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

Chemical products for killing dust mites in 2011

New research describes four highly effective dust mite-killing products designed to help patients avoid mites in allergic disease management. They are simple, safe and cost effective in the battle to control indoor mite infestation.
For patients, avoidance of mites and their allergens is the first step in managing symptoms, but as dust mites live in close proximity to man indoors, full avoidance can be quite costly or problematic. Therefore, the application of chemicals with mite killing activity is necessary.

In 2010 a team of researches from the Czech Republic investigated selected acaricide (mite killing) products for performance in a laboratory setting. They used three different species of common indoor dust mites. Two were house dust mites Dermatophagoides farinae and D pteronyssinus and the third was the storage mite Tyronphagus putrescentiae. This latter mite is associated with occupational allergies from work in barns and grain stores, but can also be found indoors in kitchens or on poorly stored grain. In all approximately 30,000 mites were tested in experiments that covered 23 different pesticides.

The results found four exceptional mite-killing products that demonstrated high efficacy at low dosage when compared with other traditionally used organophosphates or single-compound pyrethroid formulae. They are:

Multi-compound formula Permethrin/S-bioallethrin/piperonyl butoxide Permethrin/pyriproxyfen/benzyl benzoate and Benzyl benzoate - a colourless oily ester Neem - oil pressed from the fruits and seeds of neem tree (Azadirachta indica)

Other highly effective pesticides tested were named as flufenoxuron and abamectin.

The study concluded; 'In the present study it was found that organophosphates have low activities at high dosage and return low security index values in comparison with synergised pyrethroids. This means that restrictions on the use of organophosphates will have no influence on future mite control'. The safety of organophosphates on the environment and human health is a concern.

Benzyl benzoate has been proven effective in separate clinical and field trials but currently is not allowed to be sold for use indoors in the EU. Why, because as one manufacturer wrote, 'consumers simply do not purchase the volume necessary to justify paying and maintaining the very expensive EU Regulatory registration costs'. Elsewhere in the world it is freely available.

Allergic conditions which can be associated with mite exposure include rhinitis, sinusitis, asthma, hypersensitive pneumonia, extrinsic allergic alveolitis, conjunctivitis, urticaria, eczema, dermatitis, anaphylaxis, angioedema, allergic and migraine headache, and certain gastrointestinal disorders in which IgE-mediated allergy are involved.

Researchers of this study requested that their findings be confirmed in field studies.


References

'Efficacy of selected pesticides against synanthropic mites under laboratory assay'. Stara J, Stejskal V, Nesvorna M, Plachy J, Hubert J, Pest Manag. Sci. 2011, (wileyonline.com) DOI 10.1002/ps.2083

Correspondence from Bissell Homecare October, 11, 2010

politics.co.uk/briefings-guides/issue-briefs/environment-and-rural-affairs/organophosphates-$366556.htm

Allergic conditions noted. freepatentsonline.com/EP1230931.html