If you've looked at APRÍ's labels or product pages, you've seen the name HeiQ Mint. It's the technology behind APRÍtech™ — our plant-based anti-odour treatment. But what is it, how does it work, and why does it matter that it's plant-based rather than the silver-ion approach used by most of the industry?

Here's the full picture.

What is HeiQ?

HeiQ is a Swiss materials science company that develops advanced functional technologies for textiles. Founded by researchers from ETH Zurich, HeiQ has built a portfolio of textile treatments used by brands across performance apparel, medical textiles, and outdoor equipment.

Their Mint technology is part of HeiQ's AeoniQ and bio-based materials platform — a range of treatments derived from natural sources rather than synthetic chemicals or heavy metals. HeiQ Mint uses the natural antimicrobial properties of peppermint as its core active ingredient.

How HeiQ Mint Works

The odour from workout clothes isn't actually caused by sweat itself — sweat is almost odourless. The smell comes from bacteria. Specifically, microorganisms that live on the skin and embed in fabric fibres, breaking down compounds in perspiration and producing the volatile organic compounds (VOCs) that create that familiar post-workout smell.

Peppermint has been used for its antimicrobial properties for centuries. At a molecular level, compounds in peppermint oil — particularly menthol and related terpenoids — disrupt the cell membranes of bacteria, preventing them from colonising and multiplying on the fabric surface.

HeiQ has stabilised and concentrated these natural properties into a textile treatment that:

• Bonds durably to fabric fibres during the manufacturing process
• Remains active across many wash and wear cycles
• Works by preventing bacterial activity — not by masking odour with fragrance
• Contains no silver, zinc, or other heavy metals

The distinction between preventing odour and masking it matters. A perfumed garment smells fine until the fragrance fades, then the underlying bacterial odour returns — often worse than before. HeiQ Mint prevents the odour from forming in the first place, so there's nothing to mask.

The Problem With Silver-Ion Treatments

The activewear industry has known about the synthetic fabric odour problem for years. The standard response has been to add silver or zinc ions to the fabric — heavy metals that kill bacteria on contact.

Silver-based treatments do work, to a point. But they come with significant limitations:

• Washout: Silver and zinc ions aren't permanently bonded to fibres. They wash out progressively — often losing significant effectiveness within 10–20 wash cycles, depending on water hardness, temperature, and detergent type.
• Environmental release: Silver and zinc ions that wash out of clothing enter wastewater systems. Multiple studies have found that silver nanoparticles and ions from textiles are toxic to aquatic organisms at relevant concentrations.
• Regulatory trajectory: The EU's REACH regulation already restricts certain heavy metals in textiles. France's 2025 PFAS ban — banning "forever chemicals" from textiles — signals the direction of travel for European regulation. Heavy metal antimicrobial treatments are expected to face increasing scrutiny.

HeiQ Mint avoids all three of these problems. It's plant-derived, designed for durability, and leaves no heavy metals to leach into water systems.

The Data: 94% After 20 Washes

Independent testing shows that HeiQ Mint retains more than 94% of its antimicrobial effectiveness after 20 wash cycles at 30°C. That's 20 complete wash cycles — not 20 days — with near-full performance still intact.

For context: if you train 4 days a week and wash your activewear after every session, 20 washes is about 5 weeks of heavy use. Most silver-based treatments are showing significantly degraded performance by this point; HeiQ Mint is still performing at 94%+ of initial effectiveness.

Washing at 30°C is key — both for preserving the treatment and for reducing the energy footprint of laundry. Higher temperatures accelerate the breakdown of any anti-odour treatment, regardless of the technology used.

What APRÍtech™ Actually Means

APRÍtech™ is APRÍ's label for garments treated with HeiQ Mint. When you see it on a product, it means:

• The garment has been treated with HeiQ Mint during manufacturing — integrated into the fabric, not sprayed on after the fact
• The treatment is plant-based, free from silver, zinc, and heavy metals
• Independent testing confirms 94%+ effectiveness retention after 20 washes at 30°C
• The fabric base is TENCEL™ Lyocell — which naturally resists bacterial build-up, making the treatment even more effective

HeiQ Mint vs NordShield: What's the Difference?

APRÍ uses two plant-based anti-odour technologies across the collection:

• APRÍtech™ — HeiQ Mint: Mint-derived, bio-based, Swiss technology. Strong track record of wash durability, particularly effective against the most common odour-causing bacteria strains.
• APRÍshield™ — NordShield: Made from wood extractives — a byproduct of Scandinavian sustainable forestry. Fully biodegradable. Works by creating a surface environment hostile to bacterial colonisation, using compounds that occur naturally in Nordic wood species.

Both are free from heavy metals and biocides. Both are tested for skin safety and certified under OEKO-TEX Standard 100. The choice between them depends on the specific garment and its performance requirements. You can read more about NordShield and APRÍshield™ here, or see the side-by-side comparison on our Technology page.

Safety

HeiQ Mint is safe for direct, prolonged skin contact. APRÍ garments are certified to OEKO-TEX Standard 100, and also meet GOTS (Global Organic Textile Standard) and Bluesign requirements — three of the most rigorous independent testing and certification frameworks in the textile industry.

For people with sensitive skin, the plant-based nature of HeiQ Mint means there are no heavy metal ions in contact with the skin — a meaningful consideration given growing awareness of the effects of silver and zinc ions in textiles.

The Bottom Line

HeiQ Mint is the answer to a question the sportswear industry has struggled with for years: how do you create activewear that genuinely doesn't smell, without using heavy metals that wash out and pollute waterways?

Plant-based technology, durably applied, tested to retain 94%+ effectiveness after 20 washes, combined with a Lyocell fabric base that naturally resists bacterial accumulation. That's what APRÍtech™ delivers.

Want the full overview of both our technologies side-by-side? Visit our Technology hub.

If you want to experience the difference — and not have to think about gym clothes smell again — explore the APRÍtech™ collection →