How heat kills dust mites
Dust mites are microscopic animals that live in bedding, carpets and stuffed furniture, and they do badly in heat. National Jewish Health, a respiratory hospital in Denver, recommends washing bedding weekly in hot water, at least 130°F (about 54°C). A steam cleaner runs far hotter than a washing machine.
Two lab studies tested that on real textiles. In a Scottish study, Colloff and colleagues steam cleaned carpet squares seeded with dust mites. They found no live mites in the treated squares at any point over four months, while the untreated squares grew from 11 mites to 185. In a Journal of Medical Entomology study, Glass and Needham used a hard surface steam cleaner at 96°C (about 205°F) and recorded 100% mite mortality in both carpet and mattress.
What steam does not do
Killing the mite is only half the job. Mites leave allergen behind in their droppings, and Glass and Needham note that these allergens are known to resist decay in a normal home and are thought to accumulate until something removes them.
That is why the allergen numbers matter. In the Scottish study, the allergen in treated carpet fell by 86.7%, against 4.7% in untreated areas. In the Glass and Needham study, carpet allergen fell 61.4% after two passes and 100% after five. A third study, from Saint Louis University, compared vacuuming, steam vapour, neem oil and a chemical treatment on worn carpet. Steam vapour gave the biggest drop in live mites and denatured the allergen in the lab.
Two honest limits. These were lab and test-room results on carpet and mattress fabric, so a real home will vary. And steam does not stop new mites arriving. It is one tool, not a cure, and it is not medical treatment. If you have allergies or asthma, your doctor should guide the plan.
Mattresses, sofas and pillows
Bedding, pillowcases and washable pillows can go in a hot wash. Mattresses, sofas and carpets cannot, and that is where steam fits.
Go easy on moisture. Health Canada warns that mould can begin to grow within 48 hours on mattresses and furnishings that stay wet, so any method that soaks the fabric does more harm than good. Steam uses very little water, which is why it suits upholstery and mattresses. Most fabric sofas are dry within a few hours.
Leather and vinyl are a different case. National Jewish Health suggests wood, leather or vinyl furniture instead of upholstered furniture in the bedroom.
What else cuts dust mites
Steam works best alongside the basics. National Jewish Health lists these for the bedroom:
- Zipped, dust-proof covers on the mattress, pillows and box spring.
- Weekly hot washing of bedding, at least 130°F (about 54°C).
- Indoor humidity below 40%. Health Canada puts the general range for a healthy home at 30% to 50%, and a dehumidifier helps in humid Ontario summers.
- Washable area rugs in place of wall-to-wall carpet in the bedroom.
There is no agreed schedule for steam cleaning in these studies. Sensible moments are when you swap bedding for the new season, when you move in, or when a mattress or sofa has gone a long time untouched.
Get the room ready
A few steps make any steam clean, professional or DIY, work better:
- Strip the bed and wash the bedding hot, at least 130°F (about 54°C), as National Jewish Health recommends.
- Vacuum the mattress and sofa first so loose dust is out of the way. National Jewish Health advises that a person with a dust mite allergy should not vacuum, or be in the room while it is being vacuumed.
- Clear the area and open a window afterwards so the fabric dries quickly.
- Put dust-proof covers on the mattress and pillows once it is dry, so the work lasts longer.
Where Steam Shines fits
We use high-temperature steam with no harsh chemicals and no detergent residue, and it kills dust mites on contact. Our sofa and mattress cleaning covers mattresses, headboards, cushions and sofas, with attention to the seams where mites collect. It is safe for kids and pets. Our carpet and rug cleaning uses the same steam on carpets and rugs.
We are based in Toronto and come to you, and all we need is access and a standard power outlet nearby. To ask about a mattress or sofa, get in touch.
Sources
- Colloff MJ, Taylor C, Merrett TG. The use of domestic steam cleaning for the control of house dust mites. Clinical and Experimental Allergy, 1995 (PubMed)
- Glass EV, Needham GR. Eliminating Dermatophagoides farinae and their allergens from carpet and mattresses with a hard surface steam cleaner. Journal of Medical Entomology, 2004
- Ong KH et al. Inactivation of dust mites, dust mite allergen, and mold from carpet. Journal of Occupational and Environmental Hygiene, 2014 (PubMed)
- National Jewish Health. Dust mite allergy
- Health Canada. Guide to addressing moisture and mould indoors