All you need to know about the house dust mite
For the Curious

Doctors describe how to kill dust mites in soft toys

Soft toys are a major source of house dust mites and their allergens, and sleeping with soft toys is a significant risk factor for house dust mite sensitisation. Recent clinical research has identified three practical DIY methods to control house dust mite infestation in children's soft toys.
The three methods are:

1. Place the soft toy in a plastic bag and freeze in a home freezer at -15 C for at least 16 hours then warm wash and dry thoroughly.

2. Tumble dry for one hour on the maximum (hot) setting then warm wash and dry thoroughly.

3. Submerge the soft toy in a liquid detergent with a eucalyptus oil mixture and soak for one hour, rinse and dry thoroughly.

Of the three, the detergent with eucalyptus oil is the most complicated but effective. Please note: a few mites can survive all these methods. Thoroughly drying any soft toy is essential. House dust mites thrive in damp, dark conditions and will take advantage of dampness to establish a colony.

Materials need for the eucalyptus oil solution are:

  • Eucalyptus oil (10 ml bottle)
  • Syringe (5 ml) for measuring ingredients
  • Liquid detergent, such as clear, non-biological, hand wash (for delicates) with no added beach or coloring. In Taiwan the researchers used Magic Amah detergent
  • Jug (clear glass) for measuring water (200 ml)
  • A washing bowl (5 litres)
Using the syringe take 4 ml of eucalyptus oil and add to this 1 ml of the liquid detergent. This tiny amount equals one teaspoon in measurement. Add this to a 200 ml jug of water, mix well and let stand for 10 minutes. The resulting liquid should be a stable milky, opaque solution that does not separate. If it does, you will have to try another clear liquid detergent.

Once you are pleased with the results, fill a washing bowl with 5 litres of water and then add the solution and stir well. Please note that it is important to add the solution last. Place the soft toy in the solution making sure it is totally submerged. Let this stand for one hour, stirring occasionally. Remove and thoroughly rinse under tap water and dry for 48 hours. The smell of eucalyptus will diminish during this time. Although eucalyptus has a fresh scent, not everybody finds the smell of eucalyptus pleasant.

A quote from the doctors that completed this research; 'Soft toys are a major sources of house dust mite (HDM) allergens, and at a very early age (0-2 years) sleeping with soft toys is strongly associated with HDM sensitisation'. 'These three house dust mite elimination techniques give parents of infants effective and acceptable methods of limiting house dust mite exposure.'

In this research the best results were from the freezing and eucalyptus oil mixture. They both achieved 95.1% mite reduction. Allergen removal is through washing. The research team declared that they know of no reason why eucalyptus may cause harm to infants, however it is best to check with a doctor before following these instructions.


'Effect of freezing, hot tumble drying and washing with eucalyptus oil on house dust mites in soft toys. 'Pediatric Allergy Immunology', Chang C-F, Wu FF-S, Chen C-y, Crane J, Seibers R. 2011; Doi no: 10.1111/j.1399.2011.01144.