Tel: +44 20 8996 2221
Fax: +44 20 8994 8728
Email: info@itia.info
INTERNATIONAL TUNGSTEN INDUSTRY ASSOCIATION
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 Inventories Hazard Classifications Australia
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 ... read more
Hazard Classifications of Major Tungsten Substance
GHS Hazard Classifications for tungsten substances can be found at www.itia.info/health-environment.html. These classifications were arrived at by the Technical Committee of the Tungsten Consortium after reviewing and assessing relevant hazard data against European Union’s Classification, Labelling and Packaging (CLP) guidelines. It should be noted that although the classification system is intended to be globally harmonized, different countries may apply different classifications based on other toxicity data or read across strategies. Since pure tungsten carbide is not classified as hazardous, the final classification of Hardmetal powders as dictated by the guidelines is determined by the presence and concentration of other elements, most notably cobalt, nickel and/or chromium. CLP classifications for these elements can be found on the ECHA website. ITIA members may refer to Members Only area of the ITIA website for CLP classifications of various hardmetal powder compositions.
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.
On 1 July 2020 the Australian Industrial Chemicals Introduction Scheme (AICIS) became the new national regulator for the import and manufacture of industrial chemicals in Australia, in charge of chemicals’ assessment. Search of the Inventory for “tungsten” and “tungstate” produced a total of 22 tungsten substances. The major tungsten substances (W, WO3, WS, WC, W2C, AMT, APT, and sodium tungstate) are identified as chemicals that can be manufactured or imported for commercial purpose without reporting if their company is registered in Australia.. Manufactures/importers should search the inventory to determine if they have any reporting obligations.
AICIS also contains an Assessments Search page. The page includes assessments previously published by the National Industrial Chemicals Notification and Assessment Scheme (NICNAS). ) The following assessments for tungsten substances are listed:
- Tungsten Risk: Poses no unreasonable risk to human health based on Tier I assessment under the NICNAS IMAP assessment framework
- Tungsten oxide (WO3) Risk: Poses no unreasonable risk to the environment based on Tier I assessment under the NICNAS IMAP assessment framework
- Tungsten sulfide (WS2) Risk: Poses no unreasonable risk to the environment based on Tier I assessment under the NICNAS IMAP assessment framework
- Tungsten carbide (WC) Risk: Poses no unreasonable risk to human health based on Tier I assessment under the NICNAS IMAP assessment framework
The site provides links to detailed assessments for tungsten boride and tin titanium tungsten zinc oxide
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 were as follows: hard metal 22 November 2019 (see Release 8); tungsten 27 March 2020 (see Release 15). Some of the releases are delayed due to the pandemic. ITIA will be receiving updates from Safe Work Australia and will provide input and comments as appropriate. Information on Australia's workplace standards can be found here.
Draft Workplace Exposure Standard for Tungsten (soluble and insoluble compounds) was released on February 1, 2021 with comments due by June 30, 2021. The draft includes a proposed a TLV of 3 mg/m3 for tungsten, metal and cpompounds, as respirable dust. As of 1 October 2022, the WES for souble and insoluble tungsten compounds remain at 1 mg/M3 and 5 mg/M3, respectively.
In January 2020, SWA released a proposed new – interim Occupational Exposure Limit for hard metals (containing cobalt and tungsten carbide) of 0.005 mg/m3. In February 2020, ITIA submitted comments on the proposal recommending that the exposures to hard metal instead be controlled using the current ACGIH’s TLV®-TWA for cobalt and inorganic compounds of 0.02 mg/m3 (as cobalt), inhalable particulate matter.
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
On 1 January 2021, Safe Work Australia will begin a two year transition to GHS 7. SWA has published guidance to help business navigate the transiltion to GHS 7.
Canada
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.
In the 2019 Review of Canada's Risk Assessments Priorities (published in December 2020) 443 substances are listed as needing additional data gathering. The only tungsten substance listed is cesium tungstate (CAS 13587-19-4), with the recommendation for exposure data gathering.
Ontario Province
Effective 2 July 2020 Ontario Province adopted updated Occupational Exposure Limits to include Hard Metals (0.005 mg/m3, thoracic as Co) and Tungsten and compounds (3 mg/m3 respirable as W).
Quebec Province
Quebec's Regulations Respecting Occupational Health and Safety, updated to December 31, 2020, include a Permissible Exposure Value of 0.005 mg/m3 (thoracic fraction) for Hard metals containing cobalt and tungsten carbide. The PEVs for insoluble and soluble tungsten compounds are 5 mg/m3 and 1 mg/m3, respectively.
