an eye on compliance

Visual Inspection Reference for Medical Device Pouches

understanding visual inspection

What Defines
a Good Seal?

A proper medical pouch seal shows a clean, continuous, uniform appearance across the full seal area. It should be free of wrinkles or folds that could create channels for microbial ingress. The seal must display consistent color and opacity, clear evidence that temperature, pressure, and dwell time were evenly applied. See visual failure mode reference below.

Visual inspection reference

Spot Common Seal Defects

Review the various seal failure modes on this page to better understand visual seal value. Just remember to read the visual seal inspection limitations and disclaimer before using this guide.

Normal Seal

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Seal Channel

A thin unsealed pathway across the width of the seal that may reach from the sterile to the non-sterile side of the pouch seal. The channel may appear within the seal in a variety of forms often presenting as a straight or curved thin line.

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unsealed area

A localized portion of the intended pouch seal where the two packaging materials have not formed a complete, continuous bond. The affected area may appear lighter, clearer, or otherwise different from the surrounding properly sealed region.

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seal close to edge

Is a visual condition seen as little remaining pouch material between the outer boundary of the seal and the cut edge of the package. This condition should be evaluated against the established pouch design and validated sealing process.

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over sealed

An over sealed pouch may show a rough, distorted, bubbled, or cloudy seal surface that differs from a validated seal. Watch for excess roughness, bubbling, cloudiness, unusual translucency, distortion, curling, or any seal that looks abnormal.

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narrow seal

A narrow seal occurs when the bonded width is visibly less than the validated minimum. Inspect the full perimeter of the seal for reduced width, uneven boundaries, or abnormal seal patterns. A narrow seal alone doesn’t confirm an integrity breach.

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under sealed

An under sealed pouch shows weak, incomplete, or uneven bonding. It may look lighter, mottled, or spotty and may peel with less resistance. Compare the full seal to a reference and watch for inconsistent pathways that suggest a process shift.

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fold-over or pleat

A fold over or pleat occurs when pouch material folds or gathers in the seal area, creating extra layers. It may appear as a diagonal fold, ridge, or overlap. The concern is whether it interrupts the seal and forms a channel across the width.

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severe wrinkles

Severe wrinkles are deep creases or distortions that enter the seal area and disrupt uniform bonding. Look for wrinkles that cross the seal, create irregular boundaries, gaps, or channels, or noticeably distort the validated seal pattern.

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foreign material

Foreign material appears as a speck, fiber, residue, or other visible debris trapped in the seal area. It may require proper lighting or magnification to see. The key concern is whether it disrupts bonding or creates a pathway through the seal.

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impression without bond

An impression without bond occurs when the sealer leaves a smooth, seal shaped mark but the materials never bonded. The seal shows an impression without the usual discoloration, and the expected bonding is absent or greatly reduced.

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device too close to the seal

A device too close to the seal occurs when contents sit within or near the seal area. Look for reduced clearance, pressure marks, narrowing, wrinkles, or folds. Rigid or heavy items can stress the seal and cause deformation or damage.

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More Testing and
Inspection support

More testing tools from our ISO 17025 lab to support your sterile barrier system. Have unique challenges? Contact engineering and let us help ensure the safe, sterile delivery of your medical device.

bulk premixed dye

ASTM test ready
Premixed dye solutions

Avoid messy mixing and inconsistent results. Our ASTM F1929/F3039 test-ready bulk dye ink comes premixed in 8oz, 16oz, and 32oz bottles, ideal for high-throughput workflows requiring multiple dye penetration tests throughout the day. Add dye testing to your sterile barrier quality plan.

dye penetration testing

ASTM dye penetration
Seal testing

We use multiple methods in our ISO 17025 laboratory to evaluate the sterile barrier system, performing both destructive and nondestructive testing under exacting ASTM standards to support medical device manufacturers.

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Ink test pods

Whole Pouch Dye
Testing solutions

The Ink‑Test MAX makes dye testing fast and simple. Insert a disposable cartridge into the pouch, seal it, and fold down the lid. Our third‑party‑validated 4 ml dye spreads across all four seams, enabling complete integrity testing in one step. Compatible with ASTM F1929 and F3039.

sleek wipe down design

Why risk a medical
packaging recall?

Watch our short video to see the PTT-100 in action. This powerful seal strength and seal integrity system was developed in our ISO 17025 laboratory to quickly and accurately perform tests in our busy and precise workflow.

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fast and accurate testing

SPC-2 specimen
cutting scissors

The same tool we use in our own accredited laboratory for thousands of tests each year. The SPC 2 delivers speed, safety, and accuracy for ASTM F 88 testing. Precise specimens cutting available in 15mm or 25mm with ±0.2 mm tolerance, and its solid construction ensures long-term consistency.

ISO 17025 accredited

Sterile Start ®
Validation Support

More than sealers; we support the sterile delivery of a medical devices. Our three‑tier support structure is designed to meet medical device manufacturers exactly where they are in their packaging validation journey, from basic equipment readiness to full process qualification.

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an eye on compliance

Visual Inspection Reference for Medical Device Pouches

understanding visual inspection

What Defines
a Good Seal?

Visual inspection reference