Infections

[OdinsOtherSon]

The water in a pressure cooker reaches the same temp as the steam.

Mechanism of Autoclave Sterilization

The autoclave is like a large pressure cooker and is a physical method for disinfection and sterilization. Autoclaves work with a combination of steam, pressure and time. Autoclaving does not remove chemical contamination. Steam must be in contact with the material being sterilized to be effective. Steam is generated and pumped into the chamber raising the temperature and pressure in order to kill microorganisms. Moist heat kills more effectively than dry heat because the mass transfer of heat as steam condenses is very efficient. Therefore, if a load is contained within a bag or other enclosure, then the enclosure must not be tightly sealed (e.g., in the case of surgical instruments) or the enclosure must contain some water to ensure steam production (e.g., waste bags).

Sterilization and Disinfection Parameters

Use a minimum cycle time of 121-124°C (250-255°F), = 30 minutes,15 psi for the disinfection of medical waste. These parameters are required by the California Department of Public Health for the disinfection of medical waste. Items have to be hot enough for long enough in the presence of steam to disrupt protein structure. At 121°C, or 250°F, saturated steam destroys vegetative cells and endospores in a small volume (~100mL) within 10-12 min. Treatment must continue for a total of 30 minutes to provide a margin of safety. Sterilization of larger volumes will require a longer cycle time.

Source: UC Santa Barbara, Environmental Health and Safety

[Bonaparte]

Source: UC Santa Barbara, Environmental Health and Safety

None of that contradicts what I said.
I'm on my phone, so digging up articles to link to would be a pain, but think about it: do you think the water jumps from 100 C to 121 C instantly just by changing form?

[OdinsOtherSon]

None of that contradicts what I said.
I'm on my phone, so digging up articles to link to would be a pain, but think about it: do you think the water jumps from 100 C to 121 C instantly just by changing form?

Yes, I understand and totally agree. You are correct; however, the temp of pressurized steam is greater than that of boiling water.

[Twack]

Yes, I understand and totally agree. You are correct; however, the temp of pressurized steam is greater than that of boiling water.

Won't the heat damage the seal on the vials?

So far no issue with second injection done on Mon night...hope that's a good sign.

[Bonaparte]

Yes, I understand and totally agree. You are correct; however, the temp of pressurized steam is greater than that of boiling water.

Pressure and Boiling Points of Water

Boiling water at 1 atm, yes.
Boiling water at 2 atm is the same temp as steam at 2 atm (121 C).

[OdinsOtherSon]

Pressure and Boiling Points of Water

Boiling water at 1 atm, yes.
Boiling water at 2 atm is the same temp as steam at 2 atm (121 C).

I completely agree. Pressurized water will be the same temp as pressurized steam, just as boiling water at atmospheric pressure will have the same temp as steam at atmospheric pressure. I didn't mean to try to argue that...sorry for the confusion Bonaparte. The point I was trying to make is that all sterilization equipment, be it autoclave or a home pressure cooker, (specifically an autoclave)are built so that one can not place items to be sterilized directly into the water. I use an autoclave daily. The Thermo Orion brand we use is constructed in such a manner as to completely eliminate any possibility of exposing the items to be sterilized to the water. Further more, the autoclave will not hold enough water to submerge the items, only enough to generate the steam. The items to be sterilized must be placed on a tray and inserted into the device above the water for steam and pressure exposure. All home pressure cookers are supplied with an elevated rack on which to place items above the water for steam exposure. Many people choose to remove that rack, but that is not the intended use.

Sorry again for the confusion. I didn't mean to sound as if water could be different temps just because its physical properties had changed from liquid to gas.