Chip Can MVTR Requirements: Why Moisture Barrier Matters More Than You Think

The spec sheet gets ignored until it causes a problem. In chip cans, that problem usually shows up at the approval sample stage—or after production—when a dimension is off or a material grade doesn't match the brief. ThisPrivate Label Chip Can Supplier Checklistcovers the technical numbers that matter most, with the context to understand why.

What Is MVTR and Why Chip Can Manufacturers Track It

MVTR stands for Moisture Vapor Transmission Rate and it is, quite simply, the single most important metric for any chip can packaging. It measures how much moisture passes through the can wall over a 24-hour period, expressed in grams per square meter per day (g/m²/24h). A chip can with a high MVTR rating allows moisture to reach the product inside, turning crispy snacks stale, degrading nut oils, and ruining the texture of baked goods.

The industry standard for snack packaging is an MVTR of less than 5 g/m²/24h. Premium chip cans targeting long shelf life (12+ months) or humid markets (Southeast Asia, Middle East, coastal US) should target under 2 g/m²/24h. Anything above 8 g/m²/24h and you risk noticeable quality degradation within 90 days of production.

How MVTR is Measured

The standard test method is ASTM F1249 or ISO 15106-3. A sample of the can wall material is sealed into a test cell with a dry chamber on one side and a humid chamber (typically 90% RH) on the other. Over 24 hours, the instrument measures how much moisture crosses through the material. The result is reported in g/m²/24h.

The actual MVTR of a finished chip can is affected by three factors:

Inner Liner Options Compared

The inner liner is where MVTR performance is won or lost. Here is how the common options stack up:

For most chip can applications, PE-coated Kraft at 5–10 g/m²/24h provides adequate barrier performance at a reasonable cost. Brands targeting premium positioning or export markets should specify aluminum foil laminate for the sub-2 g/m²/24h performance.

The Cap Is the Weak Link

Even the best inner liner is useless if the cap leaks. The cap-to-can interface is responsible for approximately 20–30% of total moisture ingress in chip cans. There are three cap types ranked by MVTR performance:

• Snap-fit plastic cap (standard): Adequate for domestic distribution. MVTR contribution: 3–5 g/m²/24h equivalent.
• Snap-fit with foam gasket seal: Better option. The foam compresses against the can rim, creating a partial barrier. MVTR contribution: 1–3 g/m²/24h equivalent.
• Screw cap with rubber O-ring: Best commercial option. The O-ring creates a compression seal that performs consistently across temperature and humidity ranges. MVTR contribution: 0.5–1.5 g/m²/24h equivalent.

For chip cans destined for humid markets or requiring 9+ month shelf life, specify screw cap with O-ring. The additional cost is approximately $0.02–0.04 per unit versus a standard snap-fit cap.

Industry MVTR Benchmarks by Snack Type

The Cost of Ignoring MVTR

A snack brand that ships chip cans without verified MVTR performance exposes itself to three types of loss: product returns from retailers who receive stale inventory (return rates of 3–8% in humid markets), brand reputation damage when consumers post negative reviews about stale chips, and shorter effective shelf life that forces quicker inventory turns and higher write-off rates.

The cost to upgrade from a standard PE-coated liner to an aluminum foil liner is approximately $0.03–0.06 per unit. For a brand selling 100,000 units per year, that is $3,000–6,000 in additional packaging cost. Compare that to potential losses of $15,000–40,000 from a single product quality complaint in a major retail chain, and the upgrade pays for itself many times over.