New Research Reveals Which Fabrics Start to Smell the Quickest — And Why It Matters for Your Wardrobe, Wallet, and the Planet
If your gym T-shirt stinks after just one wear, you’re not alone. Groundbreaking research conducted by AgResearch in New Zealand, in collaboration with Consumption Research Norway (SIFO), has confirmed what many of us suspected: polyester garments smell the quickest and require the most frequent washing compared to cotton and wool — particularly Merino wool, which emerged as the champion of odor resistance.
But this study is more than just about stink. It’s about rethinking our clothing choices — not just based on price or style, but how often we wash them, their impact on the environment, and our daily lives.
🔬 What the Research Found
As part of a study funded by Australian Wool Innovation, volunteers were asked to wear garments — including T-shirts, hoodies, and socks — made of polyester, cotton, and Merino wool. The garments were worn repeatedly, and participants recorded when each item started to smell enough to require washing.
Key results:
- Polyester clothes smelled the fastest and required the most frequent laundering.
- Cotton held out a bit longer, needing fewer washes than polyester.
- Merino wool significantly outperformed both, often going days longer without odor.
- As a result, wool garments had the lowest annual energy use related to washing.
🌍 Why This Matters: Sustainability & Energy Consumption
In fashion sustainability discussions, we often focus on production impacts — water usage, pesticides, carbon emissions, etc. But what’s often ignored is the “use phase” of clothing: how we use, maintain, and dispose of garments.
Here’s why that’s a problem:
- Laundering clothes accounts for up to 30% of a garment’s environmental impact.
- Frequent washing = higher water and energy consumption + faster wear and tear.
- Clothes that last longer between washes are more eco-friendly by design.
According to the study, wool garments can cut wash-related energy use by up to 50% compared to polyester. That’s a game-changer.
💡 Why Polyester Smells Worse
Let’s get technical for a second.
- Polyester is hydrophobic – it repels water and sweat, meaning moisture (and bacteria) sit on the surface.
- The synthetic nature of the fiber holds onto oily compounds from sweat, which bacteria love.
- Bacteria multiply and release volatile organic compounds (VOCs), causing odor.
- These smells linger longer and are harder to wash out.
In contrast:
- Wool is naturally antimicrobial and absorbs moisture without feeling wet.
- Cotton is breathable and absorbent, though it doesn’t fight bacteria as effectively as wool.
🧼 Rethink Your Laundry Habits
We’ve been trained to wash clothes after just one wear, especially with synthetics. But this research challenges that habit.
🧺 Here’s what you can do:
- Switch to Merino Wool (especially for socks, base layers, and athletic wear)
- Costs more, but lasts longer and requires fewer washes.
- Wash Less, Air More
- Odor often comes from bacteria, not dirt. Airing out garments — especially wool — can refresh them without washing.
- Avoid Polyester for Everyday Use
- Use synthetics only when necessary (like rainwear or certain sports gear), and opt for natural fibers when possible.
- Use Eco-Friendly Detergents
- When washing is needed, use biodegradable detergents and wash in cold water to save energy.
📉 Fast Fashion vs. Smart Fashion
The fashion industry often pushes us toward cheap, synthetic clothes made of polyester and nylon. But these come at a hidden cost:
- More frequent laundering
- More energy use
- More microplastic pollution in waterways
- Shorter garment life
- More landfill waste
Smart fashion means buying better, wearing longer, and washing smarter. Wool, especially Merino, may cost more upfront, but it saves you time, energy, money — and the environment — in the long run.
🔄 Final Thought: Sustainability Starts With You
This study gives us a powerful reminder: what you wear matters — even after you buy it. Sustainability isn’t just about the manufacturing stage. It’s about how often you wash, how long clothes last, and how you dispose of them.
So next time you’re shopping, ask not just “how much does this cost?”, but “how often will I need to wash it?” and “what will it cost the planet?”
✅ TL;DR Summary:
| Fabric | Odor Resistance | Wash Frequency | Sustainability Impact |
|---|---|---|---|
| Polyester | ❌ Poor | ❌ High | ❌ High energy, microplastic pollution |
| Cotton | ✅ Moderate | ✅ Medium | ✅ Better than polyester |
| Wool | ✅✅ Excellent | ✅✅ Low | ✅✅ Best for the planet |