Do nothing:
1.Grey Barrels should do something…like maybe it should unload water…which should propduce a fair amount of water in the location making the location flame retardant.
2. Yellow Barrels should explicitly do something in the environment…like leak a volitile substance like acid…it then should be flamable once released. and when ON fire it should be engrossing in the environment. So much so that you need to leave the freaking area.
Not saying that this is absolutely necessary…but.