When it is necessary and what is involved in hydrostatic pressure testing
In order to be in compliance with Title 49 Code of Federal Regulations (49CFR), a plastic, glass, or metal packaging needs to be subjected to hydrostatic pressure testing if the product contains any of the 3,000 substances listed in 49 CFR section 172.101 Hazardous Materials Table.
For example, a plastic cylinder bottle that contains chemicals that emit vapor will have vapor pressure build up as temperature increases. The hydrostatic pressure testing is designed to ensure the bottle and cap package will not leak as the pressure builds.
Hydrostatic pressure testing will subject the packaging component (plastic bottle, glass bottle, metal cans, and it's closures) to pressure testing to check for leakage. The duration of such test is determined by the material of the package. Metal packagings and composite packagings, other than plastic are pressure tested for 5 minutes. Plastic packagings, on the other hand, are tested for 30 minutes. Pressure is maintained constantly, continuously and evenly during the test period. A hydraulic pressure gauge is connected to the top of the receptacle to record the pressure.
Test Validation Criteria
Hydrostatic pressure testing certification applies to the bottle and caps for as long as the packagings technical specification remains intact. If there are specification changes in any nature, the certification will no longer apply.
In addition to specification changes, certification will also become invalid if the manufacturing origin is changed, or there is a change in the resin for the bottle or closure or the USP glass type.