ISO bath to sterilize

[Sampei]

Guys, can anyone of you explain to me in details how to do a proper iso bath to sterilize stoppers and caps?

I'll tell you what I gathered and my doubts so you can address them.

So first of all I'll wash caps and stoppers and vials with distilled water and soap, rinse it few times, I'll than grab a metal bowl fill it with Isopropyl and bath the caps and stoppers and vials in it for 30 minutes. First question: why 70% iso and not 99% iso? I have pure ISO 99+ % should I dilute it to 70% with sterile water?
So after the bath I take the caps and stoppers and rinse them with distilled water, I'll do this twice and then I'll put first the vials it in a oven (only used to sterilize things) at 160c to dry heat sterilize. After they are sterile I'll decrease the temperature and take the stoppers and caps and place it in the oven to dry, when they are dried I'll take the vials + stopper + caps out, fill the vials and crimp everything together.

Is it safe done like this?
Can I reutilize the Isopropyl left in the bowl where I bathed everything or I have to throw it away every time I do an Iso bath?

more questions to come but first let's start with these.

@narta @nightprowler7 @Spaceman Spiff @Dirthand @bighunanballs

 

[narta]

1) wash with detergent to remove any residual dirt and oils from manufacturing
2) rinse with tap water until detergent is removed
3) rinse with iso
4) rinse with distilled water
5) dry heat sterilize/dry

for stoppers after 4
put in oxygen peroxide solution for 30' and dry them when you turn off the heat in the oven with the vials

 

[Sampei]

is there a specific % of concentration of oxygen peroxide? I'm not sure but I think we talked about it already. What If I don't have access to high concentration of oxygen peroxide? I can get only 10%.
is chlorine 6-12% ok?
No rinse in distilled water after the oxygen peroxide?

Can I reuse the isopropyl or I have to discard it? Should I make 70% iso or 99+% Iso? I mean when we say rinse they need to be submerged? Do I need to keep them submerged for 30 min or just have the iso run in and over it and wash it away with distilled?

I'm quite worried about fucking up any sterilization process and giving myself an abscess from not sterilizing media bottle or vials correctly, that's why I'm trying to get it right

do I need to sterilize the caps too?

1) wash with detergent to remove any residual dirt and oils from manufacturing
2) rinse with tap water until detergent is removed
3) rinse with iso
4) rinse with distilled water
5) dry heat sterilize/dry

for stoppers after 4
put in oxygen peroxide solution for 30' and dry them when you turn off the heat in the oven with the vials

 

[nightprowler7]

Here’s my process

I wash my glassware with a brand new sponge and dawn antibacterial dish soap

Rinse with reg water

Without setting it down I pour 70% iso all over it until I see there’s no oil or water marks on the glass

Again without setting it down, I rinse it with distilled water

Then I set it directly into my preheated dry heat oven on a new aluminum foil tray I wiped with iso lightly and let dry then I cover the glassware tent style with aluminum foil so air can freely move but nothing can drop on the glassware. I use a large toaster oven I only use for sterilization and not food or anything else


I have an autoclave now but i haven’t tested it yet. They are pretty affordable if you look around.

 

[Sampei]

Pretty affordable you mean 500$ at least right?

I have an oven like you bought only for sterilization.

Why do you put the foil all over it? I was thinking to just put it on the metal tray or grill, it hasn't been touched by anything except glassware or stuff that needed sterilization.

I mean what could be dropping if it's used only for sterilization?

What about the stoppers? Do you sterilize them same as Narta?

Here’s my process

I wash my glassware with a brand new sponge and dawn antibacterial dish soap

Rinse with reg water

Without setting it down I pour 70% iso all over it until I see there’s no oil or water marks on the glass

Again without setting it down, I rinse it with distilled water

Then I set it directly into my preheated dry heat oven on a new aluminum foil tray I wiped with iso lightly and let dry then I cover the glassware tent style with aluminum foil so air can freely move but nothing can drop on the glassware. I use a large toaster oven I only use for sterilization and not food or anything else


I have an autoclave now but i haven’t tested it yet. They are pretty affordable if you look around.

 

[Dxt25]

1) wash with detergent to remove any residual dirt and oils from manufacturing
2) rinse with tap water until detergent is removed
3) rinse with iso
4) rinse with distilled water
5) dry heat sterilize/dry

for stoppers after 4
put in oxygen peroxide solution for 30' and dry them when you turn off the heat in the oven with the vials

Narta just wondering, why the HP after the iso?

 

[Sampei]

Narta just wondering, why the HP after the iso?

It's good vs mold and other stuff, it's not 100% needed. I don't have access to high concentration of HP for example so I ain't using it and just gonna use ISO.

 

[Sampei]

It's good vs mold and other stuff, it's not 100% needed. I don't have access to high concentration of HP for example so I ain't using it and just gonna use ISO.

