Our old water softener just broke and released all the resin beads into our hot water heater. I've been draining it but a significant amount of beads went into the drain pan under the hot water heater. I was a bit concerned that if these were flammable, that it would be a hazard to run the how water heater.
I took them outside and tried to light them. They did blacken after a while and let off a nasty fume, but the stack did not continue to light after the flame was removed. I would still recommend testing your own if anyone else reads this answer with a similar conscern