Provenance

Reference data from EU CLP Annex VI and published regulations — verify against your supplier's SDS before use.

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Substance profile

Dimethyl Sulfate

Dimethyl Sulfate is a colorless oily liquid and is odorless.

CAS 77-78-1 C2H6O4S 126.13 g/mol Danger

01 · Identification

What Dimethyl Sulfate is

Dimethyl Sulfate is a colorless oily liquid and is odorless. Its molecular formula is C2H6O4S and its molecular weight is 126.13 g/mol. It boils at 188 °C, melts at -27 °C.

Under the GHS it carries the signal word Danger. It is classed as hazardous Air Pollutants (HAPs).

02 · Identifiers

Dimethyl Sulfate identifiers and molecular data

Dimethyl Sulfate CAS number and EC number

CAS number77-78-1
EC number201-058-1
Index number (CLP Annex VI)016-023-00-4

Dimethyl Sulfate molecular formula and molecular weight

Molecular formulaC2H6O4S
Molecular weight126.13 g/mol
Chemical class Hazardous Air Pollutants (HAPs)

Other names for Dimethyl Sulfate

  • dimethyl sulphate

03 · GHS classification

Dimethyl Sulfate hazard classification

Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.

Dimethyl Sulfate pictograms and signal word

Signal wordDanger

Dimethyl Sulfate hazard class and category

GHS hazard classes Dimethyl Sulfate falls into
Hazard class Category From code Pictogram
Acute toxicity - oral GHS chapter 3.1 Category 3 H301 GHS06
Acute toxicity - inhalation GHS chapter 3.1 Category 1 or 2 H330 GHS06
Skin corrosion/irritation GHS chapter 3.2 Category 1A or 1B or 1C H314 GHS05
Skin sensitisation GHS chapter 3.4 Category 1 or 1A or 1B H317 GHS07
Germ cell mutagenicity GHS chapter 3.5 Category 2 H341 GHS08
Carcinogenicity GHS chapter 3.6 Category 1A or 1B H350 GHS08

Where two values are shown with “or”, the hazard statement is shared by more than one category or by more than one class, and the code alone does not say which. H272, for example, belongs to oxidising liquids and to oxidising solids — the physical state decides. The binding answer for a specific entry is in the CLP Annex VI table itself.

Dimethyl Sulfate hazard statements (H-codes)

Hazard statements assigned to Dimethyl Sulfate
CodeHazard statement
H350 May cause cancer <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>.
H341 Suspected of causing genetic defects <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>.
H330 Fatal if inhaled.
H301 Toxic if swallowed.
H314 Causes severe skin burns and eye damage.
H317 May cause an allergic skin reaction.

This page lists only the codes assigned to Dimethyl Sulfate. The full reference lives on the hazard statements hub, the precautionary statements hub and the GHS pictograms hub.

Safety Data Sheet

Getting an SDS for Dimethyl Sulfate

A Safety Data Sheet is written for a product, not for a substance: the supplier of the grade you actually buy issues it, so two suppliers of Dimethyl Sulfate issue two different sheets. That is why there is no single authoritative SDS for a substance to download — what there is, is the job of collecting the sheets for the products you hold and keeping them current as suppliers revise them.

04 · Precautionary statements

Dimethyl Sulfate precautionary statements

CLP Annex VI assigns 15 precautionary statements to Dimethyl Sulfate. They are grouped the way a label groups them: what to do before handling, what to do when something has already happened, how to store it and how to dispose of it.

Reading the notation. is a blank the supplier fills in — not a truncated sentence.· [square brackets] mark a part printed only when it applies.

05 · Names in the regulation

Dimethyl Sulfate name in 23 EU languages

CLP Annex VI Part 3 is published in every language edition of the regulation, and the identification column is written out in each of them. Nothing below is translated by us: each line is the name as that edition prints it. Under Art. 18(2) the substance name from Annex VI is a lawful product identifier, so this is the wording to put on a label going to that market — and where the cell lists several designations, any one of them qualifies.

