Which Chemical is the Best Disinfectant? (Disinfectant Lore) 

5:23 my mom always told me “there are two categories of cleaners: bleach, and things you don’t mix with bleach.

So a fun fact in case no one else mentioned it: Bleach is used as a last resort method in my local hospital, for example if someone had MRSA. The reason for this is that we don’t want a situation where bacteria becomes resistant to bleach, which, for obvious reasons, would be pretty bad.

It’s 2 minutes into the upload. I better not see anyone talking about how they watched the video that fast

My very cold and poorly ventilated dorm room used to get lots of mold on the walls during winter until the day I built an ozone generator with parts from old TV sets, and left it running while I was away to class. The problem pretty much ended there.

This was super cool! Its nice to learn actually h o w the disinfectants work rather than just "Kill microbes"

"...it's effectively oxygen gas that got into a car accident" I laughed way harder than I should have at this.

I love the fact that I fell asleep to the irritant video last night, now I can fall asleep to this one. There’s something soothing about chemistry and this guy’s delivery, I love this channel!

Chloraseptic works for sore throat better than anything else I've tried. Smells and tastes like evil rotting plastic, but when you're in pain and can't sleep, sometimes evil rotting plastic is tolerable.

I was hoping to see mercuric chloride in this list... I had a neighbor many years ago who worked for the state Health Department. One day we were talking about disinfectants, and I mentioned mercuric chloride to him. His eyes nearly popped out of his skull. He told me a story where they took a Petri dish full of ultra-nasty stuff and they put in a solution (probably 1:3000 or similar) of mercuric chloride. They examined the dish under a microscope ten minutes later, and NOTHING was alive.

According to one of my chemistry profs, because there's no such thing as iso-propane then there can't be such a thing as iso-propanol. He made me change all mention of iso-propanol is a lab report to 2-propanol. Yeah. The reaction you're having now was my reaction too.

I had a high concentration phenol put on my toes when I got surgery for ingrown nails! My podiatrist explained everything that was happened because chemistry is fun. I got shots that made my toes completely numb so I felt nothing at all. The skin turned completely black and it was really interesting to watch! My toes are pretty much fully healed now

I used to work in a turkey egg farm. A mixture of permanganate and methanol (producing formaldehyde gas) was used to disinfect the eggs after collection. Killed bacteria but did not harm the avian foetus.

Have you done detergents yet? Because they're a lot more interesting than they get credit for imo, and also I'm itching to share some fun facts about detergents.

Isopropanol is an excellent disinfectant. Also makes great cryofluid too

Don’t forget radioactive materials. Radiation is used a lot for sterilization of single use medical equipment apparently. According to the IAEA, 40% of single use medical devices worldwide are sterilized using gamma irradiation. Although I am not sure what exactly is used to produce those rays. 🤓 (yes, I am aware this is probably a misinformed and very annoying comment. Take it with a grain of salt. Great content as always. 👍)

I appreciate the cutaways containing more detailed explanations of some of the terminology

10:25 hey finally a chemical store I can add! I was gargling with hydrogen peroxide as a kid (had a mouth ulcer iirc) and had two of those small paper cups set out in the bathroom. One I was using with water to rinse the taste out of my mouth and one for hydrogen peroxide. I mistakenly swallowed a small amount of hydrogen peroxide (~10 mL or so) and promptly freaked out. Taste was horrible and tingled/slightly burned going down my throat. Parents called poison control and they said to just drink a bunch of water and monitor for other symptoms. 0/10 do not suggest taking shots of H2O2.

My wife worked in the hospital and they used peroxy-acetic acid formed by a mixture of hydrogen peroxide and acetic acid for sterilizing surfaces.

IPA is effective on de-roaching small articles of electronic equipment by dumping some into a garbage bag and placing the object inside and sealing the bag for 2 or 3 days, would not recommend for anything plastic or with lots of glued on labels and decals

As someone who’s had Spinal Fusion twice.. Povidone-Iodine 1% is something I’m very used to. I would have to have that poured onto my back every time they changed my bandage. I remember one time they spilt the bottle onto me and I thought it broke open the wound since it looked like blood. 😂

I've always been curious why there's so many disinfectants in use, some of them make sense but there's just so many! Great content as always!

3:25 Speaking of cleaning throats, some people use those sprays as a way to relax muscles in the throat. For what reasons, I shall leave to your imagination.

