Methanesulfonyl chloride
HMT May 2026Methanesulfonyl chloride
Methanesulfonyl chloride (mesyl chloride) is an organosulfur compound with the formula CH3SO2Cl. Using the organic pseudoelement symbol Ms for the methanesulfonyl (or mesyl) group CH3SO2–, it is frequently abbreviated MsCl in reaction schemes or equations. It is a colourless liquid that dissolves in polar organic solvents but is reactive toward water, alcohols, and many amines. The simplest organic sulfonyl chloride, it is used to make methanesulfonates and to generate the elusive molecule sulfene (methylenedioxosulfur(VI)). Wikipedia
Substance Data
Source: PubChemCAS-Number124-63-0 |
Flash Pointn/a | Boiling Pointn/a |
| Emergency Response Guide No. 156 |
Hazardous Materials Table
Source: 49 CFR §172 (2026/05)(3) Hazard Class6.1Poisonous Material |
(4) Identification number |
(5) Packing Group |
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(6) Labels |
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(7) Special Provisions (§172.102)
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| 2 | |
|---|---|
| B9 | |
| B14 | |
| B32 | |
| T20 | |
| TP2 | |
| TP13 | |
| TP38 | |
| TP45 |
(8) Packing Authorizations (§173.***) 
| (8A) Exceptions | None | |
|---|---|---|
| (8B) Non-bulk | 227 | see 49 CFR §173.227 |
| (8C) Bulk | 244 | see 49 CFR §173.244 |
(9) Quantity Limits 
| (9A) Passenger aircraft/rail | Forbidden |
|---|---|
| (9B) Cargo aircraft only | Forbidden |
(10) Vessel stowage 
| (10A) Location | |
|---|---|
| (10B) Other |
Segregation chart for load, transport, and storage
This chart shows whether loading, transport, or storage with other hazard classes is permitted, prohibited, or restricted. Based on 49 CFR §177.848.
Scope & sources (important)Click to show CFR references
This check evaluates segregation per 49 CFR §177.848. Additional loading/unloading and handling requirements may still apply; see 49 CFR §177 Subpart B (Loading and Unloading):
- §177.834 - General requirements
- §177.835 - Class 1 materials
- §177.837 - Class 3 materials
- §177.838 - Class 4 (flammable solid) materials, Class 5 (oxidizing) materials, and Division 4.2 (pyroforic liquid) materials
- §177.839 - Class 8 (corrosive) materials
- §177.840 - Class 2 (gases) materials
- §177.841 - Division 6.1 and Division 2.3 materials
- §177.842 - Class 7 (radioactive) material
- §177.843 - Contamination of vehicles