If you can find 6-12% concentration than you can to the HP bath too

 

[Dxt25]

If you can find 6-12% concentration than you can to the HP bath too

I only have 3% what they sell in the pharmacies.

 

[egruberman]

Should I make 70% iso or 99+% Iso?

I'm going to add this for the your benefit and the benefit of others. 70% is the correct concentration if iso for sterilization. 99% is *not* better. It will evaporate too quickly and fail to penetrate the cell walls of the microbes you're trying to kill.

 

[29trt]

I'm going to add this for the your benefit and the benefit of others. 70% is the correct concentration if iso for sterilization. 99% is *not* better. It will evaporate too quickly and fail to penetrate the cell walls of the microbes you're trying to kill.

That only applies for wiping stuff down so the alcohol as you say has time to work before evaporating, for bath evaporation is a non issue so 99% should work better and faster but it's overkill and costs more...

Also you can usually find 10% h2o2 online quite easily but it's not necessary, you can just leave the stoppers in the 3% for longer.
Also careful when buying h2o2 don't buy a huge quantity as it will go bad relatively quickly after bottle is opened, and always check if it's good before using it to sterilize stuff.

 

[narta]

Narta just wondering, why the HP after the iso?

HP is better than iso or anything else for our purposes if you can find a ~10% or better. It's a bit of a bitch to handle in those concentrations.

 

[Sampei]

I'm going to add this for the your benefit and the benefit of others. 70% is the correct concentration if iso for sterilization. 99% is *not* better. It will evaporate too quickly and fail to penetrate the cell walls of the microbes you're trying to kill.

Yeah i had already Google that forgot to come back and write the solution to my question.

That is 100% correct

isopropyl alcohol need water to sterilize, 70% is the perfect concentration to do it. It's funny because we always think more should be better but indeed it's not, in chemistry especially it really depends.

 

[Sampei]

HP is better than iso or anything else for our purposes if you can find a ~10% or better. It's a bit of a bitch to handle in those concentrations.

I have read that 12% for example can't kill bacterial spores and it's deemed inferior to isopropyl 70%.

On the other hand 35% concentration is superior to iso 70%.

 

[Sampei]

That only applies for wiping stuff down so the alcohol as you say has time to work before evaporating, for bath evaporation is a non issue so 99% should work better and faster but it's overkill and costs more...

Also you can usually find 10% h2o2 online quite easily but it's not necessary, you can just leave the stoppers in the 3% for longer.
Also careful when buying h2o2 don't buy a huge quantity as it will go bad relatively quickly after bottle is opened, and always check if it's good before using it to sterilize stuff.

Doesn't really work like that, 3% can't just kill bacterial spores and other stuff doesn't matter how long you keep in it.

 

[narta]

I have read that 12% for example can't kill bacterial spores and it's deemed inferior to isopropyl 70%.

On the other hand 35% concentration is superior to iso 70%.

Have a link?

 

[Sampei]

Have a link?

Evaluating different concentrations of hydrogen peroxide in an automated room disinfection system - PubMed

This research allows hospital infection control teams to consider the impact and risks of using low concentrations of hydrogen peroxide for disinfection within their facilities, and to question automated room disinfection system providers on the efficacy claims they make. The evidence that low...

pubmed.ncbi.nlm.nih.gov

Unless I have not grasp what it's written correctly.
The assumption it's better than iso 70% at 35% concentration is because it can kill stuff that iso can't.

 

[29trt]

Yeah my bad, I assumed 99% would be better because all the sources I could find talked about surface sterilizing and evaporation ...i completely glossed over the h2o helping penetrate the cell wall...

The 3% thing is parroted everywhere for brewing , and probably is good enough as most people use that and don't get infections(myself included), but going overboard can't be a bad thing when sterilizing
Will shut up now.

 

[Sampei]

Yeah my bad, I assumed 99% would be better because all the sources I could find talked about surface sterilizing and evaporation ...i completely glossed over the h2o helping penetrate the cell wall...

I was thinking the same before I started googling it to understand why I kept reading around use 70% and not 99%.

 

[narta]

Evaluating different concentrations of hydrogen peroxide in an automated room disinfection system - PubMed

This research allows hospital infection control teams to consider the impact and risks of using low concentrations of hydrogen peroxide for disinfection within their facilities, and to question automated room disinfection system providers on the efficacy claims they make. The evidence that low...

pubmed.ncbi.nlm.nih.gov

Unless I have not grasp what it's written correctly.
The assumption it's better than iso 70% at 35% concentration is because it can kill stuff that iso can't.

Your assumption is correct. But we have extra steps, detergent, rinse with distilled, iso and then HP. If there is something that survives the whole ordeal, well fuck it it has the right to cause an infection in my book