9 Facts About “Airtight” Cannabis Packaging You Need To Know

March 16, 2021

You’ve crafted an awesome product. Now you need ‘airtight’ cannabis packaging to deliver it to your customer in the freshest condition possible. (And it needs to be child-resistant too!)

But not all ‘airtight’ packaging is the same. And when your products sit on a retailer’s shelf for a few weeks, your customers may be disappointed with the contents.

This post answers common questions people have about ‘airtight’ packaging — and it answers some questions people should be asking as well.

Why is ‘Airtightness’ so Important for Pharmaceuticals & Cannabis?

When pharmaceutical manufacturers select a package for their new products, they’re focused on more than aesthetics. Above all, they need to protect their product and determine its shelf life.

Humidity degrades most medications, and manufacturers need to accurately label the medication with an expiration date based on real-world humidity conditions in real-world packaging. And that means they need to test their product with a container that provides a verified protection from vapor transmission.

The ‘airtightness’ rating of a package is the starting point for figuring out the shelf life as it will occur in the real world. With a quantified level of ‘airtightness,’ manufacturers can predict how their product will lose potency over time. Only then can they accurately set an expiration date that will hold up to FDA standards for accurate labeling.

Is ‘Airtightness’ Even a Term?

Not really. The word ‘airtight’ perfectly describes the concept of humidity protection for people who aren’t package engineers. That’s why we use ‘airtight’ in our advertisements at AssurPack®. But package engineers and the United States Pharmacopeia (USP) have more specific terms. The USP, which is a nonprofit organization that set standards for medicines, describes containers as “tight” or “well-closed” based on the results of specific tests described in USP 671.

The “tight” rating is reserved for containers with the best protection against vapor transmission. A “tight” rating means that a package resists vapor transmission for months or years, depending on the ambient conditions.

Containers rated “well-closed” are appropriate for less sensitive products. Containers that don’t meet the testing standards are used for applications that don’t require as much humidity protection.

Does a USP Rating Matter for Cannabis Packaging?

Yes. A good USP 671 rating extends shelf life, which affects quality, which in turn affects consumers — and your business. Accurately labeling a product’s shelf life means you’re keeping your promises.

In the coming era of federal legalization, accurate shelf-life labeling will be non-negotiable. When cannabis is legalized, expect mandatory standards similar to foods, medicines, and alcohol. Nancy Warner, AssurPack’s CEO, is helping set those standards. Nancy is proud to sit on the Cannabis Committee of the American Society for Testing Materials (ASTM). As an independent entity, ASTM is working hard to set standards for safe access.

How Can You Prove that a Package is ‘Airtight’?

You may see videos showing a cannabis package’s ‘airtightness’ online. In some of those videos, the lid of the package seals in a piece of smoking dry ice. It’s a compelling demonstration — the lid visibly stops the dry ice vapor from escaping.

In reality, we can’t see most gaseous vapor so it’s impossible to tell if the container in the video prevents vapor transmission. And if the container was truly tightly sealed, the vapor pressure from the melting dry ice would cause the lid to pop open after a few minutes.

Sadly, many cannabis packages protect products for a matter of days, not months. Lab tests of a popular cannabis container scored a 12-day protection rating. For high-terpene flower, that’s unacceptable.

To truly know the ‘airtightness’ of your package, you’ll want to look beyond the marketing messages that claim the package is ‘airtight.’ Ask to see the lab results instead! How Do USP Laboratories Test for ‘Airtightness’?

USP-accredited laboratories use several test methods depending on the product type (e.g., liquid, injectable, tablet). Most cannabis products require a multiple-use container for solid oral dosage forms. That’s usually a plastic jar, box, or bottle.

We worked with a third-party laboratory to certify the ‘airtightness’ of our long-anticipated AssurSeal®. The AssurSeal® is a child-resistant flip-top box available in two formats: a D-shaped package designed for edibles and the rectangular M-line, which resembles a classic pack of smokes.

Here’s how the USP 671 testing process went for the AssurSeal®:

We submitted 12 AssurSeal® D-Line packages and 12 AssurSeal® M-line packages to a validated laboratory in New Jersey.

The lab technicians opened and closed each package 30 times to simulate real usage (as per the USP 671 Method 4 requirements).

Then, they placed a precise amount of desiccant in each AssurSeal® container. A desiccant is a material that readily absorbs moisture, such as the silica gel canister found in vitamins. The containers were placed in a controlled environment at 23 ℃ and 75% relative humidity for 14 days.

After 14 days, they weighed the desiccant to see how much water it absorbed. To score the highest rating of ‘tight,’ each container could not absorb more than 200mg/day/liter of desiccant. How Did AssurSeal® Perform?

The desiccant in every AssurSeal® stayed well below the 200mg threshold, easily scoring a ‘tight’ rating. In fact, none of the containers exceeded 36mg (for the D-shaped variant) or 46mg (for the M-Line variant).

That means both containers create an incredibly tight seal — a seal that our designers are proud of! The design of the lid and opening of the container opening is the key to AssurSeal®‘s performance.

Moreover, AssurSeal® is as easy to open as it is ‘airtight’ and child-resistant. Physically compromised patients report being able to open the AssurSeal® D-Line container with only one hand. What About Humidity Packets?

With AssurSeal®, you don’t need humidity packs for your flower. But testing by a leading humidity pack manufacturer showed some incredible results.

According to the tests by the manufacturer, the AssurSeal® can extend the life of their 62% 4-gram pack up to 36 months. That means — even after three years — the humidity inside the AssurSeal® is a perfect 62%.

What Else Affects ‘Airtightness’?

When consumers open and close your package, it upsets the balance of humidity. And multiple openings and closing can affect the seal performance.

We produced multiple iterations of the AssurSeal® throughout our R & D process, constantly refining the lid and opening shape. When one element of a design changes, others do too, and the result can be a package that doesn’t hold up to multiple openings.

Once again, laboratory test results are the only evidence that you have a package that can reliably withstand the life of the product. Make sure to request lab results when choosing a design for preroll multipacks and multi-serving edibles.

Is an ‘Airtight’ Package Right for My Product?

Many cannabis products can benefit from an ‘airtight’ package — not just flower. An extended shelf life is critical for premium edibles and quality control. Ready to see the AssurSeal® for yourself? Reach out to your AssurPack® representative today to find the AssurSeal® variant that’s right for you.

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