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Most people with allergies know they should wash their bedding regularly. What they don't always know is that washing it the wrong way — with the wrong products, at the wrong temperature, on the wrong schedule — can leave allergens behind, damage allergy covers, and, in some cases, actively worsen symptoms.
We hear from customers every week who are doing everything right — covers on the bed, sheets washed weekly — but still waking up congested. More often than not, the problem is somewhere in the laundry routine. Here are the mistakes we see most often, and exactly how to fix them.
Mistake #1 — Washing in Hot Water Without an Additive and Expecting It to Work
The standard advice from allergists is to wash bedding in water at 130°F or above to kill dust mites. That's accurate — but it's only half the story, and acting on it literally creates two problems.
First, most home water heaters are set well below 130°F for safety reasons. Unless you've specifically turned your water heater up before doing laundry — and remembered to turn it back down afterward to avoid scalding — your "hot" wash cycle probably isn't reaching the temperature needed to kill mites.
Second, water at 130-140°F is genuinely damaging to fabric over time. It causes fading, accelerates fiber breakdown, and is particularly hard on the urethane membranes in waterproof allergy covers. We've been washing our own bedding in cold water for years, and it still looks great.
The fix: Wash in warm or cold water and use a laundry additive specifically designed to eliminate dust mite allergens at any temperature. De-Mite Laundry Additive is added alongside your regular detergent and eliminates dust mites and their allergens in cold, warm, or hot water. Allersearch Allergen Wash replaces your detergent entirely and removes a broader range of allergens, including pet dander, mold, and pollen, in addition to dust mites. Not sure which is right for you? Read our comparison guide.
Mistake #2 — Using Fabric Softener on Allergy Bedding
This is one of the most common mistakes we see — and one of the most directly counterproductive ones.
Fabric softener works by depositing a chemical coating on fabric fibers. That coating stays on your sheets and pillowcases long after the wash is done, releasing fragrance compounds and chemical residue into the air and against your skin all night. For allergy and asthma sufferers, this is continuous exposure to allergens and irritants that can trigger symptoms even when everything else in your routine is right.
For allergy bed covers specifically, there's an additional problem: fabric softener degrades the tight micro-weave of cotton allergy fabrics over time, potentially widening pore sizes and reducing their effectiveness as allergen barriers. On urethane membrane covers, such as AllergyCare™ Stretch Knit, fabric softener can interfere with the membrane bond.
The fix: Skip fabric softener entirely for all bedding and allergy covers. Replace dryer sheets with wool dryer balls for static control. If you want to understand more about why fragrance and softener products are problematic for allergy sufferers, read our full guide on fragrance and fabric softener allergy triggers.
Mistake #3 — Using Chlorine Bleach
Bleach is effective at killing mites and whitening fabric — but for allergy and asthma sufferers, the costs often outweigh the benefits.
Bleach fumes are a known airway irritant. For people with asthma or multiple chemical sensitivities, the off-gassing from bleach during and after washing can trigger respiratory reactions. It's also highly caustic — it breaks down fabric fibers over time, shortening the life of your bedding and allergy covers.
For allergy covers made from urethane-coated fabric — like AllergyCare™ Stretch Knit — chlorine bleach is an absolute no. It will damage the urethane membrane and compromise the cover's waterproofing and allergen-barrier properties. This applies even to a single wash.
The fix: For stain removal and whitening, use a non-chlorine oxygen whitener. We use and recommend Clearly Clean Oxygen Whitener — it uses sodium percarbonate to remove stains without the caustic fumes or fabric damage of chlorine bleach, and it's safe for allergy covers.
Mistake #4 — Not Washing Frequently Enough
Even with allergen-proof mattress and pillow encasements in place, allergens accumulate on the surface of your sheets and pillowcases between washes. A week is long enough for that buildup to become significant — particularly for dust mite allergens, which come from your own shed skin cells and accumulate continuously.
We know people who wash their encasements carefully but only change their sheets every two or three weeks. The encasements are doing their job perfectly — but the sheets on top have become the problem.
The fix: Wash sheets and pillowcases every week without exception. Pick a specific day and make it a habit — strip the bed, walk the sheets straight to the laundry room, and don't go to sleep that night until the bed is remade. It sounds rigid but it works. Your encasements only need washing once or twice a year — that's the trade-off that makes the weekly sheet routine manageable.
