18/8 Stainless Steel: What Is It and Why Does It Matter for Your Flask?

Introduction

If you’ve browsed our website or held a Lizzard Flask in your hands, you’ve likely seen the term 18/8 Food Grade Stainless Steel. If you’re like most people, you probably thought: "What on earth is that, and why should I care?"

I had that exact thought when I first started working with these designs in 2017. Back then, I didn’t have a summary to turn to—so I did the digging for you. Here is the research that actually matters for your daily coffee, water, and smoothies.

1. Truly Food Safe (Grade 304)

18/8 stainless steel is also known as Grade 304. It is the highest standard for kitchenware and medical tools because it is non-reactive. Whether you’re filling your flask with acidic orange juice or hot morning coffee, the steel won't react with your drink. This ensures your beverage is safe for consumption and free from chemical interference.

2. Built for Durability: The 18% and the 8%

The numbers 18/8 represent the composition of the steel: 18% Chromium and 8% Nickel.

Chromium binds to the surface to protect against oxidation (rust).

Nickel adds a layer of corrosion resistance and high-temperature durability.

This means your flask can handle the "thermal shock" of switching from an icy breakfast smoothie to a steaming hot tea without warping or degrading the metal.

3. The "Self-Healing" Surface

One of the coolest things about 18/8 steel is its ability to regenerate. Stainless steel has a microscopic film that repairs itself when exposed to oxygen. This smooth, non-porous surface means bacteria have nowhere to hide. It makes cleaning effortless and ensures your flask stays hygienic with minimal scrubbing.

4. Flavour Integrity (No Ghosting)

Have you ever had a plastic bottle that tasted like the juice you finished three days ago? That’s called "flavor ghosting." Because 18/8 stainless steel is so stable, it doesn't absorb odors or flavors. You can switch from a cocktail to a coffee, and provided you give it a quick rinse, the flavors won't transfer.

5. Minimal Leaching

All containers—whether plastic, glass, or metal—interact with their contents on a molecular level. However, because Grade 304 steel is so stable, any "leaching" is miniscule and safe. Unlike low-grade plastics that can release harmful BPA, 18/8 steel is a safe, inert material that protects your health over years of use.

The Conclusion

Simply put, we chose 18/8 stainless steel for Lizzard Flasks because we believe in quality that lasts a lifetime. It’s an investment in your health, your taste buds, and the planet.

References

Steelmor (2024). Stainless Steel – What Do All The Numbers Mean?

Naoum, K. and Lichtig, A. (2024). The Differences Between 18/8, 304, and 316 Stainless Steels.

Gopal, R. (2024). 18/8 Stainless Steel. Corrosionpedia.

Life Without Plastic (2024). Stainless Steel Purity Standards.