EO STERILIZATION
Introduction to EO Sterilization
What is EO Sterilization?
EO sterilization, or ethylene oxide sterilization, one of the most commonly used sterilization method. It is widely applied during sterilization of medical apparatuses in the sterile pharmaceutical industry.
EO sterilizer is the device critical for disposable sterile medical device manufacturers, with its set of special requirements in installation procedures and usage management. The sterilizer takes EO as a broad-spectrum sterile agent and annihilate microorganisms at room temperature, including but not limited to spores, mycobacterium tuberculosis, bacteria, viruses, fungi, etc.
Supplies are unaffected with EO’s strong penetrating sterilization process, thus most of the supplies that are not suitable for general sterilization methods can be disinfected and sterilized by EO. Some examples include electronic instruments, optical instruments, medical apparatus, books, documents, fur, cotton, chemical fibers, plastic products, wood products, ceramics and metal products, endoscopes, dialyzers, disposable diagnosis and treatment supplies. EO sterilization is one of the most applied low-temperature sterilization method.
Jana Sterilization Technology (Hangzhou) Co., Ltd. had introduced EO sterilization equipments compatible with domestic and EU standards. Pre-conditioning rooms, sterilization rooms, aeration rooms and sterility test laboratories are all built in strict accordance with the international standard ISO11135.
Rationale of EO Sterilization
What is the Rationale for EO Sterilization?
While EO sterilization is in progress, its cyclic structure breaks and hydroxylates, alkylation with the amino, carboxyl and hydroxyl groups on bacteria protein. EO sterilization interferes with enzyme’s metabolistic functions, leads to the death of microorganisms and ultimately achieve the sterile state.
EO remains a colorless gas at normal pressure and temperature, condenses into liquid at 4°C, and boils at 10.4°C. Highly active with chemical activities, flammable and explosive. EO is one of the most effective cold chemical sterile agents because of its broad-spectrum high-efficiency sterilization characteristics. Usually, EO is utilized in industrial sterilization and disinfection. In recent years, EO had also been widely utilized in heat and moisture sensitive medical apparatuses deployed in hospitals. Due to EO’s toxicity in nature, supplies sterilized with EO processes have highly adhesive toxin residuals, which requires volatilization before application in the medical industry. Medical workers need to be fully aware of EO’s properties, sterilization rationale, and strictly follow a professional guideline during all medical procedures. It is important to monitor and control EO sterilization processes, in order to safely supply and apply EO sterilized supplies.
EO has a non-specific alkylation reaction with proteins, DNA, and RNA of microorganisms, while being a broad-spectrum sterile agent that kills a variety of microorganisms, including vegetative bacteria, spores, viruses, and fungal spores. The EO in the aqueous solution has an alkylation reaction with free carboxyl, sulfhydryl and hydroxyl groups on the protein, as the reaction takes place, the protein loses the reactive groups for basic metabolism. The normal chemical reaction and metabolism of bacterial protein are blocked due to the replacement of unstable hydrogen atoms, compounds with hydroxyethyl radicals, and the groups on the protein are alkylated, thus leading to the death of microorganisms.
As studies and data suggests, the sterilization effect of EO is irreversible, meaning that EO is a sterile agent, not a disinfectant. Supported by various clinical and scientific research results, EO is the most effective chemical sterile agent among all chemical sterile agents. EO inhibits the activity of some microbial enzymes, including phosphokinase, peptidase, choline oxidase and cholinesterase. EO also has an alkylation reaction with DNA and RNA, resulting in the inactivation of microorganisms.
Advantages of EO Sterilization
What are the Advantages of EO Sterilization?
Among the sterilization technologies for medical apparatuses and sanitation supplies, EO gas sterilization is a matured technique widely deployed. Early 1960s, advanced countries had applied EO gas sterilization technology to the fields of medical treatment, health, industrial industries and agricultural and environmental sanitation. Early 1990s, EO gas sterilization starts to spread across China.
Specific Advantages:
- EO sterilization is applicable for heat and moisture sensitive medical apparatuses.
