Testing standard
Packaging for terminally sterilized medical devices — Part 1: Requirements for materials, sterile barrier systems and packaging systems
Written and technically reviewed by Dak System Inc. engineeringLast reviewed
ISO 11607-1 is a requirements standard for packaging that keeps a terminally sterilised medical device sterile until use. It is not itself a test method. The mechanical requirement that reaches a testing machine is seal strength — the capacity of the seal to withstand force — normally demonstrated by a peel test. The current edition is ISO 11607-1:2019.
ISO 11607-1 is not itself a test method — it is a requirements standard, and that distinction is the most useful thing to know about it. It specifies what a sterile barrier system must achieve and points to test methods that demonstrate it.
The mechanical requirement that reaches a testing machine is seal strength. Where a sterile barrier system is formed by sealing, the standard requires that specified requirements for seal width and seal strength are met, seal strength being the mechanical capacity of the seal to withstand force. In practice that is demonstrated by a peel test on the two bonded materials, measuring the force required to separate them — which is also the force a nurse feels when opening the pack.
A sterile barrier system has two jobs that pull against each other. It must maintain sterility until the point of use, which argues for the strongest possible seal, and it must open cleanly at the bedside without shedding fibres or tearing the web, which argues for the weakest seal that will hold. Seal strength is where those two requirements are reconciled, and both an upper and a lower limit are normally specified.
Failure mode matters as much as the force. An adhesive peel, where the two webs separate cleanly at the interface, is what a peelable pouch should do. Delamination of the paper, or fibre tear, means the seal is stronger than the substrate — the pack will open by ripping rather than peeling, and it may shed particles into a sterile field.
The regulatory weight behind this is considerable. ISO 11607 is the primary reference for medical packaging validation and is required for both FDA submissions and CE marking, so a seal strength result is part of a regulatory file rather than a production statistic.
A pouch seal is made by different parts of the sealing tooling on each edge. Which edge the specimen came from is part of the result.
Average peel force divided by specimen width
Reported per unit width so specimens of different widths compare.
Sterility argues for a strong seal; clean opening argues for a weak one
The pack has to hold until use and then open at the bedside without shedding fibres. Both limits are normally specified.
Adhesive peel, or fibre tear and delamination
A pack that tears rather than peels can shed particles into a sterile field. Force without failure mode is half a result.
Light jaws with a soft or rubber-coated face, holding a thin film and a coated paper without cutting either. Jaw alignment matters: a peel that starts crookedly never straightens, and the trace shows it as a slow rise rather than a fault.
SpecificationsSeal peel forces are typically a few newtons and sometimes under one. A cell sized in newtons rather than kilonewtons is what makes the difference between a readable trace and a flat line — this is a resolution problem, not a capacity one.
SpecificationsPeel forces are very low: typically a few newtons, sometimes under one. This is the least demanding test in the batch in terms of force and among the most demanding in terms of resolution, so a low-capacity frame with a load cell sized in newtons rather than kilonewtons is essential. Force accuracy to ISO 7500-1 Class 1 over that working range is the requirement.
Grips must hold a thin film and a coated paper without cutting either. Light-duty pneumatic jaws with a soft or rubber-coated face are the usual answer, and jaw alignment matters because a peel that starts crookedly never straightens.
The result is taken from an average force over a length of peel rather than from a peak, so continuous logging over the whole separation and enough crosshead travel to complete it are both required.
Reporting a peak instead of an average is the commonest analysis error and it overstates the seal. Specimens taken from one edge of the pouch miss the weak edge. A load cell sized for the frame rather than the seal turns a two-newton trace into noise. And reporting a force without the failure mode leaves out the half of the result that says whether the pack will peel or tear.
