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Information on tungsten: sources, properties and uses

HSE Regulatory

ITIA HSE Committee monitors national and international regulations and proposals that may impact the tungsten industry, particular in member company countries.  Where appropriate, ITIA works closely with regulatory agencies by providing information and comments to assist in the development to reasonable measures to protect health and the environment.  The following are examples of some of the regulatory programmes the ITIA has been following: 

Worldwide Inventory List of Major Tungsten Substances

An increasing number of countries around the world, and particularly in Asia, are working to either implement or enhance their chemicals management legislation.  This is usually in response to the United Nations ‘Strategic Approach to International Chemicals Management’ (SAICM) initiative.  It has a target date of 2020 for countries to significantly improve existing, or introduce new, legislation to build knowledge about chemicals substances to ensure their safer handling and use.

As part of this chemical legislation, countries keep an inventory of tungsten substances.  The table reflects the current situation for major tungsten substances in different countries such as  Australia, Canada, China, EU, Japan, Taiwan Korea, New Zealand, Philippines, and USA (TSCA).  Also click to access a full inventory list for all tungsten substances.  The regulatory motivation to check the list for each country (relevant links to the inventories are included in the bottom of the table) is that if a substance is not already on the ‘existing’ Inventory, it can often mean that it is deemed a ‘new’ substance, and then frequently the hazard and risk assessment compliance requirements are more extensive, challenging and time-limited when the chemicals legislation is enacted.

National Industrial Chemicals Notification and Assessment (NICNAS) Inventory Multi-tiered Assessment and Prioritisation (IMAP), Australia

NICNAS is assessing the human health and environmental impacts of previously unassessed industrial chemicals listed on the Australian Inventory of Chemical Substances (AICS). NICNAS has implemented IMAP as an innovative framework to accelerate the assessment of these chemicals. The chemicals in the first group are identified as "Stage One Chemicals". The 3,000 Stage One chemicals were identified based on characteristics agreed by stakeholders as priorities for early consideration and sources subsequently identified by NICNAS and stakeholders.

In July 2012, NICNAS commenced assessing existing chemicals identified as Stage One Chemicals. The Tier I assessment has been finalised and tungsten carbide has been placed on the list of chemicals that “not considered to pose an unreasonable risk to health of workers and public health”.  

The IMAP-NICNAS Tier I assessment assigned “Tranche 14” to Tungsten Carbide which lists chemicals “not considered to pose an unreasonable risk to health of workers and public health”. The assessment was available for public comment on 28 August 2015.  The outcome of this assessment may amend the existing classifications for worker health and safety, and the Australian Safe Work may consider whether current controls are adequate to minimise the risk to workers (a Tier III assessment may be necessary to provide further information).  The tungsten carbide Environmental Assessment status still remains as a priority.

On 12 December 2019, NICNAS published Tranche 28 of the IMAP assessments.  Tungsten is included on Tier 1 (human health) of Tranche 28. These are chemicals that are not considered to pose an unreasonable risk to the health of workers and public health on the basis of the Tier 1 assessment (high throughput assessment).  

A Tier II assessment of cobalt has been finalised NICNAS recommends that a Tier III assessment may be necessary to provide further information to determine the adequacy of protection to workers under the current exposure control framework.

Safe Work, Australia

On 14 June 14 2018, Safe Work Australia (SWA) announced that it published the methodology it will use to review the regulatory frame for workplace exposure standards for airborne contaminates. The chemicals that will be evaluated for addition to the workplace exposure standards list include hard metal (containing cobalt and tungsten carbide). The evaluations of individual chemicals will commence in the second half of 2018. Recommendations will be for values and notations for carcinogenity, sensitization of the skin and respiratory tract, and a skin notation where there is a risk of the chemical being absorbed through the skin. Estimated release dates for draft exposure standard evaluations are as follows: hard metal 22 November 2019 (see Release 8); tungsten 27 March 2020 (see Release 15).  ITIA will be receiving updates from Safe Work Australia and will provide input and comments as appropriate.

