Elastane is normally made with petroleum distillades that are non-renewable resources. Elastane is used together with other fibers to give the fabric elasticity.
Recycling the other fibers from elastane blend fabric can be difficult. However using elastane is nearly necessary when it comes to lingerie. With elastane it's possible to make skin tight fit, support and stretch to last after after several uses.
Well-known trade names for elastane are e.g. Lycra and Spandex.
There are also recycled elastane fibers which environmental impacts are smaller than with regular elastane. For example Roica Eco Smart -fibers are recycled elastane fibers.