OEKO-TEX and Activewear: What the Certification Actually Means
OEKO-TEX Standard 100 is an independent third-party certification that tests textiles for harmful substances. A garment or fiber carrying this certification has been tested for more than 1,000 chemicals including PFAS, phthalates, formaldehyde, heavy metals, azo dyes, and known endocrine disruptors, and found to contain none at harmful levels. It is the most widely recognised textile safety certification available and the most reliable consumer indicator that a fabric has been independently screened for chemical safety. For activewear, it is the most meaningful certification to look for because it directly addresses the chemicals of concern in conventional synthetic fabrics.
- OEKO-TEX Standard 100 tests for more than 1,000 harmful substances including PFAS, phthalates, formaldehyde, and heavy metals
- Certification is issued by independent OEKO-TEX member institutes, not by the brand itself
- Applies at different levels: fiber, yarn, fabric, or finished product — each covers a different scope
- Finished-product certification provides the most complete consumer protection
- Bellissima holds OEKO-TEX Standard 100 certification at fiber level through Lenzing AG for TENCEL Lyocell
- Finished-product OEKO-TEX certification for Bellissima garments is in progress
- OEKO-TEX is not an environmental or sustainability certification — it specifically tests for chemical safety
What Is OEKO-TEX?
What does OEKO-TEX mean?
OEKO-TEX is an independent international association of textile research and testing institutes, founded in 1992. It administers several certification standards for textile safety and sustainability. The most widely known is OEKO-TEX Standard 100, which specifically tests textiles for harmful substances. The name is derived from the German word for ecological (ökologisch) and textile. OEKO-TEX member institutes conduct testing and issue certification independently of the brand or manufacturer seeking certification, which is what gives it credibility as a third-party standard rather than a self-declared claim.
What is OEKO-TEX Standard 100?
OEKO-TEX Standard 100 is a product certification for textiles that tests for the presence of harmful substances at every stage of production. It covers raw fibers, yarns, fabrics, and finished garments. A product carrying the OEKO-TEX Standard 100 label has been tested by an independent OEKO-TEX member institute for more than 1,000 substances including PFAS, phthalates, formaldehyde, heavy metals, pesticide residues, azo colorants that can release carcinogenic amines, allergenic dyes, and pH levels. The test limits are set based on the intended use of the product, with stricter limits applied to products intended for contact with sensitive skin and baby products than for outerwear.
Is OEKO-TEX a sustainability certification?
No. OEKO-TEX Standard 100 is a chemical safety certification, not an environmental or sustainability certification. It tests for harmful substances in the finished product or material. It does not evaluate carbon footprint, water use, labor conditions, or end-of-life environmental impact. Brands sometimes present OEKO-TEX certification alongside sustainability claims, which can create confusion. If a brand claims OEKO-TEX as evidence of environmental responsibility, that is an overstatement of what the certification covers. For environmental and supply chain standards, the relevant certifications are GOTS (Global Organic Textile Standard), the EU Ecolabel, and FSC or PEFC for fiber sourcing.
Are there different types of OEKO-TEX certification?
Yes. OEKO-TEX administers several distinct standards. OEKO-TEX Standard 100 is the chemical safety product test described above. OEKO-TEX LEATHER STANDARD applies the equivalent substance testing to leather. OEKO-TEX STeP (Sustainable Textile and Leather Production) certifies production facilities against environmental and social responsibility criteria. OEKO-TEX MADE IN GREEN is a product label that combines Standard 100 substance testing with STeP facility certification, providing both chemical safety and supply chain accountability. For the purposes of activewear chemical safety, Standard 100 is the relevant certification to evaluate.
What Does OEKO-TEX Actually Test For?
Does OEKO-TEX test for PFAS?