Safe Work Australia announced on May 9, 2018, that it completed an update of HCIS, a web-based system that provides information on GHS classifications, as well as workplace exposure standards. The update incorporates classification information published in tranches 8 to 20 of the IMAP Program run by NICNAS. The amended list includes:

12141-67-2 Hexasodium Tungstate hydrate: Acute toxicity – category 4; Eye damage – category 1; Hazardous to the aquatic environment (chronic) – category 3

Environmental Protection Act, Canada

The following four tungsten substances have undergone screening assessments by the Canadian Departments of Environment and Health:

 CAS Number DSL Name
 12138-09-9  Tungsten sulfide (WS2)
 68647-36-9  Xanthylium, 9-(2-carboxyphenyl)-3,6-bis(diethylamino)-, tungstatesilicate
 103443-41-0  Xanthylium, 3,6-bis(diethylamino)-9-[2-(methoxycarbonyl)phenyl]-, molybdatetungstatephosphate
 121754-49-2  2,4-Pentanedione, reaction products with 2-methyl-2-propanol, nonylphenol and tungsten chloride (WCl6)

Based on the assessments it was concluded that none of the substances meet any of the criteria of harmful substances under section 64 of the Canada Environmental Act.  The Minister of the Environment and the Minister of Health propose to take no further action on these substances at this time.

Under Canada’s Chemical Management Plan, chemicals engineered as nanoparticles are subject to reporting if they are not on the Domestic Substances List (DSL).  In a 2009 notice, use of tungsten carbide in quantities greater than 10 kilograms per calendar year, where the substance is engineered to contain particles of particle size ranging from 1 to 100 nanometeres is identified as a significant new use and subject to reporting.  In 2016, calcium tungstate (CAS 7790-75-2) was added to a list of 206 nanomaterials subject to prioritization for risk assessment. 

Canada’s overall Chemical Management Plan includes provisions for updating the Domestic Substances List (DSL) to assure that it contains commercially relevant substances.  On 14 January 2017 the Department of Environment published a Notice with respect to substances included as part of the 2017 Inventory Update in the Canada Gazette.  Tungsten carbide (CAS 12070-12-1), sodium tungstate, dehydrate (CAS 10213-10-2), and sodium tungstate (CAS 13472-45) are included in Part 3 of the list of approximately 1,500 substances.  Persons who manufactured or imported these substances in quantities greater than 100 kg in calendar years 2014 or 2015 are required to submit certain information of the quantities and functions of the substances as described in Schedule 3 of the notice.  This information is to be provided by 17 July 2017.

In May 2017, a Final Screening Assessment for Cobalt and Cobalt-containing Substances was released. The final screening assessment concludes that cobalt and soluble cobalt compounds are harmful to the environment and meet the criteria under paragraph 64(a) of CEPA 1999. In June 2019 cobalt and soluble cobalt compounds was added to the List of Toxic Substances in Schedule 1 to CEPA 1999 based on environmental concerns. The screening assessment concluded that the substances do not meet the human health criterion as defined in the Canada Environmental Protection Act (CEPA).

No inorganic tungsten substances are included in the list of substances in the Third Phase of the Chemical Management Plan.


China's Ministry of Ecology and Environment (MEE) published on January 8, 2019, the "Chemical Environmental Risk Assessment and Control Regulation (Draft)" for public comment. The Regulation would update MEP Order No. 7, "Environmental Management of New Chemical Substances" and would include existing chemicals, as well new chemical substances. The update will include provisions for an Inventory of Existing Chemical Substances in China and Risk Assessment and Reporting of Existing Chemical Substances.

China's National Health Commission (NHC) published a notice (Document ID 00280033) on August 29, 2019, updating its occupational exposure limits (OELs) for Standard GBZ 2, Harmful Factors in the Workplace, for the first time since 2007.  It will become mandatory on April 1, 2020. The appended Standard GBZ 2.1-2019 (Document ID 00280029) includes tungsten and insoluble compounds with a Time Weighted Average OEL of 5 mg/m3 and Short Term Exposure Limit of 10 mg/m3, as W.

In December 2019, China proposed revisions to its National Catalog of Hazardous Wastes.  The draft proposing "Alkali slag (tungsten slag) produced by alkali decomposition during the production of ammonium paratungstate and wastewater treatment of sludge" to be exempted as a hazardous waste under the Category of "Disposal" if following exemption conditions: "Fulfil the Cement kiln co-processing of solid waste pollution control standard (GB30485) requirement, enter the cement kiln for co-disposal".  Comments on the proposal were due in February 2020 and the proposal is now under consideration. 

Proposed Ban on Tungsten Shot for Shooting, Denmark

A proposal by the Danish Environmental Protection Agency would have banned the use of tungsten shot in all forms of shooting in 2014.  As of 7 April 2014, ITIA commented on the proposal pointing out that the toxicological study upon which the proposal was based was not applicable to the tungsten material used in shot and consequently the proposed ban was withdrawn.  

