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Life cycle analysis for cotton and polyester
| Fibre production |
| |
Polyester |
Cotton |
| Energy (megaJoules) |
97 MJ |
60 MJ |
| Oil or gas |
1.5kg |
- |
| Fertilisers |
- |
457g |
| Pesticides |
- |
16g |
| Water |
17 litres |
22,200 litres |
| Carbon dioxide emissions |
2.3kg |
3.0kg |
| Approximate cost |
£0.78 |
£1.13 |
| Fibre production |
| |
Polyester |
Cotton |
Energy recovery from incineration
(megaJoules) |
33 MJ |
7 MJ |
| Landfill biodegradable |
No |
Yes |
| Carbon dioxide from landfill |
- |
5.5 |
| Recycled |
Yes |
Yes |
| Fabric weaving |
| |
Polyester |
Cotton |
| Energy (megaJoules) |
33 MJ |
40 MJ |
| Water |
1,291 litres |
3,900 litres |
| Carbon dioxide emissions |
1.5kg |
2.3kg |
| Use |
| |
Polyester |
Cotton |
| Energy per wash (megaJoules) |
3.4 MJ |
3.4 MJ |
Energy per dry
(megaJoules) |
Cannot tumble dry |
12.6 |
Shrinkage
(100 washes) |
4% |
7% |
| Loss of strength (100 washes) |
8% |
17% |
| Water per wash |
49 litres |
49 litres |
|
Click on the stages in the life cycle to compare the two fibres.
Figures relate to 1kg of fibre/fabric. |
Summary of life cycle analysis
Over a lifetime of two years, which includes 12 washes, the results show how 1kg of each fabric performs. |
|
Energy |
Polyester uses 171.5 megaJoules of energy.
Cotton uses 140.1 megaJoules of energy. |
Cotton  |
Oil and gas |
To make 1kg of polyester takes 1.53kg of oil or gas.
Cotton grows naturally. |
Cotton |
Fertilisers and pesticides |
Growing 1kg of cotton uses 457g of fertilisers and 16g of pesticides.
Some growers are organic, and do not use chemicals, but this is less common. |
Polyester |
Emissions |
1kg of polyester is responsible for 3.8kg of carbon dioxide while cotton causes 5.3kg.
Sulfur dioxide causes acid rain. Cotton results in 4g and polyester 0.2g.
|
Polyester |
Water |
Polyester uses 1,900 litres (including washes). Irrigating the cotton crops means 1kg requires 26,700 litres of water during its life. |
Polyester |
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