*4.3.1 System perspective*

As was mentioned above, the life cycle assessment (LCA) methodology is selected to calculate the environmental impacts of denim fabrics having different recycled contents in the same article so that the whole system can be taken into consideration. This means that we have to calculate the effect of every step in the life cycle to see the whole impact of our choices, including cultivation/production of the fiber, fabric production, garment manufacturing, distribution, consumer laundering, reuse, and final disposal [76–77]. One may think that using recycled cotton reduces the impact drastically, but parameters such as increased waste during production and increased energy usage should also be taken into account in a system perspective.

If only one process or only fabric production as a system were calculated, this would have represented a single framed approach which is generally not preferable as calculations for production of single frames may lead to unwanted and unforeseen effects elsewhere in the whole system.

#### *4.3.2 Five environmental impact categories*

The specifications of the denim article selected for the work is given in **Table 4**. Life cycle assessment (LCA) was conducted for 1 m of the article in accordance with the process steps including fiber cultivation, transportation, and all the production steps covered in the Turkish denim manufacturing company. The five environmental impacts are presented in **Figure 4**. For the comparative study, the results are


#### **Table 2.**

*A taxonomy of environmental impact categories for textiles.*

given in terms of percentages (%) so that unit differences of the impact categories

Article A 150 14.89 100% cotton

**Indicator Unit Description Example impact Methodology**

Climate change IPCC 2013

Water scarcity Life cycle

Deforestation ReCiPe 2016

Mineral scarcity CML-IA

**) Composition**

Nutrient loading to water streamwater pollution

**2**

GWP 100a [68 –69]

inventory

CML-IA baseline [72 –75]

Midpoint (H) [70 –71]

baseline [72]

Emission of greenhouse gases

*Understanding Denim Recycling: A Quantitative Study with Lifecycle Assessment Methodology*

Excessive freshwater taken from the environment

The amount of agricultural

Emission of substances to water contributing to oxygen

Measure of mineral, metal, and fossil fuel resources used to produce a product

area uccupied

depletion

**Article Code Width (cm) Weight (oz/yd**

(GHGs)

This section aims to determine the impact of recycled cotton content in the denim fabric under discussion (**Table 4**). Accordingly, different recycled cotton contents are used in the life cycle assessment calculations of Article A. These are as

In denim production, the hottest spot for the selected four categories is the fiber growth stage. In the fifth impact category, abiotic resource depletion, fiber stage has the second highest impact. This clearly shows the importance of raw material

were eliminated.

*Article specifications.*

Global warning potential

Freshwater use lt

Land use m

Eutrophication potential (EP)

Abiotic resource depletion

**Table 3.**

**Table 4.**

kg CO <sup>2</sup> eq (kilogram carbon dioxide equivalent)

*DOI: http://dx.doi.org/10.5772/intechopen.92793*

(liters)

2 a (meter square per annum)

kg PO 4 3 eq (kilogram phosphate equivalent)

kg Sb eq (kilogram antimony equivalent)

*Selected environmental impact categories.*

follows:

**73**

selection for denim fabric production.

*4.3.3 Impact of recycled material content*

• Article A-1: 100% cotton

• Article A-2: 80% cotton +20% recycled cotton

• Article A-3: 70% cotton +30% recycled cotton

• Article A-4: 60% cotton +40% recycled cotton

• Article A-5: 50% cotton +50% recycled cotton

*Understanding Denim Recycling: A Quantitative Study with Lifecycle Assessment Methodology DOI: http://dx.doi.org/10.5772/intechopen.92793*


#### **Table 3.**

*Selected environmental impact categories.*


#### **Table 4.**

*Article specifications.*

given in terms of percentages (%) so that unit differences of the impact categories were eliminated.

In denim production, the hottest spot for the selected four categories is the fiber growth stage. In the fifth impact category, abiotic resource depletion, fiber stage has the second highest impact. This clearly shows the importance of raw material selection for denim fabric production.

