**7.3 Land use**

When the land use for the production of bio-based fibers, cotton, Tencel®, Refibra® and PLA is taken into account, cotton requires a drastically high amount of land compared to the rest of the fibers. PLA land use, here has the lowest value. Tencel and Refibra are slightly higher than PLA. Data shows that cotton requires 65% more land than Tencel and 95% more land than PLA.

The other fibers are syntethised from petroleum, and therefore, Article 02 an 03 have the lowest impact in the impact category under discussion.

#### **7.4 Eutrophication**

Eutrophication is the indicator of water emission of substances, mainly nutrients contributing to oxygen depletion and is an indicator of water pollution. The eutrophication potential is mainly originated by the emission of phosphate and nitrate from fertilizers that are used in cotton cultivation.

Although 20% of cotton is replaced by PET in Article 02, the eutrophication level almost stays the same since fiber production requires high energy. Article 04 with PLA and Article 03 with recycled PET score third and fourth with regard to eutrophication impact. Articles with Tencel ® and Refibra® have the lowest impact because of the energy resources that used for their production. Besides, these fibers are compostable and biodegradable in freshwater, marine and soil conditions.

#### **7.5 Abiotic depletion**

Abiotic depletion reflects the environmental impacts from using non-renewable energy and material resources. As regular PET fiber is made from crude oil, it has higher abiotic depletion impact compared to other fibers (**Table 4**). This fact increases this impact for Article 2 compared to Article 1–100% cotton version. PLA follows PET for the abiotic depletion impact due to high energy consumption in the lactic acid and lactide production [102]. The differences between manufacturers must be identified and the same calculation should be conducted when renewable energy sources and heat recovery systems are used as in Lenzing® manufacturing system. Therefore, abiotic depletion values for Article 05 and 06 are recorded as the lowest in the study.

*An Evaluation of Recycled Polymeric Materials Usage in Denim with Lifecycle Assesment… DOI: http://dx.doi.org/10.5772/intechopen.99446*