European Integrated Pollution Prevention and Control (EIPPC, EU)

The EU revised the Best Available Technology Reference (BREF) document for nonferrous metals (NFM) industries under the European Integrated Pollution Prevention Control (IPPC) directive.  The concerned ITIA members in Europe were in favour to have the chapter on Tungsten revised and included in the document.  ITIA had joined force with Eurometaux and Austrian Non-Ferrous Metals Federation in writing to the head of the EIPPCB and the NFM BREF team to express this opinion in April 2013 (click to view the letter). 

The final draft of the BREF (October 2014) does not include a chapter on tungsten.  However, the Recommendation for Future Work section of the final draft BREF contains a recommendation that the next NFM BREF include a new chapter dedicated to the production of refractory metals (including tungsten production).


In response to the EU's legislation "REACH", Tungsten Consortium, with membership includes the world’s leading producers and processors of tungsten and tungsten compounds, which was established by ITIA to assist the industry in the development of scientific data and to support registration of several soluble and insoluble tungsten compounds.  Further information on tungsten and REACH can be found on the Tungsten Consortium website

ECHA published on 4 December 2019, a list of more than 21,000 REACH-registered substances mapped in its chemical universe.  The reaction mass of ditungsten carbide and tungsten carbide; tungsten; tungsten carbide; tungsten dioxide; tungsten oxide; and tungsten trioxide are identified as requiring additional information to conclude whether further regulatory action is needed.  Other tungsten compounds, including blue oxide, tungsten trioxide and tungsten disulfide, have not been assigned a regulatory action category. 

European Food Safety Authority, EU

The Authority adopted a favourable scientific opinion on the use of the substance tungsten oxide (WOn (n = 2,72-2,90)) (FCM substance No 1064 and CAS No 39318-18-8). The Authority concluded that the substance is not of a safety concern for the consumer if the additive is used as a reheat agent in polyethylene terephthalate (PET). The Authority considered that due to the insolubility of the substance, low migration is expected for any foreseeable use as a reheat additive in PET. Therefore, verification of the migration limit is not necessary. For other technical functions or for use in other polymers, the Authority concluded that the migration should not exceed 0,05 mg/kg (expressed as tungsten).

Agence nationale de sécurité sanitairede l’alimentation, de l’environnement et du travail (ANSES), France

The French Agency for Food, Environmental and Occupational Health and Safety (ANSES) has been entrusted by the Ministry of Labour to conduct scientific assessments prior to the setting of occupational exposure limits (OELs) for certain chemicals. In order to contribute to the setting of these values, the ANSES issues calls for pre-expertise consultations prior to and following the collective expert assessment work. ANSES has already conducted the pre and post-expertise consultation for cobalt’s OEL, and only the pre-expertise consultation for cobalt combined with tungsten carbide has been requested. 

In December 2012, ITIA responded to ANSES’ request on cobalt combined with tungsten carbide. ITIA’s pre-expertise submission included information on health effects, and information on methods assessing the occupational exposure and biological exposure indicators.

In May 2013, ANSES heard the arguments against the new cobalt OEL of 2.5 μg/m3 presented by Movement of the Enterprises of France (FEDEM) however it went ahead and recommended the new value. The ANSES recognises that this 2.5 μg/m3 is different from other authorities around the world OELs, and the biological indicators (eg urine) remain need to be assessed.  Currently this new cobalt OEL is not enforceable, but ANSES completed and published the report in September 2014 in order to propose to Direction Generale du Travail (DGT) the new OEL value.  The compromise given by ANSES was to suggest DGT to delay the submission by giving a low priority on the new cobalt OEL.  ANSES confirmed that they would consider WC + Co as a distinct matter, but it is not on their immediate agenda as they have other priorities.

International Agency for Research on Cancer (IARC), France

Tungsten is included in the Report of the Advisory Group to Recommend Priorities for IARC Monographs during 2015-2019. The document cites the carcinogenicity classification of Co metal with WC as Probable Carcinogenic to Humans (Group 2A); and Kalinish et al 2005 first embedded pellet study on W/Ni/Co pellets (but not the 2nd study). 

Also refers to other experimental in vivo and/or in vitro studies showing pulmonary inflammation, and production of reactive oxygen species, as well as increased expression of genes associated with oxidative and metabolic stress and toxicity; and genotoxicity and epigenetic modification have also been indicated. IARC’s advisory group recommends as a “high priority” to complete the monograph “after completion of ongoing bioassay”. 

