Rubber Chronicle 24: Why Stretch Denim and Socks Could Be Much Lower Impact with Natural Rubber

Stretch in everyday textiles — from stetch jeans to performance socks — is almost always provided by spandex (elastane). It’s strong, elastic, and durable, but it comes at a high environmental cost: it’s petroleum-derived, energy-intensive to make, and has a hidden water footprint tied to fossil fuel extraction and refining.

When those same products use cotton as their main fiber, adding spandex increases the overall water and GHG footprint well beyond cotton alone — especially once you include the polymer production and finishing steps.

Replacing spandex with YULASTIC® natural rubber fine filaments changes the equation.

1. Water Impact

• Stretch Denim (with spandex/elastane) — Cotton accounts for most visible water use, often 8,000–10,000 L per kg fiber and spandex adds a hidden blue water footprint from its fossil fuel supply chain.

• Stretch Denim (with natural rubber) — The cotton component is the same, but the stretch fiber comes from rain-fed, rubber trees (~500 L/kg fiber, all green water). No added irrigation or fossil fuel–linked water burden.

• Result: A blended fabric with natural rubber has a lower total water footprint than one with spandex, especially in high-water-stress sourcing regions.

* Green water is rainfall stored in the soil and used by plants.  Blue water is freshwater taken from rivers, lakes, or aquifers for irrigation or processing.  Grey water is the volume of clean water needed to dilute pollution—such as fertilizer runoff—back to safe levels. Malin Falkenmark (1995) and Arjen Hoekstra (2002 onward).

2. GHG Emissions

• Spandex — Production relies on petroleum feedstocks and high-heat, high-energy, chemical reactions, creating substantial CO₂ emissions.

• Natural Rubber — Low synthetic nitrogen use fertilizers in plantations means fewer nitrous oxide (N₂O) emissions; trees store carbon in biomass and soil for 20–30 years.

• Result: Substituting natural rubber for spandex reduces Scope 3 emissions from both fertilizer-related N₂O and fossil fuel–related CO₂.

* Ammonia is the building block for all nitrogen-based fertilizers, including NPK blends. Virtually all synthetic nitrogen fertilizers originate with ammonia produced via the Haber–Bosch process. The process synthesizes ammonia (NH₃) directly from atmospheric nitrogen (N₂) and hydrogen under high pressure and high temperature using a metal catalyst.

3. Soil & Regenerative Potential

• Spandex — No soil benefits; production happens in industrial plants.

• Natural Rubber — Perennial canopy and leaf litter mulch improve soil organic matter and reduce erosion; intercropping can replace synthetic nitrogen entirely and increase biodiversity.

• Result: The stretch fiber itself becomes a source of positive land stewardship.

Bottom Line for Brands
Every stretch textile — from premium denim to athletic socks — has two fiber stories: the main fiber (often cotton) and the stretch fiber (often spandex). Swapping petroleum-based spandex for fine-filament natural rubber in these blends does not change performance, but it slashes water use, cuts GHG emissions, and adds soil health co-benefits. For companies chasing water, climate, and “nature-positive” goals, it’s one of the most direct raw-material switches they can make.