Mercury Inventory Toolkit

Introduction

UNEP's Toolkit for identification and quantification of mercury releases, hereafter referred as the Toolkit, is intended to assist countries to identify and quantify the sources of mercury emissions and releases. With the Toolkit, a comprehensive national mercury inventory can be developed. These inventories will assist countries in setting priorities and reduction targets, and enhance international co-operation, knowledge sharing and enable targeted technical assistance. Moreover, inventories from countries contribute to the scientific knowledge of the scale of worldwide mercury emissions and releases as demonstrated in Global Mercury Assessment.

The Toolkit is user-friendly, and it provides clear guidance on different stages of inventory development, including identifying mercury sources, quantifying the consumption and calculating the final emissions and releases. It provides a detailed manual, calculation spreadsheet and a standard template for reporting. The Reference Report and Guideline for Inventory Level 2 includes a concise description of all mercury sources and can be used broadly by all interested in the mercury topic. The latest version of the Toolkit has been released in 2023.

The Minamata Convention

The Toolkit has been a standard tool in over 90 GEF-funded Minamata Initial Assessment projects implemented by UNEP, UNIDO and UNDP. Furthermore, the Toolkit is also one of the methods recommended in guidance from the Minamata Convention on preparing inventories of emissions pursuant to Article 8.

Which version of the toolkit should I use?

Which inventory level to choose depends very much on the type and accuracy of the results needed, and on your experience in inventory development. In broad terms, the differences between the levels can be summarised as follows:

• Inventory Level 1 (IL1) is a simplified model which is designed to be easy to use. It requires less reading to get started, less data, calculations are fully automatic, and it includes in-cell guidance within the spreadsheet. It uses national activity rate data and you can reflect mercury pollution controls in place, though you cannot reflect local variations in estimation factors. Brief but useful guidance for data collection is included in the IL1 Guideline.

  Being a standardised model, it will be useful for first-time inventories, for easy monitoring of changes due to the implementation of mercury controls (BAT/BEP), and for easy prediction of expected changes when planning introduction of control measures. As a standardised model, less accuracy of emission/release estimates should be expected.
   

• Inventory Level 2 (IL2), the first estimation level developed in the Toolkit, is a detailed mercury inventory tool where all factors of the emission/release estimation can be adjusted fully to national or local conditions. While default estimation factors are pre-entered in the IL2 spreadsheet for ease of use, some choices have to be made and reflected manually. Hence, IL2 requires more reading and experience to operate the calculation spreadsheet correctly and avoid mistakes. In principle, IL2 can be enhanced to a high level of accuracy, provided that the data needed for this are available. Note however that the real variation in natural mercury concentrations, and in decisive process conditions applied, can be significant, and this should be taken into consideration when estimation results are used for planning control measures and other implementation actions.

  The Reference Report and Guideline for IL2 also includes the detailed database on which the entire Toolkit (all levels) is based. Besides providing background data, the database in its Chapter 5 is useful as a quick introduction to all mercury sources, with their key features and the factors that are decisive for the significance of their mercury emissions/releases.
   

• Inventory Level 3 (IL3) goes a step beyond IL2 by integrating all mercury sources into their entire mass flow through and out of society to the environment. This enables the highlighting of the links between the different mercury sources, as well as the potential for a further increase in accuracy and reflection of local conditions. With the full mass flow integrated, the fate of mercury-bearing wastes is further detailed quantitatively (fate of sector-specific waste). This is possible though the automatic links between mercury amounts used in products and materials and their treatment as wastes, as well as a new inventory element where the local fate of sector-specific waste can be reflected quantitatively. The key results produced from the  inventory are presented in flowcharts showing the causal links between the mercury sources.

  IL3 requires more data and more experience to use than IL2, but enhances the possibility of reaching higher accuracy of the calculated emission and releases estimates, and provides more knowledge about the mercury fates. On the other hand, some of the robustness of IL2 is sacrificed in IL3, in order to facilitate the potential for higher accuracy. For users with less experience or less data, it is therefore recommended to start with making an inventory on Level 2. For a detailed description of the differences between Inventory Level 2 and Level 3, please see the introduction to the IL3 Guideline.

  The IL3 guideline gives a concise description of the methodology aspects and data that are different from IL2, and as such, it should be read in conjunction with the Reference Report.

Download the Toolkit

Inventory Level 1

Inventory Level 1 calculation spreadsheet is a simple and easy to use tool. The calculation spreadsheet is accompanied by the guideline manual and the reporting template. In the 2017 version, it is also possible to record and take into account existing mercury controls and managements practices for selected source-categories.

