chlorophacinone

Chlorophacinone is a first-generation anticoagulant rodenticide. The mechanism of action results in internal bleeding due to non-functional clotting factors. It was used as a toxin to control rodent populations. It is classified as an extremely hazardous substance in the United States as defined in Section 302 of the U.S. Emergency Planning and Community Right-to-Know Act (42 U.S.C. 11002) and is subject to strict reporting requirements by facilities which produce, store, or use it in significant quantities.

== History == The French company Liphatech (formerly known as Lipha), which had previous experience with creating anticoagulants for the treatment of heart patients, created chlorophacinone in 1961 and branded it “Rozol”. Chlorophacinone belongs to the first-generation anticoagulant rodenticide group, first being developed during the 1940s to 1960s to control rodents in terrestrial environments. Its use began being replaced during the 1970s, along with the use of other rodenticides of its group, by the more potent second-generation anticoagulant rodenticides, when several studies provided information which depicted a developed resistance of rodents to Warfarin (another first-generation anticoagulant rodenticide) in northern Europe and the United States along with a discovered cross-resistance to all first-generation anticoagulant rodenticides. This was found to be caused by a single, dominant and autosomal gene which raised the rodent's dietary requirement for vitamin K (the vitamin whose production anticoagulants primarily inhibited) to twenty times the normal amount. Even though its use has diminished, chlorophacinone can still be bought for rodenticide use, for situations in which conventional bait for rodenticidal purposes cannot be used.