Libya has been working on chemical and biological weapons since the early 1980s. Its first poison gas site, in Rabta, 40 kilometres southwest of Tripoli, disguised as a factory for pharmaceuticals, was damaged by fire, allegedly set by Western agents, in March 1990. The CIA said the fire might have been a hoax that allowed Libya to evade international inspection and officials claimed in 1993 that Rabta remained the largest chemical-weapons complex in the Third World.
In 1993, US intelligence agencies confirmed reports that Libya was building a subterranean chemical-weapons plant capable of producing and storing poison gas. The new complex was disguised as part of a water project, deep in a hillside near Tarhunah. The construction began in 1992 and the plant was expected to begin operations in 1993. In 1996 it was reported that Libya was close to completing the huge chemical weapons plant in the hollowed-out mountain 64 kilometres southeast of Tripoli. Libyan leader, Colonel Moammar Gadhafi, said the project was an irrigation system, but western intelligence services commented that it was nonsense. The intelligence officials said that the subterranean plant was the world's largest and might be completed in 1997 or 1998. They said it covered 15 square kilometres and already then stored most of Libya's stockpile of chemical weapons – about 100 tons. It was expected that the plant would be able to produce the ingredients for tons of poison gas a day.
In 1996, more than 25 countries were believed to be developing or stockpiling chemical weapons.
In 1996, the USA has shelved the Chemical Weapons Convention, the global norm prohibiting chemical weapons, signed by 161 countries after 20 years of negotiation. This action placed the United States of America, one of the two avowed possessors of chemical weapons, outside the nearly universal consensus behind the norm.
It has surfaced in the press in 1993 that the Spanish government was running a secret chemical warfare facility located only a couple of kilometres from the outskirts of Madrid, in La MaraÃ±osa. As a result of work by scientists and technicians from that installation, Spain's late dictator, General Franco, had at his disposal 'sizeable quantities' of mustard gas during the 1936-39 civil war. Modern activities of the facility included research and testing of protective clothing, detection equipment, and decontaminants, as well as the production of tear gas for riot control and napalm for industrial use, but also chemical warfare agents, although only in quantities suitable for laboratory use. However, the complex was officially described as a factory by the Defence Ministry, not as a research centre.
Libya has refused to sign a 1993 United Nations convention banning the use, development and storage of chemical weapons. According to the CIA, in 1996 it was one of 18 nations working on chemical weapons programmes.