The Minamata Convention on Mercury [1] represents an international legal milestone in the regulation of the metal—toxic, highly persistent in the environment, and extremely harmful to human health—recognized by the global community for its chronic and acute adverse effects.
The treaty was adopted in 2013, within the framework of the United Nations Environment Programme (UNEP), and entered into force globally in 2017. Its content covers:
Control of the supply, trade, and use of mercury in industrial products and processes;
Phase-out of specific uses, including mercury-dependent manufacturing; Prohibition of the establishment of new mercury mines and measures to close existing ones; Import and export procedures; Identification and remediation of contaminated areas; Measures to protect human and environmental health.
Promulgated in Brazil through Federal Decree No. 9,470 of August 14, 2018, the convention is an international treaty that obliges States Parties to adopt rigorous measures to protect human health and the environment from anthropogenic emissions and releases of mercury and its compounds.
This promulgation of the convention by the Presidency of the Republic incorporates the Minamata Convention into the national legal system with binding normative force, requiring the State and regulated agents to comply with the international obligations assumed.
The toxicity of mercury stems from its ability to be transformed in the environment into methylmercury, a highly bioaccumulative compound that contaminates aquatic and terrestrial food chains, with direct consequences for public health—in particular, for the neurological, reproductive, and immunological systems of exposed populations.
Environmental Protection
From a legal standpoint, the Minamata Convention is part of the international framework for environmental protection as an instrument that embodies the precautionary principle [2] and the responsibility of States in preventing transboundary and cumulative damage to the environment and human health. The effectiveness of this international standard depends, however, on its internal normative implementation, monitoring mechanisms, and robust environmental governance. In Brazil, the internalization of the Minamata Convention conferred upon the Brazilian Institute of Environment and Renewable Natural Resources (Ibama) the role of competent authority to receive requests for authorization to import and export metallic mercury, in addition to exercising control, monitoring, and oversight of activities involving the toxic metal, in accordance with the National Environmental Policy and its sectoral regulations.
In early 2026, Ibama launched Operation Almadén, which involved inspections of industrial units in the states of São Paulo, Rio de Janeiro, and Pernambuco to verify the environmental compliance of production processes that historically used mercury—such as the manufacture of chlor-alkali—in accordance with Brazilian commitments under the convention. [3]
These inspections aim to verify, in practice, the cessation of the use of metallic mercury, the technological transition to safer alternatives, and the environmentally sound disposal of the metal removed from production systems. The deadlines for the complete elimination of the industrial use of mercury in certain sectors have already expired, imposing the need for strict compliance on the part of economic agents.
Illegal Use of Mercury
In addition to industrial oversight, federal environmental agencies have also been active in operations against the illegal use of mercury in artisanal mining, especially in contexts where informal gold extraction persists as a significant vector of environmental contamination—a situation that puts traditional populations and ecosystems at risk, particularly in the Amazon.
This approach is consistent with the jurisprudence of the Supreme Federal Court, which recognizes environmental protection as a fundamental right and legitimizes preventive and restrictive measures in the face of significant environmental risks, even in the absence of absolute scientific certainty (e.g., ADI 3.540 and RE 627.189). Similarly, the Superior Court of Justice has repeatedly affirmed that the principles of prevention and precaution authorize the imposition of strict conditions and the limitation of potentially polluting activities, regardless of proof of concrete damage (e.g., REsp 650.728/SC and AgRg in REsp 1.318.051/SP).
Despite its undeniable importance, the Minamata Convention faces challenges in implementation and effectiveness. International organizations have highlighted gaps in its capacity to block illegal mercury in global trade and to eradicate practices that still depend on the toxic metal, such as artisanal gold mining, which remains one of the main sources of mercury pollution in the world.
International reports and investigations indicate that, despite the restrictions that, despite the restrictions imposed by the Minamata Convention, the illegal international trade in mercury remains active, sustained by traceability failures, weaknesses in customs controls, and gaps in cooperation between states [4]. Organizations such as the Environmental Investigation Agency and the International Pollutants Elimination Network point out that discrepancies between official export and import data and the misuse of regulatory exceptions provided for in the treaty itself allow the metal to continue circulating outside the bounds of international legality [5].News reports and technical studies also indicate that this illicit flow is largely directed towards supplying prohibited or severely restricted activities, such as artisanal and illegal gold mining, highlighting that the main contemporary challenge lies primarily in the low effectiveness of global enforcement [6] and not only in the absence of international norms.
Compliance with international standards
At the national level, ensuring the effectiveness of environmental standards requires close coordination between international standards, domestic legislation, and enforcement instruments—including licensing, monitoring, civil and administrative liability, and environmental education—as well as ensuring institutionally adequate resources for bodies such as Ibama. [7]
In light of this understanding, the Minamata Convention should be understood as a structuring instrument of Brazilian chemical risk management policy, whose effectiveness depends less on normative production and more on continuous, coordinated, and technically robust regulatory action, otherwise its environmental and health objectives will be practically emptied.
[1] The Convention was named after the Japanese city of Minamata, the site of one of the most serious industrial disasters of the 20th century, in which discharges of mercury compounds by a chemical company caused massive methylmercury poisoning in human populations and ecosystems—the so-called “Minamata Disease”. Available here.
[2] The precautionary principle guides the actions of the Public Authorities and economic agents in the face of potential risks of serious or irreversible damage to the environment or human health, even when there is no absolute scientific certainty about the extent or probability of such damage. In legal terms, the principle establishes that the absence of full scientific evidence cannot be used as justification for postponing effective environmental prevention measures. Thus, the focus shifts from repairing the damage to anticipating the risk, prioritizing the preventive protection of environmental assets. In this regard: MILARÉ, Édis. Environmental Law: Environmental Management in Focus – Doctrine, Jurisprudence, Glossary. 12th ed. São Paulo: Revista dos Tribunais, 2023; and ANTUNES, Paulo de Bessa. Environmental Law. 23rd ed. Rio de Janeiro: Lumen Juris, 2023.
[3] In this regard here.
[4] ENVIRONMENTAL INVESTIGATION AGENCY. Traffickers leave no stone unturned: the global illicit mercury trade feeding Amazon gold mining. London; Washington, DC, 2023. Available here.
[5] INTERNATIONAL POLLUTANTS ELIMINATION NETWORK. Massive amounts of mercury for gold mining are smuggled from Mexico, polluting the Amazon and threatening communities. Gothenburg, 2023. Available here.
[6] ASSOCIATED PRESS. Despite global treaty, illegal mercury trade continues to poison communities. New York, 2024. Available here.
[7] In Brazil, we indicate a study prepared by the Instituto Escolhas: here.
Conjur Portal, March 23, 2026, 4:22 PM
https://www.conjur.com.br/2026-mar-23/desafios-na-implementacao-da-convencao-de-minamata-sobre-o-mercurio/