In March 2019 an Advisory Group of 29 scientists from 18 countries met to recommend priorities for the International Agency for Research on Cancer (IARC) Monographs programme during 2020–24.  Weapons-grade alloy (tungsten, nickel, and cobalt) was recommended for evaluation with high priority on the basis that new bioassay evidence warrants re-evaluation of the classification.

Auschuss für Gefahr Stoffe Committee for Hazardous Chemicals (AGS), Germany

The AGS is a governmental committee composed of various shareholders, including ministry representatives, Workers Compensation representatives, union representatives, and selected scientists.  This cross-functional “expert” group in Germany recommends substance classifications to the German government.  In 2009, the “Expert Group” requested a compilation of recent hardmetal literature as well as ongoing confidential studies to be completed in 2010.   ITIA developed and presented a summary to AGS in late 2009.

By late 2010, AGS had still not reviewed ITIA's submissions in detail but asked the summary be updated to include any new published articles or studies.  The updated summary was completed and submitted to AGS in late February 2011.  
AGS in 2013 is ready to release based on cancer risk an ERB (Expositions-Risiko-Beziehung=Exposure Risk Correlation) tolerance limit (additional cancer risk of 4:1000 in 40 working years over 8h exposure) of 5 μg/m³ for Cobalt (as for alveolar dust, and the criteria is <10 µm particle size for Cobalt) including hardmetal, with an acceptable risk (additional cancer risk of 4:10000) limit until 2018 of 0.5 μg/m³ (500 ng/m³).  Latest 2018 the acceptable risk limit (additional cancer risk of 4:100 000) will be 0.05 μg/m³ (50 ng/m³).  These cobalt values are not yet officially enforceable as they need to be published in the TRGS 910.

Chemical Substances Control Law, Japan

Japan Ministry of Economy, Trade and Industry (META) request manufactures/importers of more than certain amount of the substance (≥ 1 tpa) manufactured/imported in Japan to provide tonnage details.  METI will narrow down and prioritise the chemical substances for detailed assessment.  The manufacturers and importers (M/I) of selected substances will be requested to submit information on the level/type of hazard.  Influences of such chemicals on human health, etc, will be evaluated and classified.  Based on the results, manufacturing and use of the hazardous chemical substances and products containing these substances will be restricted. 

METI requests Japanese companies (and importers) to provide them with hazard information about tungsten carbide and some other compounds for their risk assessment based on Japanese Chemical Substance Control Law by 2 March 2015 if available.  More information can be found at: www.meti.go.jp/policy/chemical_management/english/.

The Japanese Ministry of Health, Labor and Welfare has published an English translation of its guidance on labeling and SDSs under Industrial Safety and Health Law (ISHL). The translation provides detailed information on GHS implementation in Japan and is based on the GHS. The translation includes an overview of the ISHL and related laws covering labeling and SDSs, information required in labeling and SDSs under ISHL, and a list of substances subject to labeling and SDSs under ISHL. Tungsten and its watersoluble compounds are subject to the obligations of labeling and notification with Cut-Off values of 1% for both labeling and SDS requirements. Cobalt and compounds is also listed with Cut-Off values of 0.1% for both labeling and SDS.

The guidance includes the "Exemption of Solids from the Obligation of Labelling (from June 1, 2106)," which notes that of the pure substances for which labeling is mandatory, including tungsten in forms other than powder, are exempt from the obligation of labeling.


Korea (K)-REACH is scheduled to be implemented on 1 January 2015 and will require the mandatory reporting, registration and notification of manufactured and imported new chemical substances, existing chemical substances, and products containing hazardous substances.  

On 31 October 2014, the Korean Ministry of Environment (MoE) published its First List of Designated Existing Substances for Registration which includes high volume substances and substances that are carcinogenic, mutagenic or reproductive toxins (CMR), or persistent bioaccumulative and toxic (PBT).  Registration with extensive hazard identification data, similar to those required for the EU REACH, must be submitted to the Korean authorities within 3 years.  The First List of 518 substances contains no tungsten compounds thus a data gathering/sharing exercise is not triggered at this time.  A Second List for further substances will be published 3 years from now. 

