How do Food Grade Containers fare long term?

It's been 8 years since I purchased my food grade storage tubs. So how have they fared? Will they stand the test of time? My wheat should last 30 years packed in these, providing the temperature is right as well. This particular tub was interesting, as the top had water on it, there was mould all over the outside of the tub...

Yet this is the inside. Not one speck of dirt.

These are the contents of the container. Wheat that is still sealed, the oxygen absorbers are still working and there are no signs of any punctures. You can see the lid is a little cracked. I was a bit worried about that until I saw how tidy everything still was inside. Phew!

What it looked like once the lid had been taken off. No signs of internal damage.

The outside of the container was a bit messy. Mould and dirt were all over the container. It had been stored in my garage and this has been the wettest summer so far, so if these storage tubs have done their job properly, I'm very impressed.

Another view of the outside of this tub. Yes, that's mould. I wiped a bleach/water solution over it, checked each mylar bag and re-stored the entire container upstairs.

I have to note too that this was the only container that appeared to be a little more brittle than the others. Perhaps it was already old when I purchased it. Who knows how long the company I had bought it from had it. The company apparently had them outside. Anyways, it will be okay upstairs. I'm moving all my food storage from my garage into my 'spare' kitchen up there. To cut a long story short - it is a separate granny flat with its own kitchen.