IBC totes

I recently purchased 2 300 gallon IBC totes to replace a couple 55 gallon barrels for garden rainwater cachement. Seller bought a trailer load from someone else, and told me that it previously contained water. However, once home I discovered a white powdery residue that feels like dry laundry detergent at the bottom. Upon closer examination I found a couple labels that fallen behind the metal cage and it seems like the tote has at some point contained a corrosion inhibitor (Protech 1650) and an unknown, probably also metal/mineral related substance from Alcoa. I have a SDS for Protech 1650, and it is a Class 1 chemical for both skin and eye irritation.

Any thoughts on how safe I can make these totes? Or thoughts on best practices to clean? I've looked at a couple videos, but the explanations on why to use the solvents (soap, baking soda, bleach, etc) they use weren't very clear to me. I feel a little better guessing that these probably never contained agricultural chemicals, but still feel nervous.

I got a decent deal on these and could just resell to someone who doesn't want food grade. Also, have only picked up one, so thought about asking for refund for the one I haven't picked up...but I was real excited to seriously up our water storage for cheap and without taking up much space.

Josh (using Sybilla's, my wifes, account)

I would request ... if not insist ... a full refund.

Seller said they contained water.  You discovered that wasn't the case.

Original contents must have been *nasty* if seller had to lie.  I mean, if the containers really did contain laundry soap, well, I'm thinking seller wouldn't have lied about THAT .  Sigh, look at me trying to measure where the line is that a dishonest person would cross.

Hey Josh (and Sybilla) I think the seller has been unfair to you.

The first move is to get a refund or replacement if you can. Make it clear these are being used to water your FOOD, not water your lawn or wash your car.

The second move is to look up the MSDS for the chemicals you suspect are involved. Not all chemicals are evil, and not all seep into the pores of the polyethylene liner. Many (I suspect like this one) are shipped as dry powder concentrates and then washed out into the process/equipment. If the operator was in a hurry, some powder may have been left behind.

So, try to clarify what you're dealing with. When you read the MSDS, keep in mind you are looking at the health/safety risks of the pure concentrate, not necessarily the diluted substance. My 2c.