Md. Code Regs. 26.11.16.09 - Levels Used to Review Ambient Impacts
A. Special Screening Levels (SSL) and
Acceptable Ambient Levels (AAL).
| CAS Number | Substance | Concentration (micrograms/ cubic meter) |
Averaging Time | Type of Level | |
| (1) | 7664-41-7 | Ammonia (a) (b) |
300. 450. |
8 hours 1 hour |
AAL AAL |
| (2) | 124-38-9 | Carbon Dioxide (a) (b) (c) (d) |
288,000. 2,088,000. 900,000. 2,700,000. |
8 hours 1 hour 8 hours 1 hour |
SSL SSL AAL AAL |
| (3) | 10049-04-4 | Chlorine Dioxide (a) (b) |
5. 15. |
8 hours 1 hour |
AAL AAL |
| (4) | 611-19-8 | 1-Chloro-2-(chloromethyl)-benzene (OCBC) |
9.1 | 8 hours | SSL |
| (5) | 81777-89-1 | Dimethazone | 27.4 | 8 hours | SSL |
| (6) | 598-56-1 | Dimethylethylamine | 1.6 | 8 hours | SSL |
| (7) | 75-00-3 | Ethyl Chloride (a) (b) |
2.6 13. |
8 hours 1 hour |
SSL SSL |
| (8) | 107-44-8 | GB (Sarin) (a) (b) |
0.0003 0.04 |
8 hours 15 minutes |
SSL SSL |
| (9) | 96-64-0 | GD (Soman) (a) (b) |
0.003 0.012 |
8 hours 15 minutes |
SSL SSL |
| (10) | 7647-01-0 | Hydrogen Chloride (a) (b) |
7. 117. |
Annual 1 hour |
AAL AAL |
| (11) | 541-25-3 | L (Lewisite) | 0.0004 | 15 minutes | SSL |
| (12) | 74-87-3 | Methyl Chloride (a) (b) |
105. 525. |
8 hours 1 hour |
SSL SSL |
| (13) | 50782-69-9 | VX (Ethyl S-Dimethyl amino ethyl
Methyl-phosphonothiolate) (a) (b) |
0.0003 0.004 |
8 hours 15 minutes |
SSL SSL |
| (14) | 7733-02-0 | Zinc Sulfate | 18.8 | 8 hours | SSL |
Notes
State regulations are updated quarterly; we currently have two versions available. Below is a comparison between our most recent version and the prior quarterly release. More comparison features will be added as we have more versions to compare.
No prior version found.