What is bubble emission testing?
Bubble emission testing is a pass/fail package integrity test that examines a packaging system for leaks. This test is used to find leaks in flexible packaging that contains gas headspace.
What is bubble emission testing used for?
Medical devices and products can be contaminated through packaging leaks. Leaks are openings often found at small pinholes in packaging or breaks in the seals between packaging components that allow the escape or entrance of substances or microorganisms into a sterile barrier system. Bubble emission tests for large leaks in flexible packaging under vacuum.
What types of packages can be tested with bubble emission testing?
Bubble emission testing is performed for flexible packaging systems.
How is bubble emission testing performed?
For this procedure, a test fluid must be selected. Ideal options for immersion fluid include water, water with a wetting agent, denatured alcohol, and mineral oil. The immersion fluid that the packaging will be immersed in should not degrade the packaging being tested and should have low surface tension. The test samples and test fluids are all at room temperature for bubble emission testing.
For bubble emission testing, the sealed package is fully submerged in the immersion fluid within a vacuum chamber. The surface of the specimen needs to be completely covered with at least an inch of fluid. Next, the cover on the vacuum chamber is set and the vacuum is turned on. The vacuum level chosen must be as large as possible to create maximum sensitivity for the test. This will vary based on the specific needs of the packaging system being tested. The degree of package expansion and test-fluid vapor pressure influence the maximum vacuum pressure that can be held. As vacuum pressure rises, the submerged package is assessed for air bubbles that would indicate a leak in the packaging system. The vacuum is held for around 30 seconds during which time the submerged specimen is again examined for leaks via air bubble emissions. The vacuum is then released, and the package is examined for any test fluid leaks inside the sterile barrier system. Multiple packages may be tested at the same time if every package can be adequately observed for leakage during the procedure.
If bubbles indicating a leak are present under full vacuum or the rise of vacuum, the package failed the bubble emission test. If fluid resides inside of the packaging system after the test, the packaging also failed the test. If no bubbles due to leakage are observed and no fluid due to leakage exists inside of the package following testing, the packaging system passes the test.
Limitations of Bubble Emission Testing
Small leaks are not always detected with this procedure. Large amounts of entrapped air may not be able to pass through small openings and the positive pressure inside of the pouch due to vacuum may plug small leaks. Additionally, if a flexible package has little or no headspace, leaks cannot be reliably assessed with bubble emission testing.
Bubble Emission Test Summary
Bubble emission testing is a pass/fail method of detecting leaks in packaging. When bubble emission tests are performed, a report will be issued with information on the package specimen, the packaging materials tested, the test fluid used, the maximum vacuum level used, the approximate average and range of sample expansions at maximum vacuum, and the time period held at maximum vacuum. The report will also contain a determination of whether or not a leakage occurred, the approximate location of the leak (if applicable), the number of specimens tested, and the number of packaging system failures (if applicable). Overall, bubble emission testing is an important testing parameter to prove the integrity of your medical device packaging.
MycoScience is a contract manufacturing organization specializing in sterile syringe and vial filling. MycoScience also offers Preservative Efficacy Testing, Sterilization Validations, Bioburden Testing, Cleaning Validations, Microbial Aerosol Challenge Testing, Accelerated Aging, Microbiology Testing, Cytotoxicity Testing, Bacterial Endotoxin Testing, EO Residual Testing, Package Integrity Testing & Environmental Monitoring services medical devices and allied industries. MycoScience is an ISO 13485 certified facility.
References
American Society for Testing and Materials. Standard Test Method For Determination Of Leaks In Flexible Packaging By Bubble Emission. West Conshohocken, PA, United States. (ASTM D3078-02).