China
China's Ministry of Ecology and Environment (MEE) published on 8 January 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.
On 7 May 2020, the Ministry of Ecological Environment (“MEE”) promulgated the Measures for Environmental Management of New Chemical Substances (also referred to as “China REACH regulation”), which will take effect on 1 January 2021. Under these regulations, chemical substances not yet listed on the Inventory of Existing Chemical Substances in China (“IECSC”) are referred to as “new chemicals” and cannot be manufactured in or imported to China without obtaining registration certificate from MEE. The inventory contains tungsten and approximately 14 inorganic tungsten compounds. Manufacturer and importers should consult the Inventory to confirm that their substances are listed.
At the request of Chinese companies, and with supporting documentation from ITIA, the Chinese Ministry of Ecology and Environment has proposed adding cast tungsten carbide and tungsten blue oxide to the List of Existing Chemical Substances in China. Consequently, companies manufacturing, using, or importing such chemical substances would no longer be required to comply with requirements for new chemical substances, such as notification, mandatory registration, and reporting requirements. In June 2023, the Ministry of Ecology and the Environment announced the addition of reaction mass of ditungsten carbide and tungsten carbide (cast tungsten carbide) and tungsten blue oxide to the List of Existing Chemical Substances in China. Other commercially relevant tungsten substances including W, WO3, WC, WS2, sodium tungstate, AMT and APT were already on the Inventory of Existing Chemical substances.
An integrated information platform for hazardous chemicals launched by China's National Registration Centre for Chemicals (NRCC) is now fully operational, allowing companies to search for registrants and their registered products. Tungsten hexafluoride is the only tungsten compound included on the list of Hazardous Chemicals.
China's National Health Commission (NHC) published a notice (Document ID 00280033) on 29 August 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 November 2020 the China Ministry of Ecology and Environment (MEE) published the Directory of National Hazardous Wastes (2021 Edition), which took effect on 1 January 2021. “Alkali boiling slag (tungsten slag) produced by alkali decomposition in ammonium paratungstate production process, molybdenum removal slag produced in molybdenum removal process and wastewater treatment sludge” is included on the 2021 Edition as hazardous wastes, with its hazardous characteristics marked as T (for toxicity), and waste code of 323-001-48. However, the waste may be exempted if certain Pollution Control Standards are met.
In February 2021 China's National Institute for Occupation Health and Poison Control launched an online searchable database containing chemical hazard information and OELS for mote that 500 chemical substances. The database includes entries for tungsten and cobalt.
On November 13, 2021, MEE published Self-Monitoring Technical Guidelines for Pollution Sources -- Non-Ferrous Metal Metallurgy -- Secondary Non-Ferrous Metal Industry (HJ/1208-2021). As of January 1, 2022, companies in the industries covered by the standards that discharge pollutants can refer to the standards for the technical specifications regarding self-monitoring the soil and groundwater and the pollutants discharged.
In November 2021, the Ministry of Ecology and Environment (MEE) published draft opinions that would limit heavy metal pollution in several key industries including non-ferrous heavy metal mining, mineral processing and smelting. The goal is to reduce discharge of lead, mercury, cadmium, chromium and arsenic from heavy metal discharging companies.
Denmark, Proposed Ban on Tungsten Shot for Shooting
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 Union
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). The 2017 NFM industry BREF document does not contain a chapter on tungsten but recommends that the next version should consider other metals including tungsten.
REACH, EU
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. A “data generation” position in the chemical universe has been assigned for the reaction mass of ditungsten carbide and tungsten carbide; tungsten; tungsten carbide; tungsten dioxide; tungsten oxide; tungsten trioxide; tungstic acid; sodium tungstate and ammonium meta- and para-tungstate. Tungsten disulfide, has not been assigned a chemical universe position. The "data generation" position indicates that additional information is required to determine if further regulatory action is needed.
