Sterilization Workshop Gas Detection Solution

Sterilization workshops are critical production areas in the pharmaceutical, medical device, and biotechnology industries. Strong oxidizing gases such as ethylene oxide (EO), hydrogen peroxide (H₂O₂) vapor, and ozone (O₃) are widely used in low-temperature sterilization processes. While these gases ensure product sterility, they also introduce significant safety and environmental risks: excessive concentrations may endanger operator health, and leaks may cause poisoning or explosion hazards. An effective gas detection system has become an essential component of safe sterilization workshop operations. Nexisense has developed a professional solution tailored to this scenario, covering both process concentration control and leak early warning, helping enterprises achieve precise monitoring and automated response.

Major Gas Risks and Monitoring Requirements in Sterilization Workshops

Sterilization processes are typically conducted in enclosed or semi-enclosed environments where gas concentrations must be strictly controlled within safety thresholds. According to occupational exposure limits (PEL/TLV), the 8-hour time-weighted average of ethylene oxide must not exceed 1 ppm, hydrogen peroxide vapor is generally limited to 1 ppm, and the short-term exposure limit for ozone is as low as 0.1 ppm. These gases are irritating, carcinogenic, or strongly oxidizing. Once leakage occurs or residual levels exceed limits, they not only threaten personnel safety but may also cause product contamination or equipment corrosion.

Monitoring requirements fall into two categories: first, concentration control during the sterilization process to ensure both sterilization efficacy and safety; second, leak detection to prevent accidental release into workshop air. The Nexisense solution is built around these two needs, combining intelligent modules with fixed gas detectors to provide flexible and reliable deployment options.

Process Concentration Control: SGA-700 Series Intelligent Sensor Modules

For sterilization processes requiring real-time gas concentration regulation, the Nexisense SGA-700 series intelligent gas sensor modules provide a highly integrated solution. The series features unified dimensions, output signals, pin configuration, and operating methods. Users only need to complete system integration once; afterward, different gas modules can be directly replaced according to monitoring targets.

For example, during an ethylene oxide sterilization cycle, the module outputs standard 4-20mA or RS485 signals that can be directly connected to a PLC or dedicated controller for closed-loop concentration control. When replacing modules, there is no need for rewiring or reprogramming, significantly reducing maintenance difficulty and R&D costs. This “plug-and-play” feature is particularly suitable for sterilization workshops operating multiple process lines in parallel, enabling quick adaptation to different sterilants.

The module integrates high-precision sensors and signal processing circuits, offering fast response time and good repeatability to ensure stable and reliable process data. Many users report that after adopting this series, process parameter fluctuations decreased significantly and sterilization qualification rates improved.

Leak Monitoring: SGA-500 Series Online Gas Detectors

To prevent accidental gas leaks, the Nexisense SGA-500 series online gas detector is the preferred fixed installation device for sterilization workshops. Products are fully calibrated and integration-tested before delivery and can be installed directly without secondary on-site commissioning. The detector is optimized for key gases such as ethylene oxide, hydrogen peroxide, and ozone, ensuring high sensitivity in low concentration ranges.

Typical installation locations include areas around sterilization chambers, pipeline joints, valve zones, and near exhaust outlets. Once the concentration approaches or exceeds preset alarm thresholds, the device immediately activates audible and visual alarms, prompting emergency measures. In practice, these detectors are often used to monitor the dissipation of residual gases after sterilization cycles, helping determine when it is safe to re-enter the workshop.

The detector supports explosion-proof design, suitable for potentially explosive areas, with high protection ratings compatible with cleanroom environments.

Building a Complete Gas Alarm and Interlock System

While a single detection point provides localized protection, sterilization workshops often cover large areas with dense equipment, requiring a fully covered monitoring network. The Nexisense SGA-500 series can be combined with the SGA-800 alarm controller series to quickly establish a multi-point gas alarm system.

The controller supports centralized display of real-time concentrations, historical curves, and alarm status for each detection point, allowing managers to grasp the overall situation at a glance. The system is compatible with Modbus RTU, 4-20mA, and other communication protocols, enabling seamless integration into existing PLC or DCS systems. More importantly, its interlock function allows automatic activation of exhaust fans, shutdown of inlet valves, or triggering of warning signals when concentration exceeds limits, ensuring rapid response even in unattended conditions.

