The Sterilization of Polyethylene Bags by Electron Irradiation and a Bacterial Monitor as a Measure of Sterility**Chemical Control Laboratories, Merck & Co., Inc., Rahway, N. J.
✍ Scribed by Mayernik, John J. ;Daniels, Thomas
- Publisher
- Elsevier
- Year
- 1959
- Weight
- 262 KB
- Volume
- 48
- Category
- Article
- ISSN
- 0095-9553
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✦ Synopsis
By means of a bacterial monitor, it was found that a 2 megarad dose of high velocity electrons will sterilize 0.353 inch of polyethylene. A new bacterial monitor was devised which serves as a direct measure of the sterilizing effect of irradiation on microorganisms. The bacterial monitor is a sealed polyethylene envelope containing polyethylene strips infected with spores of Bacillus tbermoalimentopbilus. The bacterial monitor may be used to establish the sterilizing capabilities of electron accelerators and may be used as a routine control check on sterilization by irradiation.
ETA RAYS emitted by high voltage electron B accelerators and gamma rays emitted by radioisotopes have been shown to be capable of sterilizing a wide variety of materials including foods, drugs, surgical supplies, and human tissues (1, 2, 3). However, the number of products actually sterilized by irradiation on a practical basis is very few. One of the severest restrictions of electron irradiation to application in sterilization is the limited depth of penetration of the electron beam. Dunn (4) and Duffey ( 5 ) reported that the ionization produced by an electron beam of 2-Mev. energy is adequate for most sterilization applications. The total penetrating range of a 2-MeV. electron beam has been shown by Foster (6) and Knowlton (7) to be roughly 0.4 inch in material of unit density, and that for each additional MeV. the depth of penetration i s increased by 0.2 inch. However, only about 60% of the total penetrating depth is useful in sterilization (6). Accordingly, the sterilizing penetration of a 2-MeV. beam is estimated to be approximately 0.24 inch in material of unit density, It was desired to develop polyethylene bags for use as sterile antibiotic containers. Since polyethylene is heat sensitive, it cannot be sterilized by conventional heat sterilization procedures and therefore electron irradiation was explored as a possible means of sterilization.