Testing for hermeticity on commercial product is not normally done on standard molded devices that are not hermetic. Commercial product that this test method applies to has a construction that produces a hermetic package; examples of this are ceramic and metal packages.
Most of these tests are controlled and updated in the military standards, the two standards that apply are MIL-STD-750 for Discretes, & MIL-STD-883 for microcircuits. The test within these standards can be used for all package types.
Within these standards the tests are similar; MIL-STD-750 Test Method 1071 Hermetic Seal is recommended for any commercial hermetic requirements.
For MIL-STD-883 the applicable test method is 1014 Seal.