Language Name in CLP Annex VI Part 3
Bulgarian български диметилсулфат
Spanish español Sulfato de dimetilo
Czech čeština dimethyl-sulfát
Danish dansk dimethylsulfat
German Deutsch Dimethylsulfat
Estonian eesti dimetüülsulfaat
Greek ελληνικά θειικός διμεθυλεστέρας
English English dimethyl sulphate
French français sulfate de diméthyle
Croatian hrvatski dimetil-sulfat
Italian italiano dimetilsolfato
Latvian latviešu dimetilsulfāts
Lithuanian lietuvių dimetilsulfatas
Hungarian magyar dimetil-szulfát
Maltese Malti sulfat tad-dimetil
Dutch Nederlands dimethylsulfaat
Polish polski siarczan(VI) dimetylu
Portuguese português sulfato de dimetilo
Romanian română sulfat de dimetil
Slovak slovenčina dimetyl-sulfát
Slovenian slovenščina dimetil sulfat
Finnish suomi dimetyylisulfaatti
Swedish svenska dimetylsulfat

All 23 language editions of Annex VI carry this entry. Irish is the twenty-fourth official EU language and has no line here for a different reason: no consolidated CLP text has ever been published in Irish, so there is no Irish edition of Annex VI to quote a name from. Source: consolidated CLP, CELEX 02008R1272, language editions. © European Union, https://eur-lex.europa.eu — only the electronic Official Journal of the European Union is authentic.

06 · Label elements

Dimethyl Sulfate GHS label elements

Everything CLP Annex VI fixes for Dimethyl Sulfate, laid out the way it appears on a label. The greyed lines are the parts only the supplier can fill in.

GHS06 Skull and crossbones pictogramGHS08 Health hazard pictogramGHS05 Corrosion pictogram

Danger

Dimethyl Sulfate

  • May cause cancer <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>.
  • Suspected of causing genetic defects <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>.
  • Fatal if inhaled.
  • Toxic if swallowed.
  • Causes severe skin burns and eye damage.
  • May cause an allergic skin reaction.
  • Obtain special instructions before use.
  • Do not breathe dust/fume/gas/mist/vapours/spray.
  • Avoid breathing dust/fume/gas/mist/vapours/spray.
  • Do not eat, drink or smoke when using this product.
  • Use only outdoors or in a well-ventilated area.
  • Contaminated work clothing should not be allowed out of the workplace.
  • Wear protective gloves/protective clothing/eye protection/face protection/hearing protection/
  • IF SWALLOWED:
  • IF INHALED:
  • IF exposed or concerned:
  • Immediately call a POISON CENTER/doctor/
  • Get medical advice/attention.
  • Rinse mouth.
  • Do NOT induce vomiting.
  • If skin irritation or rash occurs:

Supplier name, address and telephone number· Product identifier·Nominal quantity

Need this as an actual label? Open Dimethyl Sulfate in the GHS label constructor →

07 · Health hazards

Dimethyl Sulfate health hazards and exposure limits

Dimethyl Sulfate hazard summary

Exposure to dimethyl sulfate is primarily occupational. Acute (short-term) exposure of humans to the vapors of dimethyl sulfate may cause severe inflammation and necrosis of the eyes, mouth, and respiratory tract. Acute oral or inhalation exposure to dimethyl sulfate primarily damages the lungs but also injures the liver, kidneys, heart, and central nervous system (CNS), while dermal contact with dimethyl sulfate may produce severe blistering in humans. Human data on the carcinogenic effects of dimethyl sulfate are inadequate. Tumors have been observed in the nasal passages, lungs, and thorax of animals exposed to dimethyl sulfate by inhalation. EPA has classified dimethyl sulfate as a Group B2, probable human carcinogen.

Source: EPA Hazardous Air Pollutants

Dimethyl Sulfate carcinogenicity classification

IARC classification Group 2A — Probably carcinogenic to humans
IARC monographs Volume 4: (1974) Some Aromatic Amines, Hydrazine and Related Substances, N-Nitroso Compounds and Miscellaneous Alkylating Agents; Volume 71: (1999) Re-evaluation of Some Organic Chemicals, Hydrazine and Hydrogen Peroxide (Part 1, Part 2, Part 3)

Evaluation: There is inadequate evidence for the carcinogenicity in humans of dimethyl sulfate. There is sufficient evidence for the carcinogenicity in experimental animals of dimethyl sulfate. Overall evaluation: Dimethyl sulfate is probably carcinogenic to humans (Group 2A). In making the overall evaluation, the Working Group took into consideration that dimethyl sulfate is a potent genotoxic chemical which can directly alkylate DNA both in vitro and in vivo.

Source: Hazardous Substances Data Bank (HSDB)

Dimethyl Sulfate: reasonably anticipated to be a human carcinogen.

Source: Hazardous Substances Data Bank (HSDB)

An IARC group and a CLP classification answer different questions. IARC judges whether the evidence for cancer in humans is strong enough; CLP Annex VI is the legally binding EU classification. A substance can carry one and not the other.

