[Ballistic]

I have bought a load of Baked Beans in High Density Polythene tubs with the intention of cleaning the tubs out and using them as reagent bottles. They have a really wide neck which is useful.
HDPE is renowned for it's low reactivity, so I was very surprised to find that the mixture of oil and tomato has severely stained the inside of the tubs.
My attempts to remove the stain include normal washing up liquid and sponge sourer and soaking for 2 weeks in bleach. The soaking in bleach did make a very slight improvement, lets say less than 5 %.
As I don't know what to try from here, I thought I would see if anyone has experience of stain removal or working with polythene type plastics?

[Arkcon]

If you're looking to remove all the color, I'd suggest you try an peroxide bleach.  It should work better than household hypochlorite, and not be to expensive.  Failing that, just soak in what you intend to store it in it.  If it can't get the stain out in a reasonable time, then it can't be contaminated in that same amount of time.

[Ballistic]

Thank you for the idea. I have got 35% Peroxide here, but I think if I use the Peroxide, I will end up with nice looking empty Peroxide bottles which cost more to buy than the Baked Beans did! One of the crazy things in this world where it costs us say £1.00 in petrol to go and pick up 89 pence worth of milk on a Sunday morning.

[Arkcon]

Right, so I did mean, while you're working in a home lab, to use some peroxide containing cleaning agent -- something meant to whiten white clothes without containing chlorine bleach.

[billnotgatez]

OxiClean
http://en.wikipedia.org/wiki/OxiClean
is a brand name

@Ballistic
Let us know how you are progressing

[Ballistic]

I though I would reply back to my own old post from way back with some information I found useful in case it helps any one else. The following article I found on the web explains about the molecular make up of high density plastics and why iodine atoms get "stuck" in them, and to me this explains the problem I had with the oily tomatoe sauce, of course, feel free to disagree if you have reason:


https://melscience.com/en/experiments/iodine-in-plastic/