SKC Limited Haz-Dust IV - Manual (Page 80)

Appendix C
Glossary of Terms
Term Definition/Standard
µm Micron, 1/1000 of a meter.
ARD Arizona Road Dust
Inhalable Dust
Particulates Particulates having a 50% cut point at 100 µm.
LPM Liters per minute.
mg/m 3 Milligrams per cubic meter.
NIOSH National Institute of Occupational Safety & Health
OSHA Occupational Safety & Health Administration.
Respirable Dust
Particulates Particulates having a 50% cut point at 3.5 µm.
STEL Short-term exposure level. Maximum dust
concentration over a 15 minute period.
Thoracic Particulates Particulates having a 50% cut point at 10 µm.
TWA Time Weighted Average. Average particulate
concentration over a period of time.
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