Yes. OEKO-TEX Standard 100 tests for per- and polyfluoroalkyl substances (PFAS) as part of its substance screening. A fiber or garment that holds OEKO-TEX Standard 100 certification has been tested for PFAS and confirmed to contain none at or above the permitted limits. This makes OEKO-TEX Standard 100 one of the most practical consumer tools for identifying PFAS-free textiles, because there is currently no legal requirement for brands to disclose PFAS on garment labels in most markets. Third-party certification that explicitly includes PFAS in its test scope provides the confirmation that label reading alone cannot.
Does OEKO-TEX test for phthalates?
Yes. Phthalates, a class of chemical plasticisers associated with endocrine disruption, are included in the OEKO-TEX Standard 100 substance list. Research by Vandenberg et al. (2012), in Endocrine Reviews, identified phthalates among the chemical classes most associated with hormonal disruption in consumer products. Their inclusion in OEKO-TEX testing means a certified product has been confirmed free from these compounds at harmful levels, providing independent assurance on a substance class that consumers cannot assess from ingredient lists because garments are not required to carry chemical ingredient disclosure in the way cosmetics or food products are.
Does OEKO-TEX test for formaldehyde?
Yes. Formaldehyde is a known carcinogen used in some textile finishing processes as a wrinkle-resistance treatment and fabric stabiliser. OEKO-TEX Standard 100 tests for formaldehyde and sets strict limits based on product category, with the tightest limits applied to products intended for baby and infant use and products worn directly against skin. Activewear falls in the direct skin contact category, which carries stricter formaldehyde limits than outerwear or decorative textiles.
What harmful substances does OEKO-TEX not test for?
OEKO-TEX Standard 100 does not cover all possible chemical hazards. It tests a defined list of substances based on current scientific understanding and regulatory priority. Emerging chemical classes not yet on the list, novel processing chemicals that postdate the testing framework, and microplastic shedding are outside its scope. It also does not test for environmental contaminants that may enter a textile from its surrounding environment during production or storage rather than from the manufacturing process itself. It is the most comprehensive available consumer textile safety certification, but it is not an absolute guarantee of zero chemical exposure from all possible sources.
Understanding Certification Levels
What is the difference between fiber-level and finished-product OEKO-TEX certification?
This is the most important distinction for consumers evaluating brand OEKO-TEX claims. Fiber-level certification means the raw fiber material has been tested and certified. It confirms the fiber itself is free from harmful substances. It does not cover what happens to that fiber after it leaves the fiber manufacturer: the dyeing process, finishing chemicals, threads, elastic, labels, and accessories used in garment construction are not covered by fiber-level certification. Finished-product certification means the complete garment as sold to the consumer, including all components, has been tested and certified. This is the more complete and consumer-relevant certification level. A brand citing fiber-level certification while implying whole-garment safety is overstating what the certification confirms.
Can a brand claim OEKO-TEX if only the fiber is certified?
Technically yes, but the claim requires accurate disclosure of what is and is not certified. A brand using OEKO-TEX Standard 100 certified fiber can state that its fiber is certified. It cannot accurately claim that its finished garments are OEKO-TEX certified unless the garments themselves have been through the certification process. The distinction matters because dyes, finishing chemicals, and garment components not present in the raw fiber can introduce harmful substances that the fiber certification does not cover. Brands that clearly distinguish between fiber-level and finished-product certification are being precise. Brands that present fiber-level certification as whole-garment certification are overstating it.
How should I read an OEKO-TEX claim on a brand's website?
Look for three things. First, which specific standard is claimed: Standard 100, MADE IN GREEN, or another variant. Second, what level is certified: the fiber, the fabric, or the finished garment. Third, whether the certification number is provided: every OEKO-TEX certificate has a unique identifier that can be verified on the OEKO-TEX website at oeko-tex.com. A brand that provides the certificate number and clearly states what is and is not covered is being transparent. A brand that references OEKO-TEX without a certificate number, without specifying the certification level, or in a way that implies broader coverage than is accurate, should be scrutinised more carefully.
OEKO-TEX and Activewear
Why does OEKO-TEX matter specifically for activewear?