Although broadly similar to EU REACH, one major difference is that all Korean manufacturers, importers and Only Representatives (OR) are obligated to report tonnage volumes annually for all substances on the Korean Existing Substances Inventory that are manufactured, imported or sold > 1 tonne, no matter if the substances are on the First List of Designated Substances or not.  The reporting data will be used, together with information on substance hazards and risks, to designate substances subject to registration.  That first deadline for annual reporting (1 January to 31 December 2015 tonnage volumes) under K-REACH is 30 April 2016.  Click to view the list of tungsten and its related compounds in the Korean Inventory.

One aspect of K-REACH pending for clarification from the Korean authorities is whether mineral ores and concentrates are exempt from K-REACH (as the EU REACH registration).  Apparently Korean MoE guidance documentation, explicitly covering this point, will be made available before the end of this year.  Members will be updated accordingly.

To assist domestic and international industries with procedures of K-REACH, the MoE has created a K-REACH Helpdesk website (in both Korean and English).  

Click to view presentations about K-REACH from Chemservice and Korea Testing Research Institute (KTR).  Useful information on K-REACH can be found online such as CIRS and ChemLinked.  

Revisions to certain provisions of K-REACH were proposed in December 2016 with comments due in early 2017.  Among other modifications, the proposal abolishes the designation of Priority Existing Chemicals, replacing it with a phase-in registration scheme for existing chemicals > 1 tonne per annum. 

In March 2018, Ministry of the Environment (MOE) amended K-REACH. Companies must pre-report the substances that they manufacture or import by June 30, 2019. Companies that fail to do so will be banned from manufacturing or importing beginning 1 July 2019.  MOE recently published guidance, in English, on K-REACH as amended on 1 January 2019.

In December 2018, the Ministry of Environment issued its final listing of CMR substances to be registered by 2021 (with pre-registration by June 2019). The final notice includes the following tungsten compounds: Lead tungsten tetraoxide (CAS Number 7759-01-5); Lead tungsten oxide (CAS Number 12737-98-3); and Cobalt metal with tungsten carbide (CAS Numbers 7440-48-4 and 12070-12-1).  These tungsten substances have also been listed as Priority Substances which are subject to ongoing management and reporting under K-REACH.

Occupational Safety and Health Act (OSHA). Under an amendment to the Occupational Safety and Health Act, passed by Parliament on 27 December 2018, companies must submit SDSs to Ministry of Employment and Labor, as well as along the supply chain. This amendment will apply beginning 16 January 2021.


In February 2020, the Malaysian Department of Occupational Safety and Health published its list of classified substances and their classifications. Nickel Tungsten Oxide (14177-51-6), with classifications Carc 1A, STOT Re1, and Skin Sens 1, is the only tungsten substance listed. Cobalt metal and several cobalt compounds are included in the list.


In October 2016, Russia approved the National Technical Regulation for Chemical Product Safety according to a Russian Federation Decree (#1019). The regulation, which will implement the UN's Globally Harmonised System (GHS) of classification and labelling of chemicals and requirements on new substance notification and chemical product registrations, will come into force on 1 July 2021.  Click here for more details.  ITIA will continue to follow development of this regulation as it may relate to tungsten substances.


The Taiwan Ministry of Labor (MOL) published a notice on 25 September 2017, announcing a draft amendment to the PEL standards for airborne hazardous substances in the workplace was announced in September 2017. The draft amendment would update the list of PELs of hazardous substances in air and the list of PELs for dusts. MOL's notice includes PELs of 5mg/m3 (as W) for insoluble tungsten compounds and 1 mg/m3 (as W) for soluble tungsten compounds. Comments were due 27 November 2017.

In March 2019, Taiwan EPA amended the Regulations of New and Existing Chemical Substances Registration. An English translation of the regulations is available.  Taiwan EPA has compiled two lists of candidate substances for future designation as Priority Existing Chemicals (PECs).  List A contains more than 1,300 chemicals that Taiwan considers hazardous or as having a high exposure potential, while List B comprises more than 11,000 substances that require more data before a determination can be made.  List B includes ammonium tungstate (12333-11-8), tungsten, tungsten(IV) sulfide, tungstic acid, tungsten trioxide,tungsten carbide, tungsten hexachloride and tungsten alloy base (W 72-80, Ni 19-28). List A includes tungsten hexafluoride.

