Lead (Pb) Standards -
Table of Historical Pb NAAQS
History of the National Ambient Air Quality Standards for Lead
During the Period 1978-2008
Final Rule/Decision | Primary/ Secondary | Indicator | Averaging Time | Level (1) | Form |
---|---|---|---|---|---|
1978 43 FR 46246 Oct 5, 1978 |
Primary and Secondary | Pb-TSP (2) | Calendar Quarter | 1.5 µg/m3 | Not to be exceeded |
Feb 21, 1991 – Agency released multimedia “Strategy for Reducing Lead Exposures” (3) | |||||
2008 73 FR 66964 Nov 12, 2008 |
Primary and Secondary | Pb-TSP | 3-month period | 0.15 µg/m3 | Not to be exceeded |
(1) Units of measure are micrograms per cubic meter of air (µg/m3).
(2) Lead in total suspended particles (Pb-TSP).
(3) Available: http://www.epa.gov/ttn/naaqs/standards/pb/data/leadstrategy1991.pdf.