Let first know about basic concept of Sustainability:
Sustainable is a pattern of resource use, that aims to meet human needs while preserving the environment so that these needs can be met not only in the present, but also for generations to come
The field of sustainable development can be conceptually broken into three constituent parts:
environmental sustainability,
economic sustainability and
Quality and Social Standards:
As organic cotton in its LC (life cycle) does not use any harmful chemicals, thus ensure sustainability in
-envronment control
-economical use of natural resources
-looking ethical and ecological issues
-social standards.
thus, it is believed that organic cotton and its processing through its life cycle is the best methods implemented unto now. GOTS(Global ORGANIC Textile Standard) concept make your idea clear in this regards.