275 gallon ibc tote for watering

I found two 275 gallon IBC totes for $15 each my problem is I don't know if they would be safe for water containers for my girls. the totes were used to store mulch dye which is iron oxide or carbon-based dye depending on the color. they say they're nontoxic and should clean up well after pressure washing. my fear is if anything can leach out of the plastic and kill my girls or make the weed unsmokable. does anybody have experience with these type of containers and can chime in or have knoledge about dye's?

i have 2 of them. i would only buy food grade used ones. if mulch dye is not food grade, pass. 15 per is cheap which should scare you

I think I'll buy them and pressure wash them, then water a tomato plant with it for a couple of moths and see if it dies. if it doesn't die I'll use them next year for my plants if it does die I'll cut the tops off and use them for trash/scrap bins. everything I find online says it's safe to humans and plants.