Substance profile
Chlorosulfonic acid
Chlorosulfonic acid is a colorless or slightly yellow liquid with a PUNGENT odor.
01 · Identification
What Chlorosulfonic acid is
Chlorosulfonic acid is a colorless or slightly yellow liquid with a PUNGENT odor. Its molecular formula is ClHO3S and its molecular weight is 116.53 g/mol. It boils at 155 °C, melts at -80 °C.
Under the GHS it carries the signal word Danger. It is classed as corrosives.
Other names for Chlorosulfonic acid
- chlorosulphonic acid
02 · GHS classification
Hazards and label elements
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
| Code | Hazard statement |
|---|---|
| H335 | May cause respiratory irritation. |
| H314 | Causes severe skin burns and eye damage. |
Supplemental EU statements: EUH014
Precautionary statements: P260, P280, P301, P310, P331
This page lists only the codes assigned to Chlorosulfonic acid. The full reference lives on the hazard statements hub, the precautionary statements hub and the GHS pictograms hub.
03 · Physical and chemical properties
Chlorosulfonic acid 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.
| Property | Value | Conditions | Source |
|---|---|---|---|
| Boiling point | 155 °C (311 °F) | at 760 mmHg | CAMEO |
| 152 °C (305.6 °F) | at 760 mmHg | DOE PAC | |
| 151.5 °C (304.7 °F) | range, midpoint shown, at 755 mmHg | HSDB | |
| Melting point | -80 °C (-112 °F) | HSDB | |
| Density | 1.75 g/cm³ | ICSC | |
| 1.75 g/cm³ | at 20 °C | CAMEO | |
| 1.75 g/cm³ | at 25 °C | DOE PAC | |
| Solubility | /COMMON SOLVENTS INCLUDE/ LIQUID SULFUR DIOXIDE, PYRIDINE, & DICHLOROETHANE. | HSDB | |
| Solubility in water: reaction | ICSC | ||
| Vapor pressure | 1.55 mmHg | CAMEO | |
| 0.9976 mmHg | at 20 °C | ICSC | |
| 1 mmHg | at 32 °C | HSDB | |
| Autoignition temperature | Not flammable (USCG, 1999) | CAMEO | |
| Lower explosive limit (LEL) | ON DROPPING INTO WATER DECOMP WITH EXPLOSIVE VIOLENCE. | HSDB | |
| Vapor density | 4.02 (air = 1) | HSDB | |
| Corrosivity | CORROSIVE MATERIAL. | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
04 · Fire and explosion
Fire and explosion behaviour of Chlorosulfonic acid
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.
Fire and explosion
Permonosulfonic acid was being prepared by reacting chlorosulfonic acid & 90% hydrogen peroxide. A sample was stored overnight at 0 °C, then removed to test tube rack. In 10 minutes it exploded.
Source: HSDB
05 · Handling and storage
Storing and handling Chlorosulfonic acid
Storage conditions
KEEP TIGHTLY CLOSED.
Source: Hazardous Substances Data Bank (HSDB)
Incompatible materials
Mixing chlorosulfonic acid with either 28% ammonia, creosote oil, 36% hydrochloric acid or 48.7% hydrofluoric acid, 70% nitric acid, 2-nitropropane or 96% sulfuric acid in a closed container caused the temperature & pressure to increase. It is dangerous in contact with combustible materials, nitrates, chlorates, metallic powders, carbides, picrates & fulminates.
Source: Hazardous Substances Data Bank (HSDB)
Planning storage for a mix of chemicals? Check Chlorosulfonic acid in the storage compatibility matrix →
Safety Data Sheet
Getting an SDS for Chlorosulfonic acid
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 Chlorosulfonic acid 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.
Nearby
Substances next to Chlorosulfonic acid
Keep going: substances starting with C, or search the whole database by name, CAS number, pictogram or signal word.