AI: 0.01% Bromethalin. FASTRAC BLOX is a single feed, weather resistant and fast-acting acute rodent bait. FASTRAC BLOX is used for controlling rodent populations in a quick effective manner. It's a small, rough, all-weather baiting blox with many gnawing edges. Secondary poisoning does not readily occur with bromethalin, however, there is no antidote with bromethalin. Keep all children, pets and non-targeted animals away from FASTRAC. The use of tamper-resistant bait stations is recommended.