The American Conference of Governmental Industrial Hygienists (ACGIH), US

ACGIH® has a procedure that provides the public with an indication of where those chemical substances and physical agents under study list (USL) fall in the development process. Tier 1 entries indicate which chemical substances and physical agents may move forward as a Notice of Intended Changes (NIC) or Notice of Intent to Establish (NIE) in the upcoming year, based on their status in the development process. Tier 2 consists of those chemical substances and physical agents that will not move forward, but will either remain on or be removed from the USL for the next year. More information on this new USL Tier 1 is available at http://www.acgih.org/TLV/Studies.htm.

Since 2012 ACGIH has listed in their “Under Study List” cobalt and inorganic compounds (as Co), hard metals (as Co and WC), tungsten and compounds (as W), and tungsten carbide.  In July 2012, ITIA provided comments on tungsten and compounds including WC.  Further to the 1st response to ACGIH in July 2012, ITIA submitted a 2nd response on 9 July 2013 which includes details of recent inhalation and DNEL publications, as well as NTP Immunotoxicity results.  As of January 2015, tungsten and compounds and cobalt and compounds remained on the under study list.  ITIA submitted updated comments on the tungsten and tungsten compounds to ACGIH TLV Committee on 20 May 2015.

On 13 June 2013 the ACGIH removed WC from the 2013 USL.  However, in its July 2015 update of the USL, Tungsten and compounds was placed on the Tier 2 list.  In 2016 the ACGIH Board of Directors voted to place tungsten and compounds, in the absence of cobalt, on the 2016 Notice of Intended Change (NIC).  The proposed recommendation is a TLV-TWA of 3 mg/m3, as W, Respirable particulate matter.   ITIA sent comments on the NIC documentation on 23 May 2016.  In 2017, the ACGIH adopted the TLV-TWA for Tungsten and compounds as proposed (3 mg/m3, as W, respirable).  ACGIH considered ITIA’s comments and made changes/additions to the TLV Documentation based on part on ITIA comments.  

In 2016 the ACGIH Board of Directors voted to adopt the proposal for Hard Metals containing Cobalt and Tungsten Carbide.  The adopted recommendation is a TLV-TWA of 0.005 mg/m3, as Co, Thoracic particulate matter. Cobalt and compounds was placed on the Tier 2 list and will not move forward with a NIC proposal in 2016.  

In 2017, ACGIH placed the Threshold Limit Value (TLV) for cobaltand compounds on the Notice of Intended Change list. The proposal is fora TLV-TWA of 0.02 mg/m3, as cobalt, inhalable particulate matter. While the TLVvalue is the same as the current TV, the designation of "inhalable" fraction isnew. Cobalt and compounds were also given the respiratory and skinsensitizer designations. The proposed TLV-TWA was adopted by the ACGIH Board in 2019. The new limits does not apply to cobalt in hard metals.

Note: Contact the ITIA Secretariat (info@itia.info), if readers would like to review copies of ITIA comments sent to ACGIH. 

Regional Screening Levels (RSLs), EPA, US

In May 2016 the US Environmental Protection Agency added tungsten, sodium tungstate and sodium tungstate dihydrate to its tables of Regional Screening Levels (https://www.epa.gov/risk/regional-screening-levels-rsls-users-guide-may-2016).  The screening levels in these tables are chemical specific concentrations for individual contaminants in soil, air and drinking water that may warrant further investigation or site cleanup.  The Screening Levels for tungsten are based on Provisional Peer-Reviewed Toxicity Values for Soluble Tungsten Compounds publish in May 2016 (https://hhpprtv.ornl.gov/issue_papers/Tungsten.pdf). 

Integrated Risk Information System (IRIS), EPA, US

EPA's Integrated Risk Information System is a human health assessment program that evaluates information on health effects that may result from exposure to environmental contaminants. Through the IRIS Program, EPA provides science-based human health assessments to support the Agency's regulatory activities.IRIS’ tungsten related literature searches were released on 2007, and in 2008 tungsten was included as part of EPA’s IRIS. Although tungsten does not appear to be under active review, tungsten and related compounds remain on the IRIA agenda for risk assessment.

IRIS’ tungsten related literature searches were released on 2007, and in 2008 tungsten was included as part of EPA’s IRIS. Although tungsten does not appear to be under active review, tungsten and related compounds remain on the IRIS agenda for risk assessment.

List of Estrogen Disruptor Screening Program (EDSP), EPA, US

EPA announced the initial list of chemicals to be screened for their potential effects on the endocrine system (or Tier I testing) on 15 April 2009, and the first test orders were issued on 29 October 2009. Test orders are requests for data. Now that screening is underway, EPA is reviewing test order responses and making available the status or test order responses and/or any decisions regarding testing requirements. In November 2010, EPA developed a second list of chemicals for screening and draft policies and procedures for the Agency's use to require testing of chemicals for Tier 1 screening. On 14 June 2013, EPA issued a revised second list of chemicals.

