Sterilization Temperatures
Dry Heat
Static air
Dry heat sterilization using a static-air sterilizer (basically an oven) is not suitable for most materials. Use 338°F for 60 mins, 320°F for 120 mins, or 302°F for 150 mins.1 If using a kitchen oven there should be a thermometer inside to verify temperatures, as the temperature you set it to is not a reliable indicator as to the temperature inside the oven. Some people will use two oven thermometers inside the oven to check temps in various locations as there are typically cool zones.
| Temperature | Time |
|---|---|
| 180°C/356°F | 30 mins |
| 170°C/338°F | 60 mins |
| 160°C/320°F | 120 mins |
| 150°C/302°F | 150 mins |
| 140°C | ?? |
Depyrogenation temps2
| Temperature | Time |
|---|---|
| 250°C | 30 mins |
| 200°C | 60 mins |
Forced Air
See USP Chapter 797 for these details. Will not be filled in here as we are unlikely to use this method.
Steam / Autoclave
Considered an “advanced compounding procedure”. Consult USP Chapter 1211.
This is the use of an autoclave. Commercially available pressure cookers such as stovetop units and the electric Instant Pot can be used here, but understanding how they pressurize and what temps they reach is vitally important.
121°C at 15psi for 20-60 minutes.1
There is a relationship between temperature, pressure, and time. The math is a bit beyond us so we’re not going to attempt to explain it here. But take the Instant Pot for example. It gets up to 115°-118°C at 10.2-11.6psi, a bit short of the requirements listed above. Therefore, it needs to run a sterilization cycle for at least 150 minutes. See the instant pot page for data about sterilization with that.
See this page for info about sterilizing sealed containers.