Dimethyl Sulfate occupational exposure limits

US occupational exposure limits reported for Dimethyl Sulfate. PEL is enforceable (OSHA), REL is a recommendation (NIOSH), IDLH is the concentration at which escape becomes impossible without injury.
Limit Value Source
PEL 1.0 [ppm] Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
PEL 1 ppm (5 mg/m³) Occupational Safety and Health Administration (OSHA)
PEL TWA 1 ppm (5 mg/m3) [skin] See Appendix G The National Institute for Occupational Safety and Health (NIOSH)
REL 0.1 ppm (0.5 mg/m³) Occupational Safety and Health Administration (OSHA)
REL Ca TWA 0.1 ppm (0.5 mg/m3) [skin] See Appendix A The National Institute for Occupational Safety and Health (NIOSH)
IDLH 7 ppm ; A potential occupational carcinogen. (NIOSH, 2024) CAMEO Chemicals
IDLH 7.0 [ppm] Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
IDLH NIOSH considers dimethyl sulfate to be a potential occupational carcinogen. Hazardous Substances Data Bank (HSDB)

These are United States values. The European Union sets its own indicative and binding limits, and the figure that applies at a given workplace is the one in the local regulation — not the one shown here.

08 · Physical and chemical properties

Dimethyl Sulfate properties

Every value is shown with the conditions it was measured under and the source it came from. Where sources disagree, all values are listed rather than one being picked — the difference is usually a different form of the substance, not an error.

Dimethyl Sulfate boiling point

Property Value Conditions Source
Boiling point 188 °C (370.4 °F) approximate HSDB
187.78 °C (370 °F) approximate CAMEO
187.78 °C (370 °F) decomposes NIOSH

Dimethyl Sulfate melting point

Property Value Conditions Source
Melting point -27 °C (-16.6 °F) HSDB
-31.67 °C (-25 °F) NIOSH
-31.75 °C (-25.1 °F) CAMEO

Dimethyl Sulfate density

Property Value Conditions Source
Density 1.33 g/cm³ NIOSH
1.3322 g/cm³ at 20 °C HSDB
1.3283 g/cm³ at 20 °C CAMEO

Dimethyl Sulfate solubility

Property Value Conditions Source
Solubility Sol in ether, dioxane, acetone, aromatic hydrocarbons. HSDB
Sparingly sol in carbon disulfide, aliphatic hydrocarbons. HSDB
Miscible in ethanol; soluble in ethyl ether, carbon tetrachloride and benzene; insoluble in carbon disulfide HSDB

Dimethyl Sulfate vapor pressure

Property Value Conditions Source
Vapor pressure 0.1 mmHg NIOSH
0.5 mmHg at 20 °C CAMEO
0.677 mmHg at 25 °C HSDB

Dimethyl Sulfate flash point

Property Value Conditions Source
Flash point 83.33 °C (182 °F) HSDB

Dimethyl Sulfate autoignition temperature

Property Value Conditions Source
Autoignition temperature 187.78 °C (370 °F) HSDB
470 °C (878 °F) ICSC

Dimethyl Sulfate lower explosive limit (LEL)

Property Value Conditions Source
Lower explosive limit (LEL) 3.6 % by volume HSDB
Class IIIA Combustible Liquid: Fl.P. at or above 140 °F and below 200 °F. NIOSH

Dimethyl Sulfate upper explosive limit (UEL)

Property Value Conditions Source
Upper explosive limit (UEL) 23.3 % by volume HSDB
Moderate fire potential when exposed to heat or flame. (EPA, 1998) CAMEO

Dimethyl Sulfate vapor density

Property Value Conditions Source
Vapor density 4.35 (air = 1) HSDB
4.4 (air = 1) ICSC

Dimethyl Sulfate corrosivity

Property Value Conditions Source
Corrosivity Corrosive HSDB

Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.

09 · Fire and explosion

Dimethyl Sulfate fire and explosion behaviour

These are descriptions rather than measured values, so they are kept out of the table above and quoted here with the source that reported them.

Dimethyl Sulfate fire potential

MODERATE, WHEN EXPOSED TO HEAT OR FLAME.

Source: Hazardous Substances Data Bank (HSDB)

10 · Handling and storage

Dimethyl Sulfate storage and handling

Dimethyl Sulfate safe storage

Separated from food and feedstuffs and incompatible materials. See Chemical Dangers. Cool. Dry. Well closed. Ventilation along the floor. Store in an area without drain or sewer access.

Source: ILO-WHO International Chemical Safety Cards (ICSCs)

Dimethyl Sulfate storage conditions

PRECAUTIONS FOR "CARCINOGENS": Storage site should be as close as practicable to lab in which carcinogens are to be used, so that only small quantities required for ... expt need to be carried. Carcinogens should be kept in only one section of cupboard, an explosion-proof refrigerator, or freezer (depending on chemicophysical properties ...) that bears appropriate label. An inventory ... should be kept, showing quantity of carcinogen & date it was acquired ... . Facilities for dispensing ... should be contiguous to storage area. /Chemical Carcinogens/

Source: Hazardous Substances Data Bank (HSDB)

Dimethyl Sulfate incompatible materials

Can react with oxidizing materials.

