Current through Register Vol. 48, No. 51, June 17, 2024
Part 4717.8250 - TABLE OF MHRVs FOR MULTIMEDIA EXPOSURE TO AIR TOXICS The heading for each item contains the chemical name and, in parenthesis, the CAS RN. Each item lists the MHRV and the variables necessary for the equation. The equations used to develop the MHRV are designated as follows: "A" means applying the equation under part 4717.8350 for noncarcinogenic effects of toxicants and "B" means applying the equation under part 4717.8450 for carcinogens. The endpoint of concern is listed for use in determining a cancer index under part 4717.8550 or a hazard index under part 4717.8600.
TABLE OF MHRVs
A. Antimony (7440-36-0) | MHRV ( µg/kg-day) | 0.4 |
| Endpoint of concern | Hematologic system |
| Equation | A |
| LOAEL (mg/kg-day) | 3.5E-1 |
| Uncertainty factor | 1,000 |
B. Arsenic (7440-38-2) | MHRV ( µg/kg-day) | 0.007 |
| Endpoint of concern | Cancer |
| Equation | B |
| Potency slope [mg/kg-day]-1 | 1.5 |
C. Benzo[a]pyrene (50-32-8) | MHRV ( µg/kg-day) | 0.001 |
| Endpoint of concern | Cancer |
| Equation | B |
| Potency slope [mg/kg-day]-1 | 7.3 |
D. Cadmium (7440-43-9) | MHRV ( µg/kg-day) | 0.5 |
| Endpoint of concern | Renal system |
| Equation | A |
| NOAEL (mg/kg-day) | 5E-3 |
| Uncertainty factor | 10 |
E. Manganese (7439-96-5) | MHRV ( µg/kg-day) | 140 |
| Endpoint of concern | Nervous system |
| Equation | A |
| NOAEL (mg/kg-day) | 1.4E-1 |
| Uncertainty factor | 1 |
F. Methylmercury (22967-92-6) | MHRV ( µg/kg-day) | 0.1 |
| Endpoint of concern | Nervous system and developmental |
| Equation | A |
| BMD (mg/kg-day) | 1E-3 |
| Uncertainty factor | 10 |
G. Nickel (7440-02-0) | MHRV ( µg/kg-day) | 20 |
| Endpoint of concern | Decreased body and organ weights |
| Equation | A |
| NOAEL (mg/kg-day) | 5 |
| Uncertainty factor | 300 |
H. Polychlorinated biphenyls (PCB) (1336-36-3) | MHRV ( µg/kg-day) | 0.05 |
| Endpoint of return | Developmental |
| Equation | A |
| LOAEL (mg/kg-day) | 5E-4 |
| Uncertainty factor | 10 |
Statutory Authority: MS s 144.12