Sulphur Mustard (HD)
Definition
Bis(2-chloroethyl) sulphide. The prototype vesicant (blister agent). Alkylates DNA and proteins via an ethylene sulfonium ion intermediate. First used at Ypres (1917). Used at Halabja (1988, ~5,000 deaths). OPCW biomarker: thiodiglycol-sulphoxide in urine.
- Chemical name
- Bis(2-chloroethyl) sulphide
- Agent class
- Vesicant (blister agent)
- Mechanism
- Alkylates DNA and proteins via ethylene sulfonium ion
- First use
- Ypres, 1917
- OPCW biomarker
- Thiodiglycol-sulphoxide in urine
Common questions
Why is sulphur mustard called the prototype vesicant rather than just a poison?+
It defines the vesicant class because its alkylating mechanism produces the characteristic delayed blistering, eye injury, and airway damage that other agents in the category are compared against. Symptoms are typically delayed by hours after exposure, which historically complicated early treatment and battlefield recognition.
How does the OPCW confirm sulphur mustard exposure after an alleged attack?+
Laboratories in the OPCW-designated network test urine for thiodiglycol-sulphoxide, a specific metabolite produced when the body breaks down absorbed mustard agent. Its presence provides biological confirmation of exposure independent of clinical symptoms or environmental sampling.
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