The difference between OEKO-TEX and FSC
Short answer: OEKO-TEX tests the finished fabric for harmful substances. FSC concerns how the raw material was grown and harvested. The two say completely different things.
What OEKO-TEX covers
OEKO-TEX Standard 100 is a test of the finished product. Every component, including thread, buttons and prints, is tested against a long catalogue of substances that can be problematic for skin. If the item passes, the label may be used.
What FSC covers
FSC concerns forestry and how the plant material was grown and harvested. It says nothing about chemistry in the finished fabric but something about where the raw material came from. See FSC certified items.
Why both are relevant
For clothing against the skin, OEKO-TEX is the most directly relevant, because it is about what is in the fabric. FSC answers a different question about origin. See OEKO-TEX certified items and bamboo underwear for women.
Frequently asked questions
Does OEKO-TEX mean no chemistry was used
No. It means the finished fabric has been tested and sits below the limits for a long list of substances.
Does the label cover the whole item
Yes, under Standard 100 it covers every component of the finished item.
Can a product carry both labels
Yes. They test different things and do not exclude each other.