Blue signifies ‘natural spring’, green ‘flavoured’: Decrypting the colours of packaged drinking water bottle caps

Access to sufficient, continuous and safe drinking water is a human right recognised by the United Nations. Safe drinking water points toward a number of essential principles, including purification and treatment. Filtration, disinfection and chemical treatment are counted among purification methods that remove contaminants, making water safe for consumption. Although health experts have time and again raised concerns about the health risks of packaged drinking water - from the presence of microplastics, leached chemicals and biological impurities to mineral loss, hygiene issues and environmental damage - many people still prefer it because of convenience. 

It is commonly perceived to be purified through ‘RO+UV+Ozonisation’ - a strong, multi-level water purification system that combines Reverse Osmosis (RO) to rule out dissolved solids and contaminants, Ultraviolet (UV) light to eliminate microbes and Ozone (O3) as a disinfectant and oxidizer. Additionally, the Ultrafiltration (UF) process is followed for more holistic purification. Some brands also claim to source water from natural sources, while also adding minerals for taste and health benefits.    

That said, it’s important for consumers to understand the different types of packaged drinking water. But how would one know that? The message is hidden in the colour of the bottle cap. Yes, the bottle cap tint can serve as a quick visual marker for the type of water contained in the bottle. Let’s decode them:

Blue: The colour blue indicates ‘natural spring water’, which contains minerals like calcium and magnesium.

Green: If the bottle cap is green, it means the water is ‘flavored’ or ‘infused’. For instance, lime or mint.

Red: A red cap points toward ‘electrolyte-enhanced’ or ‘carbonated’ water.

Black: ‘Alkaline’, or ‘premium’, water, in which the pH level is higher, comes in a bottle with a black cap.

Yellow/Golden: If the water is ‘vitamin-enriched’, the cap of the bottle will be yellow or golden in colour.  

White/Clear: A white or transparent bottle cap denotes the water is purified, filtered or distilled.

The above mentioned colour codes may come in handy. However, it’s also important to note that these colours are not necessarily government-mandated, and their meanings may vary among brands or used for aesthetics. Thus, it’s always advisable to carefully read the label and confirm the water’s type, source, nutrients and other details - such as ISI or FSSAI certification, expiry date and storage conditions - before consumption.