Overview

Mercury is used primarily for the manufacture of industrial chemicals or for electrical and electronic applications. It is also used to produce chlorine gas, caustic soda, medical devices, dental fillings, and batteries. Exposure to mercury vapor leads to serious adverse health effects. Exposure occurs through contaminated air, water and food and through dental and medical treatments. High levels may damage the brain, kidneys, and developing fetuses.

Under the Basel Convention, waste consisting of, containing or contaminated with elemental mercury or mercury compounds may be categorized as hazardous wastes. Improper handling, collection, storage, transportation or disposal of mercury wastes can lead to emissions or releases of mercury, affecting human health and the environment.

The growing global trend towards phasing out mercury-added products and processes using mercury will result in the generation of an excess of mercury if mercury supplies remain at the current level. Therefore, ensuring environmentally sound management of mercury wastes will be a critical issue for most countries. Towards this end, the Minamata Convention on Mercury, which is a global treaty to protect human health and the environment from the adverse effects of mercury, was adopted in 2013 and entered into force in August 2017.

Mercury wastes listed in annexes I, II and VIII to the Convention

Entries with direct reference to mercury

Y29

Wastes having as constituents:

Mercury, mercury compounds

A1010

Metal wastes and waste consisting of alloys of any of the following:

…

- Mercury

…

but excluding such wastes specifically listed on list B.

A1030

Wastes having as constituents or contaminants any of the following:

…

- Mercury; mercury compounds

…

A1180

Waste electrical and electronic assemblies or scrap containing components such as accumulators and other batteries included on list A, mercury-switches, glass from cathode-ray tubes and other activated glass and PCB-capacitors, or contaminated with Annex I constituents (e.g. cadmium, mercury, lead, polychlorinated biphenyl) to an extent that they possess any of the characteristics contained in Annex III (note the related entry on list B B1110)

Other entries related to wastes which may contain or be contaminated with mercury

Y1

Clinical wastes from medical care in hospitals, medical centers and clinics

Y2

Wastes from the production and preparation of pharmaceutical products

Y3

Waste pharmaceuticals, drugs and medicines

Y4

Wastes from the production, formulation and use of biocides and phytopharmaceuticals

Y11

Waste tarry residues arising from refining, distillation and any pyrolytic treatment

Y12

Wastes from production, formulation and use of inks, dyes, pigments, paints, lacquers, varnish

Y46

Wastes collected from households

Y47

Residues arising from the incineration of household wastes

Y48

Plastic waste, including mixtures of such waste, with the exception of the following...

A1170

Unsorted waste batteries excluding mixtures of only list B batteries. Waste batteries not specified on list B containing Annex I constituents to an extent to render them hazardous

A2030

Waste catalysts but excluding such wastes specified on list B

A2060

Coal-fired power plant fly-ash containing Annex I substances in concentrations sufficient to exhibit Annex III characteristics (note the related entry on list B B2050)

A3170

Wastes arising from the production of aliphatic halogenated hydrocarbons (such as chloromethane, dichloro-ethane, vinyl chloride, vinylidene chloride, allyl chloride and epichlorhydrin)

A3210

Plastic waste, including mixtures of such waste, containing or contaminated with Annex I constituents, to an extent that it exhibits an Annex III characteristic (note the related entries Y48 in Annex II and on list B B3011)

A4010

Wastes from the production, preparation and use of pharmaceutical products but excluding such wastes specified on list B

A4020

Clinical and related wastes; that is wastes arising from medical, nursing, dental, veterinary, or similar practices, and wastes generated in hospitals or other facilities during the investigation or treatment of patients, or research projects

A4030

Wastes from the production, formulation and use of biocides and phytopharmaceuticals, including waste pesticides and herbicides which are off-specification, outdated, or unfit for their originally intended use

A4070

Wastes from the production, formulation and use of inks, dyes, pigments, paints, lacquers, varnish excluding any such waste specified on list B (note the related entry on list B B4010)