Doctor here with some more or less educated corrections: 0:13 The effective agent in most skin disinfectants is isopropanol and/or ethanol though. Yes, some products also contain chlorhexidine or octenidine, but that is usually put there to have a continuous antimicrobial effect even after the initial disinfections, which is useful for catheters etc. that pierce the skin and are to remain in place for a longer period. The isopropanol is doing the main bug killing work though. There are also some products where the chlorhexidine or octenidine are the main effective agent, but those are rarely used for preoperative or preinterventional skin disinfection, but mostly for wound care or disinfection of mucosae or genitalia. One case where octenidine is actually used for skin disinfection is before taking a blood sample for alcohol testing, to avoid any potential preanalytical falsifications. 7:29 Endoscopes are not sterilized but disinfected. Anything that goes into a sterile field, respectively inside a person (the digestive tract is technically just a tube of "outside" going through the body, so in there doesn't count) has to be properly sterilized. That also counts for laparoscopic instruments and optics which are typically autoclaved. In general, the most common sterilisation methods for any sort of medical product are autoclaving, ethylene oxide or radiation. Stuff that gets re-used will typically be autoclaved. AFAIK glutaraldehyde cannot be used for sterilisation, at least under the guidelines of the RKI, the German federal public health office. Finally I'm a little sad you didn't include peracetic acid as its own thing (yes, you mentioned it in "bleach", but eh). Peracetic acid actually has a cultural heritage where I'm from, East Germany. East Germany kept huge stockpiles of that stuff to use as disinfectant in case of a biological warfare attack. However since it's so sensitive to... everything and decomposes over time, it cannot be stored for long and had to be constantly produced... and therefore also used. So in East Germany it was used to disinfect just about everything. From antimicrobial soaps, to cleaners to mop floors with to disinfecting livestock bays. Many visitors to East Germany remarked of the characteristic smell of East-German buildings.

damn. weve been getting back to back videos and theyre all still really thorough, this is great

Bro iam crying "Prepare your endo for the scopes"

I think ozone is my favorite, it oxidizes just about everything. Plus it can be used for the same things potassium permanganate + greensand like getting rid of dissolved iron. I have heard ozone plus UV light can even break down PFAS.

Bro really edited My Little Pony on that jar 💀

91% Isopropanol is pretty good as a cleaner though, especially if you put a bit on a qtip to clean small electronics. In this case, the evaporation helps!

Benzalkonium chloride is great for disinfecting when you get an IV or a shot because it doesn't cause that burning sensation the same way as alcohol and other disinfectants. With alcohol, you can wait for all of it to evaporate, but many times nurses and lab techs don't have time to wait that long every needle poke, but if they have benzalkonium chloride, it doesn't matter.

There's actually UV wavelengths deeper than the typical 254 nm UV-C light from mercury lamps which are completely safe at fluxes capable of sterilizing 90+% of microbes. Photons between 215-235 nm are fully absorbed in the first few micrometers of skin (which are all dead cells) and so can't DNA damage in living tissue. This is true even for your eyes, because they too have a very thin layer of dead cells on the surface.

Surgical technologist here! Here's some more insight into chlorhexidine (CHG) and iodine. CHG is used in many surgical scrubs and preps as it not only has a broad spectrum effect that drives quickly, but also builds up on the skin over time with multiple uses. Many patients are given CHG wipes to use at home one to two days before surgery to help build up that film of antimicrobial good stuff. In addition, CHG is frequently found in IV start kits, and is a well used antiseptic right alongside an alcohol swab. For iodine, it will stain a little bit, but that's good because we want to see where exactly we need to still hit with the iodine prep. We would typically use this when someone is allergic to CHG, but you need to be very careful with iodine. If you have an allergy to shrimp or shellfish, you will be allergic to iodine prep It has similar chemical indicators to shellfish. Last thing to be picky, c h g and iodine are both considered antiseptics, but can also be used as disinfectants. This is a legitimate difference, but that's just me nitpicking. This is an awesome video man, very well done

Fun fact, chlorine and chlorinating agents are added during water treatment to also bind to reactive cyanide groups.

Very nice video as always! Another video auto played after and I realised your mic quality has really improved! One thing I will say though, you didn't mention my favourite disinfectant, singlet oxygen!

I used to have a cleaning contract with a local Dentist office. We used Parsons Ammonia to wipe down all the dental stations. Fabuloso for the floors. The dentists were clean so we rarely had to use bleach. Maybe in the bathroom that the patrons use. Honestly was one of the best places I ever worked and it was just me and sometimes another guy, for like 2 hours, 5 days a week. Super nice people. Heritage in Dundas/Northfield. Ya. Where Jesse James did his thing at the bank.

They use isopropyl alcohol pads for injections, vaccines and IV prep. They are using the stronger stuff for surgery like iodine and clorahexadine

Hey guy I've seen more than a few of your Chem vids and this is the 1st 1 featuring - well you. Kewl content man. I like the way you show the molecular formulas for the chemicals. Any body can write a chemical formula like H20, but not everyone can draw a molecular formula that looks super nice.

