Mustard agent was first synthesised in 1822, but its detrimental effects were not realised until about 37 years later.It was first used as chemical warfare agent during WWII and was the cause for the numerous eye and lung damage to troops of which many continued to suffer 30 years down the road with chronic respiratory malfunction and eye injury.
The Bari Incident, in which a German air strike on the Italian port caused a mustard leakage and contaminated the water in which many people were swimming in, served as a warning sign of the delayed effects of mustard agent.
During the Iran-Iraq war of 1979-88, Iraq used large amounts of chemical agents. As many as 5000 Iranian soldiers were reported killed, 10-20% by mustard agent. Moreover, there were 40 000 to 50 000 injured.
A common effect of warfare with mustard agent is that the medical system is loaded with several injured.To date, Iran has reported to have chemical weapons and Iraq has been alleged to have been producing VX gas with the disguise of a pharmacy.