Interpretation of ISO 14644 - 7 Series

Driving Compliance & Quality ①: The Truth Behind ISO 14644-7’s 500–1000 Pa Pressure Setting!

Note: The views expressed here are based on our own experimental data and technical experience. We welcome feedback and corrections.

Since the update of the EU GMP Annex on Sterility, Glove Integrity Test has become a mandatory requirement for compliance for sterile manufacturing enterprises. As a professional service provider specializing in glove integrity testing systems, we fully understand that industry partners are often troubled by various technical questions in practical operation. To address this, we are pleased to launch a series of articles interpreting the ISO 14644 - 7 standard. Divided into three installments, these articles will conduct an in-depth analysis of the core pain points in testing, helping you clarify technical logic and avoid cognitive misunderstandings.

ISO 14644-7 was published by the International Organization for Standardization (ISO) on October 1, 2004. It defines requirements for separative devices used in controlled environments, such as clean air hoods, glove boxes, isolators, and microenvironments. As of today, the 2004 version remains the latest official release.

This section outlines the equipment and procedures for positive pressure glove leak testing. Key points include:

•  Cover the glove port with a sealing cap and connect it to the air supply and a micro manometer.

•  Inflate the glove space to 500–1000 Pa and observe the pressure changes.

•  Minor fluctuations of ±3 Pa to ±4 Pa do not affect the test results.

•  Stable pressure indicates the glove is intact, while a continuous pressure drop suggests leakage.

For full details, refer to ISO 14644-7:2004, Annex E.5.3.

Myth Busting: Will High Pressure Damage Gloves? Data Speaks!

Take nitrile gloves like Ansell AlphaTec® 37-185 as an example: its tear strength exceeds 75N, and puncture strength is over 150N. To rupture this glove, a pressure of approximately 2500–4000 Pa is required. In contrast, 1000 Pa is equivalent to 7.5 mmHg—far below the failure threshold.

A common industry claim is that "500–1000 Pa is set to avoid glove damage from high pressure." However, material mechanics analysis and experimental verification prove this inaccurate.

The Real Reason: Upper Limit Determined by Sensor Accuracy

If high pressure doesn’t damage gloves, why not set a higher pressure to improve detection sensitivity? The core lies in the accuracy limitations of differential pressure sensors.

ISO 14644-7 requires stable pressure fluctuations within ±2 Pa to ±10 Pa during testing. Sensor accuracy (typically ±0.2%FSV to ±1%FSV) directly defines the achievable pressure range:

Based on metrology principles—sensor accuracy should be 1/3 to 1/4 of the target range—1000 Pa aligns with the upper limit of commercially available industrial sensors. This value is not arbitrary but an optimal balance between sensor performance, test sensitivity, and equipment cost.

Conclusion: 500–1000 Pa Is a Scientific Trade-off

The 500–1000 Pa inflation range in glove integrity testing is not driven by concerns over glove material strength, but by scientific considerations of differential pressure sensor accuracy and system verifiability. This range ensures both test safety and compliance with ISO 14644-7’s micro-pressure stability requirements, representing the optimal balance between regulatory compliance and practicality.

That’s all for the first installment of our ISO 14644-7 series! Having clarified the pressure setting puzzle, the next issue will focus on the industry’s most concerned question: According to ISO 14644-7, what is the minimum leak size detectable in glove integrity testing? Why can many companies not provide reliable leak size validation?

Follow us for more insights～ We look forward to exploring key technical points for aseptic manufacturing compliance with you next time!