## *4.3.3 Impact of recycled material content*

This section aims to determine the impact of recycled cotton content in the denim fabric under discussion (**Table 4**). Accordingly, different recycled cotton contents are used in the life cycle assessment calculations of Article A. These are as follows:


**References Global**

**72**

**Acidification Eutrophication**

 **Ozone**

**Abiotic**

**Photochemical**

**Freshwater**

**Human**

**Water**

**Terrestrial**

**Greenhouse**

**Nonrenewable**

**Carcinogens**

 **Land**

**Aquatic**

**Mineral**

**Ecotoxicity Freshwater**

**Freshwater**

**Ionizing**

**Water**

*Waste in Textile and Leather Sectors*

**occupation**

**eutrophication**

**extraction**

**eutrophication**

**aquatic**

**radiation**

**depletion**

**ecotoxicity**

1

 1

**layer**

**depletion**

**oxidant**

**use**

**toxicity**

**consumption**

**ecotoxicity**

**gases**

**energy use**

**(GHG)**

**formation**

**depletion**

**warming**

**potential**

**(GWP)**

**climate**

**change**

[55] [56] [57] [58] [59] [60] [61] [62] [63] [64] [65] [66]

[9] [67] Total **Table 2.** *A taxonomy of* 

*environmental*

 *impact categories for textiles.*

10

8

8

5

5

4

3

3

3

3

3

3

3

3

2

2

2

2

2

2

2

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1

1 1

1

1

1

1

1

1

1

1

1

1

1

1

1 1 1

1

 1 1

 1

1

 1

1

1

1

1

1

1

1 1

1

1

1

1

1

1

1

1 1

 1 1

 11

 1 1

1

 1

 1 1

1

1

1

1

1 1

1 1

1

5%, eutrophication drops by 8%, and abiotic resource depletion drops by 3% with

*Understanding Denim Recycling: A Quantitative Study with Lifecycle Assessment Methodology*

two main stages: fiber cultivation and spinning. The energy usage in spinning increases when the recycled cotton content is increased, which implies a negative impact of the use of such fiber on global warming potential. However, since the percentage of the virgin cotton usage is decreased, this decline delivers a high positive impact for global warming potential, lessening the effect of energy usage. In eutrophication calculation, the main effect derives from usage of fertilizers, pesticides, and insecticides at farm level. During irrigation of cotton, the probability of water pollution caused by these chemicals increases. Once the usage of virgin cotton decreases in the blend, the value of eutrophication decreases. Overall, the

Water use and land use impacts decrease by 10% with an addition of 10% recycled cotton. Since cotton uses land, and a high amount of water in the field during cultivation, avoiding the use of virgin cotton creates a high decrease in impact categories. If one can spin and weave a blend of 50% virgin and 50% recycled cotton, the overall impact on these two categories decreases 50%, which is a considerable figure when the amount of fabric produced reaches approximately 3

This section aims to determine the impact of blending recycled cotton with organic cotton. Organic cotton data used in the calculations is generated from the literature [78–79]. The percentages used in the life cycle assessment (LCA) calcula-

Once organic cotton is used, at least 25% decrease appears in three categories: namely, global warming potential, eutrophication, and abiotic resource depletion. The decrease in water use (11%) is comparably low. On the other hand, real decrease happens in the land use, nearly 40%. This is due to the data for Aegean Region organic cotton. The yield in Turkish organic cotton is comparably high. The land use for 1 kg of lint organic cotton is 4.65m<sup>2</sup> for Turkish organic cotton. The same figure appears to be 19.7 for global production and 20.9 for the US organic

The virgin cotton used in study for calculations is a blend of the US, Turkish,

The results of the life cycle assessment (LCA) calculations are presented in **Figure 7**. The data shows that diverting from 100% regular cotton to 100% organic cotton reduces global warming potential by 27%, eutrophication by 26%, abiotic depletion by 24%, and land use by 39%. In addition, as in Article A-7, blending organic cotton with 20% recycle cotton generates an additional 10% decrease in land use. With the aid of this blend, the comparably lowest impact in land use is achieved in this study. The same is true for global warming potential and abiotic depletion. Article A-7 has the lowest values compared to the rest of the articles in

Global warming potential, in other words climate change impact, is affected by

each addition of 10% recycled content in the blend.

*DOI: http://dx.doi.org/10.5772/intechopen.92793*

decrease results as 8% with a use of 10% recycled cotton.

*4.3.4 Impact of organic cotton and recycled cotton*

billion meters annually.

tions are as follows:

cotton (**Figure 6**).

**Figures 5** and **7**.

**75**

Greek, and Brazilian cotton.

• Article A-1: 100% cotton

• Article A-6: 100% organic cotton

• Article A-7: 80% organic cotton +20% recycled cotton

**Figure 4.** *Five environmental impacts of selected fabric according to process steps.*

#### **Figure 5.**

*Results of LCA calculations of virgin and post-consumer recycled cotton blends.*

In each version, the recycled cotton content was increased by 10%. The recycled cotton used in the calculations is post-consumer recycled cotton, and its industrial data such as production and transportation data is obtained from a local supplier.

The results of the life cycle assessment (LCA) calculations are presented in **Figure 5**. As may be seen from these results, global warming potential decreases by
