Dec. 7, 1941 and the Chemical Warfare Service
When Japanese planes attacked on December 7th, 1941, one of the units on duty at Hickam Field was the 5th Chemical Service Company (Aviation). They were tasked primarily with providing defense against what might well have been bombs filled with mustard agent, phosgene or any of the other toxins Japan had used against soldiers and civilians in China. Although a service unit not usually engaged in direct combat, soldiers of the 5th CSC helped man anti-aircraft guns and are credited with downing an enemy plane. One 18-year-old soldier in the unit paid a heavy price. Pvt. John Lawrence Harrison, Jr. was seriously injured on December 7th when struck in the head by a Japanese machine gun bullet.
Lt. Col. George F. Unmacht, Chief Chemical Officer of the Hawaiian Command, was having breakfast when he saw the attacking planes. He had good reason to believe these might be the initial wave of an invasion force, similar to the Japanese forces then moving to occupy Guam, the Philippines, Hong Kong, Singapore, and Malaya. Unmacht was quite right to anticipate as well that any Japanese troops headed for Hawaii’s beaches might come ashore behind clouds of toxic gas. It was Unmacht’s responsibility to organize the chemical defense and counterattack. Hawaii was, in fact, relatively well prepared for toxic chemical warfare. Within hours of the initial attack on Pearl Harbor and Hickam Field, the 5th Chemical Service Company and other CWS units began distributing their stock of 60,000 gas masks. They also had 90 tons of bleach, 25,000 gallons of other decontaminating agents, and 110 tons of chemicals to impregnate protective clothing. Within a few days, they began operating a plant to produce protective clothing and another plant to produce chloride of lime for use in decontamination. They also converted a Pacific Guano and Fertilizer Company plant to produce more bleach.
Unmacht’s preparations were not all intended as protection against Japanese toxic munitions. He prepared to fight back against invading Japanese troops by opening a plant that could fill American land mines and shells with mustard agent and other toxic chemicals. He had almost 500 tons of bulk toxic chemicals available for use. An even better indication of Unmacht’s readiness to fight a chemical battle on the beaches and mountain slopes of Hawaii is his possession of 4.2-inch chemical mortars. Only 44 of these new, rifled mortars were available in the entire U.S. Army at the time, and Unmacht’s soldiers had 32 of them. The same mortars would later become a vital tool for firing high-explosive shells, but in 1941, they were intended for firing mustard agent and phosgene.
Civil defense was another vital part of Unmacht’s plan and of the work done by chemical units in Hawaii. In the first months of the war, Unmacht gave hundreds of public talks and radio broadcasts and arranged classes on chemical warfare defense attended by 68,000 civilians. When the mainland CWS answered Unmacht’s request and sent 478,000 new and used gas masks for distribution to Hawaii’s diverse civilians, Unmacht organized a program for “reconditioning the masks and modifying them with sponge rubber padding to fit oriental faces and the faces of children.”
The invasion of Hawaii by chemically equipped Japanese troops never came, and attention gradually shifted to America’s offensive response. Hawaii became a central staging point for troops, ships and supplies heading further into the Pacific. Reorganization and expansion of CWS activities included deactivating the 5th Chemical Service Company and incorporating its soldiers into the 757th Chemical Depot Company (Aviation). The 757th remained at Hickam Field throughout the war, operating one of the island’s chemical depots, handling both toxic chemical and incendiary munitions. America’s toxic chemical munitions were never used in battle. Still, their availability for a massive “response in kind” was an essential factor in deterring Japan from resuming its use of similar munitions. The incendiary munitions that passed through Hawaii were used extensively, particularly during B-29 raids that burned large parts of Tokyo and other Japanese cities.