Trafigura, the international oil company blamed for dumping the waste that led to seven deaths in Ivory Coast, has denied that the waste was toxic.
The Holland-based firm said independent tests showed the chemical sludge met international safety standards.
The environmental group Greenpeace maintained pressure over the scandal by blockading the Probo Koala, the tanker that carried the waste, in an Estonian port to demand an EU investigation.
Ten people, including two French Trafigura executives, have been charged with violating toxic waste laws and have been imprisoned in Abidjan.
Thousands suffered from vomiting, stomach pains and breathing difficulties after the black sludge was dumped around the town of Abidjan.
The Ivorian government resigned following a wave of public anger at the dumping.

Al-jazeera article here

About these charges, Trafigura has issued this press release:
TRAFIGURA TESTS CONTRADICT MEDIA SPECULATION, 24 September 2006

From Greenpeace, this:

International - Toxic waste from Europe openly dumped on the streets of an African capital city. Six people dead and thousands requiring medical treatment. The Ivory Coast cabinet resigns but still no one owns up to the dumping. How could this be allowed to happen?
The scandal of the toxic waste dumped in the Ivory Coast first came to light on September 6 when the first casualties where reported and protests broke out on the streets against the government, which was blamed for allowing the dumping.
There is no doubt that the wastes are deadly. Four of the six dead are children and 23 people have required hospital treatment so far. The fact that the toxic waste was dumped openly on the streets of a city is shocking enough. The fact that the waste was delivered by a ship chartered by Trafigura LTD (controlled by Dutch firm Trafigura Beheer BV), who claimed they thought the waste would be ‘properly treated’ in a poor African nation raises serious questions about why they sent it to Africa. The fact that international law may have been broken makes it a serious scandal that such deadly incidents still occur today.

Full article here