HazMat Tool — substance information
Dimethyl sulfate
HMT May 2026Dimethyl sulfate
Dimethyl sulfate (DMS) is a chemical compound with formula (CH3O)2SO2. As the diester of methanol and sulfuric acid, its formula is often written as (CH3)2SO4 or Me2SO4, where CH3 or Me is methyl. Me2SO4 is mainly used as a methylating agent in organic synthesis. Me2SO4 is a colourless oily liquid with a slight onion-like odour. Wikipedia
Substance Data
Source: PubChemCAS-Number77-78-1 |
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 | |
| B77 | |
| 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.
Note: The HMR prohibit only those Division 6.1 liquids that meet the definition of a Packing Group (PG) I and Hazard Zone A. See special provision 1 and PHMSA Interpretation #09-0252.
Packages with POISON or POISON INHALATION HAZARD labels, or a POISON label displaying “PG III,” or “PG III” marked next to a POISON label may not be transported with foodstuffs, feed or any other edible material, intended for humans or animals. For exceptions see 49 CFR §177.841(e).
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

