Ethylene Oxide Gas Sterilizer

Description

An ethylene oxide gas sterilizer (also known as an EO sterilizer) is a highly specialized sterilization system that utilizes ethylene oxide (EO) — a colorless, flammable gas — as the primary sterilizing agent. This advanced technology is essential for effectively eliminating bacteria, viruses, fungi, and spores from medical devices, surgical instruments, and other items that cannot withstand high heat or moisture.

In healthcare facilities, hospitals, pharmaceutical manufacturing plants, and medical device production units, ethylene oxide sterilization has become the gold standard for processing heat- and moisture-sensitive materials. Unlike traditional autoclave steam sterilization, which relies on high temperatures, EO gas can penetrate deep into complex device geometries, intricate tubing, porous materials, and sealed packaging without causing damage or deformation.

Salient Features of Ethylene Oxide Gas Sterilizer

Easy to operate
Used to sterilize disposable syringes, I.Vs, disposable surgical set, gloves, infusion sets, urine collecting bags, birth control apparatus and plenty of medical devices
Contact parts made of SS 304 and 316

Chamber with modular construction
IQ, OQ and DQ documentation can be provided
Prevention of micro biological contamination

Working Principle of Ethylene Oxide Gas Sterilizer

Let’s take a look at the working principle and several stages involved in the sterilization process. Since, there is no standardized process owing to a vast diversity in exposure periods and gas concentration, the process below is a typical one and must be taken into consideration for reference purposes only.

The machine uses single use EO cartridges of 40, 100 and 170 grams. The chamber is facilitated with a single door and a simple locking system. There is an electronically controlled heating system in place to ensure a uniform heating at 50 degrees centigrade. The machine is designed for optimum durability as it contains venturi of adequate capacity inside a robust cabinet. There are control buttons for heating, gas purging and power supply requirements.

Product exposed to warm and humid environment

The product is exposed to a warm and humid environment for about 12 hours. 70 percent RH and 55 A Cº is maintained for a uniform temperature and humidity.

Introduction of ETO gas

Now the vacuum is pulled and ETO gas is introduced at this stage. The exposure is for about 4 to 8 hours at the same RH and temperature as before.

Removal of ETO gas

Vacuum is continually pulled for the removal of ETO gas and air is introduced into the sterilization chamber to clear out the entire ETO gas. This process lasts for about 8 to 12 hours.

Technical Specification of Ethylene Oxide Gas Sterilizer

Model	AETOS – 2.6	AETOS – 4.5	AETOS – 8
Working Capacity in Cu. Ft.	2.6	4.5	8
Working Volume	70 Liters	125 Liters	200 Liters
Chamber Size	12” (W) x 12” (H) x 32”	12” (W) x 12” (H) x 54” (D) OR 15” (W) x 15” (H) x 36” (D)	20” (W) x 18” (H) x 38” (D) OR 16” (W) x 16” (H) x 54” (D)
Sterilant Gas	40 grams cartridge	100 grams cartridge	170 grams cartridge
Sterilization Cycle	Warm & Cold Cycles are possible.	Warm & Cold Cycles are possible.	Warm & Cold Cycles are possible.
Aeration	In-built aeration facility provided.	In-built aeration facility provided.	In-built aeration facility provided.
Utility	Compressed Air (100 psig)	Compressed Air (100 psig)	Compressed Air (100 psig)
Power Supply	1 K.W.	2 K.W.	2.5 K.W.
Power Voltage	220 volts, Single Phase, 50 Hertz	220 volts, Single Phase, 50 Hertz	220 volts, Single Phase, 50 Hertz

* Power voltage can be adjusted as per customer’s domestic power voltage requirements.
* Rights of technical improvements & modification reserved.
* Illustrations & dimensions are shown for information purpose only.

Types of Sterilization Equipment

Industrial ETO Sterilizer

Horizontal Autoclave

Dry Heat Sterilizer

Cath Lab Ethylene Oxide Gas Sterilizer

Steam Sterilizer

Bung Washer cum Processor

Sterilization and Depyrogenation Tunnel

Pure Steam Generator

Applications of Sterilization Equipment

Pharmaceutical Industry
Nutraceutical Industry
Herbal Industry
Ayurvedic Industry
Biotech Industry
Cosmetic Industry
Chemical Industry

Benefits of Ethylene Oxide Gas Sterilizer

Penetrates breathable packaging for in-package sterilization.

Low-temperature process preserves delicate materials.

Compatible with most plastics, metals, and composites.

High efficacy against bacteria, viruses, spores, and fungi.

Key Components of Ethylene Oxide Gas Sterilizer

An Ethylene Oxide gas sterilizer is a complex, multi-system machine designed for low-temperature sterilization of heat- and moisture-sensitive medical devices, instruments, and materials. The main components work together to control the critical process parameters (EO concentration, temperature, humidity, pressure/vacuum, and time)

Sterilization Chamber (Vessel)
- Pressure- and vacuum-rated steel or stainless-steel (typically SS 304 or SS 316) enclosure.
- Often jacketed for temperature control.
- Designed to withstand deep vacuum (near complete vacuum) up to moderate positive pressure.
- Equipped with a sealed door (manual, pneumatic, or automatic) and high-integrity gaskets (silicone or similar) for leak-tight operation.

Vacuum System
- High-capacity vacuum pump (often water-sealed or dry type).
- Used for initial air removal, post-exposure evacuation, and multiple air/nitrogen washes.
- Essential for creating conditions that allow EO gas penetration and for safe gas removal.

