Why does Hydrogen peroxide is so toxic?

[Pawelk198604]

I  wonder what cause it's have one more oxygen atom more than water, in Poland we use it for disinfection of wound if someone is wounded.

 

I once read article about TIR truck it's our European word for 18 wheeler in Europe  who transported tank trailer with Perhydrol with in our Polish terminology means Hydrogen peroxide solution with over 30% concentration have crash and special firefighter squad that is trained to dealt with chemicals was called to decontaminate that place   

[Steel]

44 minutes ago, Pawelk198604 said:

I  wonder what cause it's have one more oxygen atom more than water, in Poland we use it for disinfection of wound if someone is wounded.

 

I once read article about TIR truck it's our European word for 18 wheeler in Europe  who transported tank trailer with Perhydrol with in our Polish terminology means Hydrogen peroxide solution with over 30% concentration have crash and special firefighter squad that is trained to dealt with chemicals was called to decontaminate that place   

It is not that toxic, but it is potentially highly explosive when concentrated. It decomposes exothermically (releases a lot of heat), so if it's not treated with care it can suddenly explode without much of a warning

Edited September 30, 2017 by Steel

[softweir]

There is a complex chemical process used to generate hydrogen peroxide. You can read about it On Wikipedia.

Hydrogen peroxide (H₂O₂) is highly unstable: that extra oxygen atom is not a stable addition to a water molecule! For instance, when it comes in contact with copper and some other metals it spontaneously decomposes into oxygen and water, releasing so much energy that the water is converted to superheated steam. (This is used by some of those "rocket jetpacks" that you can find details about online - H₂O₂ is pumped through a copper mesh, and the resulting steam and oxygen can be used as a propellant. This can, of course, be very dangerous.) Also, when it comes in contact with some hydrocarbons (such as vehicle fuels) then it will spontaneously catch fire; that is, there doesn't need to be any spark to set the mixture alight. If there is enough fuel and H₂O₂ then the fire can be extremely hot: this is because the H₂O₂ generates heat as it decomposes, and more heat is generated when the fuel burns.

Even when there is no fire or other emergency, H₂O₂ will slowly decompose, releasing oxygen. It can release enough oxygen that this can be hazardous to health, if it is in an enclose area. Not only that, but the buildup of oxygen in the air can make normally stable materials burn readily, so the tiniest spark can trigger a fire or explosion.

In addition, when H₂O₂ comes in contact with living tissue it releases the excess oxygen, creating highly reactive free radicals that can damage and destroy the living tissue. The effect on fish and other waterborne organisms can be devastating: it kills them all!

So: if H₂O₂ gets spilled on a road then there is a very serious risk of poisoning waterborne life or a major fire starting. It is imperative that

1. Action is taken to prevent fuel coming into contact with the H₂O₂ spill
2. Action is taken to prevent people touching the spill, as it can damage skin
3. Barriers are set up to prevent it flowing into drains that lead to waterways
4. It is neutralised using a suitable material. There are dry powders which safely absorb the H₂O₂, allowing it to be swept up. If there is no danger to waterways, then it can be washed into a drain using a very large volume of water to dilute it to safe concentrations
5. Action is taken to repair the roadway, as H₂O₂ corrodes the tar used in many road surfaces

 (The exact order of actions depends on risks at a given spill site. For instance, if there is already a fuel spill when firefighters reach the scene then the first priority is to cover the spill with a suitable foam or dry powder.)

Very dilute H₂O₂ is sometimes used in very small quantities as an antiseptic on minor cuts and abrasions. It is sufficiently oxidising that it kills almost all bacteria, while at the same time there are enzymes in the blood that can neutralise small amounts, preventing it causing deep damage to the wound. However, this practice is now frowned upon in much of America and Europe, as it does damage superficial tissues, which in turn can seriously slow down the healing process - and the damaged tissues can act as food for any bacteria that get into the wound later on.

Instead of using H₂O₂, it is much better to use a sterile gauze to clean a wound and then dress it with a sterile bandage. If there is some special need to use antisepsis (such as the wound being open, the patient having some illness which predisposes them to infection, or the agent causing the wound being thought to be contaminated) then iodine is preferred: it damages tissues much less readily than hydrogen peroxide does, while being a very effective bactericide.

[Helmetman]

Hydrogen Peroxide is used for bleaching and sometimes found in other cosmetics.

Maybe in high concentrations one will have a problem but it is actually prescribed for such things and people don't die from it so go figure.

I even used a diluted dose of it to kill bacteria (user above it explains me) from the cut of my pulled wisdom tooth. It got blue and greeny at the cut so I needed to disinfect with Hydrogen Peroxide.
A whole flask went down, .................. I'm still here. Don't expect to get any hiccup or burp when trying a dilated flask from the chemist without you falling on the floor. This is normal. Just try to avoid the pure stuff.

[Exploro]

On 9/30/2017 at 11:14 AM, Steel said:

It is not that toxic, but it is potentially highly explosive when concentrated. It decomposes exothermically (releases a lot of heat), so if it's not treated with care it can suddenly explode without much of a warning

It's toxicity lies in the fact it is an oxidizer. It will damage human tissue through corrosion in sufficent concentrations.

[DDE]

@Pawelk198604, here's your copy of Ignition!, find the relevant chapter, it has some... explosive things to say about 90% and purer H2O2.

[Snark]

On 10/1/2017 at 10:18 AM, Exploro said:

It's toxicity lies in the fact it is an oxidizer. It will damage human tissue through corrosion in sufficent concentrations.

^ This.

Funny story.  A relative of mine was working in a lab and cut herself on some glassware.  "Oh gosh, I should disinfect this.  Hey look, there's some hydrogen peroxide, I can use that.  I'll just pour a little bit on my finger, there we go.  Wow, look at that, it's really bubbling.  Wow, it's really... OW!  OW OW OW OW OW!  AAAAAAAAAAH"

Turns out that the peroxide sitting there in the lab was reagent-grade, which is very, very different from the stuff you get at the pharmacy for disinfecting wounds.  Drugstore peroxide is something like 3%.  The stuff in the lab was much, much higher-- I forget the exact number, but I think it was 30% or 50% or something along those lines.

You seriously don't want the strong stuff to get on you.  It's not fun.

(For the record, my relative was okay and didn't lose a finger or anything... but you better believe she sure never made that mistake again.  And I guess she did disinfect the heck out of that cut...)