Humidisafe capsuleThe Humidisafe device is a small flow-through capsule containing the patented and proven antimicrobial material Aquastat XR. A non toxic all natural antimicrobial material that has been used in the Food and Beverage Industry for years to control the growth of bacteria in drinking water storage tanks. This technology is now brought to the home to control bacteria and mold within the residential humidifier.

Bacteria and Mold growth within portable consol humidifiers has long been a concern due to the ability of the humidifier to emit this bacteria into the surrounding room where children, elderly and other family members are at risk of serious illness from inhalation of these microorganisms.

Studies have shown that regular cleaning of the humidifier is not sufficient to control bacteria growth in the water and mist as airborne bacteria drawn into the humidifier and common bacteria found in tap water and bottled water automatically introduce a new population of bacteria for growth right from startup. These studies have shown that significant growth of bacteria and mold in humidifiers can occur within hours after cleaning. The only way to control the growth of bacteria in the humidifier tank and mist is to treat the water.

How does it work?

The Humidisafe capsule contains the advanced patented antimicrobial media Aquastat XR, which was custom-designed to inhibit the growth of a wide variety of bacteria and algae found in humidifier water. The technology utilizes the known antimicrobial properties of various minerals, along with other metal oxides, to interfere with the microorganisms cell replication, electron transport and overall organism function.


Unfortunately the problem is not only limited to humidifiers that have gone uncleaned for extensive periods of time. Even fresh chlorinated tap water contains bacteria called HPCs or Heterotrophic Plate Count bacteria that are a common constituent in the public water supply. Therefore, right from startup, bacteria are emitted from clean humidifiers. Additionally, several studies have shown that bottled water and distilled water can also contain significant quantities of bacteria. Using either of these water sources will allow the humidifier to emit these bacteria into the air right from initial startup. These bacteria, along with other airborne bacteria drawn into the humidifier water tank from normal operation can result in a significant bacteria and mold bloom and health hazard for anyone in the vicinity. To date the only method of limiting the emission of these bacteria into the air has been to regularly clean and disinfect the humidifier using harsh and toxic chemicals. This regular maintenance, although effective at cleaning the humidifier has no residual effect at controlling the bacteria once the humidifier tank is rinsed and refilled with new water. Once you fill the tank with fresh water, you are automatically introducing a new population of bacteria for growth.


An Independent University Laboratory performed a test to evaluate the ability of the Humidisafe capsule to control the growth of bacteria and fungi in the water tank and mist of a standard room humidifier/vaporizer. The test compared the bacteria concentration in a humidifier with the Humidisafe capsule in the tank versus a humidifier without the Humidisafe capsule.

After only 72 hours of operation the humidifier without the Humidisafe capsule contained over 12,000 cfu/ml of bacteria in the water tank ( that’s 12,000 bacteria for every 4 drops of water!) and over 8,000 cfu of bacteria were found in a two (2) second exposure to the mist. In contrast, the humidifier that used the Humidisafe capsule contained no bacteria in either the water tank or mist.

Comparison of Various Antimicrobial Products in preventing bacterial growth in humidifier water over a 3-week period.

By David Collart, Ph.D. and Sharifeh Mehrabi, Ph.D. of Clark Atlanta University


Several products were evaluated for their ability to control bacteria growth in the water reservoir of humidifiers. For this test the following products were tested:

  1. One Holmes® evaporative humidifier with Microban® incorporated into the bottom pan plastic.
  2. One Kaz® evaporative humidifier without Microban® was tested as a control.
  3. One Duracraft® model DF-1 containing a Humidisafe® capsule was tested.
  4. One Duracraft® model DF-1 containing the Ion Stick® was tested.
  5. One Duracraft® model DF-1 was tested as-is as a control.


  • One Holmes® Evaporative Humidifier Model HM1230 with Microban®.
  • One Kaz® Evaporative Humidifier Model 3020 without Microban®.
  • One Duracraft® DF-1 Humidifier containing the Ion Stick®.
  • One Duracraft® DF-1 Humidifier containing a Humidisafe® capsule.
  • One Duracraft® DF-1 Humidifier operated without any additive.

Sample collection

Water was drawn from the Holmes® Model 1230 at two locations: 1) directly from the bottom collection pan (daily) and 2) from the water reservoir tank (weekly). For all other units water was drawn and tested daily from the water reservoir.

From each unit 0.5 ml of water was collected and plated onto a R2A agar plate and incubated at room temperature for 3-5 days. In addition, dilutions of water samples were prepared and plated on R2A agar plates and incubate as described above. Following incubation the colony forming units (CFUs) were counted and recorded.

Sample collection was identical for all test units.

Results and Discussion

After the first day of operation the Holmes® unit, Ion Stick® Unit, Kaz® Evaporative Unit, and control unit all showed a moderate level of bacterial growth. By the end of week one significant contamination was evident in both the bottom collection pan and the water reservoir in the Holmes® unit. Significant growth was also present in both the Ion Stick®, Kaz® Evaporative unit, and DF-1 control unit.

After week one by comparison the Duracraft® unit containing the Humidisafe® capsule showed no growth present.

By week two bacterial levels in the Holmes® unit had reached over 240,000 cfu/ml. Bacteria growth in the Ion Stick® and Kaz® unit had reached 328,000 and 282,000 CFU/ml respectively. While the Duracraft® unit with Humidisafe® still showed no bacterial growth.

By the end of week three, all units contained significant bacterial growth with the exception of the Duracraft® DF-1 unit containing the Humidisafe® capsule, which showed only 6 cfu/ml present in the water. All data is exhibited in Figure 1 below.

fig. 1

Disclaimer | All results are based on independant study conducted by their noted authors. K2 Concepts, Inc maintains no involvment in these findings.

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Additional Humidisafe Resources

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