GB/T 15171-2025 and ASTM D3078: Vacuum Leak Testing of Flexible Packages

A common way to check the seal of a non-porous flexible package, such as an aluminium foil pouch or an all-plastic bag, is to hold it under water, draw a vacuum on the chamber and watch for bubbles. The Chinese national method standard for this test has been revised: GB/T 15171-2025, Test method for sealing performance of package, took effect on 1 February 2026 and fully replaces GB/T 15171-1994, Test method for leaks in sealed flexible packages. This article covers what changed, how the test parameters are approached, what counts as a leak, how the method relates to ASTM D3078, and which accreditation mark a SUNGO report can carry. It deals with this one method standard, not overall packaging validation strategy.

Key points

• The new title drops the word "flexible". GB/T 15171-2025 is a recommended national standard, published on 1 August 2025 and effective on 1 February 2026. It fully replaces GB/T 15171-1994, which was withdrawn the same day.
• Two methods instead of one. According to a published explanation by Jinan Labthink Electromechanical Technology Co., Ltd., one of the drafting organisations, the 2025 edition keeps only Method 1 of the 1994 edition, renamed the "underwater bubble method", and adds a "vacuum decay method". The scope widens to flexible, semi-rigid and rigid packages, excluding vacuum-packed items. The standard text prevails on technical details.
• The pass/fail call is about continuous bubbles. The same explanation gives the criterion for the underwater bubble method: if no continuous bubbles appear during evacuation or during the vacuum hold, and (where applicable) no water is found inside the package on opening, the specimen is judged leak-free; otherwise it is judged to leak.
• SUNGO accepts only non-porous packages with headspace gas under this method, such as foil pouches and all-plastic bags. Packages with a porous face, such as medical paper or nonwoven, are not accepted under this method.
• The report mark depends on the edition. The CNAS scope of Shanghai SUNGO Medical Technology Co., Ltd. lists the item 真空泄露 (vacuum leak) under GB/T 15171-2025 and ASTM D3078-02(2021)e1. Its CMA scope lists only GB/T 15171-1994. Its IAS scope lists GB/T 15171 and ASTM D3078 by standard number and title only, without a year. The CMA mark corresponds only to the 1994 edition, which was withdrawn on 1 February 2026; if you need a CMA report against that edition, check with the laboratory first. ASTM D3078 reports can carry CNAS accreditation, or IAS accreditation (confirm the edition with the laboratory before the report is issued).

The standards and their scope

The registration details below come from China's national standards information platform (std.samr.gov.cn) and the national standards full-text disclosure system (openstd.samr.gov.cn), checked on 22 October 2026.

GB/T 15171-2025, Test method for sealing performance of package

• Chinese title: 包装件密封性能试验方法.
• Recommended national standard, status "current"; published 1 August 2025, effective 1 February 2026.
• Issued by the State Administration for Market Regulation and the Standardization Administration of China; responsible committee: TC49, the national technical committee for packaging standardization (全国包装标准化技术委员会).
• Fully replaces GB/T 15171-1994.

The replaced GB/T 15171-1994, Test method for leaks in sealed flexible packages

• Chinese title: 软包装件密封性能试验方法.
• Published 16 August 1994 and effective 1 March 1995, issued by the then State Bureau of Technical Supervision; reviewed on 28 December 2023 with the conclusion "revise"; withdrawn on 1 February 2026.
• Its adoption record states that it is a non-equivalent adoption of ASTM D3078.

Which packages the method suits

According to the drafting organisation's explanation, the 2025 edition covers non-vacuum packages, whether flexible, semi-rigid or rigid, and does not apply to vacuum-packed items. The underwater bubble method is for packages whose outer material is not noticeably affected by the test water. For medical device packaging, this works out as follows.

• Suitable: non-porous flexible packages such as foil pouches and all-plastic bags that contain some headspace gas. The scope of ASTM D3078 likewise refers to flexible packaging containing a headspace gas.
• Not accepted under this method: vacuum packs, which the 2025 edition excludes (as above); and porous packages (one face of medical paper, nonwoven or another breathable material), under SUNGO's own acceptance policy: a porous material lets gas through, which makes bubbles hard to interpret. A January 2006 article in the trade journal MD&DI also describes finding leaks in a package designed to breathe as a difficult job, and notes that when a flexible sterile barrier system containing porous material is bent or creased, the porous sheet can separate internally and cause false positives in bubble-leak and dye-penetration tests.
• Check first: rigid and semi-rigid packages fall within the 2025 scope, but please confirm with the laboratory whether they can be accepted under this item.

