Anti-odour activewear: finishes, tests and claim rules

What does an anti-odour finish actually do?

Odour in sportswear builds up as bacteria grow on sweaty fabric, and suppliers tackle it in three quite different ways. The table separates them, because the right test and the legal position follow from the mechanism, not from the marketing name.

Ask the supplier of the finish, not only the fabric mill, for its trade name, active substance and CAS number, safety data sheet and application method. A finish built into the fibre and one applied after dyeing need separate durability evidence.

Which test supports which claim?

Test exactly what the hang tag says. ISO 20743 measures antibacterial activity on any textile, whatever the agent or application method, using absorption, transfer or printing inoculation and comparing bacterial counts with an untreated control. AATCC TM100 is the established US quantitative method, and AATCC notes that when killing bacteria is intended or implied, a quantitative evaluation is necessary.

The ISO 17299 series measures something else: how far a fabric lowers the concentration of specific odour gases in a closed container, using detector tubes, gas chromatography, condensation sampling or metal-oxide sensors. The series represents sweat odour by ammonia, acetic acid and isovaleric acid, adding nonenal for body odour. Neither family of tests reproduces a wearer after training, so a structured wear trial is a useful extra, not a substitute.

How many washes should a durability claim survive?

As many as the claim implies, tested on your own fabric. An unwashed result only proves the fabric worked when it left the finishing line, and there is no single industry wash count to fall back on, so the number belongs in both the claim and the contract. A supplier’s brochure figure may come from its own reference fabric, which can differ from yours in fibre, weight and dyeing.

Agree these points in writing before the first test:

• Washing procedure: ISO 6330 or an AATCC laundering method, with programme, temperature, detergent and load.
• Drying method, since tumble drying adds heat and mechanical action that line drying does not.
• Cycle count matched to the claim, plus an unwashed baseline from the same fabric lot.
• Pass rule after washing, such as a minimum antibacterial activity value or odour reduction, set with the laboratory.
• Care conditions that the finish supplier says will reduce performance (ask specifically about softener, bleach and high heat), so the care label supports the claim.

What do EU and British rules require for biocidal finishes?

Under the EU Biocidal Products Regulation, (EU) No 528/2012, a garment treated with a biocidal product is a treated article. Its active substances must be approved, or still under evaluation in the EU review programme, for the relevant product type, and for imported garments the importer carries these duties. Great Britain runs its own version of the regulation, so check the substance against the GB list as well.

Consumers may ask what an article was treated with and must receive the answer free of charge within 45 days. Sweden’s Chemicals Agency adds that words such as “odourless” or “antibacterial” can trigger labelling, and that claims to protect the wearer rather than the fabric may make the garment a biocidal product needing its own authorisation. A purely odour-capturing finish with no biocidal action falls outside these rules, but it must not then be described as antibacterial.

Once a biocidal property is claimed, Article 58 requires a label, in the local language, stating:

• that the article incorporates biocidal products;
• the biocidal property, where substantiated;
• the name of every active substance;
• any nanomaterial, followed by “(nano)”;
• relevant instructions and precautions for use.

What can a US hang tag say?

EPA’s treated-article exemption, 40 CFR 152.25(a), covers a garment only if its antimicrobial is registered for that use and protects the article itself. PR Notice 2000-1 accepts odour wording such as statements that a product is odour-resistant or has been treated to resist bacterial odours. Claims of antibacterial, germicidal or disinfecting action, named pathogens such as Staphylococcus aureus, and unqualified “antimicrobial” are public-health claims that require the product itself to be registered as a pesticide.

Laboratory antibacterial reports usually name their test organisms, often including Staphylococcus aureus. Keep the report on file, but keep the organism names off US packaging and product pages.

What should the buyer keep on file?

SenLin publishes no anti-odour test results, and tests are agreed per order. If a finish is part of the brief, name the finish, its supplier, the test method and the wash count in the enquiry, so the costed bill of materials and the bulk inspection record describe the same specification. Approve the treated sample for wicking, colour and hand feel too, because any finish adds chemistry to the fabric.

Whoever finishes the fabric, keep one file per fabric and finish containing:

• Finish supplier, trade name, active substance, CAS number and safety data sheet.
• Regulatory status: EU and GB approval for the product type, and US registration for textile use.
• For OEKO-TEX STANDARD 100 products, confirmation that the agent is on the accepted ACP list.
• Test reports naming your fabric reference, colour and finishing lot, unwashed and washed.
• The approved hang tag and online wording, checked line by line against the reports.