your Hands, Feet, and Undergarments
A fire suit covers most of your body. But your hands and feet are exposed too. SFI applies to gloves and shoes for the same reason it applies to suits — because those surfaces are in a fire too.
In classes that require a 3.2A/5 suit, SFI-certified racing gloves are typically required alongside it. Ours are built from Nomex and designed to give you grip and control without sacrificing protection. Your hands work the wheel right up until you need to get out. They need to be covered.
SFI-certified racing shoes protect your feet and ankles while still giving you feel on the pedals. Required in most competitive NHRA classes, and worth wearing in any class that involves real speed.
The piece most racers overlook is fire-resistant underwear and socks. A single SFI-certified base layer worn under your suit can add 3 or more seconds to your total protection time. For 3.2A/1 suit wearers, that effectively doubles what the suit alone provides. The cost is low. The payoff in a fire is not small. Treat undergarments as part of your kit, not an optional extra.
Which Rating Do You Need in Canada?
Always confirm with your sanctioning body’s current rulebook. Rules vary by series, class, and car configuration. Use this as your starting point:
- Naturally aspirated bracket racing, 10.00–13.99 → SFI 3.2A/1 minimum
- Forced induction or nitrous below 10.00, or any car 9.99 and quicker → SFI 3.2A/5
- 7.50–9.99, open-bodied power adder cars, Pro Mod, Advanced E.T. → SFI 3.2A/15
- 7.49 and quicker, nitro or Top Alcohol → SFI 3.2A/20
- Every class, every time → Add certified gloves, shoes, and undergarments
When in doubt, run the higher rating. The minimum is the legal floor, not the safety recommendation. A fire doesn’t know what your elapsed time was.
Built in Ontario. Shipped Across Canada.
At EPIC Racewear, we build custom SFI racing suits from our workshop in Walkerton, Ontario. Every suit is made to your measurements, your design, and the SFI spec your class requires — 3.2A/1, 3.2A/5, or 3.2A/15.
You order in CAD. We ship from Ontario. No cross-border duty, no customs delays, no exchange-rate guesswork. Just a fully certified suit built the way you want it.
Ready to get started? See our full lineup of custom SFI racing suits built for Canadian racers.
Frequently Asked Questions
How long does an SFI racing suit last? SFI 3.2A/1 and 3.2A/5 suits don’t carry a mandatory expiry at most Canadian tracks. SFI 3.2A/15 suits have a 5-year certification life set by the SFI Foundation. Regardless of certification, replace any suit that’s been in a fire, has holes or thinning fabric, or has been soaked in fuel or oil. Those conditions compromise the fire resistance whether the suit looks fine or not.
Can I wear a higher-rated suit than my class requires? Yes. Always. A 3.2A/5 suit satisfies any class that requires 3.2A/1. You can only be penalized for going lower than required — never for going higher.
Does washing affect fire protection? It depends on the fabric. FR cotton and treated suits can lose some fire resistance after repeated washing. Nomex doesn’t have that problem. The fire resistance in Nomex is built into the fibre itself, not added as a surface treatment. Follow the care label on your specific suit.
What’s the difference between SFI and FIA certification? SFI is the North American standard, used by the NHRA and most Canadian sanctioning bodies including ASN Canada FIA. FIA is the international standard, required for Formula-level racing, rally, and internationally sanctioned road racing. Some Canadian road racing series require FIA suits. Your rulebook will tell you which applies.
Do I need certified gloves and shoes if my suit is already SFI rated? It depends on your class. Most classes that require a 3.2A/5 suit also require certified racing gloves and racing shoes. Even if your class doesn’t mandate them, your hands and feet are exposed in a fire just like the rest of you. The full kit is always the right call.
EPIC Racewear builds custom SFI and FIA-rated racing suits, gloves, shoes, and undergarments for Canadian racers. Every order ships from Walkerton, Ontario.
Published: July 2026 | Category: Racing Safety | Reading time: 6 minutes