A certain amount of moisture in the air is necessary for the human body to function properly. Scientific research conducted on the human body suggests that the appropriate amount of humidity required ranges from thirty to forty percent and if the humidity level is less than that, it may lead to nosebleeds, cough, and itchy eyes. The damaging effects of dry air are not limited to the human body and can also affect wall paint, furniture, wallpaper, and brittle wood.

Ultrasonic humidifiers are used in dry weather conditions to generate and maintain the adequate level of moisture in the designated area. Different models of ultrasonic humidifiers available in the market perform one basic function of circulating moisture through the air.

These devices are different from steam humidifiers that use heat to convert water into vapor. Instead of heat, they use ultrasonic sound waves to convert water into a fine mist and heavy-duty fans to circulate the created mist in the surrounding areas. These devices are increasingly being used in nurseries and children rooms, as there is no danger of steam bursts that might occur in ordinary humidifiers. They are also preferred due to their ability to perform quickly and quietly.

Some government agencies such as Environmental Protection Agency and the Consumer Product Safety Commission have in recent years expressed their concerns about the role of ultrasonic humidifiers in dispersing microorganisms and minerals in the air. However, conclusive scientific evidence is still not available on this theory and agencies have not concluded that this poses a significant health risk.

Users can follow a few basic steps to avoid any potential problems related to dispersal of microorganisms and minerals. This includes using fresh water, periodic cleaning of water tanks, using disinfectant, and using water with low mineral content or distilled water. Usage instructions issued by the manufacturer should also be followed to cut down the risk of microorganism being placed in the air.