Native and regenerated cellulose show similar environmental biodegradation behavior across global terrestrial and aquatic ecosystems
Cellulose is the most abundant natural polymer and serves as the structural scaffolding molecule of plants, and materials from cellulose fibers are considered important to the global shift toward renewable materials. Yet, uncertainty remains about their persistence in natural environments. Here we show that native and regenerated cellulose, ranging from cotton and linen to viscose, modal, and lyocell, despite minor structural differences, are biodegraded at comparable rates, indicating that there is no scientifically justified distinction regarding environmental behavior. We assessed the biodegradation of diverse cellulosic materials, including powders, loose fibers, fabrics, and nonwovens, under technical and natural conditions across soil, home compost, freshwater, and marine coastal and deep-sea environments. Our study combined a total of 152 scenarios with laboratory tests, mesocosm and field experiments, spanning from polar to tropical regions and temperatures from -1.8 {degrees}C in the high Arctic Ocean to 38.4 {degrees}C in a marine beach in the Mediterranean Sea, and between -6.1 to 54.1 {degrees}C in agricultural soil. All neat cellulosic fibers showed inherent biodegradability, with biodegradation half-lives typically ranging from weeks to months. Biodegradation rates were primarily driven by water availability, temperature, and nutrient levels, while the role of oxygen was indifferent. Standardized lab tests aligned well with field observations, confirming their validity for assessing inherent biodegradability with environmental relevance. However, biodegradation of biodegradable polymers in real-world scenarios is influenced by product-level modifications such as dyeing and finishing. By distinguishing the effects of fiber chemistry separately from those of finishing treatments, this study clarifies the role of cellulose in a sustainable materials economy and supports evidence-based regulation of fiber biodegradability claims and product labeling.