TYPE OF AGENT –Smoke/Lachrymatory Agent, Toxic
NAME (CHEMICAL) – Chlorosulfonic Acid
NAME (COMMON) – Chlorosulfonic Acid (N-Stoff WWI German), Chlorosulfuric Acid
DATE OF DISCOVERY – 1854
MOLECULAR FORMULA – ClSO3H
MOLECULAR WEIGHT – 116.52 g/mole
PHYSICAL STATE @ 20° C. (68° F.) – Liquid
VAPOR DENSITY (AIR = 1.0) – 4.02
FREEZING/MELTING POINT – -80° C. (-112° F.)
BOILING POINT – 151 to 152° C. @ 755 mm/Hg (304 to 306° F.)
LIQUID DENSITY – 1.753 g/cc @ 20° C. (68° F.)
VAPOR PRESSURE (mm/Hg) – 1.55 mm/Hg
ODOR – Sharply pungent
APPEARANCE – Colorless to yellow fuming liquid
SOLUBILITY – Violently (explosively) reacts with water breaking down into Sulfuric and Hydrochloric acids
MEDIAN INCAPACITATING DOSAGE (ID50) – 4.4 mg/m3 10 minute exposure estimated
MEDIAN LETHAL DOSAGE (LD50) – 45 mg/m3 10 minute exposure estimated
INHALATION TOXICITY – Very toxic, internal burns and pulmonary edema
SKIN TOXICITY – Causes severe chemical (acid) burns
EYE TOXICITY – Causes acid burns with possible eye damage
RATE OF ACTION – Very rapid
SYMPTOMS (PHYSIOLOGICAL ACTION) – Pain and redness on skin and in eyes, sorer throat, coughing, and burning sensation on inhalation, causes shortness of breath
TREATMENT – Removal from contamination, exposure to fresh air, rinse skin and eyes with large amounts of water
PROTECTION – Gas masks, acid-resistant suits including hoods, gloves, and overboots
DECONTAMINATION – Neutralize with alkaline materials – crushed limestone, Sodium bicarbonate, or Soda ash, then wash away with water
USE – Produces thick white smoke on exposure to air, smoke is toxic, used in grenades, mortar and artillery shells, and smoke pots/sprayers
A lack of phosphate resources within Germany forced the search for other smoke producing materials for the military other than White Phosphorus. For the upcoming combat in what would become WWI, the substitute smoke-producing material adopted was Chlorosulfonic acid. Chlorosulfonic acid is a highly reactive chemical used for a wide variety of chemical reactions as well as being a smoke producing agent. It produces a volatile and not very dense white smoke, but can meet military requirements for an inexpensive smoke agent. In spite of its relative availability, Cholorosulfonic acid had the drawback of requiring Sulfur for its manufacture, another material that German did not have in any abundance. Because of this, the Germans lagged behind the Allies who utilized smoke on the battlefield. The French began employing Chorosulfonic acid in September, 1915 with Great Britian and the United States following suit.
Exposing Chlorosulfonic acid to the air allows the materials to react with any available moisture. The smoke formed by exposure of Cholorosulfonic acid to the air is made up of dense white fumes of Hydrochloric and Sulfuric acids. These acids are in very corrosive concentrations, sufficient to bring the use Chrosulfonic acid very close to being a chemical agent rather than a smoke producer. During WWII, the Germans were continuing to use Chlorosulfonic acid as a smoke producing agent, often mixed with additional chemicals to increase its effectiveness. The admixture of other materials did nothing to reduce the toxic nature of the smoke. When the Nazis’ needed to produce huge “fog” banks to conceal one of their largest warships, the Tirpitz, they turned to smoke generators that employed Chlorosulfonic acid. The massive battleship was concealed deep inside a Norwegian fjord and the smoke did make it very difficult to bomb by Allied aircraft. That military action has left lasting marks on the Norwegian forests surround the hiding place of the Tirpitz as core samples taken from the trees show that there was no growth rings to be found from 1945. Some of the trees didn’t grow for several years following the Tirpitz action and most took a full 12 years to recover.
