How do you keep your T-shirts from lighting on fire? Roll around in some herring sperm DNA.

That’s obviously not the intrinsic response; researchers at Italy’s Politecnico di Torino lab led by Giulio Malucelli made the discovery. They dissolved the DNA in water then soaked a swatch of cotton fabric in the solution. When the researchers tried to ignite the fabric, the coating acted like a flame retardant, leaving only harmless char behind.

The DNA was able to resist the flames because of its components. The phosphate in its support system is converted to phosphoric acid, which produces a carbon-rich substance when ignited, protecting the fabric. The nitrogen in the DNA bases create ammonia, which disperses flammable gas. Watch the cotton fabric smoke a bit, then refuse to light:

Now watch a DNA-free cotton strip.

While the black char might ruin your cotton dress, at least it won’t burn off your body.

There are few snags before DNA can be marketed as a commercial flame retardant. First of all, extracting and applying DNA is too expensive, as much as five times more than repellents on the market now. Secondly, the coating dissolves in water, so one wash means all that all-natural flame  retardant down the drain.