How MiteGuard dust mite barrier bedding covers work
Scientifically proven allergen barrier fabric
Because the fibres are so tightly packed together, the fabric creates a barrier between the bed and the sleeper that Dust Mites can't pass through.
Dust Mites are 200-300 microns in size, and their allergen are 10-30 microns. This is a polite way of saying that MiteGuard covers stop faecal matter and the remains of dead Dust Mites from passing through.
The MiteGuard® fabric and construction methods have been independently tested by a leading NZ microbiologist.
- Proven to block dust mite allergen particles to below detectable levels
- Breathable: 86% of the air-flow that passes through a standard poly/cotton sheet can pass through the cover
Complete encasement for optimum protection
The MiteGuard® covers are designed to fully encase your mattress, duvet or pillow – forming an effective allergen barrier between the dust mites and the sleeper.
- Extra-strong cotton tape to secure the seams in the mattress covers
- We use high-quality, durable YKK zips
- There is an internal flap closure that provides a secure barrier against the zip (make sure that this is flat against the zip when closing)
- The covers are easy to use and the natural cotton make them very comfortable
- Although based on white, the natural cotton is not bleached with harmful chemicals and is formaldehyde free. You may get slight variations, like the occasional speckle or coloured thread in the weave due to this.
Our covers are easy to use and care for - see product care to find out how.
View more information about Dust Mite Allergies here.
An overview of Allergen Barrier Fabrics
Back in the early 1980s when the value of dust mite allergen protection was first recognised, allergen barrier mattress covers were made from vinyl - a very effective barrier but very uncomfortable to sleep on. The non-breathing vinyl covers caused perspiration which actually made symptoms worse for people with eczema. In the late 1980s some covers became available that were made from a vinyl-coated polyester cotton, which was marginally better but would still cause perspiration in summer.
In 1990 an article in the Lancet(1) medical journal described a new barrier fabric that was woven from polyester cotton and coated with a polyurethane compound which allowed moisture to diffuse through but which blocked dust mite allergen particles. This provided the allergy sufferer with protection and greater comfort, but this fabric had its shortcomings too. The membrane prevented air passing through, which made the covers warm in summer and difficult to dry after washing. The membrane also had a limited lifespan and would break down after a few year's use.
MiteGuard fabric compared to standard sheets and toweling covers:
Finally, in 1997, a study was published in the Journal of Allergy and Clinical Immunology(2) which described a new type of barrier fabric that established new levels of comfort with effective allergen protection. This fabric was a precision microweave fabric with the trade name of "Pristine™". The study by Professor Tom Platts-Mills of the University of Virginia, demonstrated that Pristine™ fabric blocked dust mite allergen (Der p 1) particles to below detectable limits yet still allowed 86% of the air-flow that passes through a standard poly / cotton sheet.
The key feature of this new fabric was the complete absence of any kind of coating or membrane that had prevented the air-flow through previous barrier fabrics. Instead, the allergen barrier property of this precision microweave fabric was achieved by the extremely tight and extremely accurate weave of the fabric. A number of different weaves with different gap sizes between the threads were initially trialed, and it was found that those fabrics with gap sizes of less than 10 microns between threads were the most effective in preventing Der p 1 particles transferring through the fabric.
Precision microweave barrier fabrics now commonly in use have average thread gap sizes in the range of 6 to 8 microns providing the ideal combination of allergen protection and comfort. An additional advantage over the older coated fabrics is in the ease of laundering these newer fabrics as they can be hot water washed and hot tumble dried without any loss of effectiveness. In comparison, coated fabrics can take a long time to dry after washing and some would break down if exposed to high temperatures in tumble dryers.
MiteGuard NZ uses 3.5 - 4.5 microns between threads to provide even greater protection.
TOWELLING "BARRIER" COVERS
Some of the older style coated fabrics which are still sold as "allergen barriers" have a towelling upper surface. They are commonly made as fitted sheets rather than full encasements, mainly because the coated fabric cannot allow sufficient airflow to prevent mould formation in the mattress. Covers made from coated towelling cannot be recommended for two reasons:
- The depth and complexity of the towelling fabric traps skin particles and humidity, creating the perfect environment for house dust mites to proliferate. If the covers are not washed in hot water every week they will become a very significant source of dust mite allergen.
- A partial cover (fitted sheet) with limited airflow through the fabric will act like a bellows, causing dust mite allergen particles to be forced from the mattress into the air of the bedroom every time the person in bed moves.
(2) Vaughan J.W., McLaughlin T.E., Perzanowski M.S., Platts-Mills T.A.E., Evaluation of materials used for bedding encasement: Effect of pore size in blocking cat and dust mite allergen. J Allergy Clin Immunol 1999; 103: 227-31.