Hydrogen Peroxide vs household bleach

This has been discussed I think just once before on these boards, but no definite conclusion was ever reached, so I’d like to throw the question up again.

3% Hydrogen Peroxide isn’t as powerful as common household thick bleach, but it’s easy to crank up the percentage so it IS as powerful (where “powerful” means it destroys approximately the number of germs about as quickly, and yes I know there’s probably germs it is better at destroying, and some which it is worse at, but we’re talking roughly). I would think around 10-15% hydrogen peroxide would be the appropriate amount, but maybe someone can else can provide a more accurate answer.

Basically, I hate the smell of standard bleach (and of course, there are reports the fumes are bad, though I’m not sure how that compares to HP). So if there’s any way one can get roughly the same strength of clean as bleach, but without the odor, then I’m all for trying out something so weird as HP.

************************** I can’t edit my post now (sigh). But instead of thick bleach, let’s change that to thin (ready to use) bleach, and the corresponding amount of Hydrogen Peroxide to something more like 5-10% as a very rough guess…?

Well, here’s the msds sheet for 30% Hydrogen Peroxide. and one for 5%
Short answer, there’s a reason it’s diluted to 3% for home use. It can be used for cleaning, but you need to leave it on the surface you are cleaning longer than you’d normally leave cleaners on to make an antibacterial impact.

Yeah, the 30% one sounds a bit dodgy (and to think you can easily get 35% strength off ebay with Amazon, some with no/little warning at all!)

But the 5% version sounds relatively okay, and I’m guessing no worse than normal thin bleach. And perhaps even just as strong?

So my question remains, why don’t we all just switch to the odorless Hydrogen Peroxide?

Oh just to add, I’m trying to reconcile the “extreme” 4 rating (4=max) for the Contact rating, when this video on Youtube shows it to be almost completely harmless:


What gives? Is the video definitely showing 35% strength, or could that percentage in the product be fake?

The Chlorox company’s marketing and the way it has always been. Also, people associate the chlorine smell with clean.

I no longer read some to the technical magazines I once did. Maybe 20 years ago somebody was pushing potassium permangnate in place of chlorine for purifying water. They claimed it left water tasting better and fewer toxic chlorinated hydrocarbons behind. I am not sure that campaign ever went anywhere.

It sure didn’t here. It’s the reason I don’t drink tap. Put the water in closed container, and it smells almost as bad as when you pour bleach on stuff.

dilute solutions of oxidizers may be more effective than concentrated for cleaning and are less hazardous.

oxidizer solutions may be used in succession because of their different effectiveness.

I’m not sure of the exact chemicals, but some variant of not-fully-reduced oxygen is in fact used extensively in drinking water purification plants – not a majority of the plants in the US, but a number of them, and fairly common in Europe from what I understand. I think it’s usually called ‘ozonation’; though as I said I don’t know the actual chemicals used.
One of the main arguments for it is exactly that it leaves fewer chlorinated compounds behind.
One of the drawbacks is that, unlike chlorine, it doesn’t leave any residual in the treated water. Which means there’s no disinfection action in the miles and miles of pipes between the treatment plant and the tap in your kitchen, leaving the risk of nasty things growing in the pipes.
I mention this because I suspect that the same issue with residuals might be an issue in some household cleaning applications – you can use less chlorine because it works for longer, wheras peroxide needs to kill everything almost immediately to be effective.

One of the big differences is shelf life. Hydrogen peroxide is highly unstable, and the two year old bottle sitting in your bathroom right now is probably just water. The shelf life for an unopened bottle is somewhere around a year, but once it’s opened it’ll only be good for another month or two.

Chlorine bleach also has a limited shelf life but it’s not quite so dramatically short. Opened or unopened the shelf life is about a year. But since bleach is such an effective disinfectant, that two year old bottle under your sink is still moderately useful. At least much more useful than the two year old bottle of peroxide.

