Penetration of sterilant gas into packaged product
Irradiation of product using photons from radioisotope
Product sterilized using ionizing energy from electron beam
Products sterilized using ionizing energy from Rhodotron electron beam
Efficacy
Process efficacy confirmed by biological indicators and/or process monitoring
Process parameters confirmed by dosimetry
Process parameters confirmed by dosimetry
Process parameters confirmed by dosimetry
Penetration
Requires gas permeable packaging and product design
Good penetration complete even at high densities (> 0.4 gm/cc)
Efficient penetration at bulk densities between 0.05 – 0.30 gm/cc
Excellent penetration for all product types
Material Compatibility
Very few material compatibility concerns Liquids are generally not recommended
Compatible with most materials; plastics need to be evaluated
Avoid acetals, PTFE (teflon), unstable polypropylene Additives are available to correct issues.
Negative effects are frequently less pronounced or eliminated
Similar to gamma, however negative effects are frequently less pronounced or eliminated
Turnaround Time
Days: Conventional = 9-10 days. EOExpress® = one day
Hours: time varies based on dose requirements
Minutes: time varies based on dose requirements
Hours: time varies based on dose requirements
Process
Complex process: Variables include exposure time, temperature, humidity and EO concentration
Non-process variables impacting lethality include load density, packaging, and winter shipping conditions.
Simple process: Variables include time in the cell and isotope load
Complex process: Variables include scan height, processing speed, number of passes, and orientation to the beam
Moderately complex process: Variables include processing speed, number of passes and number of pallets on conveyor
Product Handling
Traditional processing: pallets are transferred between stages via fork truck or conveyor system
EOExpress® processing: entire process takes place in the sterilization chamber
Aluminum totes/pallets with product placed in pre-determined loading pattern
Aluminum carriers with product placed in pre-determined loading pattern, or boxes placed directly onto conveyor
Products processed via pallets, in pre-determined loading pattern
Advantages Of Gamma Irradiation
Sterilization Method
Advantages
Disadvantages
Dry heat sterilization
Non-toxic and safe for the environment. Powders, soft parafin, glycerine can be sterilized by this method.
Needs high heats for long periods. The penetration of the heat takes a long time in large devices. Not proper for plastic and cloths.
Pressured vapor sterilization
Economic and short processing time. It is nontoxic and safe for the environment.
Materials that are sensitive to high heats and moisture, oily materials like soft parafin, liquid materials and electrical devices can not be sterilized by this method.
EtO sterilization
It is preferable for materials that are sensitive to heat. No limit for lumen. Complete penetration depending on the use of the permeable gas. It is important to define the SAL with the use of biological indicators.
The time of the sterilization and ventilation is long. EtO is toxic, cancerogenic, flammable, explosive. It needs an aeration period after the process because of the formation of ethylene chlorohydrin.
Formaldehyde sterilization
It is preferable for materials that are sensitive to high heats. There is no need for ventilation of materials after sterilization.
It is toxic and carcinogenic so it can not be used for the sterilization of liquids.
Gas plasma (H2O2) sterilization
Hydrogen peroxide is safe for the environment and it is also less hazardous to work with. Sterilization can be achieved in a period between 28 min to 74 min. There is no need for the ventilation. It is proper for the sterilization
of materials that are sensitive to temperature.
It is not a proper method for the sterilization of liquids. Measuring the hydrogen peroxide concentration within the isolator during sterilization cycles in real time may also be a problem.
Peracetic acid sterilization
No harm to the personnel and the environment. Less damaging process to delicate materials than steam sterilization, and it is compatible with a wide variety of materials-plastics, rubber, and heat-sensitive items. It is a single-use process, there is no possibility of contamination.
Only one or a small number of instruments can be processed in a cycle. Using of the materials after sterilization process is not possible.
Gamma radiation sterilization
It is an advanced technological method. It is a cold method, increase in temperature is so slight. It has a high SAL. Control of the method is very
easy that can be made only by the parameter of applied dose.
Dose rate is lower than electron beams. It has no dose flexibility.
E-beam sterilization
Very safe method. It is an advanced technology method. It is a cold method, increase in temperature is so slight. It has a high SAL. Control of the method is very easy that can be made only by the parameter of applied dose.
It needs an electron accelerator that is very rare.
