IRMA Standard for Responsible Mining (Draft 2.0)
Chapter 3.10 Mercury Management

This chapter has been flagged. The IRMA Steering Committee is especially interested in hearing from stakeholders on this chapter, as we did not receive many comments on it during our previous comment period.



Mercury can occur in both inorganic and organic forms. An inorganic form, elemental mercury is a byproduct of some mining operations, due to the presence of mercury compounds in ore bodies such as gold, silver, copper and zinc deposits.

Mercury is a persistent, bio-accumulative pollutant. When released into the environment and deposited or carried into air and water, mercury can be converted to methyl-mercury. Methyl-mercury can be transmitted up the food chain and accumulates in the tissues of animals.

Because of mercury’s potentially significant health and environmental impacts, mining operations should work to restrict the release of point source mercury emissions to surface and groundwaters and to the atmosphere by adopting appropriate mercury reduction goals and by applying suitable mercury reduction technologies.

Objectives/Intent of this Chapter

To protect human health and the environment through the responsible management of mercury.

Scope of Application

Chapter Relevance:  This chapter applies to any mining project, new or existing, that utilizes an autoclave, roaster, carbon kiln, refining furnace, retort or other process that could lead to significant emissions of mercury.


  • Removed a requirement that companies meet the applicable provision of the Minamata Convention, primarily because the convention applies to countries, not companies. Much of the material in Minamata Convention is already addressed within the IRMA requirements. However, the Convention goes into more detail on State and other parties’ interactions with artisanal miners. IRMA recognizes that it is good practice for industrial mines to engage with local artisanal miners with the goal of reducing mercury use and health/contamination issues. We are considering potential approaches for integrating artisanal mining-related requirements into the IRMA Standard. Please see the flagged item “Artisanal Mining” on page 5 of this document for more details.
  • Clarified the requirement to provide a mercury mass balance for the mine if the mine uses thermal processes in processing or refining (
  • Removed Requirement 3.10.3. Construction, which required that companies to implement the US EPA Mercury Rule. Upon review of the Mercury Rule, we realized that some requirements are too US-specific to be applied globally (e.g., reporting to EPA); and many of the important elements in the rule are already addressed in the other IRMA requirements such as Planning, Monitoring and Reporting.
  • Removed the requirement that corporate owners of an IRMA certified mine offer up a relevant mine site for mercury-related research. The IRMA Steering Committee supports the need for such research, but is looking into other ways to provide incentives for mines to participate in a research program without making a certification decision dependent on such participation.
  • Revised the reporting requirement to remove duplication with Chapter 2.8, and instead referenced relevant sections of 2.8 in the table of Cross References to Other Chapters at the end of the chapter.
  • The means of verification (MOV) have been removed from this version of the draft IRMA Standard. If you would prefer to review and comment on a version of the draft Standard that has the means of verification, you can download a pdf version of the Standard with MOV.

Mercury Management Requirements

3.10.1.  Planning  Each mine with a mercury recovery system shall perform a mercury mass balance that assesses the amount of organic and inorganic mercury in the waste rock and ore, and document (or estimate, if measurements are not available) the amount of organic and inorganic mercury during or after processing:

a. Released to air and water;

b. Produced as by-product; and

c. Resident in tailings ponds, waste rock dumps, etc.

3.10.2.  Mercury Capture and Disposal  Mercury from primary emission controls:

a. Shall not be stored on-site or disposed with tailings after removal;

b. Shall not be sold or given away either directly or indirectly to an entity engaged in artisanal mining of gold;

c. Shall be sold only for an end use listed in Annex A (Products) or Annex B (Processes) of the Minamata Convention on Mercury;[1]  or

d. Shall be sent to a regulated repository.  Mercury waste from secondary waste streams, which result from primary emission controls, containing low levels of mercury may be disposed of on-site:

a. Only after a risk-based evaluation of the on-site disposal; and

b. Only in fully lined tailings storage facilities where the liner is a synthetic material of permeability less than 10-9 cm/sec.

3.10.3.  Monitoring  For each mining project with a source of mercury air emissions a mercury monitoring plan shall be developed in consultation with affected communities.  The mercury monitoring plan shall address:

a. Potential public health impacts (e.g., food source and blood level mercury);

b. Environmental impacts monitoring (e.g., fish tissue and stream sediment mercury levels), including locations that are most likely to promote methylation, such as still waters, wetlands, and anaerobic sediment; and

c. Mercury air emission monitoring.[2]  The mercury monitoring plan shall include the monitoring of:

a. The quantity of organic and inorganic mercury released to air including fugitive emissions (to the extent technologically and economically feasible with air monitoring equipment);

b. The quantity of organic and inorganic mercury released to water, including the forms of mercury;

c. The amount of organic and inorganic mercury captured in pollution control systems; and

d. The amount of by-product mercury produced (including the mercury captured in pollution control systems).

