Health and Relative Humidity of Air

The optimum relative humidity ranges for bacteria, viruses, fungi, mites, asthma and other health conditions. Relative humidity (RH) should be within certain limits for control of the health aspect.

Health ConditionOptimal RH Range (%)
Bacteria20 - 70
Viruses40 - 80
Fungi0 - 70
Mites0 - 60
Respiratory Infections40 - 50
Allergic Rhinitis and Asthma40 - 60
Chemical Interactions0 - 40
Ozone Production75 - 100
Combined Health Conditions40 - 60
Human Comfort30 - 60

Guidelines

  • Bacteria: 20 - 70% RH
  • Viruses: 40 - 80% RH
  • Fungi: 0 - 70% RH
  • Mites: 0 - 60% RH
  • Respiratory Infections: 40 - 50% RH
  • Allergic Rhinitis and Asthma: 40 - 60% RH
  • Chemical Interactions: 0 - 40% RH
  • Ozone Production: 75 - 100% RH
  • Combined Health Conditions: 40 - 60% RH

General Comfort Range: 30 - 60% RH is optimal for human comfort.