text: how could i clean up chlordane from a concrete floor?   if alot of it spilled (like more than a few tablespoons) you need professional help. chlordane is a banned chemical, and is highly toxic. i hope for your sake that wherever it spilled it's not in your basement, or anywhere else where somoene may inhale it. if so, get out tof the house til it's cleaned up. concrete is porous, so some of it may have seeped into the floor too.