EN 13060 (adopted in Portugal by IPQ as NP EN 13060) classifies small steam autoclaves into three classes: Class B (all load types — solid, porous, hollow, wrapped), Class S (specific loads defined by the manufacturer), Class N (solid unwrapped loads only). For dental practices, Class B is the standard professional choice and is recommended for sterilizing turbines and contra-angles (hollow instruments). Class B is also the standard professional choice for tattoo and podiatry. This guide describes the technical and operational differences and helps you select the correct class for your practice.
NP EN 13060, the Portuguese adoption (by IPQ) of the European standard EN 13060, defines three classes of small steam sterilizers based on their ability to process different load types. Class B (Big autoclave) handles all loads: solid, wrapped, hollow, and porous instruments. Class N (Naked) handles only solid unwrapped instruments. Class S (Specified) handles specific loads defined by the manufacturer — its capabilities vary from model to model.
The fundamental difference is the vacuum system. Class B autoclaves use a fractionated pre-vacuum that evacuates air from the chamber and from the internal channels of hollow instruments before injecting steam. Without this pre-vacuum, steam cannot penetrate the lumens of hollow instruments (turbines, contra-angle handpieces, cannulae) — trapped air creates unsterilized pockets. EU Regulation 2017/745 (MDR), directly applicable in Portugal, reinforces the requirement that medical-device reprocessing must follow validated procedures.
In Portugal, Class B is the professional standard for dental practices. Portaria n.º 99/2024/1 does not explicitly mandate a class, but the obligation to sterilize hollow wrapped instruments — turbines, contra-angle handpieces, ultrasonic scaler tips — is in practice only met with Class B. The Sociedade Portuguesa de Instrumentação Médica (SP-Instrumédica) cites the EN 13060 / NP EN ISO 17665-1 family as the technical reference for small steam sterilizers.
For podiatrists, Class B is recommended for hollow instruments used in invasive procedures such as nail surgery. For tattoo artists and piercers, Portugal has no specific national legislation — APPTBP self-regulation strongly recommends Class B because it permits wrapping and use-by dating, which are the building blocks of professional traceability. Class N may suffice if all instruments are solid and unwrapped, but this significantly limits practice.
Class N autoclaves sterilize only solid, unwrapped, non-hollow instruments. This means instruments must be used immediately after the cycle — they cannot be stored in pouches. For a dental practice, this is insufficient: instruments must be wrapped to maintain sterility until use. For a tattoo studio using only solid tubes without pouches, Class N is technically acceptable — but Class B remains recommended for the versatility it provides and for the ability to label and date each pouch.
Class S autoclaves have capabilities defined by the manufacturer. Some models handle wrapped loads but not hollow instruments. Others handle certain types of hollow loads. It is essential to check the exact manufacturer specifications and ensure they cover the instrument types used in your practice. When in doubt, Class B is the safe choice — it covers all load types without exception.
Regardless of class, every cycle must be validated. The Bowie-Dick test verifies steam penetration for Class B autoclaves — it must be performed daily before the first load. The Helix test is specifically designed to validate sterilization of hollow instruments. A failed test means the load is not sterilized, regardless of what the cycle report shows. Annual operational qualification (OQ) under NP EN ISO 17665-1:2010 verifies that the autoclave continues to deliver the required thermodynamic parameters.
For details on mandatory controls, see the biological controls guide. SecuSteri tracks cycles from all autoclave brands (W&H, Melag, Euronda, Castellini, Tuttnauer, and others) — regardless of class.
Dental practice: Class B is the practical standard (hollow instruments, wrapped loads, prion cycle). Podologist: Class B recommended (hollow instruments in invasive procedures). Tattoo artist and piercer: Class B recommended by APPTBP if reusable hollow instruments are used; Class N acceptable only if all instruments are solid and unwrapped. Permanent makeup: Class B recommended (dermograph handpieces with hollow components).
To understand what your traceability sheet must contain after each cycle, see the traceability sheet guide.
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For a complete schedule of daily, weekly, monthly, quarterly, and yearly autoclave maintenance tasks, see our Autoclave maintenance guide.