Pressure Decay

Test Principle

Pressure decay leak detection is a deterministic, non-destructive container closure integrity testing method that evaluates package integrity by monitoring changes in internal pressure over time. The package is pressurised with compressed air or gas, then isolated and the pressure loss is measured by calibrated sensors over a set period. If gas escapes through a defect, internal pressure decreases at a rate proportional to leak size; a measurable drop in pressure indicates the presence of a leak. The method is commonly applied to rigid and semi-rigid pharmaceutical packaging, including bottles, cartridges and certain device housings.

Test Equipment in Our Lab

Zholion MC-DUO

Regulatory Requirements

USP<1207>

Pressure decay is listed as a deterministic leak test method.

USP <1207> states a preference for deterministic tests on the basis that they are non-invasive, produce repeatable and predictable results, and are suited to 100% testing.

Method validation is required to demonstrate detection capability at the product-specific Maximum Allowable Leakage Limit (MALL)

USP 382

Points directly to USP <1207> for container closure integrity testing methodologies.

System-level integrity assessment using deterministic CCIT methods – including pressure decay – is required by 1 December 2025.

ASTM F2095

The test method cover the measurement of leaks in nonporous film, foil, or laminate flexible pouches and foil-sealed trays.

These test methods will detect leaks at a rate of 1 × 10⁻⁴ sccs (standard cubic centimetres per second) or greater, in flexible packages.

The pressure decay method of leak testing is a physical measure of package integrity.

When testing medical packaging which must conform to ISO 11607-1:2006 standards, it may be necessary to verify the results of the pressure decay test method with other sterile package integrity test methods.

Test Method A covers pressure decay leak test for flexible packages without restraining plates; Test Method B covers pressure decay leak test for flexible packages with restraining plates.

EU GMP Annex 1

Container closure integrity validation is mandatory for all sterile products.

Deterministic methods such as vacuum decay and pressure decay are recognised as compliant with Annex 1 integrity requirements

Chemical Injectable Packaging System Integrity Study Technical Guideline (China)

This guideline covers the entire lifecycle of CCIT for chemical injectables, referencing both domestic and international technical guidance and standards. It addresses method selection, validation, stability testing requirements, and commercial production inspection.

Deterministic leak test methods (including pressure decay and vacuum decay) are cited as acceptable for CCIT validation.

The guideline states that deterministic methods capable of detecting the product-specific Maximum Allowable Leakage Limit (MALL) are preferred. If the sensitivity of a deterministic method cannot reach the MALL level, or the MALL is not clearly defined, at least two methods (one of which should be a microbial challenge) are recommended.