Mistake #5 — Washing Allergy Covers Too Often
The flip side of the previous mistake. Some people — understandably anxious to keep everything clean — wash their mattress and pillow encasements every week along with their sheets. This is unnecessary and counterproductive.
Frequent washing accelerates fabric wear on micro-weave covers and, for membrane covers, repeated heat exposure in the dryer can gradually degrade the urethane bond. A cover washed too often wears out faster and needs replacing sooner — which means higher costs and, during the gap before replacement, greater exposure.
The fix: Wash mattress and box spring encasements once or twice a year under normal use, or whenever something is spilled on them. Pillow covers can be washed monthly. Your sheets and pillowcases are the weekly wash — the covers stay put.
Mistake #6 — Washing Covers With the Zipper Closed
A small but important detail. When washing micro-weave mattress covers, the cover should be turned inside out with the zipper open. This allows the interior surfaces to be thoroughly cleaned and prevents the zipper from catching on other items in the wash.
For membrane covers like AllergyCare™ Stretch Knit, don't turn inside out — but do keep the zipper fully open during washing.
The fix: Before putting any allergy cover in the washing machine, open the zipper. For micro-weave fabric covers, turn them inside out. For membrane covers, leave right-side out with zipper open. See our full washing instructions for all allergy cover types.
Mistake #7 — Drying Covers on High Heat
High heat in the dryer is as problematic as hot water in the wash — and for membrane covers, potentially more so. The urethane membrane in AllergyCare™ Stretch Knit is heat-bonded to the base fabric. Repeated exposure to high dryer heat can cause the membrane to separate from the fabric, compromising both the cover's waterproofing and allergen-barrier properties.
High heat also causes micro-weave cotton covers to shrink slightly over time, which can make them harder to fit and eventually affect their performance.
The fix: Tumble dry all allergy covers on low or medium heat only — never high. For membrane covers, line drying is ideal if practical. Make sure covers are completely dry before putting them back on the bed. Any trapped moisture creates the humid conditions that dust mites and mold need to thrive.
Mistake #8 — Putting Covers Back On Before They're Completely Dry
This one catches people on busy laundry days. A cover that feels dry on the outside can still hold moisture in the deeper layers of the fabric — particularly in thicker micro-weave fabrics. Putting a slightly damp cover back on the mattress traps that moisture between the cover and the mattress surface, creating exactly the warm, humid conditions dust mites need.
The fix: Before putting any cover back on the bed, press your hand firmly against the fabric on both sides. If it feels even slightly cool or damp, put it back in the dryer for another cycle. This is especially important in humid climates or during summer months when ambient moisture is higher.
Mistake #9 — Using Scented Detergent and Thinking It's Fine Because It's "Gentle"
Many mainstream detergents marketed as "gentle," "sensitive skin," or "baby safe" still contain fragrance. The label "hypoallergenic" is unregulated and does not guarantee a fragrance-free product. For an allergy sufferer, fragrance in laundry detergent means continuous overnight inhalation and skin contact with volatile chemical compounds.
The fix: Use only detergents labeled specifically as fragrance-free and dye-free — not just "unscented" or "gentle." Or use Allersearch Allergen Wash, which is formulated specifically for allergy sufferers, eliminates allergens from fabric, and is free of the additives that cause problems.
The Allergy Laundry Routine That Actually Works
Put all of the above together, and the correct routine looks like this:
- ☐ Strip sheets and pillowcases every week — same day, every week
- ☐ Wash in warm or cold water with De-Mite or Allergen Wash
- ☐ Use a fragrance-free, dye-free detergent
- ☐ No fabric softener, no dryer sheets, no chlorine bleach
- ☐ Dry on low or medium heat — confirm completely dry before returning to bed
- ☐ Wash pillow encasements monthly
- ☐ Wash mattress and box spring covers once or twice a year
- ☐ Open zipper before washing — turn micro-weave covers inside out
The Bottom Line
Getting laundry right is one of the highest-leverage things an allergy sufferer can do. You spend 7 to 8 hours in direct contact with your bedding every night — more than any other surface in your home. Doing it correctly takes no more time than doing it wrong. It just takes knowing what the mistakes are.
If you have questions about the right products for your specific situation, call us at (800) 771-2246. We've been helping people get this right since 1989.
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This is part of our complete guide to allergy-free living. Read the full guide →
Sources
American Academy of Allergy, Asthma & Immunology — Dust Mite Allergy
American College of Allergy, Asthma & Immunology — Dust Mite Allergy