MacGyver moment - today. Peroxide, dish soap, vinegar, and Ajax

[underpants]

Last edited Sun Apr 5, 2026, 04:09 PM - Edit history (1)

My elder stepfather had a fall in the garage on Friday. Fractured his hip. The Dr.’s said it was probably better that it was artificial. Thanks to the VA he has lots of artificial joints 4 I think.

So there was some blood to clean up on the concrete floor. He said peroxide which the internets agreed with. I decided to use my complete lack of scientific knowledge in this situation. I added vinegar, dish soap, and some Ajax my mom had under the kitchen sink. Added water in an empty plastic Folgers container. Carried it out to the garage and stepped just outside in the rain and shook it up. The top started to bubble up. I quickly set it on the muni trashcan just outside, closed my eyes, turned my head, and cracked open the other side of the container - a frothy mix shot across the driveway 5-7 feet.

[Srkdqltr]

1. How fun. 😦😦 good thing you didn't breathe it in.

[underpants]

5. Yeah there were some fumes when I opened it up on the floor

Good thing I didn’t add baking soda or Clorox.

Oh it worked great. Completely clean.

[dweller]

2. You forgot

the paperclip , Mac


✌🏻

[underpants]

8. No rubber band either

[dweller]

12. You wear the rubber band

on your wrist , and during moments like this you snap yourself … hard .

🤔


✌🏻

[underpants]

16. 😃😃😃

[Lochloosa]

3. Whatever you do, don't add bleach. The fumes will kill you.

bad-chemical-combos.pdf https://share.google/Pfyh6jTH9ns6fni1q

[underpants]

7. Yes luckily I left that out. And baking soda (which I had in the counter/lab)

[Lochloosa]

9. I edited my post with a PDF. Bleach should never be mixed.

[underpants]

10. I saw that. Thanks.

👍

[Wicked Blue]

4. I think Ajax contains bleach. Mixing bleach and peroxide is outright dangerous.

[underpants]

6. My daughter, so you were making a bomb?

[Faux pas]

11. Wow! Sounds amazing!

Did it clean up the blood?

[underpants]

13. With a paper towel. The peroxide I think was the key.

I’d already scraped up much of it with a putty knife.

I thought I’d have to scrub it was a wire brush but it came right up.

[Faux pas]

22. Yeah peroxide is my most

favorite cleaning product, sanitizes without screwing the environment!

[RockRaven]

14. Rule of thumb: don't mix common cleaning liquids. They often make bad things when combined.

Of the six possible pairs which can be made from a) hydrogen peroxide, b)bleach, c) ammonia, and d) vinegar, five are dangerous or theoretically so.

Vinegar and hydrogen peroxide can make paracetic acid.

Vinegar and bleach make chlorine gas.

Bleach and ammonia make chloramine gas.

Bleach and hydrogen peroxide make oxygen gas, which sounds fine -- but it does it so fast that it can cause an explosion.

Hydrogen peroxide and ammonia -- can be bad depending on concentrations, possibly fine at household level but don't chance it.

Only vinegar and ammonia is "meh" when combined. But even then, the combo isn't a good cleaning agent.

[ProfessorGAC]

17. Too Dilute

The concentration of peroxide that causes the rapid O2 release you describe is at industrial strength like 35, 50, or 70.
There's too much dilution with drug store peroxide. Too much water means far inferior mass transfer rate, making the reaction too slow to explode.
The rest of your cautionary statements are well-placed.

[RockRaven]

18. Thank you for the correction.

[ProfessorGAC]

19. 43 Years As A Chemist Forned Hard Habits To Beeak.

39 of those were after my PhD. So, when I see a chemistry error, I'm incapable of letting it pass.

