Sciencemadness Discussion Board

Removing smell from polypropylene bottles

tandpasta - 4-5-2016 at 02:20

I have two small sauce bottles made from pp which keep smelling like their previous contents, barbecue sauce and mustard. They've been through the dishwasher multiple times, they've soaked for extended amounts of time in cleaning vinegar, diluted sodium hydroxide, and diluted nitric acid.

The smell is still there.

Why is the smell staying there? Did the sauces leach into the polymeric structure of the bottle? And how can I remove the smell (through chemical means)?

aga - 4-5-2016 at 11:32

Normal undiluted Bleach will probably work, although you'll need to rinse them a LOT.

The theory is that the dilute (5%) sodium hypochlorite will oxidise everything, including all organics and any bacteria/virii that took up residence.

I have no idea if it can also oxidide polypropylene - i guess you will find out.

Let us all know if this suggestion works or not.

MrHomeScientist - 4-5-2016 at 12:21

I thought this thread would be about the smell of the bottles themselves. I have several old empty Nalgene bottles that smell terrible inside. They all smell the same, so I suspect it's the plastic itself that smells. I wonder why this is and if it would be detrimental to anything I store inside.

Many washes with bleach is a good option to try for your problem, though.

OneEyedPyro - 4-5-2016 at 15:05

Bleach might work if allowed to soak for long periods.

PP is a fairly non reactive plastic being impervious to most bases, acids and solvents but I believe turpentine will attack it. I'm sure a few washes with that will do the trick if all else fails.

Texium - 4-5-2016 at 15:57

Quote: Originally posted by MrHomeScientist  
I thought this thread would be about the smell of the bottles themselves. I have several old empty Nalgene bottles that smell terrible inside. They all smell the same, so I suspect it's the plastic itself that smells. I wonder why this is and if it would be detrimental to anything I store inside.

Many washes with bleach is a good option to try for your problem, though.
I've noticed that about HDPE Nalgene bottles too, whether new or old. I store a lot of things in them though (probably at least 20% of my reagents) and I haven't had any problems yet...

Boffis - 4-5-2016 at 16:35

Try leaving them in the dishwasher for 10-15 cycles. This reduces the small of PE bottles that had contained benzaldehyde to an acceptable though still detectable level.

tandpasta - 12-5-2016 at 01:43

I will try the bleach solution and let you know the results in a few days.

tandpasta - 17-5-2016 at 14:02

The smell has gone, but not fully. I guess due to the low strength of the HCl solution (<5%). Is there any way to 'concentrate' the bleach?