The Biodegradable Glitter Bomb

When we think of glitter, images of childhood crafts, school projects, shimmering makeup, and sparkly festival outfits probably come to mind.

But it might surprise you to learn that the boating industry is one of the largest buyers of glitter. It's used as a gel coat additive for all those fancy sparkly paint jobs.

This little factoid has its own internet lore with a conspiracy theory about a cover-up by the glitter industry and its largest customer not wanting this widely known.

This is possibly due to another little-known fact: glitter is far from harmless.

Traditional glitter, made from microplastics like PET and coated with reflective aluminium, is a pervasive environmental hazard. It lingers in ecosystems for hundreds of years and infiltrates food chains.

As awareness grows, biodegradable glitter has emerged as a sustainable alternative—or so it claims.

But are these eco-glitters as "green" as they're marketed to be?

To answer that question, we need to take a deep dive into the science, the materials, and the challenges of achieving a sustainable sparkle.

The pervasive problem with plastic-based glitter

Conventional glitter's allure lies in its longevity, but its precisely this durability that is its biggest flaw.

Made primarily from PET and PVC plastics, it doesn't break down but instead breaks up into increasingly smaller particles.

Once glitter reaches the environment, particularly waterways, it settles into sediment, posing hazards to plant and animal life. A 2020 study found that plastic glitter reduces root growth in aquatic plants, disrupts phytoplankton levels, and even increases invasive snail populations, impacting biodiversity within just 36 days of exposure.

Glitter in soil ecosystems can harm organisms that are critical for soil health. Research from the University of Melbourne found that plastic glitter can disrupt springtail populations, tiny soil-dwelling creatures vital for decomposing organic material.

These ecological impacts are amplified by glitter's ability to spread and persist over hundreds of years. It's a ready-made microplastic that sheds into our environment from the moment of application.

Biodegradable glitter: A mixed bag

I want to keep these posts solution-oriented. I'm a girl dad, after all, and glitter is a non-negotiable for many occasions in our household.

Thankfully, there has been a glitter bomb of biodegradable and plant-based glitter options out there.

But, while the biodegradable glitter market promises a pathway to eco-friendly alternatives (typically using plant-derived materials like cellulose), the reality of biodegradable glitter's environmental impact is... complicated.

Even biodegradable options must be scrutinised for sustainability; not all "green" glitters live up to their promise of harmless decomposition:

1. Modified Regenerated Cellulose (MRC): MRC-based glitters are often derived from eucalyptus and coated in mineral pigments like mica or thin plastic layers for durability and shine. However, these additives make the glitter less biodegradable in natural settings.
2. Cellulose Acetate (CA): While derived from wood pulp, CA glitters include semi-synthetic polymers that vary in biodegradability depending on the environment. Many don't break down fully in soil or marine settings and can cause skin irritation if used in cosmetics.
3. PLA (Polylactic Acid): This bioplastic, often used in compostable packaging, needs industrial composting conditions to decompose. This means PLA-based glitter will likely persist in natural environments like soil and water for glitter.
4. Mica and Synthetic Mica: Mica-based glitters have emerged as a "natural" alternative. Yet, they carry risks of heavy metal contamination and bioaccumulate in freshwater habitats, altering sediment and potentially harming organisms.

These findings highlight a critical issue: even plant-based or "compostable" glitters can contribute to environmental pollution if they aren't disposed of under ideal conditions, which, let's face it, is unlikely for most consumer uses.

While some of these materials might degrade in controlled composting facilities, the reality is that most eco-friendly glitter ends up in the soil or waterways, where degradation rates are far slower or completely nonexistent.

Bio-based nanocrystal glitter provides a glimmer of hope

New Australian-led research has found that recent advancements from Cambridge University offer a genuinely promising solution.

By using cellulose nanocrystals, a natural polymer found in wood and cotton, scientists have created glitter that achieves its sparkle through "structural colour"—the same phenomenon seen in butterfly wings and peacock feathers. Unlike traditional glitter, which relies on reflective pigments, cellulose nanocrystal glitter is free from harmful coatings or synthetic additives.

This new cellulose-based glitter shows no toxic effects on organisms like springtails and breaks down more readily than other alternatives in both soil and water. It also sidesteps the harmful mining practices and chemical treatments associated with mica.

If this innovation reaches commercial scalability, it could revolutionise the glitter industry, offering a biodegradable alternative that doesn't compromise shine or safety.

Sustainable sparkle alternatives

While Cambridge's cellulose nanocrystal glitter holds potential, there are other ways to enjoy glitter sustainably:

• DIY Salt or Sugar Glitter: Colored salt or sugar can be used as a temporary glitter substitute. While it won't shimmer quite like the real thing, it's biodegradable and quickly cleaned up.
• Crushed Seashells: Ethically sourced seashell powder provides a natural glimmer without the pollution. While slightly less sparkly, this option offers a unique aesthetic and environmental peace of mind.
• Recycled Glass: Although less safe for skin applications, crushed glass is another way to achieve sparkle, particularly in crafts and decor.
• Bioglitter™: A market leader, Bioglitter™ is a TÜV-certified biodegradable option. The PURE range is entirely plastic-free, and the SPARKLE line, though containing trace aluminium, claims 92% biodegradability in natural environments like freshwater.

How can we make glitter truly sustainable?

Biodegradable glitters represent a step forward but are only a partial solution for sustainable sparkle. We need greater regulatory oversight, transparency, and sustainable innovation to address microplastic pollution.

Key areas to focus on include:

1. Clear Labeling and Certification: As with other sustainable products, consumers need transparent information about what's in their glitter. Certification programs should be expanded to include glitter products, verifying claims of compostability and biodegradability across diverse environments.
2. Better End-of-Life Pathways: Industrial composting facilities rarely process glitter, and home compost systems fare even worse. Until infrastructure for compostable material disposal improves, this isn't a viable pathway. Investment in composting and waste management is crucial to closing the loop on these materials.
3. Encouraging DIY and Minimalist Choices: For many consumers, making glitter at home with salt or ethically sourced materials can be a fun and sustainable alternative. Reducing reliance on single-use glitter items, like cards and decorations, is also essential.
4. Research and Development: The Cambridge cellulose nanocrystal glitter project is a step in the right direction. Continued support for research into sustainable glitter, alongside industry adoption, will ensure that actual eco-friendly alternatives can replace microplastic glitters at scale.

The glitter industry is just one example of how everyday items can hide more significant environmental impacts. While biodegradable glitter offers some relief, we must be vigilant about what "biodegradable" really means.

Obviously, if the material you are using is bio-based, it will be more likely to bio-assimilate at end-of-life (i.e. when it goes down the sink or ends up in soil).

So next time you need to glam up or add some sparkle to your life, make sure you either re-use some existing materials or go bio-based so your lustre won't last for a thousand years ✨