55 gallon PET drums

Resvordog · Aug 4, 2015

Hi,

I have two 55 gallon drums I believe are made of PET. I have had them sitting open, outside for several years. Recently, I connected them together to mix and store saltwater in for water changes. I bought them from a local car wash to use as reclamation tanks for water coming from my washing machine during a drought. At the car wash, I believe they were what the car wash soap was delivered in. So I know they had car wash soap and water containing laundry detergent and fabric softener in them. They sat empty outside for several years after that. I scrubbed them out with a dilute muratic acid solution before connecting them and making salt water in them. I noticed after a few weeks of having saltwater in them, the insides started smelling like car wash soap or some other kind of fragrance and the water was slightly more foamy than I would expect from saltwater. My question is, do you think they are safe to use? Is it possible that the plastic absorbed the soap and is leaching into the water now?

Randy Holmes-Farley · Aug 4, 2015

It's hard to gauge, but fragrance molecules (being uncharged) will potentially penetrate into plastic in ways that soaps (which are charged) mostly do not. So the smell may not be a good gauge.

You are using them for what? Storing new salt water?

Resvordog · Aug 4, 2015

Randy Holmes-Farley said:
It's hard to gauge, but fragrance molecules (being uncharged) will potentially penetrate into plastic in ways that soaps (which are charged) mostly do not. So the smell may not be a good gauge.

You are using them for what? Storing new salt water?

Yes. They also had water containing fabric softener and laundry soap/detergent in them for a little while. I'm guessing fabric softener is a lipid, kind of like like soap? There is a difference between detergents and soaps, isn't there?