"Leigh Day and Co, in the light of the expert evidence, now acknowledge that the slops could at worst have caused a range of short-term, low-level flu like symptoms and anxiety."
Leigh Day and Co has not independently commented on the settlement, which would amount to a $1,700 payout for each claimant.
But the Ivorian National Federation of Victims of Toxic Waste, which says it represents nearly all the victims, told the Reuters news agency that Trafigura was trying to push through a deal to avert a court case.
"With these kinds of settlements the plaintiffs, the people from Cote d'Ivoire and their lawyers based in London, are very often required to say nothing on the terms of the agreement"
international law expert
"Trafigura wants to excuse itself morally but it is not fair," Denis Pipira Yao, the group's president, was quoted as saying.
"The waste was toxic and lethal. Trafigura is proposing 750,000 CFA francs ($1,683) for each victim," he said.
"As people are poor in Africa, Trafigura is using money to get away with it. We are not at all happy with this way of doing business and we will work with our lawyers to make it clear."
In August 2006, Probo Koala, a ship chartered by Trafigura, dumped caustic soda and petroleum residues on city waste tips in Abidjan after first having attempted to offload the cargo in Amsterdam.
At least 17 people were reported to have died and more than 100,000 sought medical help after the illegal dumping took place, according to the Ivory Coast government.
Trafigura has repeatedly denied any connection between the victims' problems and the waste.
Eric de Turckheim, the company director, said on Sunday that the settlement, which was signed the previous evening, "completely vindicates Trafigura".
"Over the past three years, the company has been the target of numerous attacks which have wrongly asserted that Trafigura's actions led to deaths and serious injuries," he said.
|Caustic soda and petroleum residues were dumped at sites around Abidjan [File: EPA]
"These accusations have now been found to be baseless."
However, Transfigura did acknowledge that "the slops had a deeply unpleasant smell and their illegal dumping ... caused distress to the local population".
Mark Taylor, an Oslo-based international law expert, said that the outcome was expected, despite coming just weeks before the dispute was due to go to court in London on October 6.
"It is a settlement that was probably in the making for some time," he told Al Jazeera from Oslo, the Norwegian capital.
"It is quite common in these kinds of lawsuits for there to be negotiations before the court case and for the plaintiffs, in this case the people in Cote d'Ivoire [Ivory Coast], to agree with the defendants ... that will agree to drop the charges in exchange for compensation.
"With these kinds of settlements the plaintiffs, the people from Cote d'Ivoire and their lawyers based in London, are very often required to say nothing on the terms of the agreement.
"It may be that this is the last we hear about this case."
However, Taylor said that there were other cases proceeding in other jurisdictions, both in The Netherlands, where Trafigura has a presence, and in Norway, where a similar case but not involving Probo Koala is planned.
"It remains unclear what role the people of the Cote d'Ivorie, the 31,000 plaintiffs in this case, will have in those other cases," he said.
Trafigura had previously agreed to a $198m out-of-court settlement with the Ivory Coast government in 2007, which exempted it from legal proceedings in the West African country.