Ever since I enrolled myself in an Environmental Ethics class my freshmen year of college, it seems that I have enrolled my life in the basis of environmental ethics and concern as a result. I had been so focused on what foods to buy, what brands not to use, and conserving how much I drive in my car, until I read something that added a significant focus to my list of do’s and don’t’s. What did I read? I read a book summarizing how much water goes towards industrial usage, agriculture, and other human uses and how much of our world’s supply is left as uncontaminated, safe drinking water; it is lower than one percent. One aspect of water conservation that never crossed my mind was recently discovered in something unexpected: the clothing I wear. There’s always a pair of new boots, a blouse that is to-die-for, and that collared work shirt needed for one’s work uniform. People fall in love with clothes every day, but what if they knew that they could practice an environmental ethic while purchasing a new item of clothing? I am exploring the environmental impact, regarding water use, one is supporting when purchasing a Naturellement Chanvre 100% hemp tee shirt versus a Hanes 100% cotton tee shirt. Through analyzing these two products, I will then be able to determine which material is more environmentally friendly in regards to water usage.
Figure 1: Hemp Tee-shirt
Figure 2: Cotton Tee-Shirt
Cotton is probably a more popular source for clothing in comparison to hemp and is often integrated with other materials into fabric. It is grown globally; however, I will be analyzing Hanes tee shirts, which is (nearly) all grown and manufactured in the United States (Hanesbrands Inc). The figure below shows, globally, which countries are currently growing industrial cotton.
Figure 3: The Global Display of Cotton Being Currently Grown (farmhub.com, 2011)
I will now run through the life of Hanes cotton tee-shirt and then state how much water goes into growing enough cotton to produce one. The life of this cotton tee shirt begins at the “cotton growing” stage. Cotton grows best in drained soils able to hold water, and actually takes up a bigger area of land than growing hemp due to hemp’s ability to grow vertical and tall, up to 15 to 20 feet tall (Soiferman). 256.6 gallons of water goes into growing enough cotton for one tee shirt; and then the crop is harvested and processed (Cotton Facts). Processing includes the extraction of cotton fibers for the shirt, weaving it into material, and dying it, along with many elementary steps. The fiber extraction is aided by the use of a modern cotton gin, which has to “dry and clean the seed cotton, separate the fiber from the seed, further clean the fibres and place the fibres in to an acceptable package for commerce” (Bajaj and Sharma). This extraction creates emissions, but there is also an output of fabric scraps and waste that can be later turned into yarn for socks (Hanesbrands Inc.).
Next, the product is packaged and transported to a clothing store or a consumer who bought the product online. Once the tee shirt “dies”, it can be converted into other uses- such as rags- or thrown away. According to the California Cotton Ginners and Growers Association (CCGGA), the quantitative value shown below is the amount of water needed as an input in the “growth stage” of cotton’s LCA to produce one tee shirt.
*256.6 gallons of water/tee shirt
|Figure 4: Life Cycle Assessment of Cotton Tee-Shirt|
Hemp is one of the oldest cultivated fiber plants in the world and has been growing in popularity and use diversity over the years. The following table shows the display of hemp growth in different countries around the world:
|Figure 5: Global Industrial Hemp Growth (truthonpot, 2011)|
Naturellement Chanvre, an online-established brand of hemp tee shirts I am researching, are partnered with operations in Eastern Europe to develop their commodities. I am looking further into how much water is needed to produce one hemp tee-shirt from this website, specifically in the beginning “Hemp Growth” stage, the origin. The Life Cycle Assessment of this hemp tee shirt begins at the origin, the plant’s growth. On average, is takes 12-15 inches of water to grow one hemp plant each season; and there are generally 35-50 industrial hemp plants per square foot of land. Next, the plants are harvested by hand usually, and decorticating then follows. This process involves extracting the primary bast fibres, which are used for the actual hemp tee shirt material. Primary bast fibres make up over 50% of each hemp plant, and are thin, long, and rich in cellulose, having a relatively significant amount of strength (harbay). Before technology like steam explosion was put into practice, this bast fibre extraction was tedious, work-intensive, and took a long time to complete. Just for some background, the Steam Explosion Technology (STEX) website states, in regards to this process:
“Hemp fibres are treated with steam under high pressure and subsequently released through a cyclone. STEX enables the production of special fibres, which can be modified according to product requirements. Through adaptation of the process parameters, "tailor-made" fibres can be manufactured, which can be spun into new types of hemp yarn using cotton spinning systems” (de Vries).
Furthermore, steam explosion is one method gaining in popularity due to its efficiency in separating the desired fibres.
After these specific fibres are extracted, they are sent to apparel textiles, which I believe is located in France for this particular brand, to “cotton-ize” them, which involves spinning, weaving, and dying them into the materials used for tee shirts. The last few steps include transporting the hemp to the actual clothing stores where the tee shirt is sold and, assumingly, worn by a person until the end of its life. The death of a hemp tee shirt could involve throwing it away, using it as a rag, or finding another use for it. Shown below are calculations to find the amount of water needed, only looking at the growth phase of the Life Cycle Assessment, to create one hemp tee shirt. Multiple conversions are necessary.
*(1 acre/5 tons of dry hemp fibre stalk) x (42.5 hemp plants/1 ft2) x (4350 ft2/1 acre) x (1.083 ft3 water/1 hemp plant)
= 3081.25 ft3 of water/ ton of dry hemp fibre stalk
How much water per tee shirt?
Assumptions made: one hemp tee shirt is approximately 6oz
*(3081.25 ft3 of water/ton hemp fibre stalk) x (1 g/cm3 water) x (1 cm3/3.5315x10-5 ft3) x (3.125x10-5 ton/1 oz) x (6 oz/one hemp tee shirt)= 16361.8 g water/one hemp tee shirt
*(16361.8 g water/one hemp tee shirt) x (1 gallon water/3780 g water)
= 4.3285 gallons of water/one hemp tee shirt
|Figure 6: Life Cycle Assessment of Hemp Tee-shirt|
|Table One: Overview of Hemp versus Cotton|
From analyzing the water input of growing hemp versus cotton plants to produce one tee shirt of the given material, hemp arrives as the winner for most “environmental friendly”, consuming less water to make its product. Cotton needs almost 60 times the amount of water as hemp just to produce one tee shirt, which further supports why hemp is more“environmentally friendly” in the water-use aspect of its growth stage.
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Bajaj, Lav and Sharma, M.K., “Recent Advances in Ginning for Lowering Costs and Improving Efficiency.” Bajaj Steel Industries Unlimited, n.d. Web. 20 Oct. 2013.<icac.org>
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De Vries, Romke. “Stextile.” n.d. Web. 20 Oct. 2013. <stextile.com>
Ehrensing, Daryl T. "Feasibility of Industrial Hemp Production in the United States Pacific Northwest, SB681." Feasibility of Industrial Hemp Production in the United States Pacific Northwest, SB681. Oregon State University, May 1998. Web. 20 Oct. 2013. <oregonstate.edu>.
Hanesbrands Inc. “Product Raw Materials.” Hanesbrands Inc. 2010. Web. 20 Oct 2013. <hanesbrandscsr.com>
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