Great vid! As usual, great information and cool presentation

Woah, this will be so useful for when a ton of strawberry jam is spilled in my attic.

This video is great! I see the effort in the research, its good stuff. (love the mechanism stuff) I'd love if you did a tierlist on preservatives. (Isothiazolinones, bronopol, pyrithiones, glycols, organic alcohols etc.) I work in an analytical chemistry lab with these and three's some interesting chemistry with them. EDIT: i just watched again and comment up top was covered with benzalkonium chloride.

By regulation (EU-MDR) for medical device cleaning, disinfection and sterilization, the S-tier would be heat for both disinfection (90-95°C for 5 min) and sterilization (three cycles of 121°C steam and then vacuum), the A-tier is ethylene oxide or ozone for sterilization and peracetic acid for disinfection and the B-tier would be formaldehyde for sterilization and glutaraldehyde for disinfection. The others are rated worse for application on medical devices (in Europe).

5:27 - Thanks, I’m on yet another watchlist from your videos 😂

as a person who accidentally made chlorine gas using bleach in my kitchen, yea listen to this guy don't mix it lol

My lab had an over zealous crackdown on health and safety and we replaced all the common lab disinfectants with household cleaners using Benzalkonium Chloride. Since then we've been finding more surviving Salmonella and resistant E.coli from our routine monitoring. Interesting to know there's different chain lengths with different efficacies. We also found that it deteriorates our plastic equipment over time but that could be other compounds in the solution I guess.

Quaternary ammonium deserves S tier! If you’ve ever worked back of house towels in a bucket of quat sanitizer are the universal cleaner during service.

I love info being described as lore

Man, excellent video. Can you do one video of the best chemicals for cleaning and decontamination of indoor spaces?

Phenol works really well when you have sore throat. It's like (and might be) that initial numbing stuff the dentist gives you before using that big needle of numbing. Cough painlessly!

I use 29% hydrogen peroxide to bleach animal bones from BBQ, hunting, etc. Last time I used 6 litres of it, it FUMES a LOT. Boy I wish I had a fume hood, but I always do it outside. It takes like a week to turn really nasty bones into fine museum specimens.

the s3rl music..... mr thatchemist you have made my day. this video has 3 of my special interests at once!!!!

Back when I used to work at cvs our manager would tell us to pour bleach and ammonia within the bags of candy or whatever we had to throw out so that no one could get to em when we threw em out back. You’d tie the bag and then it’d puff up real good. I always thought it was messed up but I didn’t want to lose my job

thanks for the drinks tier list, much appreciated

Thanks for the educational and keep it up!

As a chemistry lover, this video is amazing!

Love to see the mechanism of action of these different disinfectants, which I've found hard to find in one place. I'm a microbiologist and would personally rank these based on their sporicidal activity, since some bacteria and most fungi can form dormant spores which are very resistant to many disinfectants. This is why I'm not a big fan of hand sanitizer since ethanol does nothing to these spores - wash your hands instead!

Great clip! Informative and comprehensive. That said, while it’s primarily used as a biocide preservative in things like growth media, I’m surprised you didn’t cover sodium azide. It’s remarkably potent, effective, and persistent.

I was just chilling, listening to some chemistry, and then BAM, PONY.

Okay I really love the mic ad :D

2 that chemist video's in the same day!? christmas came early!

damn big homie got the microphone spot but the shure sm7xx in the bg lol :P stay frosty mi amigo.

Dude best ad for a mic ive seen

In 2018, quaternary ammonium compounds became my kryptonite. Messes up my mitochondria almost instantly after inhalation of even miniscule amounts.

Hearing that "this substances kills your own cells" then seeing a picture of a medication I use frequently flashed on screen in the same sentence was definitely an *experience* today 😂

Of all the places i didnt expect to hear S3RL.

Bacteria can evolve UV resistance, there are some extremophilic bacteria and archaea which are resistant to UV and other ionizing radiation but chances are your average pathogenic bacteria will never be able develop or obtain genes for something like that.

"Chlorhexidine is also used in toothpaste..." Me: Cool. "...and is also possible that chlorhexidine may be a potential carcinogen." Me: WTF? (I'm running to check my toothpaste ingredients.)

I’m loving all the water treatment shoutouts as I’m sitting in a water treatment plant.

Propylene glycol also finds use as an antifreeze in potable water lines (RVs, seasonal cabins, etc).

Loved the synthesis hardcore!

