ISO 11607 Heat Seal Requirements for Sterile Packaging

ISO 11607-1 covers materials, sterile barrier systems and packaging systems for terminally sterilized medical devices. ISO 11607-2 covers the development and validation of the forming, sealing and assembly processes. Both parts are in their second edition, and ISO lists one amendment for each.

The two parts are written to work together. Part 1 states that a sterile barrier system or preformed sterile barrier system must also meet the requirements of Part 2. A pouch that passes every material test still needs a validated sealing process behind it.

Three defined terms come up again and again. A seal is the result of joining surfaces by fusion to form a microbial barrier. Seal strength is the mechanical capacity of the seal to withstand force, while seal integrity is the ability of the seal to minimize the ingress of microorganisms.

Keep the last two apart in your plans. A strong seal can still have a channel, and a seal with no channel can still be too weak for transport.

Clause 5.1.9 of Part 1 lists the requirements for sterile barrier systems and preformed sterile barrier systems. Four of them apply directly to heat seals.

• If the system is formed by sealing, the specified requirements for seal width and seal strength must be met.
• Peel-open characteristics must be continuous and homogeneous, without delamination or tearing that can affect aseptic opening.
• Once formed, the system must provide seal integrity or closure integrity until it is opened at the point of use.
• Opening a seal should be irreversible, or it must be clearly evident that the seal has been opened.

The material side carries its own sealing duties. Clause 5.1.6 asks for an evaluation of material compatibility with the forming, sealing and assembly processes. For adhesive-coated materials, clause 5.1.8 adds a continuous coating pattern and a minimum specified seal strength against a specified mating material.

Questions about a model or a test? Email Amy Zhao, Export Manager, at [email protected].

Clause 5 of Part 2 covers the validation in subclauses on installation, operational and performance qualification, followed by subclauses on formal approval, process control and monitoring, and process changes and revalidation.

The definitions show what each stage must prove. IQ gives objective evidence that the equipment and its installation comply with the approved specification. OQ shows that the installed equipment operates within predetermined limits when run to its procedures. PQ shows that the process, under anticipated conditions, consistently produces product that meets all predetermined requirements.

Everything rests on a process specification. Part 2 defines it as the documented procedure covering all equipment, process parameters, monitors and materials needed to make conforming product. For a heat sealer, the process variables are the ones the standard gives as examples, such as time, temperature and pressure.

Part 1 does not tie you to one test. It asks you to record a rationale for the tests you select and for the acceptance criteria you apply. The table below compares three ASTM methods that cover the strength and integrity of sealed pouches.

ASTM F88 itself describes seal strength as a quantitative measure for process validation, capability and control. Our ASTM F88/F88M-23 standard overview covers specimen width, pull rate and report items for that test.

Publishing a method does not make it valid in your laboratory. Part 1 requires every test method used for conformity to be validated by the lab that runs it. That validation covers repeatability, reproducibility and, for integrity tests, the sensitivity of the method.

Part 2 gives process development its own informative annex. This is the stage where a sealing window is first explored, usually before qualification runs on the production sealer.

A laboratory heat sealer helps at this stage, with one caution. ASTM F2029 notes that a lab sealer can differ from manufacturing equipment in scale, sealing area and speed. Its heat seal curve is a starting point for production settings, not a replacement for validation on the real line.

Our STH-5 gradient heat seal tester has five 40 × 10 mm jaws, each set to its own temperature up to 250 °C. It prepares seal specimens across a temperature range in one run, and the strength is then measured on a tensile tester to ASTM F88.

We sell direct from our factory, so you work directly with our factory team. Questions about a model or a test? Email Amy Zhao, Export Manager, at [email protected].