ASTM D4783-01(R2021) pdf free download

ASTM D4783-01(R2021) pdf free download.Standard Test Methods for Resistance of Adhesive Preparations in Container to Attack by Bacteria, Yeast, and Fungi
1. Scope
1.1 These test methods cover the determination of the resistance ofliquid adhesive preparations to microbial attack in the container by challenging adhesive specimens with cultures of bacteria, yeast, or fungi, and checking for their ability to return to sterility. These test methods return qualitative results. 1.2 The values stated in SI units are to be regarded as the standard. The values in parentheses are for information only. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appro- priate safety, health, and environmental practices and deter- mine the applicability of regulatory limitations prior to use. These test methods are designed to be used by persons trained in correct microbiological technique. Specific precautionary statements are given in Section 8. 1.4 This international standard was developed in accor- dance with internationally recognized principles on standard- ization established in the Decision on Principles for the Development of International Standards, Guides and Recom- mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
4. Summary of Test Method
4.1 The adhesive specimen is challenged by inoculation with a culture of bacteria, yeast, or fungi, which may be a single species or a mixed culture of several species, following the guidelines given in Note 6. The inoculated adhesive specimen is stored at 21 to 27°C (70 to 80°F) for 7 days, during which time cultures (streak plates) are made at preset intervals. See Note 2. At any point in the series of challenges, if the inoculated specimen shows microbial growth on the streak plates made during the week following the challenge (indicat- ing that it has not returned to sterility), the test is discontinued,and the sample is reported as not resistant to attack in the container by the species or combination of species used as the inoculum. If the cultures show no growth, the test is repeated with up to four challenges. If the specimen tests out as sterile following the fourth challenge, it is reported to be resistant to attack in the container by the species or combination ofspecies of bacteria, fungi, or yeast used as the inoculum. At the discretion of the biological laboratory, the test may be discon- tinued after the second or third challenge. See Section 16 for further interpretation. 4.2 The time necessary to kill is determined by noting the earliest streak plate to read sterile. If the 4-h plate is positive and the 24-h plate is negative, the kill time could be narrowed down further by repeating the challenge and making streak plates at intervals of 4, 8, 12, and 24 h following the challenge. 4.3 The testing laboratory has the option of changing the timing of the challenges, the sterility checks, and the incuba- tion period. N OTE 2—Two proposed schedules for the challenging and sterility checks are shown in Table 1 and Table 2, Schedule A for bacteria and yeast, and Schedule B for fungi. The exact format to be followed will vary, according to the convenience of the schedule to the testing laboratory and special circumstances relating to the problem being addressed. N OTE 3—A serial-dilution plate-count method of checking for sterility may be used when numerical information is needed on the population of viable organisms or the reduction in population with increasing levels of biocide. Letheen broth is recommended for the diluent and Letheen agar for the pour plate. See Note 1.
5. Significance and Use
5.1 These test methods are used to demonstrate whether an adhesive preparation is sufficiently protected with biocide to resist attack by bacteria, yeast, and fungi during its storage life. They are patterned after methods used by biological laborato- ries serving the adhesive industry.