EPA will use a two-tiered screening and testing process: Through Tier 1, EPA hopes to identify chemicals that have the potential to interact with the endocrine system. Through Tier 2, EPA will determine the endocrine-related effects caused by each chemical and obtain information about effects at various doses.

EPA has listed tungsten, tungsten carbide and C.I. Basic violet, molybdatetungstatephosphate (CAS1325-82-2) on the EDSP List to examine the effects to estrogen, androgen, and thyroid hormone-related processes. To this date none of the tungsten substances have been included in the 1st or 2nd Tier 1 Screening List for testing. A list of Federal Notices on the Endocrine Disruptor Screening Program can be found at https://www.epa.gov/endocrine-disruption/endocrine-disruptor-screening-program-federal-register-notices.

Toxic Substances Control Act (TSCA), EPA, US

Under the TSCA the US EPA can regulate new and existing chemical substances.  In 2008 EPA issues request for health and environmental data and exposure information for several tungsten compounds.  Because of voluntary information submitted by ITIA, EPA dropped those tungsten substances from further regulatory consideration.  

In June 2016 the US Congress passed into law a bill to reform the Toxic Substance Control Act.  The new law strengthens the existing provisions on new chemicals, existing chemicals and EPA’s authority to require testing.  Under the existing chemical provisions EPA is required identify high priority chemicals, evaluate their risks, and regulate those chemicals deemed to present an unreasonable risk.  The initial chemicals targeted for risk assessment will be drawn from EPA’s TSCA Work Plan chemicals, which at this time does not include any tungsten compounds but does include cobalt (https://www.epa.gov/assessing-and-managing-chemicals-under-tsca/tsca-work-plan-chemical-assessments-2014-update).  

An important provision for companies who manufacture or import chemical substances in the US is the Inventory Reset. EPA issued a rule in August 2017 requiring companies to report chemicals they currently manufacture/import.  This reporting will allow EPA to create a list of “active” chemical substances.  Reporting for the Inventory Reset will eliminate the need for a company to petition the EPA to change the substance to “active” in the future. On 13 January 2017, the rule requires a retrospective electronic notification of chemical substances on the TSCA Inventory that were manufactured (including imported) for non-exempt commercial purposes during the ten-year time period ending on 21 June 2016. However, substances on the interim List of Active Substances are exempt from reporting.  Tungsten substances on the Interim List of Active Substances include:

 Name as listed CAS No
 Sodium tungsten oxide (Na2WO4)  13472-45-2
 Tungstate (W12(OH)2O386-, ammonium (1:6)  12028-48-7
 Tungstate (W12(OH)2O4010-, ammonium (1:10)  11120-25-5
 Tungstate (WO42-), hydrogen (1:2), (T-4)  7783-03-1
 Tungsten  7440-33-7
 Tungsten carbide (W2C)  12070-13-2
 Tungsten carbide (WC)  12070-12-1
 Tungsten chloride (WCl6), (OC-6-11)-  13283-01-7
 Tungsten fluoride (WF6), (OC-6-11)-  7783-82-6
 Tungsten oxide   39318-18-8
 Tungsten oxide (W4O11)  12608-26-3
 Tungsten oxide (WO3)  1314-35-8
 Tungsten sulfide (WS2)  12138-09-9

Click to view more information on the Inventory Update Rule

In February 2019 the EPA released an update of the Toxic Substances Control Act (TSCA) Chemical Inventory, which lists chemicals that are "active" versus "inactive" in commerce in the US.  Manufacturers, importers and processors are required to notify EPA before reintroducing into commerce a substance currently identified as inactive on the TSCA Inventory.

A final rule on Nanoscale Materials, published by the EPA on 12 January 2017, establishes reporting and recordkeeping requirements under TSCA for manufacturers and processers of chemical substances, including tungsten and related compounds, when they are manufactured or processed at the nanoscale. Persons who manufacture or process a discrete form of a reportable chemical substance at any time during the three years prior to 14 August 2017 must report to EPA by 14 August 2018.  Nanoscale materials manufactured or processed after that date must be reported 135 days prior to manufacturing or processing.  Click to view details on the reporting requirements.

