INC4 met briefly in Plenary in the morning and afternoon to hear reports from contact groups. Contact groups met throughout the day and into the night seeking common ground on the most complex issues, namely, financial resources and technical assistance, supply and trade, implementation and compliance, products and processes, emissions and releases, storage and wastes, and Section J. The legal group also met to consider text forwarded by Plenary.

The Fourth Session of the Intergovernmental Negotiating Committee to Prepare a Global Legally-binding Instrument on Mercury (INC4) met in Plenary to hear reports from contact groups, and to discuss: how to regulate trade and supply of mercury products; final provisions of the treaty; institutional arrangements; health aspects; and national implementation plans. Contact groups met throughout the day and into the night to discuss finance and technical assistance, products and processes, implementation and compliance, emissions and releases, and supply and international trade. A “Swiss Break” was held in the evening.

The Fourth Session of the Intergovernmental Negotiating Committee to Prepare a Global Legally Binding Instrument on Mercury (INC4) met in Plenary in the morning to deal with reports from contact groups, as well as how to regulate mercury in products and processes. Contact groups met throughout the day, and into the night, on compliance matters, emissions and releases, financial and technical assistance, products and processes, and information. A "Swiss break" was held in the evening for delegates to interact informally and seek solutions to outstanding issues.

The Fourth Session of the Intergovernmental Negotiating Committee to Prepare a Global Legally Binding Instrument on Mercury (INC4) met in Plenary throughout the day to deal with reports from contact groups, as well as emissions and releases, financial and technical assistance, and compliance matters. Contact groups also met throughout the day to discuss: technical assistance; storage, wastes and contaminated sites; emissions and releases; and research, development and monitoring.

INC4 opened on Wednesday, 27 June 2012 at the Conrad Resort in Punta del Este, Uruguay, to continue negotiations on a treaty to regulate mercury use at the global level. Plenary meetings were held in the morning and afternoon, with contact groups established to finalize their consideration of items outstanding from INC3, including artisanal small-scale gold mining (ASGM), wastes and storage, and information and awareness-raising.