The earliest predecessors to the United States Army Chemical Corps owe their existence to changes of military technology early in World War I. By 1915, the combatants were using poison gases and chemical irritants on the battlefield. In that year, the United States War Department first became interested in providing individual soldiers with personal protection against chemical warfare and they tasked the Medical Department with developing the technology. Nevertheless, troops were neither supplied with masks nor trained for offensive gas warfare until the U.S. became involved in World War I in 1917. By 1917, the use of chemical weapons by both the Allied and Central Powers had become commonplace along the Western, Eastern and Italian Fronts, occurring daily in some regions.