Inventory Level 1 consists of the following components:

• Guideline for Inventory Level 1
  • English (Version 2023)
  • French (Version 2015)
  • Russian (Version 2013)
  • Spanish (Version 2015)
  • Portuguese (Version 2015)
• Calculation spreadsheet (requires Excel 2010 or newer)
  • English (Version 2023)
  • French (Version 2019)
  • Russian (Version 2019)
  • Spanish (Version 2019)
  • Portuguese (Version 2019)
• Inventory Reporting Template
  • English (Version 2017)
  • French (Version 2013)
  • Russian (Version 2013)
  • Spanish (Version 2013)
  • Portuguese (Version 2013)
• Data request letter with annexes
  • English: Data request letter template
  • English: Data request letter - Annex (Mining)
  • English: Data request letter - Annex (Cement, paper industry)
  • Portuguese: Data request letter template
  • Portuguese: Data request letter - Annex (Mining)
  • Portuguese: Data request letter - Annex (Cement, paper industry)

Inventory Level 2

Inventory Level 2 calculation spreadsheet is detailed and comprehensive, allowing users to adjust all factors included in the calculations, resulting more accurate understanding of the release sources. Inventory Level 2 also includes a detailed Reference Report, containing detailed descriptions of all included mercury sources. The Reference Report is not only helpful for preparing a Level 2 inventory, but it also gives more insight on release sources when preparing a Level 1 inventory.

Inventory Level 2 consists of the following components:

• Reference Report and Guideline for Inventory Level 2
  • English (Version 2023)
  • French (Version 2005)
  • Russian (Version 2013)
  • Spanish (Version 2015)
  • Portuguese (Version 2015)
  • Arabic (Version 2005)
  • Chinese (Version 2005)
• Calculation spreadsheet (requires Excel 2010 or newer)
  • English (Version 2023)
  • French (Version 2019)
  • Russian (Version 2019)
  • Spanish (Version 2019)
  • Portuguese (Version 2019)
• Inventory Reporting Template
  • English (Version 2017)
  • Spanish (Version 2013)
  • Portuguese (Version 2013)
• Data request letter with annexes
  • English: Data request letter template
  • English: Data request letter - Annex (Mining)
  • English: Data request letter - Annex (Cement, paper industry)
  • Portuguese: Data request letter template
  • Portuguese: Data request letter - Annex (Mining)
  • Portuguese: Data request letter - Annex (Cement, paper industry)

Inventory Level 3

Inventory Level 3 goes a step beyond IL2 by integrating all mercury sources into their entire mass flow through and out of society to the environment. This enables the highlighting of the links between the different mercury sources, as well as the potential for a further increase in accuracy and reflection of local conditions. With the full mass flow integrated, the fate of mercury-bearing wastes is further detailed quantitatively (fate of sector-specific waste).

Please note that the IL3 calculation spreadsheet uses macros. When opening the file, it is therefore needed to click (accept) “Enable contents”. While the file is developed in a controlled digital environment, and it is believed to be safe to use, enabling macros in the file is on your own responsibility. Neither UNEP, UNITAR nor any individuals involved in the development of the file shall be liable for any injury, loss, damage or prejudice of any kind that may be caused by the use of the file.

• Guideline for Inventory Level 3
  • English (Version 2023)
• Calculation spreadsheet (requires Excel 2010 or newer)
  • English (Version 2023)
• Inventory Reporting Template
  • English (Version 2023)

Research

To better understand the global sources of mercury emissions and releases and to further develop the Toolkit, UNEP collaborated with Biodiversity Research Institute to conduct an analysis of the available inventories produced as a part of the Minamata Initial Assessments (MIAs). The report "Global Mercury Inventory Synthesis - An Initial Examination of the MIA Mercury Inventories" was published in December 2019. For the report, the inventories from 43 countries from around the world were compiled and analyzed. The selected countries represent a range of socio-economic backgrounds, regions, and sizes (both in population and geographic area).

Further aggregation and analysis of Toolkit results from MIAs was conducted to produce an interactive dashboard, allowing users to explore data from inventories and gain insights into patters of mercury releases by sector and region. 

Available training

Learn online

Based on the Toolkit, the e-learning platform MercuryLearn has been developed in co-operation with UNITAR (available in English and Spanish). MercuryLearn is developed to introduce the Toolkit to first-time users, serve as a reference tool for trained users, and enhance the usability of the Toolkit as a standard methodology. The platform provides an interactive online learning experience, enhanced with video lectures, quizzes and a forum for experts to exchange information and experiences. MercuryLearn was funded by the European Commission and the government of Switzerland.

