RSD has developed a specific control system for the industrial ethylene oxide (EO) sterilisers.
The EO sterilisation is a process that requires a high level of safety to get an optimal, safe and reliable process to ensure the personnel and installation safety.
The EO gas should be carefully used because of its explosive, flammable and toxic properties. This emphasises the importance of the control system and its functions.
Control system: PLC and SCADA
It is good to remind that the programmable logic controller (PLC) and the supervisory control and data acquisition (SCADA) should always be implanted in an EO steriliser. The PLC is the brain that manages all the process operations of the equipment.
RSD uses a safety PLC based on high-quality (Siemens/Allen Bradley) and safety integrity level (SIL) certified as per the International Electrotechnical Commission (IEC) 61508.
Regarding the SCADA, it is in charge of analysing and communicating all the information coming from / going to the PLC. It allows the operators to control the process in a safe way.
Cycle recipes can be created and visualised thanks to configurable parameters as per humidity, temperature, gas concentration, flow and pressure, as well as user management and alarms. Automatic/manual modes are some of the items that RSD’s SCADA can handle for an ETO sterilisation process.
The customer’s needs are evolving, and the constant technology improvements lead RSD to develop its own control system to meet these new requirements.
What to know about our control system?
RSD has developed its own control system based on SCADA technology and safety PLC. It is programmed in accordance with the Hazard and Operational Stability (HAZOP) analysis and SIL definition for each project, always fulfilling the 21 Code of Federal Regulation (CFR) Part 11.
The main characteristics of RSD’s SCADA system include:
- The company uses Intouch to develop its SCADA according to each customer’s needs and fulfilling the Good Automated Manufacturing Practice (GAMP) 5 recommendations
- The data of the sterilisation cycles are kept in a structured query language (SQL) database, and are protected by a password. Backups are created to save the data
- The system manages the whole installation interlocks
- Possibility to use an audit trail
- We propose six levels of users (operator, supervisor, director, maintenance, administrator and calibration) without users’ limitation. Certain actions will be available to specific users, according to the user level
- Each customer can design the sterilisation cycle they desire, as several parameter configurations are available according to the product
- The control system automatically calculates the inflammable diagram of each new recipe to keep the process in the safe zone
- Screen for calibration operations are available for quality operators
- Ability to operate processes in manual or automatic modes
- The final reports are automatically generated
- User-friendly screens are shown like synoptics, graphs and alarms
RSD’s PLC system features:
- The SAFETY PLC is installed in the main electrical cabinet, and it is certified according to SIL normative (IEC 61508).
- The possibility of having a failure due to the PLC during a cycle operation is much lower than a conventional PLC
- The SAFETY PLC has safe modules to control all the critical inputs and outputs of the installation, and standard functions are configured for the non-critical operations
- Well-known brands are proposed such as Siemens or Allen Bradley
Validation protocols for RSD’s control system
It is essential that the control system should be validated thanks to strict quality protocols in order to ensure that the equipment and the operations are safe and reliable. For this reason, RSD generates and executes the following protocols:
- Software and design specifications (SDS)
- Software module design specifications (SMDS)
- Software module test specifications (SMTS)
The risk analysis of the project is taken into account on the software application, as well as the GAMP and 21 FCR part 11 aspects. In that way, the customer is ensured to buy a safe, efficient and reliable control system.
RSD’s control department has a huge experience and is well qualified to define the appropriate application of every single customised project. On the other hand, the company’s control specialists are aware of the customer’s challenges, as well as the importance of the safety for both personnel and installations, in order to make as safe as possible the process.
RSD offers its programming services and control system for any ETO sterilisation equipment. These are custom services that offer optimal solutions to the pharmaceutical and medical devices industries.