Ozone is O3, an oxygen molecule with an additional atom instead of the usual O2. It’s poisionius. It’s part of the high atmosphere as the ozone layer that shields Earth from UV rays. And it’s newly part of the summer smog in low atmosphere levels - like, near the ground. Because when in summer a lot of exhaust gases from cars are met with a lot of UV rays (more than before because of the hole in the upper atmosphere ozone layer - there is a irony somewhere here, I think), the powerful UV rays break up the NOx, COx etc in the exhaust, and among the newly formed compounds is a lot of O3. In high concentrations it’s poisionus, but in low concentrations it “just” causes headaches and irritation in throat, lung etc. That’s why asthma people and other people with lung problems are advised to go outside only early morning and late evening; similarly sports should not be done during the day, because deep breaths from the exertion are not healthy when the ozone content is high.*

  • The second irony is that while most of the exhaust is produced in the cities, the presence of much chemicals in the air also means that compounds are quickly broken down again, so in the evening, the cities have less ozone; but if wind carries the pollution to the “healthy, clean air” countryside, the ozone will stay there much longer.

A lot of small villages in the countryside put up signs in the 60s and 70s advertising their “ozon-rich air” to draw tourists and health spa people; obviously they had all failed high school chemistry and thus seemed to advertise poisionos air.
And saying that their air was “oxygen-rich” would have been equally asinine; people enjoy walking in the forest because the trees filter pollution and less cars means less pollution in the first place, but the O2 level in the air is pretty much the same.

A few swimming pools in Germany advertise “ozone” as part of their process, because people hate the smell of chlorine - to be exact, the smell comes from the bonded chlor, or chloramine, that is created when the free chlorine gas bonds to the organic molecules in the water. This also creates the red eyes. In the past - 70s and 80s - the chlorine levels, both free and bound, were much higher, but today, new technology allows better monitoring of the level, and thus, reduced dosage of chlorine; and because of health concerns (chloramines cause cancer) the levels of allowed chlorine is much lower.
Ozone-treated water is also false advertising, though, because they only use less chlorine, they don’t use no chlorine.

Yes, because chlorine is not healthy for people long-term, and because the risk of an accident with deadly chlorine gas is not something nice to think about.

Quite wrong. If you build good pipes and maintain them regularly, and the water has a minimum speed, things can’t and won’t grow in the pipes. People in German cities whose water plants use Ozone instead of chlorine, or don’t use chlorine at all, don’t regularly get sick from drinking tap water. Which would be the case if things were growing in the pipes.

I realize that given the US politicans attitude towards slashing necessary maintenance and contracting to private companies, it’s safer in the US to dump a load of chlorine instead of taking care of the pipes.

What I’m baffled by is what kind of households you all have that you regularly need high-strength sanitizers. AIDS patient/ cancer patient living at home? Somebody has scarlet fever? You regularly do surgery at home? What? And why would you need a long-acting agent, instead of just cleaning the surface? You don’t have to nuke all bacteria 24/7 just because the ads for Sagrotan or bleach tell you to, you know. These companies are lying about the dangers. Unless you have a specific breed of harmful bacteria, or somebody with a compromised immune system, normal soap will take care of normal dirt, and the bacteria will live in normal equilibirium with you.

the over santization of your home environment can cause problems. you breed super microorganisms which are more difficult to kill, this can be a problem for living organisms.

unless specifically needed as constanze mentioned sanitizing a home is not a good thing. ordinary soap and water provides a microorganism level we should live with.

Personally, I’m a BIG fan of plain old soap and water. However, I have used bleach on several occassions:

  • when my father-in-law was dying of cancer at his home (as he wished) we disinfected with bleach. But then, you did mention that in your own list of reasons. We only gave him bottled water to drink, and were using other stringent infection control measures.

  • when my mother was in home hospice dying (basically, end stage cardiovascular disease) the same applied, severely debilitated human being that didn’t need a raging infection to add to her problems.

  • my spouse usually doesn’t like me to talk about this, but what the hell - he has spinal damage which means he doesn’t have full control over bladder and bowels and accidents happen to his underwear. Due to heavier than typical soiling, I used chlorine bleach on his underwear to disinfect it. Not really needed by ordinary mortals but he is handicapped.

  • when my septic tank malfunctioned this month and we had, essentially, sewage back up into the bathroom I used chlorine bleach to clean and thoroughly disinfect everything that had gotten shit on it (in this case, of course, the word shit being the accurate descriptive and not profanity). Again, not an ordinary situation but one for which bleach is well suited.