Heating / Temperature Control System
- Jacket around the chamber (hot-water circulation is common; electric heating is also used).
- Maintains precise chamber temperatures, typically in the range of 37–63 °C (commonly 50–55 °C).
- Ensures uniform heat distribution throughout the load.

Humidification System
- Steam generator or controlled water/steam injection system.
- Raises relative humidity (typically 40–80 % RH) inside the chamber.
- Moisture is critical because it enables EO to penetrate microbial cells effectively.

EO Gas Delivery / Gassing System
- Gas supply from cylinders (100 % EO or EO mixtures with CO₂ or nitrogen) or single-dose cartridges (common in smaller units).
- Evaporator/vaporizer that converts liquid EO into gas before injection.
- Precision metering and injection system to achieve the required concentration (commonly 450–1200 mg/L).

Recirculation System
- Internal fans or header systems that circulate the chamber atmosphere.
- Ensures uniform distribution of temperature, humidity, and EO gas throughout the load.

Nitrogen Injection & Air Inbleed System
- Nitrogen is often used as an inert gas for dilution, flushing, or pressure control (especially with 100 % EO cycles).
- Filtered air inbleed brings the chamber back to atmospheric pressure at the end of the cycle.

Exhaust / Sterilant Removal & Abatement System
- Removes residual EO after the exposure phase.
- Includes scrubbers (acid-water or catalytic), thermal oxidizers, or other abatement technology to neutralize toxic EO emissions before release.
- Critical for operator safety and environmental compliance.

Control & Monitoring System
- PLC or industrial computer-based controls with validated process recipes.
- Sensors for temperature, pressure/vacuum, humidity, and gas concentration.
- Touch-screen HMI, data logging, alarms, interlocks, and safety features (leak tests, door interlocks, emergency stops).

Aeration / Ventilation Features
- Many modern sterilizers integrate aeration in the same chamber (warm air circulation or repeated vacuum/air washes).
- Dedicated aeration rooms or chambers may be used for larger industrial systems to remove residual EO from absorbent materials.

FAQ for Ethylene Oxide Gas Sterilizer

What is an Ethylene Oxide Gas Sterilizer?

An ethylene oxide (EO) gas sterilizer is a specialized low-temperature sterilization system that uses ethylene oxide—a colorless, flammable gas—as the sterilizing agent. It effectively eliminates bacteria, viruses, fungi, and spores from heat- and moisture-sensitive medical devices, surgical instruments, and other items that cannot withstand high-temperature steam sterilization.

What items can be sterilized using an Ethylene Oxide Gas Sterilizer?

It is commonly used for disposable syringes, IV sets, disposable surgical sets, gloves, infusion sets, urine collecting bags, birth control apparatus, and a wide range of other medical devices. It is ideal for complex geometries, intricate tubing, porous materials, and items in sealed packaging.

How does the Ethylene Oxide Gas Sterilizer work?

A typical cycle includes three main stages:

Exposure of the product to a warm, humid environment (about 12 hours at ~70% RH and 55°C).
Introduction of EO gas under vacuum (exposure of 4–8 hours at the same temperature and humidity).
Removal of residual EO gas through continuous vacuum and air introduction (about 8–12 hours). The system uses single-use EO cartridges and maintains uniform heating (typically around 50°C).

What are the key salient features of the Ethylene Oxide Gas Sterilizer?

Key features include easy operation, stainless-steel (SS 304/316) contact parts, modular chamber construction, provision of IQ/OQ/DQ documentation, and effective prevention of microbiological contamination. It supports both warm and cold cycles with built-in aeration.

What are the available models and their capacities?

The main models are:

AETOS-2.6: 2.6 cu. ft. / 70 liters (40 g cartridge)
AETOS-4.5: 4.5 cu. ft. / 125 liters (100 g cartridge)
AETOS-8: 8 cu. ft. / 200 liters (170 g cartridge) Chamber dimensions, power requirements (1–2.5 kW, 220 V single phase), and utilities (compressed air at 100 psig) vary by model.

What are the main benefits of using Ethylene Oxide sterilization?

Benefits include deep penetration through breathable packaging for in-package sterilization, a low-temperature process that preserves delicate materials, compatibility with most plastics, metals, and composites, and high efficacy against a broad spectrum of microorganisms including bacteria, viruses, spores, and fungi.

What are the key components of an Ethylene Oxide Gas Sterilizer?

Core components include the sterilization chamber (SS 304/316, pressure/vacuum-rated), vacuum system, heating/temperature control system (typically 37–63°C), humidification system, EO gas delivery system (cartridges or cylinders), recirculation fans, nitrogen/air inbleed system, exhaust/abatement system for residual gas, control & monitoring system (PLC/HMI with sensors), and integrated aeration features.

In which industries is the Ethylene Oxide Gas Sterilizer commonly used?

It is widely used in the pharmaceutical, nutraceutical, herbal, Ayurvedic, biotech, cosmetic, and chemical industries, as well as in hospitals, healthcare facilities, and medical device manufacturing units for sterilizing heat- and moisture-sensitive products.

Does the sterilizer include aeration, and why is it important?

Yes, the units feature in-built aeration. Aeration is critical for safely removing residual EO gas from the chamber and sterilized items after the exposure phase, ensuring operator safety and product readiness while meeting environmental compliance requirements.

What documentation and construction standards are provided?

The sterilizers are constructed with contact parts in SS 304 and 316, feature modular chambers, and can be supplied with IQ (Installation Qualification), OQ (Operational Qualification), and DQ (Design Qualification) documentation. Power voltage can be adjusted to meet customer-specific requirements.