What changed from the 1994 edition

The title and replacement were checked on the national platform. The technical changes below come from the published explanation by Jinan Labthink, a drafting organisation, not from a page-by-page comparison of the two texts; rely on the standard text for protocols and test requests.

The underwater bubble method: procedure and criterion

Principle

Per the drafting organisation's explanation, the underwater bubble method places the specimen in a vacuum chamber containing test water and evacuates the chamber to create a pressure difference between the inside and outside of the specimen; gas escaping from the specimen and test water entering it are observed to judge the sealing performance. The ASTM D3078 abstract describes the apparatus as a transparent container able to withstand the pressure difference, fitted with a vacuum-tight cover that carries a vacuum gauge, a line from the vacuum source and an outlet to atmosphere. The immersion fluid must not degrade the package, and the specimen and fluid are brought to equilibrium with room temperature before testing.

Vacuum level and hold time

Two parameters drive the result: how far the chamber is evacuated, and how long that vacuum is held. Their values follow the standard text. Where the product technical requirements, the packaging validation protocol or a customer specification sets them, the agreed values apply and the report states the parameters actually used. This article gives no numbers. Three considerations matter when choosing them:

• Package strength. The settings should suit what the package itself can withstand; follow the standard text and the validation protocol.
• Effect of the contents. The scope of ASTM D3078 notes that the positive pressure inside the pouch after the vacuum is drawn may force the product to plug small leaks, and that viscoelastic effects of the product or entrapped air can also keep small leaks from showing.
• Detection capability. ASTM D3078 is a test for gross leaks; small leaks may not be detected, and the detectable leak size depends on the contents, the packaging material and the test parameters selected.

Fix vacuum level and hold time in the protocol before testing, and keep the same settings across batches and validation stages so that results stay comparable.

Immersion and the blank test

Per the drafting organisation's explanation, the 2025 edition holds the specimen under water with a perforated pressure plate on the lid, uses clean, transparent test water, and runs a blank test first (see the change table).

Criterion: continuous bubbles and checking for water

The criterion given in the drafting organisation's explanation: if the specimen shows no continuous bubbles during evacuation or during the vacuum hold, and (where applicable) no water has entered the package when it is opened, the specimen is leak-free; otherwise it leaks. Two details are worth noting:

• Both the evacuation phase and the hold phase count, not the hold phase alone.
• The water-ingress check applies "where applicable". Whether the contents can show water ingress, and whether the package should be opened, needs to be agreed in the protocol beforehand.

When a leak is found, record where the bubbles come from (seal, pouch body or a folded corner) to help the investigation; a leak at the seal may point to the heat-sealing parameters.

Number of specimens

The number of specimens follows the standard text, the product standard or the packaging validation protocol; this article gives no figure. State the rationale for the sample size in the protocol.

The new vacuum decay method

According to the drafting organisation's explanation, the vacuum decay method places the specimen in a test chamber, evacuates the chamber and monitors the change in chamber vacuum with a pressure sensor. The result is a vacuum decay rate: the difference between the chamber pressure at the start and the end of the test, divided by the test time, in pascals per second (Pa/s). It applies to non-vacuum packages of all kinds, flexible or rigid. Unlike the underwater bubble method it needs no immersion, and it produces a number rather than a visual judgement. Whether SUNGO can report under this method is covered in the FAQ below.

Comparison with ASTM D3078

ASTM D3078 is the Standard Test Method for Determination of Leaks in Flexible Packaging by Bubble Emission. It sits under ASTM Committee F02 and was developed by Subcommittee F02.40. As of 22 October 2026, the designation listed by ASTM is D3078-02(2021)e1: the standard was last revised in 2002, reapproved in 2021, and "e1" marks an editorial change. The US FDA Recognized Consensus Standards database lists this edition under recognition number 14-257, with the complete standard recognized, in the Sterility specialty task group. Recognition of the standard does not mean that any particular test report will be accepted.

The two share a principle but are separate documents, and a report cites only the standard actually followed. If one batch needs conclusions under both, list both in the test request.

Accreditation scope table

The rows below reproduce the relevant entries in the CNAS and CMA schedules and the IAS scope of Shanghai SUNGO Medical Technology Co., Ltd. In the CNAS and CMA schedules the test object is 医疗器械包装材料 (medical device packaging materials) and every limitation field is empty. The IAS scope lists only the standard number and English title, with no test object, item, clause or year. The title printed after GB/T 15171 is the 1994 title (Test method for leaks in sealed flexible packages).

Where the test is done and under which accreditation

The test is done at the laboratory of Shanghai SUNGO Medical Technology Co., Ltd., 958 Kangqiao East Road, Pudong, Shanghai, which issues the reports. The mark a report can carry depends on which schedule lists the item, and in which edition.

