PAC Database - Detailed Chemical Data
Chemical Identity
| Chemical | CAS# | UN# | Health Code Numbers | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sodium selenite | 10102-18-8 | 2630 |
14.01
11.01
14.02
4.08
4.05
7.01
8.00
7.00
11.00
4.02
|
|||||||||
| Formula | Synonyms | |||||||||||
| SeO3.2Na | SODIUM SELENITE, DISODIUM SELENITE, DISODIUM SELENIUM TRIOXIDE, SELENIOUS ACID (H2SEO3), DISODIUM SALT, SELENIOUS ACID(H2SEO3), DISODIUM SALT, SELENIOUS ACID, DISODIUM SALT, SÉLÉNITE DE SODIUM (DOT FRENCH), SELENITO DE SODIO (DOT SPANISH), SODIUM SELENATE (NA2SEO3), SODIUM SELENITE (DOT), SODIUM SELENIUM OXIDE, SODIUM SELENIUM OXIDE (NA2SEO3), SODIUM SELENIUM OXIDE[NA2SEO3], UN 2630 (DOT) | |||||||||||
Physical Properties
| Mol Wt | State | MP (°C) | BP (°C) | VP (Hg) | VP (°C) | SG | LEL (ppm) |
|---|---|---|---|---|---|---|---|
| 172.94 | S | 710 |
PAC Values
| PAC-1 | PAC-2 | PAC-3 |
|---|---|---|
| 0.21 | 2.3 | 14 |
| PAC-1 | PAC-2 | PAC-3 |
|---|---|---|
| 0.030 | 0.33 | 2.0 |
Technical Basis
A review of available sources identified a LOC and acute toxicity data (LD50, TDLo) for several routes and species. Data sources were selected according to the hierarchy listed in Table 3.1. Toxicity data were selected according to type of exposure, species, and route according to the hierarchies stated in Sections 3.3.1, 3.3.2, and evaluated using factors in Tables 3.2, 3.3, and 3.4. The LOC was selected as the TEEL-2 (Table 3.1). Analysts considering available toxicity data as a TEEL-3 basis; however, all animal toxicity resulted in TEEL-3 < TEEL-2. Considering the human (male) oral TDLo (PAC-2 = TEEL-2 = 14 mg/m3), analysts determined that these were overly conservative. Instead, the TEEL-3 and TEEL-1 values were derived according to Table 3.5.
• PAC-1 = TEEL-1 = TEEL-2/11
• PAC-2 = TEEL-2 = LOC (0.0023 g/m3)
• PAC-3 = TEEL-3 = TEEL-2 x 6
This review generated PAC-3 and PAC-1 values inconsistent with Rev. 29A, and a PAC-2 consistent with Rev. 29A. The Rev. 29A TEEL-3 basis was a rat oral LD50, while the current TEEL-3 was derived from the TEEL-2, an exposure limit (LOC). The Rev. 29A TEEL-1 basis was a weight adjusted selenium TLV-TWA (CASRN: 7782-49-2), while the current TEEL-1 was derived from the TEEL-2 (Section 3.4.2). The Rev. 29A and current TEEL-2 values, source, and methodology are consistent.
• PAC-1 = TEEL-1 = TEEL-2/11
• PAC-2 = TEEL-2 = LOC (0.0023 g/m3)
• PAC-3 = TEEL-3 = TEEL-2 x 6
This review generated PAC-3 and PAC-1 values inconsistent with Rev. 29A, and a PAC-2 consistent with Rev. 29A. The Rev. 29A TEEL-3 basis was a rat oral LD50, while the current TEEL-3 was derived from the TEEL-2, an exposure limit (LOC). The Rev. 29A TEEL-1 basis was a weight adjusted selenium TLV-TWA (CASRN: 7782-49-2), while the current TEEL-1 was derived from the TEEL-2 (Section 3.4.2). The Rev. 29A and current TEEL-2 values, source, and methodology are consistent.
References
Chemical information and acute toxicity data: https://pubchem.ncbi.nlm.nih.gov/compound/24934
LOC. Appendix C, pg. C-8. https://www.epa.gov/sites/default/files/2015-09/documents/technical_guidance_for_hazard_analysis.pdf
Human (male) oral TDLo (24 mg/kg; nausea and vomiting). Veterinary and Human Toxicology., 39(304), 1997. Retrieved from: https://pubchem.ncbi.nlm.nih.gov/compound/24934
Selenium TLV-TWA: https://www.acgih.org/selenium-and-compounds/