3.10.4.  Reporting  The operating company shall report publicly, at least annually a summary report of the findings from the implementation of the mercury monitoring plan, including the monitoring data.  Reporting shall be satisfied by publishing the results annually on the mine or company website.


The US EPA “National Emission Standards for Hazardous Air Pollutants: Gold Mine Ore Processing and Production Area Source Category regulations, effective December 16, 2010, are the only existing national mercury emissions standards for mining. The EU regulates mercury emissions from major industrial sources (EU Directive 96/61/EC on Integrated Pollution Prevention and Control). These standards do not include direct mining provisions but are intended to reduce mercury use and targeted the "metallic mercury gained from non-ferrous mining and smelting operations" by prohibiting metallic mercury export and by-product sales and requiring safe metallic mercury storage.

IRMA recognizes both the paucity of existing regulations and the cost of monitoring and collecting mercury from mine emission sources, and seeks to begin to develop better air monitoring though targeted approaches that use broad, less expensive testing protocols to determine if more testing is necessary. Given the significant health risks associated with mercury, and the challenges and costs associated with reducing mercury once it enters environmental pathways, it is important that accurate information is available on all mercury emissions from mines certified by IRMA.

This chapter of the IRMA Standard seeks to reduce the costs to public health associated with mercury exposure, and the technical challenges of removing mercury once it’s in the environment, by encouraging source control – preventing mercury from getting into the environment in the first place. However, mercury air emission testing is very expensive (hundreds of thousands of dollars annually).

Researchers have documented fugitive mercury air emissions from non-thermal sources at mines, most notably heap leach facilities.[3]  Further research is needed to assess the pervasiveness of these non-thermal sources,[4]  as well as to verify the reliability of the thermal-source measurements. The IRMA Steering Committee is considering ways to incentivize companies to engage in research to help elucidate the scale and scope of these emissions.

Cross Reference to Other Chapters



1.1—Legal Compliance As per Chapter 1.1, if there are host country laws governing mercury transport, storage, use, etc., the company is required to abide by those laws. If IRMA requirements are more stringent than host country law, the company is required to also meet the IRMA requirements, as long as complying with them would not require the operating company to break the host country law.
2.2—Occupational Health and Safety Mercury may present an occupational health and safety (OHS) hazard, and if so, may be included in the OHS risk assessment process.
2.3—Emergency Preparedness and Response The protection of communities and workers during emergencies related to the transport and storage of hazardous substances, such as mercury, may be addressed in Emergency Response Planning. Chapter 2.3 mandates emergency response planning for a spill, and requires coordination between the mine and emergency responders in adjacent communities.
2.7—Community Health and Safety Mercury emissions may present health risks to local communities, and if there are thermal mercury sources at the mine risks from mercury exposure should be analyzed during the community health and safety risk and impact assessment process.
2.8—Community and Stakeholder Engagement Requirement shall conform with the stakeholder engagement requirements in Chapter 2.8.

In particular, criterion 2.8.3 is important to ensure that stakeholders have the capacity to participate in mercury monitoring.

Also, regarding reporting of data in 3.10.4, requirement requires that communications be in formats and languages that are culturally appropriate, accessible and understandable to affected communities and stakeholders.
2.13—Grievance Mechanism and Access to Other Remedies Stakeholders who have complaints related to a operating company’s use of cyanide, can raise complaints through the company’s operational-level grievance mechanism. As per Chapter 2.13, the operating company is required to have an operational-level grievance mechanism available to stakeholders, including procedures for filing complaints, and having complaints recorded, investigated and resolved in a timely manner.
4.1—Environmental and Social Impact Assessment Potential risks to the environment and human health may be identified during the ESIA process, and information from that process may feed into the mercury monitoring plan (e.g., selection of sampling locations, etc.). If mercury is identified during ESIA as a key risk to human health or the environment, stakeholders shall be provided with the opportunity to propose independent experts to collaborate with the company on the company on the design and implementation of its monitoring program; and the company is required to facilitate the independent monitoring of key impact indicators where this would not interfere with the safe operation of the project.



1. Annex A and B also list phase out dates after which the manufacture, import or export of the product shall not be allowed. Companies are expected to comply with those phase out dates. View the text and Annexes of the Minamata Convention.

2. This includes air monitoring required as part of a regulatory permit requirement.

3. See: Joyce, P and Miller, G. Mercury Air Concentrations in Northern Nevada: Monitoring Active Metals Mines as Sources of Mercury Pollution. University of Nevada, Reno, Department of Natural Resource & Environmental Science, January 2007; and most recently: Miller, M and Gustin, M. Testing and Modeling the Influence of Reclamation and Control Methods for Reducing Non-Point Mercury Emissions Associated with Industrial Open Pit Gold Mines. Journal of the Air & Waste Management Association, 2013 Jun;63(6):681-93.

4. Eckley CS, Gustin M, Miller MB, Marsik F. 2011. Nonpoint source Hg emissions from active industrial gold mines-influential variables and annual emission estimates. Environmental Science and Technology 45 (2) 392-399.