Expired Hanna Reagent still good?

[Timrpn]

Hello,

So, I have a bunch of expired Hanna Phosphate reagent packets that I never used, because I got real lazy and stopped testing. They expired back in Late 2023. Are they really no good? or are they like canned goods where they are still good past the date. They are sealed in individual packets. So I can't really see how they can go bad?

 

[Formulator]

I wouldn’t use them. Complex molecules like some used as color indicators tend to degrade and for a test kit, even if there is only a small amount of degradation, that may directly impact the result in a way that you wouldn’t necessarily detect. Like it would seem to be working but actually give you a false low result.

Maybe someone else knows exactly what those reagents are to make a more concrete conclusion, but personally I wouldn’t risk it.

 

[EricR]

I have no idea but, if you use them, are you even ever going to trust your test results?
*It'd be interesting to buy new reagents and do a compare but, beyond that, I think I'd just lean towards buying new for the confidence factor alone

 

[TARHEEL78]

I have no idea but, if you use them, are you even ever going to trust your test results?
*It'd be interesting to buy new reagents and do a compare but, beyond that, I think I'd just lean towards buying new for the confidence factor alone

I had a handful of expired phosphate reagents and did exactly that. None of the old reagents read the same as the new ones, if I remember correctly they all read low.

 

[Ziggy17]

I had expired Hanna Alk reagent ( 1 year past the expiry date). Bought new ones. Thought I’d compare the old with the new for sh!ts and giggles. Identical reading.

 

[felda001]

Be aware that it’s possible your results may not be accurate. That being said if you are just trying to see if they stay consistent I would probably still use them. I’ve used expired ones on accident and they measured close to or the same as the new ones I had

 

[EricR]

I had expired Hanna Alk reagent ( 1 year past the expiry date). Bought new ones. Thought I’d compare the old with the new for sh!ts and giggles. Identical reading.

That's funny -- seems to me that, of the common Hanna reagents, liquid alkalinity reagent is the one that has the worst shelf-life.
*tangent from this thread,,, sorry

 

[Ziggy17]

That's funny -- seems to me that, of the common Hanna reagents, liquid alkalinity reagent is the one that has the worst shelf-life.
*tangent from this thread,,, sorry

You would think it would be the most unstable for sure. But now that I think of it, does the Neptune apex reagents have a past due date? I’ve never looked.

Edit. I just looked and their bottles aren’t stamped with a date. Nether is the ABC bottles….

@Randy Holmes-Farley. What is your thought?

 

[PharmrJohn]

I've used a little past the expiration date but only by a month or two. What I had going for me was very little temperature variation in my house so I was comfortable stretching a little.

 

[Dburr1014]

That's funny -- seems to me that, of the common Hanna reagents, liquid alkalinity reagent is the one that has the worst shelf-life.
*tangent from this thread,,, sorry

If you keep the alk in the fridge it's good long past shelf life.

Thread 'Important findings according how to store open bottles of the reagent for Hanna Marine alkalinity checkers' https://www.reef2reef.com/threads/i...-for-hanna-marine-alkalinity-checkers.893762/

 

[Timrpn]

I can see the Alk reagent going bad as it is open to air etc and subject to evaporation of the reagent, but the packets are not exposed to the same elements

 

[Ziggy17]

If you keep the alk in the fridge it's good long past shelf life.

Thread 'Important findings according how to store open bottles of the reagent for Hanna Marine alkalinity checkers' https://www.reef2reef.com/threads/i...-for-hanna-marine-alkalinity-checkers.893762/

I don’t think the “how or why” putting it in the fridge makes it last longer is explained by Lasse though. Or was it and I missed it?

 

[Dburr1014]

I don’t think the “how or why” putting it in the fridge makes it last longer is explained by Lasse though. Or was it and I missed it?

My food stays longer if I keep it refrigerated also.
LOL
It just does, somethings are better longer if kept in a cool dark place.
Hanna bunked the idea but I keep mine in the refrigerator and it just went out of date a couple months ago. It gives me readings that seem to be in line what I expected.

 

[GARRIGA]

I'd call Hanna

 

[Ziggy17]

My food stays longer if I keep it refrigerated also.
LOL
It just does, somethings are better longer if kept in a cool dark place.
Hanna bunked the idea but I keep mine in the refrigerator and it just went out of date a couple months ago. It gives me readings that seem to be in line what I expected.

Fair enough, but I don’t keep mine in the fridge and I get the same result. They put them in brown bottles so I presume light exposure will affect the stability. When I was a nurse working in the hospital, some injections were required to be refrigerated, some weren’t, just room temp. Other than a few people that read that thread, I don’t think these bottles are ever refrigerated. So I’m sceptical there’s a benefit.

Disclaimer: I’m not a molecular physicist or chemist.

 

[Reeferbadness]

I'd buy a new set of Phos reagent packets and test with new and old to compare. If both are about the same, then you can use old for a bit and will have some back up. Wouldn't trust without comparing

 

[ErikVR]

Expired reagents always read lower in my experience. Same with no3 and alk.

 

[Jasongtr]

Might be ok, might not be, but in any event would you trust what it says, personally no, in the bin

 

[Townes_Van_Camp]

That's funny -- seems to me that, of the common Hanna reagents, liquid alkalinity reagent is the one that has the worst shelf-life.
*tangent from this thread,,, sorry

Truth.

 

[gbroadbridge]

Hello,

So, I have a bunch of expired Hanna Phosphate reagent packets that I never used, because I got real lazy and stopped testing. They expired back in Late 2023. Are they really no good? or are they like canned goods where they are still good past the date. They are sealed in individual packets. So I can't really see how they can go bad?

For $10 why would you bother given you would not be able to trust the result.