Environmental Impacts of Denim or Blue Jeans

Is Blue Jeans or Denim Environmentally Friendly?

Denim, especially blue jeans, is the biggest single textile product type sold around the world. This is because of its popularity in all geographic regions, social strata, and age groups. The production chain is optimized for bulk production and with the capacity to meet this global demand. This means that the overall environmental impact of denim or blue jeans manufacture is significant. Improvements in each step of denim or blue jeans production offer potentially significant reductions in overall environmental impact as well as cost-saving for the industry.

In assessing the environmental impact of denim or blue jeans manufacture, it is important to take a holistic approach that accounts for all of the activities involved in the creation of a product, such as raw material extraction, manufacturing, transportation, use, and disposal. A standard approach is Life Cycle Assessment (LCA), which is internationally recognized in standards such as ISO 14040 and 14044. There are four key stages in LCA:

1. Goal and scope definition,
2. Inventory analysis,
3. Impact assessment,
4. Interpretation.

The first stage is critical in establishing the boundaries of the LCA, for example, whether the study includes all production, distribution, and use stages for the product from ‘cradle to grave’, including how finished products are used and then disposed of by consumers. Inventory analysis includes categories such as energy requirements, raw material needs, emissions (to air, water, and land), and waste related to the production of raw material and finished products. Life cycle impact assessment evaluates the potential environmental impacts of a product throughout its life, whilst interpretation identifies the most significant types of impact and makes recommendations for improvement.

Environmental Impacts of Denim or Blue Jeans Manufacturing:

In 2007, Levi Strauss & Co. conducted an LCA study to assess the environmental impact of a pair of Levi’s blue jeans from cotton seed to landfill. This study has provided insights on the environmental impact caused by blue jeans outside the bounds of the direct sphere of influence of the company. The environmental impact was assessed in the following categories, which environmental scientists and LCA experts used to calculate overall environmental impact:

1. Contribution to climate change: Quantifies amount of greenhouse gas emissions.
2. Energy use: Quantifies how much energy is used in production.
3. Renewable energy use: Percentage of energy use from renewable sources.
4. Water consumption: Measures water usage in cubic meters.
5. Land occupation: Amount of land needed to produce a product.
6. Qualified sustainably grown fiber content: A content analysis of fibers grown under a recognized cultivation program to address areas of sustainability.
7. Waste generation: Surveys the primary solid waste content during production and finishing.
8. Materials efficiency: How much of the primary materials end up in the final product.
9. Recycled content: Assesses the number of materials used from post-consumer recycled sources.
10. Land transformation: Amount of land transformed from its original state by production.
11. Eutrophication: Measures the impact of harmful nutrients discharged to freshwater bodies.

It was observed that the greatest opportunity to reduce the environmental impact of a new or existing product occurs during the design phase of its life cycle. Therefore, the primary objective of this LCA approach was to provide designers and developers with the information they need to produce more sustainable products.

A secondary objective was to provide a scientific method to support any claims of environmental improvement of products. Although not an initial objective of this effort, it was later realized that the methodology also provides a rigorous means to communicate environmental performance to suppliers (Levi Strauss & Co.). Based on these studies, Levi Strauss & Co. has later launched the Water<Less and Waste< Fewer collections.

Standard Manufacturing Process for Denim or Blue Jeans:

Whilst there are variants to produce special effects in denim or blue jeans fabrics, the standard manufacturing and distribution process for denim or blue jeans is as follows:

1. Cotton production (including growing and harvesting).
2. Yarn production (including spinning and warping).
3. Warp yarn dyeing (including dyestuff and auxiliaries production and use).
4. Sizing (including size production and use).
5. Weaving.
6. Flat fabric finishing.
7. Cutting and sewing (garment manufacturing).
8. Garment washing/finishing (including the production and use of chemicals, auxiliaries, enzymes, etc.).
9. Retail (marketing, logistics/distribution, sales outlets).
10. Use by consumers (including laundering).
11. End of life (disposal or recycling/reuse).

About the Author:

Mozaffar Hosen Sohel
Assistant Manager (Dyeing & Washing),
A&A Trousers Ltd,
Pubail, Dhaka, Bangladesh
Mail: mhossain002@yahoo.com