Packaging Requirements for Light-Sensitive Vitamin B12: Dark Airless Bottle vs. Opaque Container

The product information for Vitamin B12 (Cyanocobalamin 1%) explicitly states that it is highly sensitive to light and must be packaged in a 100% opaque container to prevent rapid deterioration.

While an airless bottle is excellent for minimizing air exposure, the term "dark" does not guarantee it is "100% opaque."

• Opaque vs. Dark: A dark-colored bottle (e.g., dark brown or dark blue) typically blocks most light, but some light, especially in the UV and visible spectrum, can still pass through. Even a small amount of light penetration is enough to degrade Vitamin B12 quickly.
• Recommendation: You must ensure the container is truly light-blocking. If the dark airless bottle is made of a material that is completely solid and no light can pass through when held up to a strong light source, then it would be acceptable.

For maximum stability and to meet the 100% opaque requirement, it is safer to use materials that are inherently light-blocking, such as:

• Aluminum tubes (as suggested in the product description).
• Solid, thick, white or black plastic containers.
• Containers with an inner metallic lining.

If you choose a dark airless bottle, we strongly recommend testing it to confirm that absolutely no light passes through the container wall.