A4080

Wastes of an explosive nature (but excluding such wastes specified on list B)

A4100

Wastes from industrial pollution control devices for cleaning of industrial off-gases but excluding such wastes specified on list B

A4130

Waste packages and containers containing Annex I substances in concentrations sufficient to exhibit Annex III hazard characteristics

A4140

Waste consisting of or containing off specification or outdated chemicals corresponding to Annex I categories and exhibiting Annex III hazard characteristics

A4160

Spent activated carbon not included on list B (note the related entry on list B B2060)


Mercury waste – linkages to the Minamata Convention

Article 11, paragraph 1, of the Minamata Convention provides for a link between the relevant definitions of the Basel Convention, such as its definition of wastes, and wastes covered by the Minamata Convention. Under Article 11, paragraph 2, of the Minamata Convention, only those wastes:

  • consisting of mercury or mercury compounds (e.g., excess mercury from the decommissioning of chlor-alkali facilities, mercury recovered from wastes containing mercury or mercury compounds or wastes contaminated with mercury or mercury compounds, or surplus stock of mercury or mercury compounds designated as waste);
  • containing mercury or mercury compounds, with the following subcategories: (e.g., mercury thermometers, fluorescent lamps, batteries); or
  • contaminated with mercury or mercury compounds (e.g., residues generated from mining processes, industrial processes or waste treatment processes),

in a quantity above the relevant thresholds defined by the Conference of the Parties, in collaboration with the relevant bodies of the Basel Convention in a harmonized manner, that are disposed of or are intended to be disposed of or are required to be disposed of by the provisions of national law or this Convention. This definition excludes overburden, waste rock and tailings from mining, except from primary mercury mining, unless they contain mercury or mercury compounds above thresholds defined by the Conference of the Parties.

Each Party to the Minamata Convention shall take appropriate measures so that mercury waste is:

  1. Managed in an environmentally sound manner, taking into account the guidelines developed under the Basel Convention and in accordance with requirements that the Conference of the Parties shall adopt in an additional annex in accordance with Article 27. In developing requirements, the Conference of the Parties shall take into account Parties’ waste management regulations and programmes;
  2. Only recovered, recycled, reclaimed or directly re-used for a use allowed to a Party under this Convention or for environmentally sound disposal pursuant to paragraph 3 (a);
  3. For Parties to the Basel Convention, not transported across international boundaries except for the purpose of environmentally sound disposal in conformity with this Article and with that Convention. In circumstances where the Basel Convention does not apply to transport across international boundaries, a Party shall allow such transport only after taking into account relevant international rules, standards, and guidelines.

For more information, visit the Minamata Convention on mercury website.

It should be noted that the there is no specific definition of “mercury wastes” in the Basel Convention. The mercury thresholds described in the Minamata Convention are independent from the provisions on determination of hazardous wastes and requirements for transboundary movements under the Basel Convention.

Technical guidelines on mercury waste

The Technical guidelines on the environmentally sound management of wastes consisting of, containing or contaminated with mercury or mercury compounds was adopted by the Conference of the Parties (COP) to the Basel Convention by decision BC-10/7 (2011), then revised and adopted again by decision BC-12/4 (2015), and revised and updated once more by decision BC-15/9 (2022)

See mercury technical guidelines

At its Seventeenth meeting, in 2025, the Basel Convention COP decided to undertake a new update of the technical guidelines to reflect consequential amendments related to the adoption of new mercury thresholds agreed under the Minamata Convention and to reflect changes regarding the E-waste amendment under the Basel Convention. The work is ongoing.

Technical assistance

The BRS Secretariat implements projects and activities which aim to protect human health and the environment from the adverse effects of mercury by strengthening national and regional capacities for the environmentally sound management of mercury waste at the national, regional and global levels.

These activities are developed in collaboration with the Minamata Convention on mercury, the Basel and Stockholm Regional Centres, the GEF implementing Agencies, UNEP´s chemicals and health branch, UNITAR, the UNEP Global Mercury Partnership, and other key partners.