On 10 June 2022 the European Commissioned published a Commission Recommendation (2022/C/01) on updated definition of nanomaterials. The definition specifies particle dimensions that constitute a nanomaterial and specifically excludes a material with a specific surface area by volume of < 6m2/cm3 from the definition of a nanomaterial. The Commission recommends that this updated definition be used in preparing and implementing Commission and Member State legislation and programmes. Two guidance documents on characterization of nanoparticles have been published. In June 2022 OECD published Test Guideline No. 125, Nanomaterial Particle Size and Size Distribution of Nanomaterials. In December 2022 ECHA published Endpoint Specific Guidance applicable to nanomaterials. In 2023, the Joint Research Centre (JRD) published Guidance on the implementation of the Commission Recommendation 2022/C 229/01 on a definition of nanomaterial. The Guidance is intended to help stakeholders understand the new definition and support its regulatory implementation.
ECHA Committee for Risk Assessment
In December 2022 the ECHA Committee for Risk Assessment adopted its Opinion on scientific evaluation of occupational exposure limits for cobalt and inorganic cobalt compounds. The Committee recommended the following limits:
• Occupational Exposure Limit (8hr TWA): 0.0005 mg Co/m3 (0.5 µg Co/m3; respirable fraction) and 0.001 mg Co/m3 (1 µg Co/m3; inhalable fraction)
• Biological Guidance Limits: Females: 2 µg Co/L urine. Males: 0.7 µg Co/L urine
• Notations: “Skin sensitisation” and “Respiratory sensitisation”
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).
Eurasian Economic Union (EAEU)
A draft decision of the EEU sets out the Procedure for the Formation and Maintenance of the Register of Substances and Mixtures of the Eurasian Economic Union as required by the Technical Regulation of the EAEU 041/2017 – On the Safety of Chemical Products. Cobalt metal with tungsten carbide is listed in Annex 7 of the Registry Order: Chemicals That Have Carcinogenic, Mutagenic or Reproductive effects or Chronic Aquatic Toxicity (Class 1).
France, Agence nationale de sécurité sanitairede l’alimentation, de l’environnement et du travail (ANSES)
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)
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. In March, 2022, an Working Group of scientist finalised their evaluation of the carcinogenicity of nine agents including cobalt metal (without tungsten carbide or other metal alloys), and weapons-grade tungsten (with nickel and cobalt) alloy. Cobalt metal and soluble cobalt(II) salts were classified as “probably carcinogenic to humans” (Group 2A) based on “sufficient” evidence for cancer in experimental animals and “strong” mechanistic evidence. Weapons-grade tungsten alloy was classified as “possibly carcinogenic to humans” (Group 2B) based on “sufficient” evidence in experimental animals.
Germany
Auschuss für Gefahr Stoffe Committee for Hazardous Chemicals (AGS)
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.
Institut fur arbeitsschutx der deutschen gesetzlichen unfallversicherung (DGUV)
DGUV maintains an extensive information system on chemical substances, including health and safety data, international Occupational Exposure Limits (OELs), and Derived No Effect Levels (DNELs). The databases includes entries on tungsten and several tungsten compounds.
In September 2020, the government circulated a fifth draft of the Chemicals (Management and Safety) Rules, 20XX to certain industry groups. Under the fifth draft, the 750 priority substances imported in volumes above one tonne annually would have to be registered within 18 months of the Rules coming into effect unless already registered under another regulation in India. The only substance containing tungsten on the priority list is “Cadmium oxide (CdO), solid soln with magnesium oxide, tungsten oxide (WO3) and zinc oxide”. Cobalt powder is on the list of Hazardous Chemicals.
Japan
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 requested that Japanese companies (and importers) provide 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 water soluble 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.
In March 2023, tungsten( VI) oxide (CAS: 1314-35-8) was added to the list of substances subject to mandatory SDS and labeling requirements under the Industrial Safety and Health Act (ISHL). The proposed date of enforcement for substances on Appendix 2, which included tungsten (Vi) oxide, is April 2026.
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.
In March 2020, ITIA was advised by a member company that the Ministries of Health, Labour and Welfare, Economy, Trade and Industry, and Environment in Japan had published a draft report on the Designation of Class 1 and Type 2 Designated Chemical Substances. In the draft report, tungsten carbide is listed as a Class 1 carcinogenic and Class 1 dermal and skin sensitizer. ITIA submitted comments to the Japanese authorities stating that (1) there is no carcinogenic or sensitization evidence available for tungsten carbide and, (2) it is likely that these hazards are assigned to WC because of its association with cobalt (carcinogenic and sensitizer) in hard metal. In June 2020, ITIA was advised that tungsten carbide had been successfully removed from the list of carcinogens and sensitizers.
