The process of sterilizing materials in autoclaves depends on the interaction between pressure and temperature.
Phase 1 – Air Removal
In gravity displacement (Class N) sterilization, steam drives air out through the drain vent.
The vacuum pump in pre-vacuum Class B autoclaves eliminates 99.9% of air before steam injection begins.
Phase 2 – Sterilization
During the standard sterilization cycle, the autoclave maintains 121°C and 15 psi pressure for a period between 15 and 30 minutes.
Fast sterilization cycles run at 134°C under 30 psi pressure for durations between 3 and 10 minutes.
Phase 3 – Drying
Post-vacuum phase removes residual moisture
Typical drying time: 20-45 minutes at 80-90°C
Key Formula: The sterilization effectiveness (D-value) is calculated using: [ D{121} = \frac{\text{Exposure Time}}{\log{10}(N_0/N)} ] (N_0) stands for the initial number of microbes and (N) represents the number of microbes that survived.
| コンポーネント | 機能 | Critical Specifications |
|---|---|---|
| 会議室 | Holds items for sterilization | 316L stainless steel, ≥1.5mm thick |
| 蒸気発生器 | Produces pure steam | Output: 3-6 kg/h per 100L chamber |
| 制御システム | Manages cycle parameters | ±0.5°C accuracy, 10+ preset programs |
| Safety Valve | Prevents over-pressurization | ASME Section VIII compliant |
素材適合性:
Autoclavable: Stainless steel, borosilicate glass, polypropylene
Non-autoclavable: PVC, polystyrene, low-density polyethylene
物理的モニタリング
Chart recorders: Verify time-temperature-pressure curves
Data loggers: Track 3D chamber heat distribution
化学指標
Class 1: Process indicators (tape color change)
Class 4: Multi-variable integrators
生物学的指標
Use ジオバチルス・ステアロサーモフィルス spores (10⁶ population)
Incubation: 56-60°C for 24-48 hours
Acceptance Criteria:
No growth in test vials
Temperature uniformity ≤±1°C across chamber
ローディング:
Arrange items with 2.5cm spacing between objects
Position pouches printed-side up
サイクル選択:
Liquids: Slow exhaust gravity cycle
Wrapped instruments: Pre-vacuum cycle
荷降ろし:
Wait until internal pressure reaches 0 psi
Use thermal gloves for hot items
ドキュメンテーション:
Record cycle number, parameters, operator ID
| タスク | 頻度 | Tools/Agents |
|---|---|---|
| Door gasket inspection | Daily | Visual check, leak detector |
| チャンバー洗浄 | ウィークリー | Non-abrasive citric acid solution |
| Safety valve test | Monthly | Calibrated pressure gauge |
| Calibration | Annual | NIST-traceable thermometer |
Descaling Protocol:
Fill chamber with 5% acetic acid solution
Run 30-minute cycle at 100°C
Rinse 3× with deionized water
Autoclave machines that undergo proper operation and maintenance deliver dependable sterilization which is indispensable for controlling infections and ensuring research results remain valid. Consistent steam sterilization results can be obtained when users follow validated cycles along with regular biological monitoring and manufacturer instructions. Technological advancements such as cloud monitoring systems and automated validation tools will improve autoclave performance tracking in future years.
Q1: Can autoclaves sterilize liquids? Specialized liquid cycles with slow exhaust protect against boiling over during autoclave sterilization. Always fill containers ≤75% capacity.
Q2: How often should autoclave validation be performed? The ISO 17665 standard mandates quarterly validation of medical devices. Laboratories need to perform autoclave validation every year or following significant repairs.
Q3: Why does my autoclave take so long to reach temperature? Common causes include insufficient steam generation (check boiler capacity) or air leaks (test door gasket integrity).
Q4：オートクレーブに必要な水質は？ Prevent mineral buildup in autoclaves by using ASTM Type II water with conductivity levels below 5 µS/cm. Distilled or RO water is acceptable.
Q5: How long do autoclave cycles typically last?
