Today, medical plastics are widely used in the aseptic medical device industry. The products produced by the company determine the difference in sterilization methods. To select the correct sterilization method, the necessary scientific evidence should be carried out to ensure the adaptability of the sterilization method of the product. .
However, some medical device companies have not yet detailed the important part of the “sterilization process development†in IS011135.1-2007 “Development, Validation and Routine Control Requirements for Medical Device Sterilization Processâ€.
At present, most of the plastic products of aseptic medical device companies are sterilized by ethylene oxide, which often neglects the adaptability of the sterilization method, resulting in a change in the chemical properties of a particular product itself or a certain performance requirement. This will cause social, business, family, and individuals to suffer huge losses and other disharmony factors.
We know that conventional sterilization methods generally include: moist heat, dry heat, radiation, gas, filtration sterilization and other sterilization methods. The sterilization mechanism of these sterilization methods and the special effects on the product materials should be thoroughly understood to ensure the adaptability of the sterilization method, so as to avoid some major accidents. For example: PVC and PS.
1 ) PVC- polyvinyl chloride
Sterile medical devices of this kind can not be used for damp heat, dry heat, radiation, filter sterilization, and can only be used for gas sterilization - ethylene oxide sterilization.
If: use damp heat, dry heat sterilization, the shape of the product will change, or even dissolved by heat; the use of radiation sterilization will cause the PVC material itself to react chemically, so that PVC releases chlorine and some toxic substances; filter sterilization is generally used Sterilization of liquid or liquid, also not suitable for medical devices with PVC materials.
Ethylene oxide has almost no chemical effect on PVC because its sterilization mechanism does not destroy the shape and material properties of the product. However, due to the sterilization of ethylene oxide, the product itself should be strictly controlled for the residual amount of ethylene oxide, and the carcinogenesis of EO. Although the nature is not clear, its toxicity, sensitization and fertility can not be ignored.
We know that there are many factors that affect the amount of EO residues, but the most important is the molecular structure of the material itself.
2 ) PS- polystyrene
In general, this material uses a radiation sterilization-gamma ray sterilization method.
First, we need to have a brief understanding of some of the properties of PS so that we can draw conclusions and choose the appropriate sterilization method.
a. Physical
Ordinary polystyrene resin is non-toxic, odorless, colorless transparent particles, glass transition temperature of 80 ~ 90 ° C, like glass brittle material. The product has high transparency, light transmittance of over 90%, good electrical insulation performance and easy coloring. Good processing fluidity, good rigidity and good chemical resistance.
The shortcomings of ordinary polystyrene are brittleness, low impact strength, easy stress cracking, poor heat resistance and boiling water resistance.
b. Chemistry Â
Polystyrene has poor chemical stability and can be dissolved by various organic solvents (such as aromatic hydrocarbons, halogenated hydrocarbons, etc.), which is corroded by strong acid and alkali, does not resist grease, and is easily discolored after exposure to ultraviolet light.
The above properties determine that PS cannot be used for damp heat or dry heat sterilization, otherwise the product will be softened and deformed; it can not be used for filtration sterilization.
And gas - commonly used EO sterilization? As we all know, ethylene oxide is organic, very chemically active, also known as ethylene oxide, is the simplest cyclic ether.
Ethers are also common organic solvents such as diethyl ether, propylene oxide, and the like. Ethylene oxide has a certain solubility in polystyrene. Although it is sterilized by EOG, its residual amount is difficult to pass the time, ventilation and other factors, even for half a year or longer.
Radiation sterilization-γ-ray has no damage to PS raw materials and raw materials, and no other toxic substances are produced. It is the main sterilization method for food packaging and medical equipment using polystyrene as raw material.
Photoluminescent Exit Sign,Luminescent Sign,Afterglow Exit Sign,Afterglow Tunnel Sign
JINAN REALGLOW CO.,LTD , https://www.realglowsign.com