The Japanese Ministry of Health, Labor and Welfare maintains a searchable database of model SDS and Label information on chemical substances. The database includes entries for sodium tungstate, tungsten trioxide, tungsten and tungsten hexafluoride.
The Japanese National Institute of Technology and Evaluation (NITE) maintains a comprehensive searchable database, the NITE Chemical Risk information Platform, that provides information on risk assessments and laws and regulations on chemical substances. A search of the NITE database for "tungsten" yielded 325 hits. Similar chemical specific information can also be found by searching the ASEAN-Japan Chemical Safety Database.
Korea-REACH
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.
As of May 2020, manufactures and importers pre-registered nearly 17,000 substances, including many tungsten substances. Complete registrations must be submitted before the following deadlines:
- 31st December 2021 for 1000+ t/year and CMR substances ≥1 t/y
- 31st December 2024 for 100-1000 t/y
- 31st December 2027 for 10-100 t/y
- 31st December 2030 for 1-10 t/y
The searchable National Chemicals Information System database provides basic information on chemical substances and classification of hazardous chemicals in order to support industry implementation of the “Act on Registration and Evaluation of Chemical Substances” and the “Chemical Substance Management Act”, which have been in effect since 1 January 2015. It also provides unified information to the public by integrating and providing information such as test data.
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 No 7759-01-5); Lead tungsten oxide (CAS No 12737-98-3); and Cobalt metal with tungsten carbide (CAS Nos 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. In November 2021, MOE amended the information disclosure rules under CCA to cover priority chemical substances. MOE will now publicly release business and chemical information on priority chemical substances obtained from the survey on safety and discharge of chemicals conducted by National Institute of Chemical Safety (NICS).
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.
Malaysia
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.
Russia
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 Russian Ministry of Industry and Trade has published a consolidated transitional inventory of chemicals. The inventory is open for submissions from companies based in Russia, and it will inform the Eurasian technical regulation on chemical products TR EAEU 04/2017, which is often referred to as Eurasia-REACH. An extended deadline for submitting notifications to the inventory has been set for 1 August 2020. The searchable inventory currently contains 58 inorganic and organic tungsten compounds.
Taiwan
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.
Thailand
Thailand's Department of Industrial Works has issued its first Inventory of Existing Chemicals. A search of the Inventory found the following inorganic tungsten substances: tungsten, tungsten trioxide, tungsten disulfide, cesium tungstate, calcium tungstate and sodium tungstate. Chemicals not listed on the Inventory are considered new chemicals. Companies doing business in Thailand should consult the inventory to confirm the status of their chemicals.
United States
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.
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 its compounds including WC. ITIA submitted a 2nd response to ACGIH 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 cobalt and compounds on the Notice of Intended Change list. The proposal is for a TLV-TWA of 0.02 mg/m3, as cobalt, inhalable particulate matter. While the TLV value is the same as the current TV, the designation of "inhalable" fraction is new. Cobalt and compounds were also given the respiratory and skin sensitizer 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.
Drink Water Contaminant Candidate List 5, EPA, US
On July 19, 2021, EPA published the Draft Fifth Contaminant Candidate List (CCL 5). Tungsten is included in the draft CCL. The CCL is a list of contaminants that are currently not subject to any proposed or promulgated national primary drinking water regulations, but are known or anticipated to occur in public water systems. Contaminants listed on the CCL may require future regulation under the Safe Drinking Water Act (SDWA). ITIA will monitor this program for any potential regulatory developments related to tungsten.
On 14 November 2022 EPA announced the availability of the Final Fifth Contaminant Candidate List (CCL 5 ). Tungsten was retained on the final list. Contaminants on the CCL are evaluated based on health effects and occurrence information and those contaminants with sufficient information to make a regulatory determination are then evaluated based on the in Safe Drinking Water ACT to determine whether a regulation is required or not required.
ITIA provided comments on the Draft CCL 5 noting that data from the NTP sodium tungstate studies (see below) were not included in the determination to place tungsten on the draft CCL 5. EPA responded that the Agency would have the opportunity to examine tungsten’s entire toxicity database, including recently published toxicological information such as the NTP Technical Report on Sodium Tungstate studies, during the Regulatory Determination process. The Technical Support Documents for the Final Fifth Contaminant Candidate List can be found on the EPA CCL website.
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). 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. Tungsten is not currently included in its list of Program Activities.
