One of the prominent benefits of using glass bottles over single-use bottle like a plastic bottle is you don’t have to worry that compounds of essential oils will get dissolve with plastic. But, glass has its own side effects too just like any other material would have.
We know that Ultraviolet rays (UV) are harmful to us. They can damage our skin and eye if exposed to UV rays for a long time.
Same is the case with essential oils. If they are exposed to UV rays for a longer period of time and not stored in darker or cooler place then eventually their quality degrades quickly.
Now, you may wonder what all of this has to do with colored or clear glass bottles and how does it affect the essential oils? Well, that’s what we are going to learn about in this article so that next time when you purchase any essential oil you will know what factors to consider before buying.
Effect of UV rays on Essential Oils
Light is categorized into two parts on the electromagnetic spectrum: Visible rays and Invisible Rays.
Visible rays are usually what human eye can see like red light, blue light, green light, etc. These rays are pretty much non-harmful for us or any food.
Our main concern here is UV rays that come under invisible category in the electromagnetic spectrum. UV rays are responsible for the oxidation of essential oils. Oxidation disintegrates the oil and brings down the therapeutic value of essential oils gradually.
Most of the essential oils are rich in vitamin A.
Also, terpenes found in essential oils helps one improve their focus ability, reduce inflammation and assists with sleeping. Oxidation in essential oils can affect all these properties.
This oxidation process in bottles is related to wavelengths of light. Wavelengths are usually measured in nanometers. Sun transmits these UV rays to earth of wavelengths ranging from 10 nm to 400 nm which are harmful to any food product like they are harmful to us.
You must have noticed glass bottles comes in various colors. But, did you ever know that the color of the bottle has a great impact on the product contained in it?
Yes, you heard that right. color bottles are not made for only decorations or for making them visually appealing. It has a lot to do with the product that’s going to be inside it.
Most essential oils are photochemically inactive in the visible region but they do have some reaction in the UV region of the electromagnetic spectrum. So, color does really matter here.
The most common colored bottles in which essential oils come are:
- Vintage green
- Cobalt blue
- Amber or brown
Different glass color has a different response to UV light. Some colors can absorb the UV light and some colors cannot absorb it.
So, which colored glass bottle is best for storing Essential oils?
- Amber glass: This is the best color option for storing essential oils. Amber glass offers a great protection against UV rays. It absorbs the rays of wavelengths up to 450 nm. As we know that wavelength of UV rays comes under this category, amber glass can prevent chemical reactions in essential oils from occurring, that can degrade its value.
- Cobalt blue: An alternative to amber glass is the cobalt glass. It offers the medium range of protection from UV radiation as compared to amber glass. Although it can absorb some of the UV rays, it is still not as good as amber glass.
- Vintage green: You won’t see this color used for storing the essential oils very often. But, if you do then I would advise you to stay away from buying it. I know it might be more visually appealing but this color is not as effective as the other two about which we just learned when it comes to protection against UV radiation.
Apart from these colors, essential oils also come in clear glass bottles. That means UV rays can easily pass through the glass as clear glass does not offer any kind of protection as compared to colored glass.
However, that doesn’t mean we can’t use clear glass at all. In some cases, you can use clear glass. We will talk about that in detail a bit later in this article.
So, by now you must have already known that amber glass is the best suitable color for storing essential oils and then next is cobalt blue. So, next time when you purchase any essential oil bottle make sure your first preference is the one with Amber glass.
Clear glass bottles
We know that clear glass bottles can’t absorb UV rays thus, leaving the essential oils exposed to harmful radiations. But, if you are going to keep the bottle at some dark place where sunlight can’t reach then even clear glass bottles can keep essential oils safe for a longer period of time.
The reason we store essential oils in colored glass bottles is to prevent UV rays from entering the bottle. So, if we keep the bottle at a safe place or darker place where UV rays can’t enter then clear glass bottles are perfectly good to go for storing essential oils.
Now keep in mind that as a vendor you should never use clear glass bottles. As bottles are going to be on the shelf for a long amount of time they will be exposed to outside environment.
If you do want to use the clear bottle as a vendor then make sure you put the proper instructions on the bottles or oil doesn’t last for long.
So, is it preferable to use the clear glass bottles?
This really depends upon the type of the oil because for some essential oils UV rays isn’t the only thing that we need to worry about.
Aside from UV rays, essential oils that contains chamazulene compound are vulnerable to intense visible lights as well. That means you can’t keep the clear glass bottles containing those oils under heavy lighting conditions.
Chamazulene compound has a strong ability of absorption under the visible region of the spectrum. That results in the more intense blue color of these oils.
So, whenever you see an intense colored liquid then that means there is a considerable amount of activity in the visible region as even normal light can affect the product because clear glass is transparent to all frequencies of the visible spectrum.
Are there any other factors you should consider aside from preventing harmful rays?
Yes! You should even watch out for two biggest enemies of essential oils, thermal degradation, and reaction with oxygen.
Chamazulene containing oils and refrigerating oils like citrus and chamazulene containing oils are more vulnerable to thermal degradation and reaction with oxygen as compared to other oils.
Also, I would advise you to keep the airspace in oil to the minimum as oxygen plays a major role in decomposition. Doing so will extend the life of the oil.
So, to sum the things up we can draw few interpretations about all the crucial things that we have learned so far,
- colored bottles are preferable over clear glass bottles most of the time as they offer better protection against UV rays and in some cases even against visible rays.
- In color glass bottles amber glass color bottle is the most preferable option to store essential oils as it absorbs all the harmful rays of wavelength up to 450 nm.
- You should always keep essential oils at a cooler place to increase its useful lifetime.
- If you are using clear glass bottles then make sure you keep it at a cool dark place where sunlight can’t reach.
- One should never store chamazulene containing oils in clear glass bottles as such oils are even vulnerable to normal lights.
- Always try to keep the minimum airspace in oil to increase the longevity.