World leaders have finished the latest round of negotiations on a proposed treaty to end global plastic pollution. 

According to the Associated Press, the meeting in Ottawa wrapped up on April 30, where the United Nations' Intergovernmental Negotiating Committee on Plastic Pollution (INCPP) made substantial progress toward an agreement. This was the fourth time INCPP representatives have gathered to discuss the treaty, marking what Canadian parliamentary secretary Julie Dabrusin called a "monumental change in the tone and energy." 

According to the AP, leaders began negotiating on treaty language for the first time, progressing from previous sessions that had focused more on high-level ideas. That included potential limits on the amount of plastics countries can manufacture, concerns over chemicals in plastic products, and measures that focus on recycling and reuse. Production limits were a sticking point for plastic producers and chemical companies, who are pushing for a treaty centered more around recycling. 

Read More: Majority of Companies Failing to Curb Plastic Pollution, Says Nonprofit

One recent report from environmental nonprofit 5 Gyres Institute found that five companies were responsible for nearly a quarter of two million branded plastic pollution items gathered by volunteers between 2018 and 2022. A separate study from nonprofit CDP concluded that thousands of companies aren't taking the needed steps to curb plastic pollution in their value chains. 

The INCPP will continue fleshing out proposals for the treaty in lead-up to one final meeting in the fall in South Korea.