Protocol on Heavy Metals

The 1998 Aarhus Protocol on Heavy Metals

The Executive Body adopted the Protocol on Heavy Metals in Aarhus, Denmark, on 24 June 1998. This Protocol targets three particularly harmful metals: cadmium, lead, and mercury. One of its primary obligations requires Parties to reduce emissions of these metals to levels below those of 1990 (or an alternative year between 1985 and 1995).

The Protocol focuses on reducing emissions from major sources, including:

• Industrial processes, such as the iron and steel industry and the non-ferrous metal industry
• Combustion processes, including power generation and road transport
• Waste incineration

It establishes stringent emission limit values for stationary sources and promotes the use of best available techniques (BAT), such as specialized filters or scrubbers for combustion sources and mercury-free processes. The Protocol also mandates the phase-out of leaded petrol and includes measures to reduce heavy metal emissions from products like mercury-containing batteries. It encourages management measures for other mercury-containing items, such as:

• Electrical components (e.g., thermostats, switches)
• Measuring devices (e.g., thermometers, manometers, barometers)
• Fluorescent lamps, dental amalgam, pesticides, and paints

In 2012, the Parties adopted decision 2012/5, amending the Protocol to strengthen controls on heavy metal emissions and introduce flexibilities for new Parties, particularly from Eastern Europe, South-Eastern Europe, the Caucasus, and Central Asia. Additionally, decision 2012/6 updated BAT guidance, as outlined in Annex III. These amendments entered into force on 8 February 2022.

In 2013, the Minamata Convention on Mercury was adopted under the auspices of the United Nations Environment Programme (UNEP). Building on the foundation of the 1998 Protocol on Heavy Metals, the Minamata Convention elevated the issue of mercury emissions to a global scale.