[ProfessorGAC]

15. Vinegar?

From my chemist's point of view, I'd suggest the vinegar did nothing. There is calcium & sodium carbonate in Ajax. The vinegar reacts with that to for calcium or sodium acetate. So, there wouldn't be any vinegar by the time you used it.
That's what caused the frothing. The carbonate is the other product of the reaction with the acetic acid in the vinegar.
So, you released a bunch of gas and the heat of reaction helped push that CO2 out of the liquid.
Peroxide would normally be a good choice. It sterilizes (bacteria & viruses don't play well with peroxide), and doesn't negatively affect the surfactants in your cleaning agents. Except, peroxide breaks down to water & oxygen as pH rises and sodium carbonate has a pH of 9. Peroxide is more suitable at pH 6 & lower.
I would have used a heavier duty cleaning agent lije laundry soap. Dish soap uses less aggressive active ingredients to reduce drying of oils in the skin of our hands. The formulations don't worry about that with laundry liquids since one has very infrequent skin contact with laundry detergents.
You could make it again, leaving out the vinegar. It's useless anyway.
And, you might consider a splash of laundry bleach instead of peroxide. It is stable at higher pH and even more effective on pathogens.

[underpants]

20. I repeat " my complete lack of scientific knowledge "

Bio 101. I really balked on a question about WHERE photosynthesis takes place in a plant. Root flower stem leaf. That’s the whole damn class. I still laugh about that. I got it right. Rote memorization, no understanding. I got a B.

My wife is a believer in vinegar for just about everything. Non-gun Prepper stuff. We have gallons of vinegar in the garage.

Thanks.

[ProfessorGAC]

24. Ok

Vinegar has slight grease cutting ability as would most organic solvents
The problem us it's 95% water, so smearing is a distinct possibility.
That's why cleaning products, professionally formulated, don't use vinegar; except for a few niche products likely targeting consumers like your wife.
The tough truth however, is vinegar provides close to nothing in the way of cleaning.

[Kali]

28. totally agree

vinegaroons (yes I know what they really are) drive me crazy! I am at least a third generation clorox/bleach disinfector.

also for blood, start with cold water!

[Shellback Squid]

21. Looks like it would taste nasty

[eppur_se_muova]

23. Try borax next time. On something like a floor, apply a little paste of borax and hot water, then let stand.

Google "does borax remove blood stains" and you'll get a whole bunch of info similar to this:

Homemade chemical cocktail. Borax + washing soda + Tide powder detergent in a 1:1:2 ratio (the recipe I use is 1/4 cup Borax, 1/4 cup washing soda, 1/2 cup Tide powder). Mix the whole thing in a bathtub full of the hottest water that can come out of the tap, then dump your sheets (or towels or other laundry, I guess) and let it sit there until the water is cooled. Stir it every so often with a broom handle to make sure everything gets even coverage and so that you can pretend to be a witch with a cauldron. Then you squeeze the water out and wash it in the washer with water only, no more detergent, and dry as normal.

The Borax and washing soda are detergent boosters: they make hard water soft and increase the effectiveness of detergent. It's very, very strong. If you watch videos on Youtube or TikTok of laundry stripping until the water is black, that's dye leaching out of the fabric. It is not for every day use; it's the nuclear option. I've only done it once per set of sheets I own, and I'm not going to do it again for at least another several months. I'm definitely not going to do it on my regular clothes.

But if you have extremely set-in stains that absolutely will not come out, and the fabric can take it, it makes it like new. I had a set of sheets that had yellow blobs in the shape of my fiancé and I where we sleep the most often, because our sweat and body oils and nighttime drool were seeping into the fabric, and OxyClean and repeated laundering did nothing. Stripping did.

https://www.reddit.com/r/CleaningTips/comments/nz66dt/laundry_stripping_removes_bloodstains_like_a_beast/

Unlike other cleaners, borax has few "bad" reactions, but some metal salts will form insoluble borates.

[underpants]

27. Ooh

Sounds like serial killer stuff.

thanks

[2naSalit]

25. LOL!

Glad to know your dad's okay.

[OC375]

26. MacGyver

[Kali]

29. for blood, always start with plain old cold water

it will almost work. if the blood stain is old then try peroxide or regular bleach, maybe a little powdered laundry detergent or ajax/comet. maybe even bartender's friend. don't mix cleaning products except detergent and detergent enhancers. don't mix the enhancers unless you know what you are doing.

[OAITW r.2.0]

30. Home brewed chemistry lab, Sounds like fun!