Viscose, often known as rayon, is a semi-synthetic fiber popular in the textile industry for its affordability, excellent drape, and silk-like feel. Derived from cellulose, typically sourced from wood pulp, the fiber is classified as semi-synthetic because its natural raw material undergoes extensive chemical processing. This manufacturing process, which transforms wood pulp into a soft textile, is under increasing scrutiny regarding its environmental impact. Determining if viscose is an environmentally conscious choice requires examining its sourcing, chemical treatment, and end-of-life fate.
The Link Between Viscose and Forest Destruction
The first stage of viscose production involves sourcing raw cellulose, which often links the fiber directly to deforestation and biodiversity loss. A significant portion of the dissolving wood pulp used, estimated to be up to 40%, comes from uncertified sources that include ancient and endangered forests (AEF). This demand for virgin wood pulp contributes to the destruction of irreplaceable ecosystems, which serve as carbon sinks and habitats for various species. Approximately 300 million trees are logged globally each year for the production of man-made cellulosic fibers, including viscose.
The sourcing risk is particularly high in regions like Indonesia, India, and Canada, where pulp operations have been linked to high-carbon peatlands and deforestation. To mitigate this impact, organizations like the Forest Stewardship Council (FSC) and the Programme for the Endorsement of Forest Certification (PEFC) offer certifications that track wood from sustainably managed forests. Choosing certified viscose ensures the raw material is not contributing to illegal logging or the degradation of AEFs.
Heavy Reliance on Toxic Manufacturing Chemicals
The traditional xanthate process used to convert wood pulp into viscose fiber involves a heavy reliance on hazardous chemicals. The wood pulp is steeped in sodium hydroxide and then treated with carbon disulfide ($\text{CS}_2$) to create cellulose xanthate. Carbon disulfide is a potent neurotoxin that poses serious health risks to factory workers, having been linked to coronary heart disease and other severe health issues.
The open-loop nature of this standard manufacturing method means that significant quantities of toxic chemicals are released into the environment. After the cellulose xanthate solution is extruded into a bath of sulfuric acid to regenerate the fibers, the spent chemicals are often discharged. This results in liquid effluents containing residual chemicals like sodium hydroxide and sulfuric acid contaminating local waterways. The process also generates air emissions, including hydrogen sulfide and carbon disulfide, which impact local communities and ecosystems surrounding the production plants.
Viscose Decomposition and Waste Disposal
Viscose is frequently marketed as a biodegradable fiber because it is composed of plant-based cellulose, suggesting a minimal environmental burden at the end of its life. Under optimal conditions, such as in a composting environment with adequate warmth and microbial activity, 100% viscose can decompose relatively quickly, sometimes in a matter of weeks to a few months. However, the real-world scenario of waste disposal often complicates this biodegradability claim.
The extensive chemical treatments and finishing processes applied to the fiber can impede its rapid breakdown in a standard landfill environment, which lacks the necessary conditions for quick decomposition. The decomposition timeline is further extended when viscose is blended with synthetic fibers like polyester or spandex. Finished garments containing these blends will not fully biodegrade, meaning the synthetic components will persist for decades or even centuries.
Innovations in Closed-Loop Viscose Production
To address the environmental shortcomings of traditional viscose, significant innovations have led to the development of closed-loop production systems that dramatically reduce chemical pollution. These modern methods focus on recycling the solvents and water used during manufacturing, moving away from highly polluting open-loop processes. The Lyocell process, for example, is a much cleaner method that dissolves wood pulp using amine oxide, an organic solvent that is non-toxic and can be recovered and reused at a rate of over 99%.
Lyocell fibers, often sold under the brand name TENCEL™, are produced from sustainably managed wood sources and eliminate the need for the hazardous carbon disulfide used in the conventional process. Another certified alternative is LENZING™ ECOVERO™ Viscose, which uses a modified process incorporating a closed-loop system to prevent the release of gasses and toxins. This branded viscose generates up to 50% less carbon emissions and water consumption compared to generic viscose, and its wood pulp is sourced from certified and controlled forests. These technologies represent a major shift, allowing for the production of cellulosic fibers with a significantly lower environmental footprint.