GOTS, OCS and OEKO-TEX: What Do T-Shirt Certifications Actually Tell You?

A T-shirt can be described as organic, GOTS-certified, OEKO-TEX certified or made with Better Cotton. These phrases sound reassuring, but they do not all mean the same thing.

Some standards verify the origin and chain of custody of a fibre. Others focus on chemicals and human health. Some extend into working conditions and environmental management. And some claims that look like certifications are not product certifications at all.

Certifications should therefore be treated as evidence with a defined scope — not as shorthand for “sustainable”.

A useful way to read any certification claim is to ask three questions:

What exactly is certified? The raw material, the fabric, a factory or the finished T-shirt?

What does the standard actually assess? Organic content, chemicals, working conditions, traceability — or several of these?

Does the documentation apply to this particular product? A certified supplier or factory does not automatically make every garment produced there a certified garment.

In this guide:

GOTS — Global Organic Textile Standard

GOTS is probably the most comprehensive certification commonly encountered on organic cotton clothing. It is a processing standard for textiles made with certified organic fibres and covers post-harvest stages such as spinning, knitting, dyeing and garment manufacturing. Its requirements include environmental criteria, restrictions on chemical inputs and human-rights and social criteria. The current GOTS Version 8 was released in March 2026 and becomes fully effective after its transition period on 1 March 2027.

One slightly confusing point is that GOTS itself does not certify cotton farming. The raw fibre entering the GOTS system must already have been certified organic under an accepted organic farming standard. GOTS then governs its processing through the textile supply chain.

GOTS has two principal label grades. A product labelled “organic” must contain at least 95% certified organic fibres. A product labelled “made with organic” must contain at least 70%.

What GOTS tells you

A genuine GOTS product claim can provide relatively strong evidence that:

the organic fibre input has been independently certified;
the certified material has been controlled through the textile supply chain;
processing is subject to specified chemical and environmental requirements;
relevant certified operations are subject to social and human-rights requirements;
the finished product meets the fibre-content threshold associated with its GOTS label grade.

What GOTS does not necessarily tell you

GOTS certification does not mean that a T-shirt is environmentally perfect, ethically perfect or high quality. It does not tell you whether the fabric will retain its shape, whether the collar will last, or whether the T-shirt will survive 100 washes.

It also matters what has actually been certified. A brand may use a GOTS-certified fabric, yarn or factory without the finished garment itself being a GOTS-labelled product. GOTS advises consumers to look for the actual label grade and licence information when checking whether a product itself is certified.

This distinction is important. Statements such as “made using GOTS-certified cotton”, “produced in a GOTS-certified factory” and “GOTS-certified T-shirt” are not interchangeable.

GOTS also does not normally tell a consumer the fibre grade, staple length or exact farm from which the cotton in a particular T-shirt came. And although social criteria are part of the standard, certification should be understood as evidence that defined requirements and auditing procedures are in place — not as proof that no labour problem can ever occur anywhere in a supply chain.

Takeaway: GOTS is a relatively broad and meaningful certification, but check whether the claim applies to the finished T-shirt rather than merely to one material or supplier.

OCS — Organic Content Standard

The Organic Content Standard is much narrower than GOTS.

OCS verifies organically grown material and tracks it through the supply chain using third-party certification and chain-of-custody requirements. It is designed to substantiate claims about organic content in a product.

However, OCS does not address chemical use or broader social and environmental aspects of textile production beyond the integrity of the organic material.

What OCS tells you

OCS can provide evidence that:

the claimed organic raw material originates from an accepted certified organic system;
the material has been tracked through a certified chain of custody;
the amount of organic material claimed in the product has been independently verified.

What OCS does not tell you

An OCS label does not, by itself, establish:

how environmentally responsible the dyeing process was;
which chemicals were used;
whether the factory has strong labour standards;
whether workers receive fair wages;
whether wastewater, energy or emissions were managed well;
whether the finished T-shirt is durable or well constructed.

This makes OCS a good example of why the phrase “certified sustainable” is often too vague. OCS verifies something specific and useful: the integrity of an organic-material claim. It was never designed to certify the complete sustainability performance of a garment.

Textile Exchange is currently transitioning its standards system toward its new Materials Matter Standard, which becomes effective at the end of 2026 and mandatory for relevant audits from the end of 2027. OCS is being integrated gradually into that broader system.

Takeaway: OCS is strong evidence for organic-content traceability, but relatively weak evidence for the sustainability of everything that happens after the cotton is grown.

OEKO-TEX STANDARD 100

OEKO-TEX STANDARD 100 answers a completely different question.

Its central purpose is to test textile products and components for harmful substances. OEKO-TEX states that every thread, button and accessory in a certified article is tested against a list of more than 1,000 substances, with stricter requirements for products involving greater skin contact.

