Direct comparison
Class B vs Class N Autoclave: Buying Guide
Class B, N, and S autoclaves differ in EN 13060-validated load types. Compare air-removal method, load compatibility, and which class your lab needs.
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How do Class N, Class S, Class B compare side by side?
The table below compares Class N, Class S, Class B across 12 procurement-relevant dimensions, from air removal method through typical setting.
Side-by-side comparison
| Dimension | Class N | Class S | Class B |
|---|---|---|---|
| Air removal method | Gravity displacement (sometimes single air-admission step) | Manufacturer-specified method, varies by model | Fractionated (pulsed) pre-vacuum |
| Solid, unwrapped loads | Validated | Validated | Validated |
| Porous loads (textiles, gauze) | Not validated | Only if manufacturer declares it | Validated |
| Wrapped / packaged loads | Not validated | Only if manufacturer declares it | Validated |
| Hollow instruments (narrow-lumen, Type A) | Not validated | Only if manufacturer declares it | Validated |
| Hollow instruments (wide-lumen, Type B) | Not validated | Only if manufacturer declares it | Validated |
| Mixed / multi-layer loads | Not validated | Limited, model-specific | Validated |
| Load validation basis | Fixed standardized (solid only) | Manufacturer-declared, not fixed | Fixed standardized (full range) |
| Compatible with Bowie-Dick / Helix testing | No | Model-dependent | Yes |
| Relative cycle time | Shortest | Moderate | Longest (extra vacuum pulses) |
| Relative cost | Lowest | Mid-range | Highest |
| Typical setting | Single-room, immediate-use, unwrapped instruments only | Narrow, unchanging validated load mix | General clinical, dental, and research lab use |
Common questions
Common questions about Class N vs Class S vs Class B
Which autoclave class do I need?
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Match the class to your actual load types, not your budget or lab type by default. Solid, unwrapped, immediately-used loads only: Class N is sufficient. Any wrapped, porous, or hollow (lumened) loads, or loads that need to stay sterile until later use: Class B. A narrow, unchanging, specifically validated load mix: Class S can work if the manufacturer's declared scope genuinely matches your instrument list.
Is a Class B autoclave necessary for a research lab?
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Only if the lab's loads include wrapped/packaged items, porous materials, or hollow labware. A lab that exclusively sterilizes solid, loose glassware or media doesn't strictly need Class B, but most general-purpose shared labs have a mixed enough load profile that Class B is the safer default.
What's the difference between Class S and Class B autoclaves?
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Class B is validated against the full standardized EN 13060 load battery. Class S is validated against a manufacturer-declared subset of additional loads beyond Class N, and that scope varies between models rather than being fixed and standardized.
Can a Class N autoclave be upgraded to Class B?
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No. Class B depends on fractionated pre-vacuum hardware (a vacuum pump plus pulsed steam injection). A Class N unit built around gravity displacement cannot be retrofitted to Class B performance.
Does the EN 13060 classification apply outside the EU?
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EN 13060 is a European (CEN) standard, but its B/N/S classification is widely used internationally as a de facto reference point by manufacturers and buyers outside the EU, even where it isn't the formal local regulatory requirement. Always check your own jurisdiction's health authority or accreditation body for what it formally requires, since local rules may reference EN 13060, a different standard, or their own criteria.
