Does Oxalic Acid go off?

[BMX1973]

As it says in the title. Does Oxalic Acid go off?  Basically I have a dustbin with it in which is about a year old. It's sunk to the bottom but give it a stir and it mixes again. Is it still any good? 

Thanks in advance. 

[rodriguez]

I think once you've used it and it's sat for a while it does get a bit weaker but it should still work though might just take longer.

I've stuff I've had for ages I keep in a drum and use to clean the concrete paving in the yard.

[BMX1973]

Maybe I'll add a bit of fresh to it. 

How do you clean your paving then? Just tip it onto it and give it a scrub?  Sounds like a plan if it works. 

I think once you've used it and it's sat for a while it does get a bit weaker but it should still work though might just take longer.

I've stuff I've had for ages I keep in a drum and use to clean the concrete paving in the yard.

[rodriguez]

Yup, just tip it out and give it a scrub, leave for 5 mins and hose off, it's bio-degradable so your not killing the planet   

Maybe I'll add a bit of fresh to it. 

How do you clean your paving then? Just tip it onto it and give it a scrub?  Sounds like a plan if it works. 

I think once you've used it and it's sat for a while it does get a bit weaker but it should still work though might just take longer.

I've stuff I've had for ages I keep in a drum and use to clean the concrete paving in the yard.

[BMX1973]

Cool. 

Yup, just tip it out and give it a scrub, leave for 5 mins and hose off, it's bio-degradable so your not killing the planet   

Maybe I'll add a bit of fresh to it. 

How do you clean your paving then? Just tip it onto it and give it a scrub?  Sounds like a plan if it works. 

I think once you've used it and it's sat for a while it does get a bit weaker but it should still work though might just take longer.

I've stuff I've had for ages I keep in a drum and use to clean the concrete paving in the yard.