A humidifier, more specifically an ultrasound humidifier, is commonly used in many households to maintain the relative humidity of a room or the entire house somewhere between 30% - 50%. This range is considered to be ideal for indoor surroundings. By optimizing moisture level in the air, an ultrasound humidifier prevents health problems like dry skin, itchy eyes, cough, etc., that arise due to low moisture content in air. Besides these, other problems like drying of furniture, cracking paint, and peeling of wallpaper is also substantially reduced.

Unlike other humidifiers, an ultrasonic humidifier utilizes ultrasonic vibrations to form a cool mist which is dispersed in the surrounding air, thereby increasing moisture content. Some humidifiers boil water for the same purpose, however, this one generates a fine mist due to the vibration of a metal diaphragm at ultrasonic frequency, which cannot be heard by humans. Since water used in the humidifier is not boiled, impurities within the appliance are spread along with the fine mist generated.

Dangers of Using Ultrasonic Humidifiers

Reasons behind risks of an ultrasonic humidifier are the impurities that are added to an indoor environment along with moisture content. These impurities are nothing but minerals present in tap water that is used in the appliance, and microorganisms that grow in the device due to presence of stagnant water. Minerals present in water, when dispersed, form a white dust over surfaces. These layers of white dust turn out to be breeding grounds for microorganisms. As the process of heating does not take place in an ultrasonic humidifier, microbes tend to flourish within the appliance and are dispersed along with the fine mist. A humidifier is used in the presence of occupants who come directly in contact with these impurities. This may lead to health hazards like respiratory infections etc. People suffering from asthma and other lung diseases are more prone to ill-effects of ultrasonic humidifiers. Parents of infants often use them to ease their baby's difficulty due to cough and cold, without being aware that its impurities can make their infant suffer from respiratory irritation or serious lung problems. With increased level of humidity in the surrounding, chances of mold growth on indoor surfaces is also increased. This is again a risk factor for the development of health issues in an individual.

Another very common danger that is associated with every electrical appliance is the risk of an electric shock. Keeping the device plugged-in all the time, and using wet hands to switch on the appliance may be reason enough to fall prey to an electric shock. As a word of caution, children and pets must be kept away from the appliance so that no such happening takes place. Burns are also one of the dangers which people must be careful about. As the fine mist-producing diaphragm vibrates at an ultrasonic speed, the appliance becomes substantially hot. Touching the appliance when it is plugged-in can cause undesired burns.

The U.S. Environmental Protections Agency (EPA) and the Consumer Product Safety Commission (CPSC) have conducted studies to figure out whether ultrasonic humidifiers actually have health hazards or not. Results obtained confirm the dispersal of minerals and microbes into indoor air which is, without a doubt, a cause for concern. However, there is only limited information on this subject and requires further study.

Tips to Reduce the Risk Associated with Ultrasonic Humidifiers

Health risks of using an ultrasonic humidifier can be minimized by following a few precautionary measures. Tips given below are derived out of recommendations given by the U.S. EPA for the use of this appliance.
  • Avoid using tap water for humidification. Instead, use distilled water or water with low mineral content so that white dust or a layer of minerals does not become a part of the household.
  • Learn how to clean an ultrasonic humidifier and clean the appliance regularly to prevent microbial growth which gets dispersed in the environment.
  • Do not let water stand in the reservoir for a long period of time as it will get contaminated. Use of contaminated water for mist production will ultimately contaminate indoor air.
  • Maintain relative humidity not more than 50%. Anything above this limit will make the interior too humid and promote mold growth in the house.
  • Follow the instruction leaflet provided by the manufacturer to learn the correct way of cleaning and maintaining the appliance.
  • Give special attention to asthma patients who are more likely to develop health problems arising from the use of a humidifier.
  • Lastly, contact the doctor immediately if someone develops symptoms of respiratory problems or has other health-related issues.
Dangers of using an ultrasonic humidifier are quite a few. However, its use has not been restricted. With a few precautionary measures like keeping the appliance clean and using low mineral content water, it can be safely used in households so as to maintain a comfortable living environment.