Fire retardant material?

[toonces]

I've seen the suggestion to either carry some kind of fire extinguisher or a fire retardant material on trail rides. I doubt I'll be taking on the weight of even a small fire extinguisher, but I'd still like to have some way to put out a fire. What would be a good 'fire extinguishing material' I could bring along that would work say if a fire started in a hard to reach part of the motor that I could just maybe grab a hand full of and throw it on? I'm imagining it would be something granular like sawdust (but of course not sawdust).

Thanks