Glass bottles and glass jars have already been around since 1500 BC but what, do you think, made the glass industry realize the importance of colored glass containers? It was believed that it all began in the beer industry.
According to the history of bottle colors, beer bottles were once transparent but brewers noticed that the beer’s taste and smell changed when exposed to the sun for too long. This made them decide to start using tinted bottles to protect the beer from the harmful UV light. But what colors do the best job in blocking UV light most?
In this article, we are going to discuss the importance of colored glass containers in product packaging along with the best bottle colors for light-sensitive products.
Before we dive into our topic for today, let us first have a quick discussion about what UV light is and a few examples of light-sensitive products.
Ultraviolet light is a type of electromagnetic radiation produced by the sun. Just as long-term exposure to UV light damages your skin, UV light also affects a lot of products. This is because the energy from UV radiation is strong enough to damage the chemical composition of many light-sensitive products.
Here are some examples of light-sensitive products.
#1 Beverages
Beverages containing flavoring, artificial colors, and vitamins are more sensitive to UV light. Their color, odor, and/or taste will be affected when exposed to UV radiation which shortens their shelf life. Examples are enriched waters, juices, and beers.
#2 Pharmaceuticals
Pharmaceutical products contain a lot of chemicals which is why they should not be exposed to UV light. It has long been a practice to store pharmaceutical products in amber glass bottles because they can block UV light completely.
#3 Products that Use Flexible Packaging
Using flexible packaging (pouches, shrink films, bags, etc.) for your products is not recommended, especially if your products are light-sensitive. If you use flexible packaging, you can add an extra layer of protection for blocking UV light.
Why is the glass container color important? This is because it determines what types of light can pass through the surface of the container. Red glass only permits red light, blue glass only permits blue light, and so on. The kinds of light that a glass container permits have varying effects on the product packaged inside.
For food products, light is the biggest enemy. When a food product absorbs UV light, the food can deteriorate. In most vegetables and fruits, their surface reflects light which causes discoloration. Meanwhile, in liquid products, light causes unfavorable chemical reactions. This can ultimately change the liquid’s chemical composition, causing it to spoil.
Take note though that the light sensitivity of food and beverage products can vary depending on the factors below:
Amber, cobalt, and green glass containers offer UV light protection for food, beverage, and beauty products that are light-sensitive. Each glass color provides different levels of protection from UV light with amber giving the highest protection, cobalt offering medium protection, and green the lowest one.
Amber glass containers are created by adding carbon, iron, and sulfur into the raw material mixture. These materials provide the iconic color of amber glass – a rich amber color. There is a reason behind the color of amber glass bottles and jars which is related to the way they protect their contents from UV light.
Amber glass can offer optimal protection against harmful UV light because it can absorb nearly all light wavelengths below 450 nanometers. It can also block blue light. That is why it is the most ideal material for packaging light-sensitive products. It is also the most preferred color by essential oil producers, pharmaceutical companies, and plant-based product manufacturers.
Cobalt glass containers normally have deep blue colors. They are made by adding copper oxide or cobalt oxide into the mixture but copper provides a more delicate color compared to cobalt.
Cobalt glass can provide enough protection against UV light because it can absorb more light compared to clear glass containers. But, this depends on the type of product you are packaging. It provides medium protection and just like amber, it can absorb UV radiation. But, it cannot filter blue light.
A lot of manufacturers use cobalt glass instead of amber glass because the attractive feature of cobalt glass allows their products to stand out from the competition on the shelves. Cobalt glass vials are also popular for packaging medicinal and apothecary products.
Green glass bottles are manufactured by adding chrome oxide into the molten mixture. You might have seen beer and other similar products packaged in green glass containers. However, it offers the least protection against the harmful effects of light compared to other tinted glass colors.
Although green glass bottles can block some UV light, they cannot absorb light as much as cobalt and amber. Thus, green glass packaging is only ideal for products with mild sensitivity to light. Green glass containers do have an advantage. Like clear glass bottles and jars, green glass containers are ideal for displaying your products more prominently. They might also be great options depending on your product’s chemical composition.
Aside from providing the highest protection for your products from UV light, why are amber glass bottles and jars your ideal packaging choices? Let us find out why in this section by discussing the advantages of amber glass packaging.
The energy absorbed from light triggers a chemical reaction in products, known as photochemical reaction, which can change the products’ chemical compositions. This turns the products into states with different properties compared to the original. Let us take beer as an example. Beer contains many reactive components such as sulfur. When these components react with light, the beer’s chemical composition changes which cause the beer to go stale.
Photodegradation is another type of photochemical reaction. It is the degradation of food, liquids, medicines, and other materials caused by exposure to light. For liquid and food products, photodegradation typically affects those containing vitamins, fat, and proteins in high amounts. It changes the liquid or food product’s color and taste as well as destroys important vitamins.
Amber glass packaging is completely inert. This means that it does not leach or break down chemicals in the product it is storing.
The materials used to manufacture amber glass containers are widely available which makes them relatively inexpensive.
Aside from the mentioned practical qualities of amber glass, it is also known for its classic appeal and attractive color. It is perfect for decorators and designers who are striving to balance the contemporary and the rustic in their packaging design.
Amber glass containers are the perfect barriers between UV radiation and your products from pharmaceuticals to brewing. Some of these products include the following:
As you may have noticed, beer products are commonly packaged in glass containers. Beer is very sensitive to light. The photooxidation process destroys the key components of the beer which produces a skunked taste – a sign that the beer is already spoiled. This makes amber glass the most ideal choice for beer packaging.
Amber glass bottles are also frequently used to package essential oils. The prize of these oils is based on their distinctive scents. The reactions in photooxidation can change their properties. Using plastic to store oils is a bad idea because UV light damages plastic compounds which lead to leaching.
As we have mentioned earlier, pharmaceutical products are commonly stored in amber glass bottles. Tinctures, eye drops, and antibiotics are all packaged in amber containers recently. Although there are some products that are stored in plastic containers, amber glass is still used in a lot of cases because of the issue of chemical leaching in plastic containers.
You can spend your time under the sun as long as you want, especially in the summertime, but make sure that you protect your products from the harmful rays of the sun. Now that we have talked about colors and light and their impact on food and beverages, it is clear that amber bottles do the best job. If you are looking for a reliable glass container manufacturer, feel free to contact Roetell, a leading glass packaging manufacturer since 1984.
We help you avoid the pitfalls to deliver the quality and value your glass bottle and jar need, on-time and on-budget.
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