Hydrogen Peroxide

[Shirley]

I've been told that hydrogen peroxide turns to water on being exposed to the air. When I'm using it, I'm in the habit of pouring a little into a dish rather than having my whole bottle sit open as I work. If the air is turning it to water, does that mean I'm wasting my time applying it?

[King_of_orchid_growing:)]

It takes a few minutes for it to turn into water. The complete effect is not immediate. However, as soon as the H2O2 comes out of that bottle, it'll start reacting.

[RosieC]

As philip has said. You have a few minutes to use it, but the longer you leave it out the less effective it is.

It will also react in the bottle and if the top is left off the bottle then it's possible it would all just turn in to water and oxygen.

[Ray]

Pharmacy-type H2O2 is stabilized with a tiny amount stannic chloride (SnCl4) so it doesn't decompose instantly. As such, sitting out will not instantly break it down, so you shouldn't have an issue.

[RosieC]

Good to know Ray.

[PaphMadMan]

Rosie is correct that it turns to water and oxygen, not just water, and this will happen even in the bottle. You should buy a new bottle every few months if you want it to be an effective disinfectant.

Being open for a few minutes when you use it won't hurt much, it doesn't change that fast under most circumstances. Never pour any back into the bottle though Any contaminants will speed up the reaction dramatically.

It is the ability to supply oxygen that lets it do its job. It reacts quickly with any organic material, acting much like bleach. It does its job in the first few minutes, killing bacteria and mold, and then it is completely harmless before it can hurt the more resistant healthy plant cells.

[trdyl]

So how effective is it for sterilizing seed for sowing?

[cricketerry]

Originally Posted by trdyl

So how effective is it for sterilizing seed for sowing?

Very! and it has the advantage that you do not need to wash the seed after, as you would with a chlorine based bleach.

I use a 3% solution and soak the seeds for approx 12-15 mins. then sow directly onto the agar.

[got ants]

Originally Posted by cricketerry

Very! and it has the advantage that you do not need to wash the seed after, as you would with a chlorine based bleach.

I use a 3% solution and soak the seeds for approx 12-15 mins. then sow directly onto the agar.

Good to know! I have it on my outside fridge next to my other orchids supplies. I only use it to dissenfect my hands, and wipe onto my hair (so as to not spoil my clothes). I know, just another dumb blonde.

[ericst11]

cricketerry how effective is that do you soak your seed the night before in sugar water then , put it in a 3% bleach solution. I'd love to know more