PAC Database - Detailed Chemical Data
Chemical Identity
| Chemical | CAS# | UN# | Health Code Numbers | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Dipotassium metasilicate | 10006-28-7 |
14.01
11.01
14.02
4.08
11.00
4.09
4.06
4.07
3.09
5.00
|
||||||||||
| Formula | Synonyms | |||||||||||
| K2.Si.O3 | ||||||||||||
Physical Properties
| Mol Wt | State | MP (°C) | BP (°C) | VP (Hg) | VP (°C) | SG | LEL (ppm) |
|---|---|---|---|---|---|---|---|
| 154.263 | S |
PAC Values
| PAC-1 | PAC-2 | PAC-3 |
|---|---|---|
| 3.5 | 38 | 260 |
| PAC-1 | PAC-2 | PAC-3 |
|---|---|---|
| 0.55 | 6.0 | 41 |
Technical Basis
A review of available sources did not identify exposure limits or acute toxicity data for dipotassium metasilicate. Instead, analysts evaluated acute toxicity data for a similar chemical (Na2SiO3, sodium silicate, CASRN: 6834-92-0) for TEEL development (Section 3.4.6). A rat oral LD50 for sodium silicate (CASRN: 6834-92-0) was selected as the TEEL-3 basis. TEEL-2 and TEEL-1 values were derived according to Table 3.5.
• PAC-1 = TEEL-1 = TEEL-2/11
• PAC-2 = TEEL-2 = TEEL-3/6
• PAC-3 = TEEL-3 = Rat oral LD50 (sodium silicate; CASRN 6834-92-0; 1153 mg/kg)
This review generated PAC values inconsistent with Rev. 29A. The Rev. 29A TEEL-3 basis was a rat oral LD50 not identified during this review. Instead, the current TEEL-3 basis is a rat oral LD50 for a similar chemical, sodium silicate (CASRN: 6834-92-0). The Rev. 29A and current TEEL-2 and TEEL-1 use the same methodology, with differences due to the change in TEEL-3.
• PAC-1 = TEEL-1 = TEEL-2/11
• PAC-2 = TEEL-2 = TEEL-3/6
• PAC-3 = TEEL-3 = Rat oral LD50 (sodium silicate; CASRN 6834-92-0; 1153 mg/kg)
This review generated PAC values inconsistent with Rev. 29A. The Rev. 29A TEEL-3 basis was a rat oral LD50 not identified during this review. Instead, the current TEEL-3 basis is a rat oral LD50 for a similar chemical, sodium silicate (CASRN: 6834-92-0). The Rev. 29A and current TEEL-2 and TEEL-1 use the same methodology, with differences due to the change in TEEL-3.
References
Chemical information: https://pubchem.ncbi.nlm.nih.gov/compound/66200
Rat oral LD50 for sodium silicate (CASRN 6834-92-0), 1153 mg/kg. Toxicology Letters., 31(Suppl)(44), 1986. Retrieved from: https://pubchem.ncbi.nlm.nih.gov/compound/Sodium-silicate