  • I will use bleach on stubborn mold or mildew infestations that do not respond to normal cleaning. Personally, I’d prefer to mix up a dilution of bleach than use some of the “special” cleaning chemicals promoted for that, as I have no clue what some of them chemicals in them are, but I do know how to use chlorine bleach safely and it does the job. I actually use this more often at work than at home (I work some of the time for a landlord and have had to do clean outs of sorely neglected and filthy units. We cleaned, nuke with bleach, and let everything air out for a day or two to get it ready for the next tenant)

So, again, while normally I use much milder cleaners I do find occasion to use chlorine bleach. With protective gloves, ventilation, etc. I also use the proper dilution for the task at hand, no need to go crazy. Just enough to do the job and no more.

soap is not good enough for those jobs. bleach is necessary for those cases.

mixing bleach with other chemicals can be hazardous. mixing may also lessen the effectiveness of each of the chemicals.

Absolutely correct. I do NOT mix cleaning products as a rule, it’s too easy to result in hazards.

This is what immediately sprang to my mind too. There’s even evidence that a small amount of germs can be good (what doesn’t kill you makes you stronger etc.).

As for the big marketing thing, well, I would think that a supermarket shelf stocked with “Odorless bleach (NEW!)” from a random startup company would actually be a big hit. ‘Common wisdom’ and tradition can often be mistaken. For example in the knot world, the “Zeppelin bend” is a new knot (well rediscovered actually) used to simply tie two rope/string ends together. It’s better than other rival knots in almost every way (ease of tying, no tightening even after tons of pressure, firm grip etc. etc.). It’s only now finally beginning to become recognized.

Even soap smells, so I just use standard washing up liquid which is better at removing grease and less smelly. There’s also stuff like “Swarfega” which I haven’t tried but is supposed to very effective.

Which is why you’re often told to store it in fridge (or the freezer for the 35% grade stuff). I’ve heard of reports of 1% loss per year for the fridge I think. I don’t think that’s unreasonable, and I’m sure the freezer would fare even better.

Finally, I’m still interested in why that Youtube video shows 35% strength Hydrogen Peroxide as almost totally harmless in complete contradiction to the deadly 4 rating in the specs. I’ve actually bought some of the stuff now, so what’s the easiest way of telling that it really is 35% as it claims and not something less like 10 or even 3%?

Just to add some balance to this thread and for fear of over-hyping HP, here’s an interesting thread from another forum which would appear to at least partially explain why hospitals may not use HP (at least for certain bacteria such as C. difficile). The post in question was from a pharmacist with 10 years of graduate research:


He links to this BBC article which says that some cleaning agents (which use HP partially) can even encourage spore growth:

However, those solutions contain other ingredients and the strength of the HP may be low for all we know. If I was that researcher, I’d test for the basic things first (pure HP+water etc.) to get an understanding before trying out various commercial products with complex concoctions that can easily muddy the issue.

FWIW, about the 35% grade HP which didn’t burn that guy’s hand in that video, the most likely explanation after reading around is it affects some people to far higher degrees than others. I used 3% solution as mouthwash and it really seemed pretty strong - as strong as the commercial colgate 1.5% peroxyl mouthwash it seemed. I also accidentally got some 35% strength on my hand, and it turned a tiny bit of it white, but I suffered no pain or anything permanent. I would not recommend it now though after what I’ve read.

Oh come now. Yes ozone oxidizes anything that can be that it comes in contact with including lung tissue. But you are comparing it to chlorine in bleach. Bleach works by the chlorine in it reacting with things.

OTOH, accelerated hydrogen peroxide is actually gaining foothold in medical and veterinary settings. Here’s a recently published study on AHP vs. regular H2O2 vs. bleach in eradicating* C. difficile*:

BTW, random thought on hydrogen peroxide: if your pet ingests something toxic, like chocolate or rat poison (why do dogs think rat poison is so yummy?), please talk to your vet +/- an animal poison control center before trying to induce emesis with hydrogen peroxide. Hydrogen peroxide can cause gastric ulcerations or even fatal hemorrhage (it’s mechanism of causing vomiting is by irritating the stomach), and many vets are moving towards using safer injectable drugs to induce emesis except in certain cases. Besides that, depending on the toxin and the time since ingestion, the vet may need to institute other treatments. /PSA