• CNAS laboratory accreditation, CNAS L22083. The schedule lists the 真空泄露 (vacuum leak) item under GB/T 15171-2025 and ASTM D3078-02(2021)e1, so reports under these can carry the CNAS accreditation mark. The CNAS certificate states that CNAS is a signatory to the ILAC and APAC mutual recognition arrangements.
• CMA qualification (inspection and testing body qualification), certificate 240015340087. The schedule lists the item under GB/T 15171-1994 only. The CMA mark can be used only for items in the schedule, and the certificate states that it is valid within the People's Republic of China. Tests to the 2025 edition or to ASTM D3078 cannot carry the CMA mark. The 1994 edition was withdrawn on 1 February 2026; if you need a CMA report against it, check with the laboratory first.
• IAS accreditation, TL-1019. The scope lists GB/T 15171 and ASTM D3078 by standard number and title only, without a year. Confirm the edition with the laboratory before an IAS report is issued against any edition.

Hefei SUNGO Medical Technology Co., Ltd., in Zipeng Town, Feixi County, Hefei, is a separate legal entity. Its accreditation and qualification scopes do not include this item, so package leak testing is not done in Hefei.

Whether an overseas customer or regulator accepts a given type of report is for that party to decide; please check before placing the order.

Preparing a submission

1. State the standard and edition. GB/T 15171-2025, GB/T 15171-1994 or ASTM D3078-02(2021)e1, together with the mark you need: CNAS, CMA or IAS. Edition and mark must match the table above.
2. Describe the package. Layer structure, whether any porous material is present, seal type and package size; whether the package contains headspace gas and whether it is vacuum-packed. Porous and vacuum packages are not accepted under this method.
3. Describe the contents. Actual product, a simulant, or an empty package. The package is submerged and may have to be opened to check for water, so please provide samples dedicated to the test.
4. Provide the basis for the test parameters. If the product technical requirements, validation protocol or customer specification sets the vacuum level, hold time or criterion, send the relevant text; otherwise the standard text applies.
5. State any preconditioning. If samples are to be tested after sterilization, accelerated aging or simulated transport, state each condition and label the samples accordingly. For aging and transport services, see Shelf Life Validation and Medical Device Simulated Transport Validation.
6. Confirm the number of samples. It follows the standard text, the product standard or the validation protocol; please confirm with us before the order is opened.
7. Check sample identification. Model, specification and lot number should match the registration file; label different lots separately.

FAQ

GB/T 15171-1994 has been withdrawn. Can a report still be issued against it?

The national platform lists the 1994 edition as withdrawn as of 1 February 2026. The Shanghai CMA schedule still lists the vacuum leak item under the 1994 edition; the CNAS schedule lists the 2025 edition. If you need a CMA report against the 1994 edition, check with the laboratory first. Which edition to use depends on the product technical requirements and applicable regulatory requirements; please state it in your order.

Can this method be used on medical paper or nonwoven pouches?

SUNGO does not accept porous packages under this method; see "Which packages the method suits" above. The Shanghai CNAS schedule separately lists a 染料渗透 (dye penetration) item under YY/T 0681.4-2021 and ASTM F1929-23, both of which are titled for seal leaks in porous packaging; please ask the laboratory to confirm whether they suit your package.

Can an ASTM D3078 report carry the CMA mark?

No. ASTM D3078 is not in the Shanghai CMA schedule. A report can carry CNAS accreditation (against D3078-02(2021)e1), or IAS accreditation (no year listed; confirm the edition with the laboratory before the report is issued).

Does "no continuous bubbles" mean the sterile barrier is intact?

It means no leak was detected under the conditions used. ASTM D3078 targets gross leaks, and small leaks may not be detected. Validation of a sterile barrier system normally combines several tests.

Can SUNGO report under the vacuum decay method of the 2025 edition?

The schedules give the item name as 真空泄露 (vacuum leak) without listing clauses. If you need a report under the vacuum decay method, say so in your enquiry and the laboratory will confirm whether it can be issued and which mark applies.

Enquiries

For vacuum leak testing to GB/T 15171-2025, GB/T 15171-1994 or ASTM D3078, start with the Sterile Medical Device Packaging Validation service page. For how packaging validation links to sterilization validation, see Sterile Barrier Systems: Packaging and Sterilization Validation. To request a quotation, use the contact page and include the package structure, contents, standard and edition, the report mark you need and any preconditioning. We will check each item against the CNAS, CMA and IAS scopes and reply.