- EO is considered the most effective chemical sterile agent that kills all microorganisms, including bacterial spores.
- EO sterilization has strong penetration, applicable for medical apparatuses like long and thin catheters that are hardly sterilized with other low-temperature sterilization methods.
- EO sterilization is harmless to the supplies as it kills microorganisms by alkylation rather than oxidation, thus EO sterilization is widely adopted for the sterilization of heat sensitive precision instruments.
- During EO sterilization, supplies can be wrapped with various materials, which maintains the sterile state across storage and transport stages, enables immediate usage after opening, ultimately prevents cross contamination.
- Standardized chemical and biological monitoring effectively controls the quality of sterilization and enables immediate response for defective sterilization.
- EO sterilization is a matured technique and has been deployed for decades.
Specific Features:
- EO sterilization and residue volatilization can be completed at once, enables consistent and convenient manufacturing.
- EO sterilization consists a circulating water heating system, highly effective both in performance and energy consumption.
- EO sterilization is safe and reliable. The sterilization is performed under negative pressure to avoid EO gas leakage. Supplies are free from potential corrosion damage, easy to be stored afterwards, all being environmentally friendly.
- EO sterilization is a broad-spectrum and thorough sterilization technique with strong penetration at a low temperature.
- EO sterilization is convenient, optimal combination of temperature, pressure, time of vacuum sterilization and times of residue removal can be set according to the sterilization needs.
- EO sterilization utilizes a microcomputer with built-in firmware. Automatic warming, vacuum pumping, humidification, sterile agent fill, nitrogen fill, sterilization, cleansing, exhaust treatment and other complex procedures are controlled and automated with a single button, achieves ultimate simplicity.
- Standardized aeration process conquers the difficulties in natural aeration processes of sterilized supplies. Meets the standard requirement of residues < 10µg/g.
- To prevent leakage, provide convenient storage, ensure safety and reliability, a single-does cylinder of 100% EO gas is deployed for each sterilization.
Process of EO Sterilization
What are the Processes of EO Sterilization?
- EO sterilization includes the following processes: pre-heat, pre-wet, vacuum, EO gas concentration, sterilization, EO gas sterilization chamber ventilation, and aeration to volatilize residual EO gas from the sterilized supplies.
- Freon is forbidden for the entire EO sterilization process. 100% pure EO or EO mixed CO2 gas is to be used.
- Aeration can be processed in the EO sterilization chamber, or in the designated fume hood. Natural ventilation should never be considered. The circulating air is filtered to ensure particles ≥ 0.3 µm are eliminated above 99.6%.
- EO residues mainly refer to EO and its by-products left in the supplies and packaging materials after EO sterilization, ethylene chlorohydrin and ethylene glycol. Excessive exposure to EO residues may cause burns and irritations among patients.
- The amount of EO residuals is related to the materials of supplies, sterilization parameters, packaging materials and size, capacity, aeration parameters, etc. For PVC catheters, the aeration is up to 8h at 60°C and 12h at 50°C. For some materials, the aeration process can be shortened, namely metal and glass, which can be used immediately. For some other materials, the aeration needs to be prolonged, such as built-in pacemakers.
- EO sterilization exhaust is only emitted after final real-time concentration monitoring EO exhaust treatment device proves it meets relevant national emission standards.
Sterilization Qualification, Verification and Monitoring
- Yourfield has established a quality management system in accordance with ISO 11135:2014, ISO 13485:2016, ISO 9001:2015, EN 550 and other international standards.
- Installation qualification (IQ) and operation qualification (OQ) are required in strict accordance with ISO 11135:2014 and GB 18279-2015 Medical devices-Validation and routine control of ethylene oxide sterilization, while performance qualification (PQ) is required in combination with customer products.
- The sterilization process is qualified by a half-cycle approach. External PCDs, self-contained biological indicators (BIs) are used for routine release testing.
- Daily parameters are automatically collected and recorded by a computer and stored for at least 5 years.
Contact
Add:No.9 Innovation Park, Shuangyong Road, High-Tech District, Xiangtan City, Hunan Province
Email:yfmd@yourfield.net