Seal strength is one of four questions asked of a sterile barrier system, and it is the only one that needs a tensile frame.
| Seal strength (ASTM F88) | Burst (ASTM F1140) | Dye penetration (ASTM F1929) | Bubble leak (ASTM F2096) | |
|---|---|---|---|---|
| Tests | A strip of seal | The whole pack | The seal for channels | The whole pack for leaks |
| Equipment | A tensile frame | A pressurising rig | Dye and a light box | A vacuum tank |
| Result | A force per unit width | A burst pressure | Pass or fail | Pass or fail |
| Finds | Weak or over-strong seals | The weakest point of the whole pack | Channel defects in the seal | Pinholes anywhere |
A strip test can pass while the pack fails, because a strip does not sample the corners where sealing tooling is least consistent. Burst and leak testing challenge the whole system and are not optional extras alongside seal strength.
ISO 11607-1 specifies requirements and test methods for materials, preformed sterile barrier systems, sterile barrier systems and packaging systems intended to keep terminally sterilised medical devices sterile until the point of use. The current edition is ISO 11607-1:2019, the second edition, adopted in the United States as ANSI/AAMI/ISO 11607-1:2019 and amended in 2023. Part 2 covers validation of the forming, sealing and assembly processes.
No, and this is the most useful thing to know about it. It is a requirements standard: it says what a sterile barrier system must achieve and points to test methods that demonstrate it. Where the system is formed by sealing, it requires that specified requirements for seal width and seal strength are met, and seal strength is then measured by a referenced method — ASTM F88/F88M in most laboratories.
Because the pack has two jobs that conflict. It must maintain sterility until use, which argues for the strongest seal possible, and it must open cleanly at the bedside without tearing the web or shedding fibres into a sterile field, which argues for the weakest seal that will hold. Seal strength is where those two are reconciled, so a specification normally sets both limits and a value above the upper one is a failure just as a value below the lower one is.
Because it tells you how the pack will open. An adhesive peel, where the two webs separate cleanly at the interface, is what a peelable pouch is designed to do. Delamination of the paper or fibre tear means the seal is stronger than the substrate: the pack opens by ripping rather than peeling and can shed particles at exactly the wrong moment. Two packs with the same peel force and different failure modes are not equivalent.
From every edge of the seal. A pouch seal is formed by different parts of the sealing tooling on each side, and consistency between them is one of the things being validated. Cutting all the specimens from one convenient edge produces a tight, reassuring set of numbers about that edge, and the pack will fail at whichever edge nobody sampled.
Because the shelf-life claim is. A sterile barrier system is labelled with an expiry date, and the evidence for that date has to include seal strength after real-time or accelerated ageing and after whatever sterilisation process the product goes through. Ethylene oxide, gamma and steam all change the materials to different degrees. The as-made figure says only that the pack was sealed correctly today.
A small frame with a load cell sized in newtons. Seal peel forces are typically a few newtons and can be under one, so force accuracy to ISO 7500-1 Class 1 over that low range is the requirement and capacity is irrelevant. Grips must hold a thin film and a coated paper without cutting either, and the result is taken as an average over the peel length, so continuous logging and enough travel to complete the peel in one pass are both needed.
Dak verifies against whichever standard the method names, and where a class applies our frames sit a class tighter than it asks.
| The method asks for | Dak supplies | |
|---|---|---|
| Capacity | Very low — typically a few newtons and sometimes under one | Load cells from 1 kg to 60 ton on the Series 7200, and 0.5 to 100 kN on the Series 9000 |
| Force accuracy | ISO 7500-1 Class 1 over the working range | ISO 7500-1 Class 0.5 — a class tighter than the method asks |
| Gripping | Light pneumatic jaws with a soft face, holding a thin film and a coated paper without cutting either | Our peel and adhesion fixtures, built to the specimen |
| Environment | Specimens after the sterilisation process the product will see, and after accelerated or real-time ageing | 3009 series chambers, −150 °C to +400 °C — temperature only |
This page describes the method as practised. The governing text is the current edition from the issuing body. Tell us what you are testing and we will answer with the machine, the fixture and a quotation.
