Negotiators from 115 countries have reached tentative agreement to end the production of eight dangerous chemicals as early as 2003 or 2004, when an international treaty on phasing out the use of 12 persistent organic pollutants (POPs) is set to come into force. After six days of negotiations that ended on Saturday, the biggest unresolved issue is how to deal with DDT, which many health officials want to continue to use to kill malaria-carrying mosquitoes. Agreement also has yet to be reached on PCBs, dioxins, and furans. World Wildlife Fund accused the U.S. and Australia of pressing for loopholes to weaken the treaty. Negotiators will meet again next spring in Bonn, Germany, and later next year in South Africa, hoping to have a treaty ready for signing in 2001.