The Health Issue

Did you know...

  • A 6yr old pillow gets 1/10th of its weight from live dust mites, dead dust mites and dust mite faeces.
  • An average 3 bedroom home can generate 18 kg of dust annually (that's 27 MILLION dust mites).
  • Chemicals that you use to clean your home may cause damage to your health.
  • Chemicals cause headaches, dizziness, fatigue, eye/skin irritation and breathing difficulties.
  • Airborne dust fragments cause eye irritation, allergies, eye, ear, nose and throat infections, asthma attacks, fatigue and depression.
  • Experts say that 2-10 million dust mites live in your mattress
  • 28g of dust contains 42,000 dust mites
  • Bacteria live in your heating and cooling systems, kitchen, garbage, bathroom, and on your pets.
  • Bacteria can cause colds, flu, respiratory infections and eye infections.
  • Your air conditioner only cools or warms your rooms. It does not improve your air quality. The ductwork of these systems helps distribute indoor air pollutants throughout your home.
  • Mould spores are found in your heating and cooling ducts, in damp clothing, in moisture on ceilings, walls, carpets and curtains. Mould causes allergies, sinus headaches, irritability, fatigue and depression.
  • People are spending more than 90% of their time indoors.
  • More people are being affected by lung and heart problems. Many of these symptoms, experts say, are caused or aggravated by breathing poor indoor air.
  • Those at greatest risk are young children whose immune systems are not fully developed, and the elderly and people afflicted with asthma, allergies and other lung and heart ailments.

Safe Ozone Levels

The National Occupational Health and Safety Commission's Occupational Exposure Standard for Ozone is 0.1ppm (parts per million). Recent (April 2005) independent testing by one of our clients shows ozone levels in a confined room no higher than 0.051ppm, approximately half the OHS standard. Of course, these results apply to the tested environment and your situation may be different.

As a rule of thumb, you should be able to just notice an ozone odour when you first enter an area with an ozone generating air purifier, but after 5-10 minutes you should no longer be aware of the ozone smell. It is possible to smell ozone at a concentration of between 0.01 and 0.02ppm, which is well below the 'safe' level.

If you cannon smell the ozone at all, try turning up the purification level. If you can still smell the ozone after 5-10 minutes, try turning the purification level down.

Note that some people are especially sensitive to ozone. If you experience irritation in your eyes, nose and throat while the unit is operating you should turn down the purification level. If your symptoms persist, seek medical advice.

For those who are interested, the NOHSC standard can be found [here].

Independant Analysis

The following reports were commissioned by Bentax USA and show the effect of seveal models of air purifier on a number of indoor air pollutants.

Dust and Mould
The effect of a Bentax In-Duct air purifier on dust particles and mould spore decay.

Ion and Ozone levels
The effect of two different Bentax In-Duct air purifiers on ozone levels and ionised particles.


Some media coverage of air quality issues. Note that these links are to sites not controlled by Airganix and we have no control over their content.

Mould culprit for severe asthma
From the ABC science department, this article discusses links between mould spore in the air and the severity of asthma attacks.

Positive Effects of a Fresh Air Filtration System on Hay Fever Symptoms
From the International Archives of Allergy and Immunology, this article discusses the effect of indoor air purifiers on hay fever.