Get trained by an expert

UNEP maintains a roster of Toolkit experts who you can engage to organize training workshops, review your inventory or provide you with hands-on guidance on developing an inventory. Please contact us to acquire more information.

Toolkit Change Logs

2023 Update

The 2023 update of the Toolkit resulted in the following changes to the Inventory Level 1 (IL1) spreadsheet and Guideline:

• Fire gilding (gold plating) using mercury was added as a new mercury source sub-category. Production was added under Step 4 - Industrial Hg use. Use and disposal of products gilded with mercury (which contain traces of mercury) was added under Step 6 - Hg products and substances.
• Mercury use in traditional Asian medicines was added as a new mercury source sub-category. Also here, production was added under Step 4 - Industrial Hg use, and use and disposal of traditional Asian medicines of certain origins (see Guideline) was added under Step 6 - Hg products and substances.
• The output distribution factors for "Production of zinc from concentrates" were updated based on new data from industry. Depending on the output scenarios used, this will generally result in lower output estimates to air and water, and higher outputs to sector-specific waste treatment/disposal.
• The input factor for "Electrical switches and relays with mercury" was updated based on newer data from the EU. This will result in lower mercury input and output estimates for this sub-category.
• The following mercury source types were added (qualitatively) to the list in Step 8 - Miscellaneous Hg sources:
  • Production of non-ferrous metal concentrates (concentrating phase),
  • Use of sulphuric acid from non-ferrous metal smelters,
  • Use of sodium hydroxide (NaOH) and chlorine (Cl2) produced in mercury-cell chlor-alkali plants.

The 2023 update of the Toolkit resulted in the following changes to the Inventory Level 2 and the Toolkit Reference Report (which describes the data background for all three Toolkit Levels and provides guidance for the use of Inventory Level 2):

• Fire gilding (gold plating) using mercury was added as a new mercury source sub-category.
• Mercury use in traditional Asian medicines was added as a new mercury source sub-category.
• Mercury use in homeopathic medicines was added as a new mercury source sub-category.
• The sub-category description for "Mercury metal use in religious rituals and other traditional medicines" was adjusted to enable specific estimations for Asian and homeopathic medicines, for which data have become available (see above), and some new qualitative information about ritualistic mercury uses was added.
• The output scenarios and output distribution factors for "Production of zinc from concentrates" were updated based on new data from industry. Depending on the output scenarios used, this will generally result in lower output estimates to air and water (and higher outputs to sector-specific waste treatment/disposal).
• For Zinc, lead and copper extraction, preliminary default input and output distribution factors for the lifecycle phase "/Mining and concentrating" were added (based on new data from industry).
• The input factor for "Electrical switches and relays with mercury" was updated based on newer data from the EU. This will result in lower mercury input and output estimates for this sub-category.

For crematoria, the output scenario "With Hg filter" was added to allow for separate estimation of outputs when a mercury-capturing filter is present. For crematoria equipped with filters, this will result in lower emission estimates to air (and higher output to sector-specific waste).

2019 Update

The 2019 update of the toolkit the Toolkit introduced the following changes among other smaller refinements:

• Category 5.2.6 - Gold extraction and initial processing by methods other than mercury amalgamation: The default input factor has been changed from 15g Hg/t to 5.5g Hg/t.
• Categories 5.8.1, 5.8.5, 5.9.1 and 5.9.4 on wastes: The default input factor has been changed from 5g Hg/t to 1g Hg/t.
• Category 5.5.3 - Light sources with mercury:
  • Fluorescent tubes (double end): The default input factor has been changed from 25mg Hg/item to 8mg Hg/item.
  • Compact fluorescent lamp (CFL single end): The default input factor has been changed from 10mg Hg/item to 2.7mg Hg/item.
  • High pressure mercury vapor: The default input factor has been changed from 30mg Hg/item to 40mg Hg/item.

These changes needs to be taken into account when results calculated using earlier versions are compared to the results calculated using the 2019 version. In general, it is worth noticing that all earlier versions of the Toolkit calculation spreadsheets are different not only regarding different default factors, but also regarding introduced new source categories and new calculation methodologies. These changes affect to the calculated results, making inventories - especially Level 1 inventories - developed using different versions incompatible for straight forward comparison.

The latest versions (2019) of the Toolkit calculation sheets exists currently in English, French, Russian, Spanish and Portuguese. Guidance material available in different languages from earlier versions (2005, 2013 and 2015) can be used with the updated calculation sheet keeping in mind that some information might be outdated.

Existing Inventories

Countries are encouraged to share their inventories with UNEP Chemicals and Health Branch which will make them publicly available. Published national mercury release inventories can be found here.