Dragon

Containment foam is a yellow white liquid that becomes foam. It is flexible, porous, is highly resistant to heat and electricity, and is hard to break or tear.

I fell back through the doorway even as the tank began emptying its contents onto the floor.  It was a yellow-white, and as it poured onto the ground, it expanded like shaving cream.  The tank was probably close to three gallons, making for a hell of a lot of foam.

Tangle 6.5

> > I’d watched a discovery channel feature on this stuff.  The PRT, the Parahuman Response Team, was equipped with tinker-designed nonlethal weaponry to subdue supervillains.  This containment foam was standard issue.  It ejected as a liquid, then expanded into a sticky foam with a few handy properties.  It was flexible and it was porous when fully expanded, for one thing, so you could breathe while contained within it, at least long enough for rescue teams with a dissolving agent to get to you.  It was also impact resistant, so PRT squads could coat the ground with it to save falling individuals or keep heavy hitters from doing much damage.

> > The way it expanded, you could coat all but the strongest villains in it, and it would disable them.  Because of the way it denied you leverage and was resistant to impacts and tearing, even the likes of Lung would have trouble pulling themselves free.  Topping it all off, it was resistant to high temperatures and a strong insulator, so it served to handle the pyrokinetics and those with electromagnetic powers.

> Tangle 6.5