Comprehensive Environmental Responsibility, Compensation and Liability Act, EPA US

In January 2017, EPA proposed that owners and operators of certain classes of hardrock mines and mineral processing facilities be required to show financial ability to address risks from hazardous substances.  Among the list of commodities subject to the proposed rule are tungsten, scheelite and wolframite.  Comments on the proposal are due to the EPA by 11 July 2017.  Click to view further details of the proposal.  

On December 1, 2017 the EPA Administrator signed a federal register notice to inform the public of EPA's decision not to issue final regulations because the Agency has determined that final regulations are not appropriate.

National Toxicology Program (NTP) - Sodium tungstate carcinogenicity testing, US

In August 2002, Centers for Disease Control (CDC) nominated tungsten for study with high priority to the National Toxicology Program.  NTP, an interagency program of the US Department of Health and Human Services, is headquartered at the National Institute of Environmental Health Sciences, one of the National Institutes of Health. 

NTP routinely conducts short and long-term toxicology studies to assess the potential of an administered chemical agent to cause cancer, developmental, reproductive, immunotoxic, or neurotoxic effects in laboratory rodents. 

Based on its review of the tungsten nomination to date, NTP has an ongoing sodium tungstate testing program to address the toxicity of tungsten. Though NTP's study programs are long-term in nature, lasting several years, the research will proceed in phases so that results can be made available at NTP’s sodium tungstate testing status page (see link: http://ntp.niehs.nih.gov/?objectid=BD4AE831-123F-7908-7B6C2BD251A8B1C5).

Latest testing updates indicate that NTP’s 2-year drinking water oral study on Na2WO4.2H2O in rats and mice it is still ongoing.  The exposure and analysis portion of the study is complete and a post-peer reviewed Technical Report is In Progress.  The overall NTP testing has found that tungsten accumulates in bone and crosses the placenta, it is negative in genotoxicity assays (Salmonella and micronucleus).  The immunotoxicity study on female mice exposed to sodium tungstate has been recently published by Frawley et al 2016.  In 2019 the NTP released Pathology Tables, Survival and Growth Curves from the NTP Short-Term and Long-Term Studies.

In addition to the sodium tungstate, tungsten trioxide and tungsten sub oxide (WO2.81) were nominated for testing.  However, at this time these substances are no longer listed for testing. The testing status of tungsten compounds can be found at http://ntpsearch.niehs.nih.gov/Testing+Status.

Toxic Free Kids Act - Chemicals of High Concern, Minnesota Department of Health (MDH), US

In September 2016 the MDH added cobalt with tungsten carbide to its list of Chemicals of High Concern under the Toxic Free Kids Act.  The listing was based on its classification by IARC as a Group 2A carcinogen (probably carcinogenic to humans).

Occupational Safety and Health Administration (OSHA), US

In October 2014 OSHA issued a request for information on Chemical Management  and Permissible Exposure Limits.  While the document does not address tungsten or any other specific chemicals, it outlines option for methods to that the agency may use to establish permissible exposure limits for workers.  ITIA Responded to the OSHA’s request for information in April 2015.  ITIA provided an example of how REACH data can be used for developing Permissible Exposure Limits.  ITIA supports the sharing and use of REACH data and methods by for developing occupational exposure assessments and Permissible Exposure Limits. 

National Chemicals Inventory, Vietnam

In October 2016, the Ministry of Industry and Technology of Vietnam published the first draft version of the national existing chemical inventory for consultations.  The draft Inventory contains the following tungsten substances:

 Name as listed CAS No
 Ammonium tungstate  11120-25-5
 Tungstate (WO42-), sodium (1:2), (T-4)-  13472-45-2
 Tungsten  7440-33-7
 Tungsten carbide (WC)  12070-12-1
 Tungsten oxide (WO3)  1314-35-8

On September 15, 2018, Vietnam issued a notice announcing the availability of an updated draft National Chemical Inventory. In addition to the tungsten substances listed above, the updated inventory contains an additional 18 inorganic tungsten substance, as well as several organic tungsten compounds.

Once the Inventory is finalised, substances not on the Inventory will be considered new and will require registration before import or manufacture in Vietnam.

In June 2019 the Vietnam Ministry of Health promulgated national technical regulations for Occupational Exposure Limits (OEL) for 50 chemicals present in workplace air. While no tungsten compounds are included in the list, Cobalt and compounds are listed with a TWA OEL of 0.05 mg/m3 and IARC classification of 2B.

© 2011 International Tungsten Industry Association