This automated management approach significantly reduces the risk of human error, especially during night shifts or periods with fewer personnel, effectively preventing minor leaks from escalating into major incidents.

Practical Features for Pharmaceutical Cleanroom Environments

Sterilization workshops are often GMP cleanrooms with strict requirements for equipment materials, surface treatment, and maintenance convenience. Nexisense products use stainless steel or specially coated housings that are easy to clean and resistant to dust accumulation. Both sensor modules and detectors support remote calibration, minimizing on-site intervention and reducing disturbance to clean environments.

Additionally, the system records long-term data for compliance audits and process optimization. For example, by analyzing residual gas dissipation curves, enterprises can adjust ventilation duration to balance safety and energy consumption.

Practical Value of Implementing Nexisense Solutions

After deploying Nexisense gas detection systems, enterprises typically achieve improvements in several aspects: enhanced personnel safety with reduced incident rates; improved process consistency and product quality stability; strengthened environmental and occupational health compliance; and lower maintenance costs due to modular design simplifying servicing procedures.

Feedback from a mid-sized pharmaceutical enterprise shows that after introducing the system, gas-related abnormal events decreased by approximately 40%, while residual monitoring accuracy during sterilization cycles improved, resulting in higher overall operational efficiency. These results demonstrate that appropriate investment in gas detection delivers long-term safety and economic returns.

Nexisense also provides comprehensive services from solution consultation and site survey to installation, commissioning, and periodic maintenance, ensuring reliable long-term system operation.

Frequently Asked Questions (FAQ)

1.Why must ethylene oxide concentration be monitored in sterilization workshops? Ethylene oxide is a commonly used low-temperature sterilant but is carcinogenic and highly toxic. Excessive concentrations in workshop air may cause headaches, nausea, or long-term health damage. Real-time monitoring ensures residual levels remain below safety limits and comply with occupational health standards.

2.How does the SGA-700 intelligent module enable quick switching between different gases? The series adopts standardized interface design, with identical dimensions, pins, and output signals. Users simply remove the old module, insert a new one, and power on to switch monitoring targets without modifying programs or rewiring.

3.How are alarm thresholds set for the SGA-500 detector? Thresholds are determined based on national standards, industry guidelines, and internal risk assessments. For example, first-level alarm for ethylene oxide is often set at 0.5 ppm and second-level at 1 ppm. Nexisense supports on-site or remote threshold adjustment with hysteresis settings to avoid frequent alarms.

4.How is the system integrated with PLC or DCS? Integration is achieved through 4-20mA analog output or RS485 digital interface. Modbus protocol compatibility allows most industrial controllers to directly read concentration data for closed-loop control or recording.

5.What are the special requirements for hydrogen peroxide vapor monitoring in VHP sterilization? VHP processes involve high-concentration vapor injection followed by aeration. Monitoring must track rapid decline from high levels to safe thresholds. The SGA-500 sensor features wide measurement range and fast recovery to accurately follow the entire cycle.

6.How many detection points does the alarm controller support? The SGA-800 series supports 8–32 channels or more depending on model, with expandability. Each channel can be independently displayed and configured.

7.How is equipment maintained in cleanroom environments? Regular calibration (typically every 6–12 months) is recommended using dust-free tools. The design allows easy disassembly to minimize impact on cleanliness.

8.Will introducing a gas detection system affect sterilization efficiency? No. On the contrary, precise monitoring can optimize aeration time and reduce unnecessary ventilation energy consumption, improving overall process stability and productivity.

Conclusion

Gas detection in sterilization workshops is fundamental to safety, quality, and compliance. Through the SGA-700 intelligent sensor modules for efficient process control and the SGA-500 online detectors combined with the SGA-800 alarm system for leak protection, Nexisense provides reliable and flexible solutions for pharmaceutical and medical enterprises. These technologies safeguard personnel health while supporting process optimization and sustainable development. It is recommended that sterilization workshop managers conduct thorough risk assessments and introduce professional gas detection systems to establish a stronger safety barrier.