Sterilizers for medical purposes. Small steam sterilizers. Requirements and testing

Standard Background and Technological Evolution

BS EN 13060:2025 "Medical sterilizers — Small steam sterilizers — Requirements and tests" is the latest standard published by the European Committee for Standardization (CEN), replacing the 2014 version. This standard aims to regulate small steam sterilizers with a volume of less than 60 liters that cannot accommodate a standard sterilization module (300 mm × 300 mm × 600 mm), widely used in general practice, dentistry, podiatry, beauty, and tattooing. Compared to the previous version, the 2025 version adopts the framework of ISO/TS 22421:2021 in structure, updates normative references, and adjusts terminology to align with EN ISO 11139 and EN ISO 17665. Technological evolution is mainly reflected in a clearer distinction between process variables (temperature, time) and cyclic variables (pressure), the introduction of independent monitoring system requirements, and more stringent drying performance indicators.

Scope and Core Definitions

This standard applies to automatically controlled small steam sterilizers, whose steam can be generated by an electric heater or supplied by an external system. The sterilizer must meet the following conditions: **chamber volume less than 60 liters**, and cannot accommodate standard sterilization modules. The primary sterilization targets are medical devices and materials that come into contact with blood or bodily fluids. The standard does not cover the sterilization of liquids or pharmaceuticals, nor does it address processes involving formaldehyde or ethylene oxide. Core terms include: **sterilization cycle**, **process challenge device (PCD)**, **biological indicator**, **chemical indicator**, etc. Among these, **small steam sterilizer** specifically refers to equipment with a volume less than 60 liters that cannot accommodate 300mm × 300mm × 600mm modules.

Comparison of Sterilization Cycle Types

Key Design Requirements

The standard sets forth detailed requirements for the design of sterilizers. The chamber must have an air leak test capability, with a leakage rate not exceeding 0.13 kPa/min (when using the vacuum stage). Pressure vessels must comply with the EN 13445 series standards. A door interlock system ensures that the door cannot be opened during sterilization and can be safely restored in case of failure. The control and recording system must be independently monitored: at least two independent temperature measurement chains (or one temperature and one pressure measurement chain) are required, and anomalies are detected by comparing theoretical steam temperature with actual temperature. Software must be validated according to EN 62304, and cybersecurity must be considered. Regarding service facilities: Electrical supply must meet ±10% voltage fluctuations; water supply quality must meet the limits in Annex F (e.g., conductivity ≤15 μS/cm); and the non-condensable gas content of external steam must not exceed 3.5%. Performance Testing Methods and Indicators: The standard specifies various types of tests: type tests, factory tests, and installation tests. Core performance indicators include:
- **Sterilization Temperature Range:** The temperature must not be lower than the set value, and must not exceed the set value by more than 3 K, with a temperature difference of no more than 2 K between points.
- **Equilibrium Time:** No more than 15 seconds (this can be relaxed to 30 seconds if specific heating rate conditions are met).
- **Drying Performance:** Moisture content change of solid load ≤ 0.2%, porous load ≤ 1.0%.
- **Dynamic Pressure Change Rate:** No more than 10 bar/min to prevent packaging damage.
Instruments used in the test, such as **temperature sensors (platinum resistance thermometers conforming to EN IEC 60751)** and **pressure sensors**, must have high accuracy and fast response (τ_0.9 < 1 second). **Recorders** can be analog or digital, independent of the control system.

Explanation of Technical Terms and Application Cases

Process Challenge Device (PCD):: A device used to simulate the most challenging sterilization conditions. For example, a narrow-cavity PCD contains a long, thin tube with a chemical or biological indicator inside. The indicator will only change color or become inactive when steam fully penetrates the tube. In dental clinics, when using a Type B sterilizer to process handpieces with lumens, validation using a narrow-cavity PCD is mandatory.
Theoretical Steam Temperature: The saturated steam temperature calculated by measuring pressure. Comparing this temperature with the measured temperature determines whether the steam quality is saturated. A large deviation indicates the presence of non-condensable gases or overheating, which will affect the sterilization effect.
Case Study: A beauty salon uses a Type N sterilizer only to process non-wrapped metal forceps, without requiring a drying stage; while a hospital's sterilization supply center uses a Type B sterilizer to process wrapped, multi-hole surgical drapes and lumens, requiring a full set of tests including air leak tests and multi-hole load drying tests.

Implementation Recommendations

For manufacturing companies, it is recommended to incorporate risk management and availability engineering (compliant with EN ISO 14971 and EN 62366-1) during the design phase to ensure software reliability and meet independent monitoring requirements. Users should provide compliant water, electricity, and steam (if externally supplied) according to the manufacturer's installation instructions and conduct regular leak tests and calibrations. Users are advised to select the appropriate sterilization cycle (B/N/S) based on the actual load type and conduct routine checks using preset test cycles (such as air leak test cycles). For locations handling lumen instruments, Type B sterilizers validated by PCD should be preferred.