The incident strained Beijing-Tokyo relations just months before China hosted the 2008 Olympic Games. Millions of bags of dumplings were recalled and Chinese food products taken off shelves in Japan out of safety worries.
The official Xinhua News Agency said 39-year-old Lu Yueting was sentenced on Monday by a court in the northeastern city of Shijiazhuang. Lu had been dissatisfied with his wages and, in late 2007, injected insecticide into several boxes of frozen dumplings to get attention from his managers.
The products were later sold in Japan and in the Chinese city of Chengdu, sickening at least four people.