For a T-shirt — something worn directly against the skin — this is clearly relevant.

What STANDARD 100 tells you

It provides evidence that the certified material or product has passed OEKO-TEX testing against its applicable limits for harmful substances. The limits are reviewed regularly and vary according to product class and intended skin contact.

What STANDARD 100 does not tell you

STANDARD 100 is not an organic certification.

A conventional cotton T-shirt can be STANDARD 100 certified. The label does not in itself tell you:

where the cotton was grown;
whether it was organic;
how much water was used in cultivation;
whether workers were paid fairly;
whether the factory has good environmental management;
whether the supply chain is traceable from farm to garment.

This is one of the most common sources of confusion. OEKO-TEX STANDARD 100 is meaningful, but primarily as a product-safety and harmful-substance standard, not as a holistic sustainability certification.

And again, scope matters. An OEKO-TEX-certified yarn or fabric does not necessarily mean that the final garment itself carries a product-level STANDARD 100 certification.

White Tee Lab takeaway: STANDARD 100 is useful evidence about harmful substances. It should not be read as evidence that the cotton is organic or that the overall supply chain is socially and environmentally sustainable.

OEKO-TEX MADE IN GREEN

MADE IN GREEN is considerably broader than STANDARD 100.

A MADE IN GREEN textile must meet OEKO-TEX product-safety requirements while also involving production facilities certified to OEKO-TEX STeP, which addresses environmental performance and socially responsible production. The label also provides traceability information through a unique product ID or QR code.

This makes MADE IN GREEN closer to the kind of multi-dimensional label consumers may assume STANDARD 100 already is.

But there are still limits

MADE IN GREEN is not automatically an organic-cotton certification. The underlying fibre can be conventional unless another relevant certification establishes otherwise.

Its traceability requirements are meaningful, but they do not necessarily amount to a complete public map of every actor from cotton field to finished garment. For finished products, OEKO-TEX specifies required facilities and components that must be included in the MADE IN GREEN supply-chain system rather than simply requiring every conceivable upstream stage to appear on a consumer-facing label.

White Tee Lab takeaway: MADE IN GREEN covers considerably more than STANDARD 100, but it still pays to ask separately what is known about the cotton itself.

Fairtrade Cotton

Fairtrade adds another dimension: economic conditions for cotton producers.

The Fairtrade Cotton Mark indicates that the cotton has been produced and traded according to Fairtrade requirements and that the Fairtrade cotton is traceable through processing. For blended fabrics carrying the Cotton Mark, Fairtrade states that all of the cotton component must be Fairtrade certified.

Fairtrade also operates a separate Textile Standard, which extends into textile manufacturing and includes requirements relating to labour conditions, occupational health and safety and progress toward living wages.

This distinction matters: Fairtrade Cotton and certification of textile manufacturing under the Fairtrade Textile Standard are not the same claim.

Limitations

Fairtrade cotton tells you substantially more about trading arrangements and farmer-level economics than GOTS or OCS do, but a Fairtrade Cotton Mark alone does not certify every environmental and social dimension of the garment-manufacturing process.

Conversely, a T-shirt may contain organically certified cotton without saying anything comparable about the price or premium received by the cotton farmers.

White Tee Lab takeaway: Fairtrade and organic certification answer different questions. Neither should automatically be treated as a substitute for the other.

And what about Better Cotton?

Better Cotton is also commonly encountered, but its claims require particular care.

Historically, much Better Cotton sourcing used a mass-balance system. Under mass balance, Better Cotton could be mixed or substituted with conventional cotton after the gin, while equivalent sourcing volumes were tracked through the system. In those cases, the cotton in a particular garment could not be traced back to the claimed cotton source.

The system has changed significantly. Better Cotton now also operates physical chain-of-custody models, and its newer BCI Cotton label is associated with certified, traceable physical cotton. Its old mass-balance on-product mark was phased out for new products in 2026.

So an old statement such as “we source Better Cotton” and a current product bearing a traceable BCI Cotton label may represent quite different levels of product-level traceability.

White Tee Lab takeaway: With Better Cotton, always ask whether the claim refers to mass-balance sourcing or physical, traceable cotton.

Certification is evidence — not a verdict

The biggest mistake is probably to divide T-shirts into two groups:

certified = sustainable
uncertified = unsustainable

Reality is more complicated.

A certification can provide valuable third-party evidence, but each standard has boundaries. A certified T-shirt can still be poorly made and short-lived. An uncertified garment may come from an unusually transparent, well-run supply chain. A strong fibre certification may say little about garment manufacturing, while a chemical-safety certification may say almost nothing about farming.

At White Tee Lab, certifications are therefore considered alongside: