A French court on Monday (10 May) threw out a lawsuit by a French-Vietnamese woman against more than a dozen multinationals that produced and sold a toxic herbicide dubbed ‘Agent Orange’.

The lawsuit, which began in January, had been brought by Tran To Nga, a 78-year-old French-Vietnamese woman, against a dozen chemical multinationals for supplying the chemical ­– a herbicide and defoliant ­– to the US military during the Vietnam War.

Agent Orange was one of a class of color-coded herbicides that US forces sprayed over the rural landscape in Vietnam from 1961 to 1971 to defoliate trees and shrubs and kill food crops that were providing cover and food to opposition forces.

The companies named in the legal action included the Dow consortium and Monsanto, now owned by German giant Bayer.

Backed by several NGOs, the legal action accused the companies of being responsible for injuries sustained by Tran To Nga, her children and countless others, as well as for damage done to the environment.

The court ruled it did not have jurisdiction to judge a case involving the US government’s wartime actions, Agence France Presse reported.

One of Tran’s lawyers, William Bourdon, said in a statement that the court was applying an obsolete definition of the immunity of jurisdiction principle which contradicted modern principles of international and national law.

He said it was “astounding” that the court had backed the companies’ contention that they were acting on orders when responding to US government tenders for contracts.

The multinationals have argued that they could not be held responsible for the use the American military made of their product.

Bayer said that Agent Orange was made “under the sole management of the US government for exclusively military purposes”.

Four million people in Vietnam, Laos and Cambodia were exposed to Agent Orange, according to the NGOs, over a decade when the US military sprayed an estimated 76 million litres of the herbicide and defoliant chemical to halt the advances of communist North Vietnamese troops.

The US ended the use of defoliant chemicals in the war in 1971, before withdrawing from Vietnam in 1975.

Agent Orange destroyed plants, polluted the soil and poisoned animals, as well as causing cancer and malformations in humans, the NGOs claim.