Respirable

It can scarcely be called respirable, as it would not support life for any length of time; but it may be breathed for a few moments without any other effects, than the singular exhilaration of spirits I have just mentioned. ❋ Unknown (1813)

"This will be the first major advancement in monitoring miners' exposure to respirable coal dust," said Ed Thimons , branch chief for dust control, ventilation and toxic substances at NIOSH. ❋ Kris Maher (2011)

"Any time you have respirable particles, it's bad." ❋ Unknown (2011)

Monitoring of the concentration of airborne respirable dust and ash around the volcano beginning in August 1997 showed that concentrations of ash have regularly exceeded 50 micrograms/m3 per 24-hour rolling average in areas subject to frequent ash fall. ❋ Unknown (2009)

If concentrations of respirable free crystalline silica in the ash exceed the NIOSH-recommended limit of 50 micrograms/m3 for an extended period of time (for example, months to years), the risk of silicosis should not be ignored. ❋ Unknown (2009)

The proportion of free silica in the ash has been about 6 percent of the total respirable size particles (under 10 microns) by weight. ❋ Unknown (2009)

Exposure to respirable-sized free crystalline silica from most ash falls are typically of short duration (days to weeks), and data suggests that the recommended respirable exposure limit of 50 micrograms/m3 of air can be exceeded for short periods of times for the general population. ❋ Unknown (2009)

Exposure to respirable particles of free crystalline silica can lead to silicosis, a disease resulting in scarring of the lungs and impairment of their function. ❋ Unknown (2009)

Media caution: Within days of the 1980 eruption, there were reports in the media that the volcanic ash from Mount St. Helens contained 60 percent or more free crystalline silica — far greater than the actual 3 to 7 percent of the respirable size fraction. ❋ Unknown (2009)

Heavy ash fall may result in the collapse of roofs under the weight of ash and high levels of respirable ash in the air ❋ Unknown (2009)

Mount St. Helens contained 60 percent or more free crystalline silica — far greater than the actual 3 to 7 percent of the respirable size fraction. ❋ Unknown (2009)

An increase of bronchitis was detected even with such a small amount of ash and the relatively low respirable portion. ❋ Unknown (2009)

The U.S. National Institute for Occupational Safety and Health (NIOSH) recommended in 1974 the exposure to respirable free silica be limited to 50 micrograms/m3 of air for workers up to a 10-hour work day, 40-hour work week over a lifetime. ❋ Unknown (2009)

Potential respiratory symptoms from the inhalation of volcanic ash depend on a number of factors, including airborne concentration of total suspended particles, proportion of respirable particles in the ash ❋ Unknown (2009)