On 14 November 2022 the US Environmental Protection Agency (EPA) announced the availability of the Integrated Risk Information System (IRIS) Assessment Plan and Systematic Review Protocol for Inhalation Exposure to Cobalt and Compounds (Cancer). Specifically, the assessment plan outlines the objectives for the IRIS assessment and the type of evidence considered most pertinent to address the scoping needs. The systematic review protocol describes the methodology of how the assessment will be conducted, including dose-response considerations. EPA is releasing this IRIS assessment plan and systematic review protocol for a 30-day public comment period which runs from 14 November 2022 to 14 December 2022. Supplemental Information and methods for submitting comments may be found in the 14 November 2022 Federal Register announcement.
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. Further information on the Estrogen Disruptor program can be found on the EPA website.
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.
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.
In October 2022 the US EPA issued a Compliance Advisory clarifying that mixed metal oxides, which include Cathode Active Materials (CAMs) and modified CAMs, are chemical substances subject to the Toxic Substances Control Act (TSCA). EPA also reaffirmed that modified CAMs are not considered mixtures and are chemical substances subject to TSCA. Mixed metal oxides have numerous electrical applications in batteries, including lithium-ion batteries used in electric vehicles and renewable energy storage, sensors, biosensors, superconductors, semiconductors as well as use as catalysts, adsorbents, and in ceramics. Modified CAMs include small amounts of certain metal dopants such as aluminum, boron, tungsten, titanium, magnesium, zirconium, or niobium oxide to improve performance. Anyone who plans to manufacture (including import) a mixed metal oxide, including a CAM or modified CAM, that is not on the TSCA Inventory must comply with the TSCA Premanufacture Notification 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
Sodium tungstate was nominated for testing under the National Toxicology Program by the Center of Disease Control, National Center for Environmental Health in 2002. The testing program included a 3-month dose range finding study and a definitive 2-year drinking water study using rats and mice exposed to sodium tungstate dihydrate via drinking water. The studies in rats included a perinatal component in which female rats were exposed throughout gestation and lactation and first-generation offspring continued in the study after weaning. In the 3-month studies the animals were exposed to 125, 250, 500, 1000, or 2000mg/L; in the 2-year studies the rats were exposed to 250, 500, or 1000 mg/L and mice to 500, 1000 or 2000 mg/L.
The NTP issued the final report of its findings in November 2021. The overall conclusions (which were ratified by a review panel on April 2, 2021) from the studies with respect to the carcinogenic potential of sodium tungstate at the exposure concentrations are as follows:
- There was no evidence of carcinogenic activity of sodium tungstate dihydrate (ST) in male rats.
- There was equivocal evidence of carcinogenic activity of ST in female rats.
- There was equivocal evidence of carcinogenic activity of ST in the male mice.
- There was no evidence of carcinogenic activity of ST in the female mice
(Note: equivocal evidence of carcinogenicity is concluded when the studies are interpreted as showing a marginal increase of neoplasms that may be chemical related.)
Details of the studies and findings can be found in NTP Technical Report TR 599: Toxicology and Carcinogenesis Studies of Sodium Tungstate Dihydrate (Drinking Water Studies).
In addition to 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 can be searched on the NTP substance search page.
Agency for Toxic Substances and Disease Registry (ATSDR), US
Toxicological Profiles (Tox Profiles) are published by ATSDR and provide a compilation of toxicological information on a given substance. The Profiles are peer-reviewed and are intended to reflect an evaluation, summary, and interpretation of available toxicological and epidemiological information on a substance. A Toxicological Profile for Tungsten was initially published in 2005, with an Addendum published in 2015. Also in 2015, ITIA staff used updated data to published a peer reviewed paper entitled: An update to the toxicological profile for water-soluble and sparingly soluble tungsten substances. In 2016, ATSDR staff published ATSDR evaluation of health effects of tungsten and relevance to public health.
On 9 February 2023 ATSDR announced the availability of a draft Toxicological Profile for Cobalt with public comments due on or before 10 May 2023.
Food and Drug Administration
The U.S. FDA maintains an Inventory of Effective Food Contact Notifications. The Inventory contains 24 tungsten substances, mainly tungsten carbide alloys, but also includes tungsten oxide (CAS Reg. No. 39318-18-8) and tungsten suboxide (CAS Reg. No. 12037-57-9)
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.
Vietnam, National Chemicals Inventory
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.
Vietnam also maintains an extensive searchable National Chemical Database System which lists numerous tungsten substances.
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.
// ]]>