5.1 Leaks in medical device, pharmaceutical, and food packages may result in the ingress of unwanted gases (most commonly oxygen), harmful microbiological, or particulate contaminants. Package leaks may appear as imperfections in the package components themselves or at the seal juncture between mated components. The ability to detect leaks is necessary to ensure consistency and integrity of packages.
5.2 After initial set-up and calibration, individual test operation may be semi-automatic, automatic, or manual. The test method permits non-destructive detection of leaks not visibly detectable. The test method does not require the introduction of any extraneous materials or substances, such as dyes or gases. However, it is important to physically mask or block off any package porous barrier surface during the test to prevent rapid loss of chamber vacuum resulting primarily from gas migration through the porous surface. Leak detection is based solely on the ability to detect the change in pressure inside the test chamber resulting from gas or vapor egress from a package challenged with vacuum.
5.3 This test is a useful research tool for optimizing package sealing parameters and for comparatively evaluating various packages and materials. This test method is also applicable to production settings as it is rapid, non-invasive, and non-destructive, making it useful for either 1008201;% on-line testing or to perform tests on a statistical sampling from the production operation.
5.4 Leak test results that exceed the permissible limits for the vacuum decay test are indicated by audible or visual signal responses, or both.
1.1 Test Packages—Packages that can be nondestructively evaluated by this test method include:
1.1.1 Rigid and semi-rigid non-lidded trays.
1.1.2 Trays or cups sealed with porous barrier lidding material.
1.1.3 Rigid, nonporous packages.
1.1.4 Flexible, nonporous packages.
1.2 Leaks Detected—This test method detects package leaks by measuring the rise in pressure (vacuum loss) in an enclosed evacuated test chamber containing the test package. Vacuum loss results from leakage of test package headspace gases and/or volatilization of test package liquid contents located in or near the leak. When testing for leaks that may be partially or completely plugged with the package’s liquid contents, the test chamber is evacuated to a pressure below the liquid’s vaporization pressure. All methods require a test chamber to contain the test package and a leak detection system designed with one or more pressure transducers. Test method sensitivities cited below were determined using specific product-package systems selected for the precision and bias studies summarized in Table 1. Table 1 also lists other examples of relevant product-package systems that can be tested for leakage by vacuum decay.