PAC Database - Detailed Chemical Data
Chemical Identity
| Chemical | CAS# | UN# | Health Code Numbers | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Methyl mercaptan | 74-93-1 | 1064 |
13.00
15.01
11.01
15.02
4.08
4.05
7.01
8.00
7.00
11.00
|
|||||||||
| Formula | Synonyms | |||||||||||
| CH4S | METHYL MERCAPTAN, MERCAPTAN MÉTHYLIQUE (DOT FRENCH), MERCAPTOMETHANE, METHANEETHIOL, METHANETHIOL, METHYL SULFHYDRATE, METILMERCAPTANO (DOT SPANISH), THIOMETHANOL, THIOMETHYL ALCOHOL | |||||||||||
Physical Properties
| Mol Wt | State | MP (°C) | BP (°C) | VP (Hg) | VP (°C) | SG | LEL (ppm) |
|---|---|---|---|---|---|---|---|
| 48.11 | G | -123 | 5.9 | 750 | 5.7 | 0.8665 @ 20°C | 39000 |
PAC Values
| PAC-1 | PAC-2 | PAC-3 |
|---|---|---|
| 0.0050 | 23 | 68 |
| PAC-1 | PAC-2 | PAC-3 |
|---|---|---|
| 0.0098 | 45 | 130 |
Technical Basis
A review of available sources identified ERPGs and an AEGL-2 and AEGL-3 for this chemical. The AEGLs were selected as the TEEL-3 and TEEL-2 due to their priority among the emergency exposure limits (Section 1). Values in units mg/m3 are reported as published in the technical support document Table 2-1, per guidance (Section 3.4.7.2). The ERPG-1 was selected as the TEEL-1.
• TEEL-1 = ERPG-1
• TEEL-2 = AEGL-2
• TEEL-3 = AEGL-3
This review generated TEEL ppm values consistent with Rev. 29A. The difference in the reported TEEL-2 value in units mg/m3 may be due to conversion and rounding of this value, instead of use of the source value.
• TEEL-1 = ERPG-1
• TEEL-2 = AEGL-2
• TEEL-3 = AEGL-3
This review generated TEEL ppm values consistent with Rev. 29A. The difference in the reported TEEL-2 value in units mg/m3 may be due to conversion and rounding of this value, instead of use of the source value.
References
AEGLs (Table 2-1) and chemical information (Table 2-2) retrieved from https://www.epa.gov/aegl/methyl-mercaptan-results-aegl-program
ERPGs: https://www.osha.gov/chemicaldata/560