Why are pigments problematic for the planet?

“Pigments are possibly the most contentious yet easily reversible element of today’s packaging.” Kosior, E. 2023

Not only are pigments extremely difficult when it comes to recycling, but they’re also impacting human, animal and environmental health through their toxicity and inability to biodegrade. The pigments used to treat and decorate biobased materials can cause huge damage if not sourced correctly. 

This space remains relatively under-researched and unknown due to the lack of clarity, visibility and transparency over supply chains. At Shellworks, we’re doing our best to get to the bottom of how and where to best source pigments that consider both social and environmental impacts.  Just as we consider our material in every eventuality for end of life scenarios, what goes into our material is just as important when developing new products.


What are pigments? 

A pigment is any group of compounds that are used to colour other materials. They can either be added to other materials in their solid form, or mixed with a liquid to create dye or ink. 

Pigments date back to prehistoric times and play an important role in the storytelling of civilisation. They were originally used by humans for cave paintings and body decoration. At this time, pigments were made from the natural earth and included colours such as ochre. Over the years, we have discovered new sources and techniques for developing pigments. Today, there are many different types of pigments and they can be categorised into groups including natural, organic, inorganic and synthetic pigments – or a blend between groups. The most common pigments used today are either inorganic or synthetic organic ones. 


Natural pigments  

Natural pigments are derived from natural sources including minerals, plants and insects. Organic and inorganic pigments also occur naturally and are, therefore, subcategories of natural pigments. 

Although naturally-derived, not all natural pigments are petroleum decoupled as sometimes petroleum chemicals are used to extract the pigment from its source. 


Organic pigment

Organic pigments are primarily composed of carbon-containing compounds. They are derived from organic chemicals, typically featuring carbon and hydrogen atoms as their primary elements. This organic nature sets them apart from inorganic pigments like metal oxides, which do not contain carbon-hydrogen bonds. The vast majority of organic pigments are produced synthetically through chemical reactions.


Inorganic pigments

Inorganic pigments often contain metals and are mined from the earth. They can also be created in labs and, in this instance, are referred to as synthetic inorganic compounds or pigments. They are made by relatively simple chemical reactions. 


Synthetic pigments

These are artificial pigments that are used to replicate organic or inorganic pigments or produce new ones. They tend to have a higher saturation so they can achieve a wider and more vibrant colour range. 


How can we spot greenwashing? 

It’s important to identify non-specific terms. For example, if a company says that they use ‘sustainable’ pigments, then question them on what this means, and find out how and where they source their pigments from. 

Compostable doesn’t necessarily mean petroleum-free. Products can be compostable but they can still have petrochemicals in them. One way to spot this is by checking what the colour looks like and challenging the company on their process. For example, if you see a neon green tub that says compostable, it is likely that this product isn’t biodegradable.

Another example is when referring to synthetic organic pigments, it’s important not to be misled by the word organic. Whilst this may sound positive, synthetic organic actually means that the pigment is derived from petrochemicals. 

Aside from looking for pigments that are petroleum derived, it’s also important to look for pigments that are petroleum decoupled. This means that petroleum wasn’t used in the process of making or treating the pigment. 


What are the issues with pigments? 

Pigments can be problematic due to environmental and social impacts throughout their life cycle. We need to consider not only where the pigment is sourced from but how it is made and where it goes at its end-of-life. The main barrier to accessing this information is due to a lack of transparency and clarity over a pigment’s supply chain. Companies and suppliers do not have to include all information on material data sheets, which means that consumers do not receive enough information to create a holistic view of how good a pigment really is. 


Conventional colours that are easily available on the market, likely come from non-renewable sources. They are typically petroleum-based, which allows brands to achieve a vast range and depth of colour. This adds contamination to the soil, water and air – contributing to global warming and the climate crisis. Some pigments also contain metallic substances such as chromium, cadmium, lead and mercury, which are harmful to human and environmental health as they are extremely toxic and contribute to air pollution. At Shellworks, we avoid the use of these pigments to comply with compostability and eco-toxicity standards. 

From a social perspective, it’s important to consider what implications the sourcing of a pigment has had on local communities such as displacement of people or slavery conditions. Pigments that are often exposed to these circumstances include cobalt and micah. 

A large barrier to the adoption of sustainable pigments is the culture of standardisation. Companies and consumers typically expect coloured products to look identical to each other. This level of replication results in a high level of chemical additives to ensure stability, consistency and UV protection. The desire for perfection also results in huge waste of coloured products that might differ ever so slightly.  In order to progress towards a more equitable and environmentally friendly approach, expectations need to shift to accept sustainable alternatives that may be imperfectly perfect in colour consistency. With each item carrying it’s own uniqueness and story.


How do we work with pigments at Shellworks? 

At Shellworks, when we approach developing new colours, we do our best to ethically source pigments that are petroleum-free, compostable and vegan. From a social perspective, we check that there are no ethical issues (ie. modern slavery) in the region that the pigment is sourced from and ask for verification of this. From an environmental perspective, we only use colours that are home-compostable and don’t use any added treatments that could negatively impact the earth. We test for eco-toxicity, impact to marine life, biodegradation and soil health – whilst always keeping aesthetics in mind. To ensure our colours are stable, we do heat, UV and colour bleeding tests. 

Through continuous research, testing and verification, we do our best to ensure our pigments are as low impact as they can possibly be – whilst also remaining beautiful in aesthetic. We’re on a mission to shift the cultural narrative around the use of colour in the plastics industry. To date, we have developed a colour palette that includes over 150 different petroleum-free, compostable and vegan pigments. We’re incredibly proud of achieving the highest sustainability standards possible and creating a platform for individual companies to bring their brands to life through colours that celebrate individual personality.



Kosior, E. 2023. Why losing brand colours on plastic packaging would quickly boost recycling rates. The Grocer. https://www.thegrocer.co.uk/sustainability-and-environment/why-losing-brand-colours-on-plastic-packaging-would-quickly-boost-recycling-rates/675957.article

Splash Printing: 

Cass Art: https://www.cassart.co.uk/understanding-synthetic-pigments/