What is the definition of acceptable indoor air quality (IAQ)?

Acceptable indoor air quality (IAQ) is defined as air in which a substantial majority of people do not express dissatisfaction. This definition emphasizes the subjective nature of air quality, acknowledging that perceptions of air can vary among individuals. Acceptable IAQ accounts for health, comfort, and overall satisfaction with the indoor environment, indicating that while some pollutants may be present, they do not significantly affect the majority of occupants. The focus is on maintaining a balance that minimizes adverse health effects and maximizes comfort in indoor spaces.

Other options contrast with this definition. Air containing harmful contaminants at high concentrations represents poor IAQ, as it poses health risks to occupants. Air devoid of any pollutants is unrealistic in many scenarios and not necessary to achieve satisfactory IAQ; a complete lack of pollutants does not always correlate with comfort or satisfaction. Likewise, air with occasional odors from cleaning chemicals may indicate poor ventilation or excessive use of volatile substances, potentially leading to dissatisfaction among occupants.