Sterilization Methods PDF

Sterilization The Process Of Destroying All Microorganisms And Their Pathogenic Products (Spores). SAL sterility Assurance level = 99,9999 Choosing the correct sterilization process method...

Sterilization The Process Of Destroying All Microorganisms And Their Pathogenic Products (Spores). SAL sterility Assurance level = 99,9999 Choosing the correct sterilization process method. IFU (ISO EN 17664) Methods of sterilization Thermal Chemical High temperature sterilization Low temperature sterilization Moist heat (Steam) Dry heat Ethylene oxide (EO) Requires direct contact between the instrument and pure dry saturated steam. Hydrogen peroxide (Gas plasma) Vaporized Hydrogen peroxide Ozone sterilization  Thermal High temperature sterilization Moist heat (Steam) Dry heat Requires direct contact between the instrument and pure dry saturated steam. Parameters: 1) Steam 3) Pressure (Absence of air and dry saturated steam) means to obtain the high temperatures necessary to quickly kill microorganisms 28 – 30 psi 15 psi 2) High Temperature 4) Time 134 °C \ 121 °C 3 min 15 min Types of steam sterilization 1) Tabletop sterilizer 4) IUSS Immediate use steam sterilizer (Often used in clinics and dental) (flash sterilization) Describe the practice of fast sterilization. 2) Gravity item is placed in an open tray in a specially designed, covered, rigid container to allow for rapid penetration of steam. No assisted air removal and depends on gravity. At the point of use. In the operation room. Steam penetrate slowly. often associated with dropped item, no alternative is available , Long cycle time. urgent. Not suitable for wrapped items and lumens. Never be used for the items with lumine , implants or any products are not validated for IUSS. 3) prevacuum assisted In an unwrapped condition. The parameter cycle are 134 for 3-10 min. the item is so hot and In the beginning of the cycle, all air inside wet. the chamber are removed by increasing the pressure and vacuum the air.  Steam loading - place pouches on their edge. - place pouches paper to plastic On the first shelf. - Avoid overloading. - Keep package away from chamber walls. - Do not stack rigid containers. - Place heavier items and container on lower shelves. Steam Unloading Cool down the load wet pack - Review the sterilization printout. - Correct cycle parameters have been met. - Examine the load items Steam Advantages Steam Disadvantages - Highly effective monitored. - Moist process - inexpensitve. - Unsuitable for heat - Rapid process and validated. sensitive items - Packed items. Steam indicator Biological indicator Chemical indicator Geobacillus stearothermophilus Classifies chemical indicator into 6 types. Chemical indicator (ISO 11140)  Steam streilizer testing Routine testing of sterilize should be performed daily, weekly, quarterly and yearly (ISO 17665) Daily Weekly Quarterly Yearly Bowie –Dick test ( air removal test ) Safety check Thermometric test Steam Quality test. Test for steam penetration Vacuum leak test ( non-condensable gas / Air detector function test Steam superheat / steam Automatic control test dryness / endotoxin ) Bowie –Dick test  Thermal Used for: High temperature sterilization Glassware, Metal items, Powder, Non aqueous liquid (paraffin) A Typical cycle consist of: Moist heat (Steam) Dry heat Requires direct contact between Heating the chamber. the instrument and pure dry saturated steam. Holding the load at high temperature for a define time. The sterilant is heat. Dry heat testing. Parameter: Dry heat Advantage Dry heat disadvantages Thermocouple test 160 °C for 2 h Suitable for glassware and non - High temperature Biological indicator 170 °C for 1h aqueous fluids - Unsuitable for heat sensitive items Chemical indicator 180°C for 30 min - Long sterilization and cooling time - Items cannot be wrpped  - Effectiveness Has the capability of destroying all bacteria. Chemical - Safety Low temperature sterilization Should be no toxic residual remaining on the packaging. - Sterilization performance monitoring Must capable of being reliably monitored using physical, chemical and biological indicators. Ethylene oxide (EO) Hydrogen peroxide (Gas plasma) Ethylene oxide (EO) Vaporized Hydrogen peroxide - Operate temperature at 37c or 55 c. Ozone sterilization - Humidity required 40% to 80%. - 100% EO concentration. - Exposure time an hour to 6 hour. - Time of 8-12 hour required very long cycle duration to allow of adequate aeration. - Costly health and safety requirement for operating these machine. - EO inactivates microbes by a process called alkylation. A typical cycle consist of: Sterilizer monitors: 1- load pre-conditioning (vacuum and humidification ) 1- chemical indicator: 2- sterilization gas exposure. external ( demonstrate the pouch has been process). 3-gas exhaust. Internal: (to measure whether the sterilant has penetrated. 4- air purge (wash) from EO. 2-physical indicator: pressure gauges, temperature, time recorders and humidity. 3- biological indicator: Bacillus Atrophaeus. Advantage Disadvantage 1- suitable for heat sensitive RMD. 1- equipment is expensive. 2- extremely penetrative. 2- lengthy cycle with aeration and validation. 3- Dry process. 3- EO is toxic gas, explosive, and flammable. 4-separate accommodation is recommended.  - Effectiveness Has the capability of destroying all bacteria. Chemical - Safety Low temperature sterilization Should be no toxic residual remaining on the packaging. - Sterilization performance monitoring Must capable of being reliably monitored using physical, chemical and biological indicators. Ethylene oxide (EO) Hydrogen peroxide (Gas plasma) Hydrogen peroxide (Gas plasma) Vaporized Hydrogen peroxide - Operate temperature at 45 – 55 c. Ozone sterilization - The cycle time 45 to 75 min , no aeration is required. - Gas plasma is non toxic (water vapour and oxygen). - H2O2 concentration is 59%. - Microorganisms destroy by oxidation. - BI: Geobaillus sterothermophilus A typical cycle consist of: Advantage 1- a vacuum to remove air. 1- suitable for heat sensitive device. 2- injection H2O2 liquid inside the chamber. 2- short cycle. 3- diffusion of the H2O2 vapour when the radio frequency energy (RF) is radiated from the electrode Disadvantage screen. 4- Gas plasma generation vie radio energy 1- Non cellulose wrapping materials required. 5- venting of filter air into the chamber through (HEPA 2- may not be suitable for long narrow lumens. filter ) high efficiency particulate air.  - Effectiveness Has the capability of destroying all bacteria. Chemical - Safety Low temperature sterilization Should be no toxic residual remaining on the packaging. - Sterilization performance monitoring Must capable of being reliably monitored using physical, chemical and biological indicators. Ethylene oxide (EO) Hydrogen peroxide (Gas plasma) Vaporized Hydrogen peroxide Vaporized Hydrogen peroxide - The cycle time 28 to 55 min at less than 50c Ozone sterilization - Non cellulose packing material should be use in order to not absorb the H2O2. Typhek pouch - Microorganisms destroy by oxidation. A typical cycle consist of: 1- a vacuum to remove air and moisture. 2- leak test. 3- injection H2O2 inside the chamber. 4- Aeration. Ozone sterilization - The cycle time take 4 hours. - Exposure time take 30 min at 30.8 -36 c. A typical cycle consist of: 1- a vacuum and humidity. 2- injection O3. 3- sterilization. 4-ventilation.