| Ambient Air Quality Standards for the United States and Mexico | |||||
| MEXICO | U.S. | ||||
| Pollutant | Units | Average | Units | Average | |
| O3 | 0.11 ppm | 1 hour | 0.12 ppm | 1 hour | |
| SO2 | 0.13 ppm | 24 hours | 0.14 ppm | 24 hours | |
| 0.03 ppm | annual | 0.03 ppm | annual | ||
| NO2 | 0.21 ppm | 1 hour | 0.25 ppm | 1 hour | |
| 0.053 ppm | annual | ||||
| CO | 11 ppm | 8 hours | 9 ppm | 8 hours | |
| 35 ppm | |||||
| 1 hour | |||||
| TSP | 260 ug/m3 | 24 hours | N/A | N/A | |
| 75 ug/m3 | annual | ||||
| PM-10 | 150 ug/m3 | 24 hours | 150 ug/m3 | 24 hours | |
| 50 ug/m3 | annual | 50 ug/m3 | annual | ||
| LEAD | 1.5 ug/m3 | 3 months | 1.5 ug/m3 | 3 months | |