What size are respirable small particles (RSPs)?

Respirable small particles (RSPs) refer to particulate matter that can be inhaled and reach the lungs, making them significant for assessing indoor air quality and potential health impacts. The correct size designation for RSPs is particles smaller than 10 microns, which includes a variety of harmful elements such as dust, pollen, soot, and other pollutants.

Particles of this size can easily penetrate deep into the respiratory system, bypassing the natural filtration mechanisms in the upper respiratory tract. This characteristic poses a risk for various health issues, especially in sensitive populations such as children, the elderly, or those with pre-existing respiratory conditions. Recognizing that the significant threshold is set at 10 microns helps in understanding the risks associated with air quality and aids in the development of effective mitigation strategies.

Other size categories, such as those larger than 10 microns, do not typically enter the lungs to the same extent and are generally filtered out by the nose and throat. Consequently, while particles smaller than 25 or 100 microns and even 500 microns may have some relevance in different contexts, they do not capture the crucial aspect of respiratory health linked specifically to particles smaller than 10 microns.