Does hydrogen peroxide get too old?

How long can one keep hydrogen peroxide? I have several bottles I bought last summer and never got to us or even open. Are they still good to use to soak seeds and add to water for plants?

Thanks,

Maureen

If it contains stabilizers (check the 'ingredient' list, if it says anything other than hydrogen peroxide and water, it contains stabilizers) then it should last on your shelf about 3 years.
Food grade h2o2 is not as highly stabilized as the regular drug store type and will not last as long.

You can 'test' if it still works by making a 50/50 solution, placing it in a bowl or container with any object, plastic, metal, a seed etc. if you come back in 10 minutes there should be oxygen bubbles surrounding the object. If there isn't, its time to buy new hydrogen peroxide.

It will last longer if unopened. When you open H2O2 make sure that you recap tightly; clearly the less you open the bottle the more stable it remains. If it has destabilized it will have essentially reverted to water- not that I recommend drinking it, but it is harmless and will not harm plants, the environment, etc.

Thanks so much! That info is extremely helpful--I have about 8 large bottles that I never used.

Thanks again,

Maureen

We keep ours that we use in veterinary medicine closed and they will last at 3% for over 3 to 4 years. As soon as you expose them to air they will break down fairly fast 2 to 3 months. Its easy to tell just dip your finger in and does it fizz?

I teach chemistry and find the type you buy at the store (3%) to have an extremely short shelf life once opened like Soferdig says.
Debbie

Thanks again all, I think mine is good enough to use, as it has been unopened and is not quite 1 year old, 8 months at most. It appears to still be fizzy and bubbly too.

One more question, what ratio of peroxide to water would you use to soak seeds?

Thanks again,

Maureen

Want I used/did was

1 gallon distilled water

2 oz. of Hydrogen Peroxide

I use that for everything. watering/soaking

I use 1/2 cup per gallon. That's DS Hydrogen Peroxide in brown bottles.
Sidney

I'll probablly go with the half cup method.

Thanks for the info everyone! ☺

Maureen