A review of standards and guidelines set by international bodies for the parameters of indoor air quality

Standards and guidelines as defined by various international agencies are employed by the researchers to evaluate an acceptable quality of air in indoor as well as outdoor environments. The main objective of this paper is to establish a comprehensive review of Indoor Air Quality (IAQ) guidelines and other standard values that are implemented currently. For this purpose, the present study summarizes the main standards and guidelines related to key indoor air pollutants and levels of thermal comfort developed by different agencies around the world. These agencies and organizations include the American Society of Heating, Refrigerating and Air- Conditioning Engineers (ASHRAE), the Hong Kong Environmental Protection Department (HKEPD), the World Health Organization (WHO), and the National Health and Medical Research Council (NHMRC) of Australia. Common indoor air pollutants that are found to frequently affect indoor populations are, carbon dioxide (CO2), nitrogen dioxide (NO2), formaldehyde (HCHO), carbon monoxide (CO), sulfur dioxide (SO2), and particulate matter in sizes <2.5 and 10 μm (PM2.5 and PM10, respectively). Other factors that affect IAQ are the moisture content of the air (i.e., relative humidity), the temperature of the indoor air, and the air speed or movement. Sick building syndrome (SBS) describes the various interactions between these major pollutants and factors of IAQ that cause adverse health effects on humans. In addition, this paper reviews various stipulated guidelines that are implemented by the relevant regulatory institutions and agencies to prevent SBS.