Traditional glitter, a staple in cosmetics and crafts, is made from polyethylene terephthalate (PET) plastic film. These minuscule, brightly colored flakes are a significant source of microplastic pollution. They enter waterways and the food chain when washed down drains or improperly disposed of. Since PET plastic takes hundreds of years to break down, it creates a persistent ecological burden. Biodegradable glitter was developed to solve this issue by replacing the plastic core with a material that naturally decomposes without leaving harmful residues.
The Plant-Based Substrate Material
The foundational structure of biodegradable glitter is a plant-based film, replacing the non-degradable plastic sheet. This core material is typically regenerated cellulose, a natural polymer derived from renewable resources like sustainably sourced wood pulp, often from eucalyptus trees. The cellulose is processed into a thin film, which is then cut into the familiar hexagonal glitter shapes.
Regenerated cellulose is chosen because its chemical structure is naturally hydrophilic, or water-loving. This property differs from petroleum-based PET plastic, as it allows water and microbes to interact with the material, initiating the breakdown process. By utilizing this plant-derived substrate, the bulk of the glitter particle is designed to be fully consumable by natural organisms once it enters the environment.
How Color and Sparkle Are Achieved
Achieving the characteristic sparkle requires coating the cellulose core with additional, environmentally responsible layers. In many commercial varieties, a very thin layer of aluminum is vacuum-deposited onto the cellulose film for metallic sheen and reflectivity. Although this minuscule metal layer does not biodegrade, the trace amount is considered non-toxic and negligible when the rest of the particle breaks down.
Color is added using cosmetic-grade pigments, and the structure is sealed with a top protective lacquer. This final film is often a plant-based polymer designed to protect the glitter during use. It is also engineered to break down in the environment, similar to the cellulose core. A newer technology called “structural coloration” eliminates aluminum and pigments entirely by arranging cellulose nanocrystals to bend light, creating color and shimmer solely through structure.
Understanding the Biodegradation Process
Biodegradable glitter means the material is broken down by living organisms, primarily microbes, into simple, harmless substances. The process begins when the glitter is exposed to moisture, softening the hydrophilic cellulose core. Microorganisms like bacteria and fungi then consume the cellulose, converting it into carbon dioxide, water, and biomass.
This breakdown is not instantaneous, which is why the material remains stable on a dry shelf. Efficient decomposition requires specific conditions: active microbes, along with appropriate levels of heat, oxygen, and moisture. These conditions are typically found in soil, compost, or wastewater treatment facilities. The rate of degradation varies, with some products achieving over 87% breakdown within 30 days under ideal laboratory conditions.
The environmental claim is backed by independent certifications that define the specific conditions required for breakdown. Industrial compostable standards, such as EN13432 or ASTM D6400, require decomposition in high-heat, professionally managed facilities. More rigorous standards, like TÜV’s “OK biodegradable WATER” certification, ensure the material breaks down safely in natural freshwater environments, which is a higher bar than industrial composting. This certification addresses the core issue of aquatic microplastic pollution. Consumers should look for products certified for marine or freshwater biodegradability to ensure the glitter does not persist if it enters natural bodies of water.