The Invisible Shield: How EVOH Barriers Protect Active Ingredients

Introduction

You spent months perfecting your formula. You used 15% Pure Vitamin C and top-grade Retinol.

But 3 months after launch, customers are complaining: "The cream turned brown" or "It smells weird."

The culprit isn't your formula. It's your tube.

Standard plastic (PE/PP) is porous. To oxygen molecules, a standard tube wall looks like a fishing net—they swim right through.

Enter EVOH (Ethylene Vinyl Alcohol).

It is the "Invisible Shield" that separates professional skincare packaging from generic supermarket bottles. Here is how it works.

1. The Science: Cotton Shirt vs. Raincoat

To understand EVOH, you need to understand Gas Permeability.

• Standard PE (Polyethylene): Think of it like a Cotton T-Shirt. It covers your body, but wind and water go right through it. Oxygen enters, and volatile scents (like essential oils) escape.

• EVOH Resin: Think of it like a Rubber Raincoat. It is a high-density barrier resin. It blocks 99% of oxygen, nitrogen, and carbon dioxide from passing through.

The "Sandwich" Structure (5-Layer Co-ex):

We don't make the whole tube out of EVOH (it’s too brittle and expensive). Instead, we hide it in the middle:

1. PE (Outer Skin) – For printability and touch.

2. Adhesive – The glue.

3. EVOH (The Shield) – The micron-thin barrier layer.

4. Adhesive – The glue.

5. PE (Inner Contact) – For safety.

2. Why Your Formula Needs It (The "Big 3" Risks)

If you are selling a basic hand lotion, you don't need EVOH.

But if you are selling "Performance Skincare," EVOH is mandatory to prevent these three disasters:

• Oxidation (The "Browning" Effect):

  Ingredients like Vitamin C, Retinol, and Peptides are highly sensitive to oxygen. Without an EVOH barrier, they oxidize rapidly, turning your white cream brown and rendering the active ingredients useless.

• Scent Loss (The "Flavor Scalping"):

  Volatile organic compounds (VOCs) in natural essential oils (Citrus, Lavender, Tea Tree) can migrate through standard plastic. After 6 months on the shelf, your product will lose its top notes.

• Component Attack (The "Swell"):

  Some chemical sunscreens (SPF) and aggressive oils can attack standard PE, causing the tube to swell, warp, or become sticky. EVOH acts as a chemical resistor.

3. EVOH vs. Aluminum (Why EVOH Wins)

"Wait," you ask, "Doesn't Aluminum foil (ABL) block oxygen too?"

Yes, it does. In fact, Aluminum is the perfect barrier.

But EVOH is the Modern barrier.

The Verdict: Unless you are making medical ointment, EVOH offers the best balance of protection, aesthetics, and sustainability.

Conclusion: Cheap Insurance

Switching from a standard 2-layer tube to a 5-layer EVOH tube adds about 10-15% to the packaging cost.

But compare that to the cost of a product recall because your formula turned rancid.

EVOH is the cheapest insurance policy you can buy for your brand.

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