Think your laundry’s squeaky-clean after a hot cycle? Think again. New research reveals that even a 60 °C (140 °F) wash may leave behind stubborn, potentially harmful bacteria and could even fuel antibiotic resistance.
When “Hot” Isn’t Hot Enough
Healthcare guidelines often insist on 60 °C washes to disinfect uniforms. But Katie Laird and her team at De Montfort University tested six popular home washers using fabric samples soaked in Enterococcus faecium, a bacterium notorious for causing urinary tract infections and other health issues. They discovered that:
- Rapid 60 °C cycles in half of the machines cut bacterial counts by less than 90%.
- Standard 60 °C cycles still left one-third of machines failing to disinfect.
Why? Many machines never truly reach—or sustain—their advertised temperatures, especially on quick cycles. In one startling case, a “60 °C” wash was actually running at a chill 20 °C (68 °F), unknown to its owner.
Bacteria on the Rise
Even worse, Laird’s DNA analyses showed that bacteria lingering in your washer can develop genes that make them resistant to detergent over time. Every half-clean spin gives them a chance to adapt, meaning your laundry room might be a breeding ground for tougher microbes.
What You Can Do
While commercial laundries use industrial sanitizing protocols, your home machine needs extra TLC. To fight back:
- Disinfect regularly: Run a dedicated machine clean cycle with a washing machine disinfectant.
- Scorch with heat: Occasionally, run an empty 90°C (194°F) wash—if your machine allows it—to kill any lingering microbes.
- Descale: Hard-water deposits can coat heating elements, preventing your washer from ever hitting true hot. A monthly descaler treatment keeps the heat flowing.
Skipping these steps risks not just a funky-smelling drum, but a pocket-sized petri dish in your laundry room—complete with supercharged bacteria. So next time you throw in your whites on “hot,” remember: unless you give your washer some extra love, “clean” might only be a label.