I'm really afraid of phenol because when I had it stored in its original plastic container the smell wouldn't stop coming out. And the problem did not disappear when I put it in a borosilicate glass tube with a screw cap and PTFE liner. The problem was solved when I wrapped the lid with several turns of Teflon that sold in hardware stores.

crazy double upload

One upside of bromine as a disinfectant is the higher pKa of HOBr, meaning that more of it is in the active protonated form in neutral pH. If you add some baking soda to chlorine bleach nothing will happen initially (because it is not strong enough of an acid to significantly protonate NaOCl), but add a milligram of sodium bromide and it will turn orange from the HOBr.

Fun fact! Phenol is still used today in clinical microbiology laboratories. Phenol itself is a common part of AFB stains (looking for mycobacteria, like tuberculosis) because it both kills the bacteria and fixes them to the slide. Lactophenol is part of fungal stains for similar reasons. As both of those classes of organisms can be easily transmitted by breathing in the primary specimen, it's important to set them up in a biological safety cabinet, but then be able to read them under the microscope when all the organisms are dead.

A common disinfectant that i would’ve wanted to see in that list is Virkon S. Sometimes also called Oxone or Potassium peroxymonosulfate. It is very commonly used to kill virusses, bacteria and fungi/ molds. A friend of mine works in a viral lab and uses this stuff quite alot to clean equipment and surfaces. It’s pretty great

I didn’t realize this was another “try to get demonetized” video, love the Danny Devito easter egg

Thank you very much, it was very interesting.

Ethylene oxide is also is used in some fuel-air explosives. If it fails to fully ignite, it effectively functions as chemical weapon.

I literally had that exact bottle of phenol chloraseptic sitting next to me when it popped up

We use 70% isopropyl alcohol to clean up circuit boards and electronics. Didn't know it also disinfects them, nice.

Epclusa and vosevi are my fav anti virals. Yes I have worked with needles before.😊😊

not me knowing you were talking about lysis before you said it, i guess i am learning SOMETHING in biochem also got this alieve pain relief spray and camphor was one of the ingredients. when i saw that i thought i might’ve made it in orgo 2 so i looked back at my lab book and I SURE DID. that probably wasn’t that interesting to read but i thought it was cool

Best videos to fall asleap, also to gain what I missed out in my chemistry class😅

7:10 Was not expecting a sudden reference to the infamous "jar". Wow.

Excellent video. What are your thoughts comparing Simple Green, Mr. Clean, Clorox, Lysol for all-surface cleaning/organics in the kitchen?

I thought the title asked What chemical tastes the best and that tism had me reeeeeeeeal excited

Your thing with the ears sent a shiver down my spine. I am Shook bro.

Chlorine trifluorine is a very good disinfectant... .. in theory sorry I still have flash backs as i have said in the past with fluorine compounds...

I started studying chemistry just a few weeks ago. Besides some other youtubers your videos awoke my love for chemistry. Thank you keep the good worke going

2 videos in one day. God bless

Fucking love disinfectant lore

Potassium Permanganate should also come with a mention of Permangatic Acid. Shit's scary but fun to play with

Forgive me, but this is in my opinion the first low quality member in your high quality series. You are always reliably rigid in your criteria for the tiers, as one would expect. In this installment you move goal posts frequently and because of it, the disinfectants are spread across the tiers more or less randomly. If some mundane disinfectants make it to S-tier but UV, primary disinfectant in atmosphere and ocean and huge industry, ends up in F-tier, isopropanol and ethanol in B-tier on equal footing above phenol, chlorine above hypochlorite.. Its inconsistent in a way i think is a step down in a great series. Please reaffirm consistency for future productions. Don't jump the shark :)

Hypochlorous acid is my personal favourite, so gentle on skin compared to most of the others so great for disinfecting cuts. I spray it in my shoes too

Seeing your NMR spectra is my favorite part ⚗️

The stock mic sounds better. Especially for vr chat. It could be also a bit more noisey

Banger! ⚛️

Oh boy, got a love me some disinfectant lore!

I used some phenol based throat spray when I had tonsillitis because it also has a numbing effect

The Br + O3 reaction is problematic enough that ozone-based water treatment processes have to be suspended even at fairly low bromide concentrations. I used to work at a treatment facility that used O3 primarily to oxidize the hell out of triazines, and we were checking bromine levels about every half hour when the river was above a certain stage. An old oil operation was leaking produced water from substandard brine pits, and the bromides in the PW were on the order of 1100 ppm.

I'm personally a fan of stabilized hypochlorous acid, and I was hoping it would be covered here. That's fine, entertaining video anyways! 😅❤

speaking as someone who used to formulate mouthwashes for a living, chlorhexidine is by far the most temperamental material I have ever worked with it really doesn't like salts or alcohol, so you'd often struggle to add fluoride, sweetener or preservative to the formula without the chlorhexidine crashing out