Activewear is worn in conditions that increase the potential for chemical transfer from fabric to body. During exercise, skin temperature rises and sweat production increases, both of which can increase the rate at which substances migrate from fabric to skin. Activewear is also worn in close contact with high-surface-area skin regions during dynamic movement, and is typically laundered frequently, which can cause chemical finishes to degrade and release compounds over time. The combination of close skin contact, heat, sweat, and frequency of wear makes the chemical safety of activewear more consequential than the same chemicals in outerwear or occasional-use garments. OEKO-TEX certification addresses these concerns directly by testing for the substances most relevant to skin-contact textile safety.
Do most activewear brands have OEKO-TEX certification?
No. OEKO-TEX certification at the finished-product level is not the industry standard in activewear. Most mainstream activewear brands, including the largest global players, do not carry OEKO-TEX Standard 100 finished-product certification on their core activewear lines. Some carry it on specific product ranges or at the fabric-supplier level without extending it to the finished garment. OEKO-TEX certification requires ongoing testing and renewal, carries a cost, and involves external audit, which creates a higher bar than self-declared non-toxic or clean claims that do not require independent verification.
What is Bellissima's OEKO-TEX status?
Bellissima's Sempre collection is made from 92% TENCEL Lyocell and 8% spandex. The TENCEL Lyocell fiber used in Bellissima's garments holds OEKO-TEX Standard 100 certification through Lenzing AG, the fiber producer. This means the fiber has been tested for more than 1,000 harmful substances including PFAS, phthalates, and formaldehyde, and certified free from these at harmful levels. Finished-product OEKO-TEX Standard 100 certification for the complete Bellissima garments, which would cover dyes, threads, and accessories in addition to the fiber, is in progress. Bellissima states this distinction explicitly: fiber-level certified through Lenzing, finished-product certification pending. This is accurate disclosure rather than overclaiming certification that does not yet apply to the whole garment. Browse Bellissima's non-toxic activewear collection to see the full Sempre range.
Comparing OEKO-TEX to Other Certifications
What is the difference between OEKO-TEX and GOTS?
OEKO-TEX Standard 100 tests the finished product for harmful substances. It does not require organic fiber input or make claims about how the fiber was grown. GOTS (Global Organic Textile Standard) requires certified organic fiber input, typically organic cotton, and also covers dyeing and finishing processes against environmental and social standards. A GOTS-certified garment comes from certified organic fiber and is processed within GOTS-compliant supply chains. An OEKO-TEX Standard 100 certified garment has been tested for harmful substance residues regardless of whether the input fiber was organically grown. Both are credible independent certifications with different scopes. OEKO-TEX is more relevant for synthetic-free chemical testing. GOTS is more relevant for organic fiber provenance and supply chain accountability.
Is OEKO-TEX or GOTS better for activewear?
OEKO-TEX Standard 100 at the finished-product level is more directly relevant to the chemical safety question in activewear. GOTS requires organic fiber input, which typically means cotton, and cotton is not the strongest performing natural fiber for structured exercise. OEKO-TEX Standard 100 is fiber-agnostic and tests the finished garment regardless of fiber origin, making it applicable to TENCEL Lyocell, merino wool, and other non-cotton natural fiber activewear in addition to organic cotton. For a buyer focused specifically on chemical safety in activewear, finished-product OEKO-TEX Standard 100 is the most practically useful certification to verify.
Sources
OEKO-TEX Association (2024). OEKO-TEX Standard 100 Criteria Catalogue. OEKO-TEX Association.
Lenzing AG (2023). Annual and Sustainability Report. Lenzing Group.
Peaslee, G.F., et al. (2020). PFAS in Clothing. Environmental Science and Technology Letters.
Vandenberg, L.N., et al. (2012). Hormones and Endocrine-Disrupting Chemicals: Low-Dose Effects and Nonmonotonic Dose Responses. Endocrine Reviews.