Source: Hazardous Substances Data Bank (HSDB)

Dimethyl Sulfate reactivity

Pure DIMETHYL SULFATE and concentrated aqueous ammonia react extremely violently with one another, as is the case for tertiary organic bases, [NFPA 491M, 1991]. Dimethyl sulfate ignites in contact with unheated barium chlorite, due to the rapid formation of unstable methyl chlorite. The product of methylating an unnamed material at 110 °C was allowed to remain in a reactor for 80 min. before the reactor exploded. This involved a sulfur ester such as dimethyl sulfate, [MCA Case History No. 1786].

Source: CAMEO Chemicals

Planning storage for a mix of chemicals? Check Dimethyl Sulfate in the storage compatibility matrix →

11 · Transport

Dimethyl Sulfate UN number and transport classification

Transport classification is a separate system from the GHS classification above. It decides how a package is marked and how a load may be carried; it does not follow from the workplace label, and the workplace label does not follow from it. The entries below are linked by CAS number, never by name.

Dimethyl Sulfate under UN 1595 — shipping name, class and packing group

Europe · ADR 2025, Table A

Proper shipping name (3.1.2) Class Classification code PG Labels (column 5)
DIMETHYL SULPHATE 6.1 TC1 I
  • ADR label model 6.1 — Toxic substance
  • ADR label model 8 — Corrosive substance
6.1, 8

Source: ADR 2025, Table A of Chapter 3.2 · ECE/TRANS/352 Vol. I (UNECE). Class 6.1 is “Toxic substances” (ADR 2.1.1.1).

Proper shipping name (column 2) Class or division PG Labels (column 6)
Dimethyl sulfate 6.1 I
  • US DOT POISON label (§172.430)
  • US DOT CORROSIVE label (§172.442)
6.1, 8

Source: 49 CFR 172.101 Hazardous Materials Table · eCFR, revision 2026-08-03. Class 6.1 is “Poisonous materials” (49 CFR 173.2).

Full UN 1595 entry — special provisions, packing instructions, quantity limits and the orange plate →

12 · Questions

Dimethyl Sulfate — frequently asked questions

What is the CAS number of Dimethyl Sulfate?

The CAS number of Dimethyl Sulfate is 77-78-1. Its EC number is 201-058-1.

What is the chemical formula of Dimethyl Sulfate?

The molecular formula of Dimethyl Sulfate is C2H6O4S and its molecular weight is 126.13 g/mol.

What does a Dimethyl Sulfate label have to show?

Under CLP Annex VI the label for Dimethyl Sulfate carries the pictograms Skull and crossbones, Health hazard and Corrosion and the signal word is Danger.

Is Dimethyl Sulfate flammable?

CLP Annex VI assigns Dimethyl Sulfate no flammability hazard class. That is not a statement that it cannot burn: the harmonised list only records the hazards that were assessed for it. The flash point reported for it is 83.33 °C (182 °F) (HSDB).

Is Dimethyl Sulfate a carcinogen?

Yes. CLP Annex VI classifies Dimethyl Sulfate as a category 1A or 1B carcinogen and assigns it H350: may cause cancer. IARC places it in Group 2A: probably carcinogenic to humans.

What is the exposure limit for Dimethyl Sulfate?

The US occupational exposure limit reported for Dimethyl Sulfate is 1.0 [ppm] (Haz-Map, Information on Hazardous Chemicals and Occupational Diseases). Limits differ by country: the EU sets its own indicative and binding values, and the figure that applies at a given workplace is the one in the local regulation.

What is the boiling point of Dimethyl Sulfate?

The boiling point reported for Dimethyl Sulfate is 188 °C (370.4 °F), approximate (HSDB).

What is the melting point of Dimethyl Sulfate?

The melting point reported for Dimethyl Sulfate is -27 °C (-16.6 °F) (HSDB).

How should Dimethyl Sulfate be stored?

PRECAUTIONS FOR "CARCINOGENS": Storage site should be as close as practicable to lab in which carcinogens are to be used, so that only small quantities required for ... expt need to be carried. Carcinogens should be kept in only one section of cupboard, an explosion-proof refrigerator, or freezer (depending on chemicophysical properties ...) that bears appropriate label. An inventory ... should be kept, showing quantity of carcinogen & date it was acquired ... . Facilities for dispensing ... should be contiguous to storage area. /Chemical Carcinogens/ (Hazardous Substances Data Bank (HSDB))

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