PAC Database - Detailed Chemical Data
Chemical Identity
| Chemical | CAS# | UN# | Health Code Numbers | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Tetramethoxysilane; (Methyl silicate) | 681-84-5 | 2606 |
14.01
4.01
11.01
14.02
7.00
11.00
4.09
4.07
4.13
10.00
|
|||||||||
| Formula | Synonyms | |||||||||||
| C4H12O4Si | METHYL ORTHOSILICATE, KBM 04, METHYL SILICATE, METHYL SILICATE ((CH3)4SIO4), METHYL SILICATE ((MEO)4SI), METHYL SILICATE 39, MSP 150, ORTHOSILICATE DE MÉTHYLE (DOT FRENCH), ORTOSILICATO DE METILO (DOT SPANISH), SILANE, TETRAMETHOXY-, SILICON METHOXIDE (SI(OME)4), SILICON TETRAMETHOXIDE, TETRAMETHOXYSILANE, TETRAMETHYL ESTER OF SILICIC ACID, TETRAMETHYL ORTHOSILICATE, TETRAMETHYL SILICATE, TMOS | |||||||||||
Physical Properties
| Mol Wt | State | MP (°C) | BP (°C) | VP (Hg) | VP (°C) | SG | LEL (ppm) |
|---|---|---|---|---|---|---|---|
| 152.22 | L | -1 | 121 | 7.5 | 14.4 | 1.0232 @ 20°C |
PAC Values
| PAC-1 | PAC-2 | PAC-3 |
|---|---|---|
| 0.30 | 0.91 | 1.4 |
| PAC-1 | PAC-2 | PAC-3 |
|---|---|---|
| 1.9 | 5.7 | 8.7 |
Technical Basis
A review of available sources identified AEGLs and federal toxicity guidelines for this chemical. The AEGLs were selected due to their priority among Protective Action Criteria (Section 1). Values in units mg/m3 are reported as published in the technical support Table 7-12, per guidance (Section 3.4.7.2). TEEL-1 value was derived according to Table 3.5.
• PAC-1 = TEEL-1 = MAK-STEL (0.3 ppm, 2 mg/m3)
• PAC-2 = AEGL-2
• PAC-3 = AEGL-3
This review generated PAC-3 and PAC-2 ppm values and source consistent with Rev. 29A. Differences in the reported PAC-2 value in units mg/m3 may be due to conversion and rounding of these values, instead of use of source values. The current PAC-1 value is inconsistent with Rev. 29A. The Rev. 29A TEEL-1 was derived according to Table 3.5, while the current TEEL-1 is a MAK-STEL (Table 3.1).
• PAC-1 = TEEL-1 = MAK-STEL (0.3 ppm, 2 mg/m3)
• PAC-2 = AEGL-2
• PAC-3 = AEGL-3
This review generated PAC-3 and PAC-2 ppm values and source consistent with Rev. 29A. Differences in the reported PAC-2 value in units mg/m3 may be due to conversion and rounding of these values, instead of use of source values. The current PAC-1 value is inconsistent with Rev. 29A. The Rev. 29A TEEL-1 was derived according to Table 3.5, while the current TEEL-1 is a MAK-STEL (Table 3.1).
References
AEGLs (Table 7-12) and chemical information (Table 7-3) retrieved from: https://www.epa.gov/aegl/tetramethoxy-silane-results-aegl-program
MAK-STEL (Germany AGS): https://ilv.ifa.dguv.de/limitvalues/58235