How to Load an Autoclave: Best Practices for All Designs

Proper autoclave loading ensures effective sterilization, prevents instrument damage, and maintains safety in medical, dental, laboratory, and industrial settings. Incorrect loading can cause incomplete sterilization or wet packs due to poor steam penetration. This guide outlines best practices for loading autoclaves, tailored to different designs and configurations, ensuring compliance with CDC guidelines and AAMI ST79.

#General Principles for Loading an Autoclave

#1. Avoid Overloading

• Why: Restricts steam circulation, causing incomplete sterilization.
• Best Practice: Keep loads at 75–80% capacity for steam flow.

#2. Use Trays and Racks

• Why: Perforated trays ensure steam reaches all surfaces.
• Best Practice: Use autoclave-safe stainless steel or polypropylene trays, avoiding direct chamber floor contact.

#3. Position Items Correctly

• Why: Proper orientation prevents air pockets.
• Best Practice:
  • Open hinged instruments for steam exposure.
  • Tilt containers (e.g., flasks) at 45° to avoid air entrapment.
  • Loosen lids to allow steam entry.
  • Place heavy items on lower racks, lighter textiles on top.

#4. Separate Load Types

• Why: Different materials require specific cycles.
• Best Practice: Avoid mixing wrapped/unwrapped items or liquids with solids.

#5. Use Sterilization Indicators

• Why: Confirm sterilization conditions.
• Best Practice: Use external/internal chemical indicators and periodic biological indicators (see autoclave validation).

#6. Maintain Space from Walls

• Why: Prevents damage and ensures steam flow.
• Best Practice: Keep a 1–2 inch gap from chamber walls.

#7. Follow Manufacturer Instructions

• Why: Ensures validated cycle parameters.
• Best Practice: Consult autoclave and instrument manuals.

#Loading by Autoclave Type

#Gravity Displacement Autoclaves (Class N)

• How It Works: Steam displaces air downward.
• Best for: Unwrapped, non-porous solids.
• Loading Tips:
  • Arrange loosely in a single layer.
  • Place heavier items on lower racks.
  • Avoid wrapped/hollow loads.

#Pre-Vacuum (High-Vacuum) Autoclaves (Class B)

• How It Works: Vacuum removes air for deep steam penetration.
• Best for: Wrapped, hollow, or porous loads.
• Loading Tips:
  • Use steam-permeable pouches, placed on edge (paper to plastic).
  • Space pouches for vacuum efficiency.
  • Position hollow items for steam penetration.

#Steam Flush Pressure Pulse (SFPP) Autoclaves

• How It Works: Steam pulses remove air.
• Best for: Wrapped, sensitive instruments.
• Loading Tips: Follow pre-vacuum principles, ensuring pouch spacing.

#Loading by Autoclave Design

#Vertical Autoclaves

• Best for: Glassware, media, small instruments.
• Loading Tips:
  • Use baskets, placing heavy items at the bottom.
  • Ensure steam rises unobstructed.

#Horizontal Autoclaves

• Best for: Large loads, surgical kits.
• Loading Tips:
  • Use carts/shelves, distributing weight evenly.
  • Space textile packs for steam flow.

#Tabletop/Benchtop Autoclaves

• Best for: Dental offices, small labs.
• Loading Tips:
  • Use minimal, spaced loads in racks.
  • Avoid tight stacking.

#Double Door (Pass-Through) Autoclaves

• Best for: Hospitals, cleanrooms.
• Loading Tips:
  • Load from “dirty” side, unload from “sterile” side.
  • Use trolleys, avoid simultaneous door opening.

#Portable Autoclaves

• Best for: Field clinics, simple instruments.
• Loading Tips: Follow gravity displacement principles, using small trays.

#Additional Best Practices

• Pouch Orientation: Place paper to plastic side for steam penetration.
• Liquids: Use high-sided trays, loosely capped, 50–75% full.
• Biohazard Waste: Use autoclavable bags in rigid containers with water for steam.
• Load Sensing Probes: Place in densest areas for monitoring.
• Drying: Complete drying cycle for wrapped items.
• Documentation: Record load details and indicators.

#FAQ: Loading an Autoclave

#How should items be arranged in an autoclave?

Arrange loosely in perforated trays, heavy items on bottom, with a 1–2 inch gap from walls.

#What’s the difference in loading gravity vs. pre-vacuum autoclaves?

Gravity requires loose, single-layer unwrapped solids; pre-vacuum handles spaced, wrapped/hollow loads.

#How should sterilization pouches be loaded?

Place on edge, paper to plastic, with space for steam circulation.

#Why is overloading problematic?

It restricts steam flow, causing incomplete sterilization or wet packs.

#How do vertical and horizontal autoclaves differ in loading?

Vertical uses top-loading baskets; horizontal uses front-loading carts/shelves.

#What role do chemical indicators play?

They confirm steam exposure inside/outside packs (see Steam Penetration).

#Conclusion

Proper autoclave loading ensures effective sterilization across gravity, pre-vacuum, and other designs. By following principles like avoiding overloading, selecting appropriate cycles, and using indicators, facilities achieve compliance with CDC guidelines and AAMI ST79, ensuring safety and efficacy.