U.N. officials and delegates say more than 120 nations agreed to tighter controls on several chemicals and hazardous waste, including a gradual ban on a flame retardant and some new export requirements for other substances.

But they say an effort to rein in use of construction material Chrysotile asbestos and a powerful herbicide, Paraquat, fell short at a two-week summit of delegates to three main international treaties.

The heads of two U.N. agencies and other officials told reporters Friday the summit was ending with agreement to phase-out the commonly used flame retardant hexabromocyclododecane, or HBCD, but exempted some uses in buildings.

The officials and delegates say the summit approved tighter requirements for disclosing information about exports of insecticide Azinphos-methyl, two flame retardants, PentaBDE and OctaBDE, and a fabric protector, PFOS.