Studies indicate that tungsten has a low potential to cause harm to animals and humans at environmentally relevant levels.
In this section:
Environmental occurrence
Tungsten is a relatively rare element ranking 56th in crustal abundance, which is estimated to be 1.25 ppm (parts per million) in the continental crust. Urban soils are estimated to be slightly higher at 2.9 ppm[1].
Higher soil concentrations are expected in areas of tungsten mineralization, which is generally associated with mountain belts as, for example, in the Alpine-Himalayan and the circum-Pacific Mountain belts in the Far East, western North America and South America.
Higher localized concentrations can occur in soil and water due to natural mineral weathering, mining, and processing activities, and to a lesser extent, the use of tungsten products.
[1] https://en.wikipedia.org/wiki/Abundances_of_the_elements_(data_page) accessed June 24, 2023.
Exposure
One can be exposed to low levels of tungsten by breathing air, drinking water, or eating food that contains tungsten.
At tungsten manufacturing facilities, workers may be exposed to tungsten, tungsten compounds and other metals during powder handling and metal forming operations. For this reason, risk management measures, such as local exhaust ventilation, enclosures, respiratory protective devices, and other personal protective equipment, should be utilized during those operations.
The tungsten consumer products used by the public and commercial users are typically in the form of articles of tungsten metal, tungsten carbide and other tungsten alloys. The normal and intended use of these articles is expected to produce little or no exposure to the user.
One can be exposed to low levels of tungsten by breathing air, drinking water, or eating food that contains tungsten.
Health and Environmental Effects
Research on the health and environmental effects of tungsten has been conducted by various national and international organizations. While all chemicals and metals can cause adverse effects at high enough concentrations, these studies indicate that tungsten has a low potential to cause harm to animals and humans at environmentally relevant levels. As with all metals, appropriate care must be exercised when processing and using tungsten and tungsten substances.
Although a high-density metal, tungsten’s toxicological profile does not compare to highly toxic heavy metals such as mercury, lead, or cadmium. However, in the occupational setting, exposure to the combination of tungsten carbide and cobalt particles can cause a rare lung condition, known as Hard Metal Lung Disease (lung pneumoconiosis) in sensitive individuals.
Studies indicate that tungsten has a low potential to cause harm to animals and humans at environmentally relevant levels.
University of Pittsburgh Center for Occupational Biostatistics and Epidemiology study
In the largest epidemiological study of hard metal workers, the University of Pittsburgh Center for Occupational Biostatistics and Epidemiology coordinated studies involving researchers from ten different institutions in Europe and the US. Based on the pooled data, the researchers found “no evidence that duration, average intensity or cumulative exposure to tungsten, cobalt, or nickel, at levels experienced by the workers examined, increases lung cancer mortality risks”. They also found “no evidence that work in these facilities increased mortality risks from any other causes of death”.
US National Toxicology Program study
An extensive two-year study of the effects on sodium tungstate in drinking water in rats and mice was conducted by the US National Toxicology Program. With respect to cancer, the NTP concluded there was no evidence for cancer in male rats or female mice and only marginal evidence in female rats and male mice that may have been due to the exposure. With respect to reproductive toxicity, the study found no significant effects on reproductive performance.
Tungsten health and safety
The following publications provide more in-depth information on tungsten’s toxicological profile.
An update to the toxicological profile for water-soluble and sparingly soluble tungsten substances
Article published in Critical Reviews in Toxicology (2015)
DownloadHazard Classifications
To assist its members and the industry as a whole, ITIA set up the Tungsten Consortium to compile the necessary registration dossier required by the EU REACH regulations. After reviewing and assessing relevant hazard data, the Technical Committee of the Tungsten Consortium arrived at the following hazard classifications for the major tungsten substances found in commerce in accordance with Classification, Labelling and Packaging Regulation (EC 1272/2008):
Substance
Hazard Class
(EC 1272/2008)
Hazard Warning
Ammonium Metatungstate
Not classified
None
Sodium Tungstate
- Flammable solid 1
- Self-heating 2
- Flammable solid
- Self-heating in large quantities; may catch fire
Tungsten Powder ≤ 5.25 µm
Flammable solid 1
Flammable solid
Tungsten Powder > 5.25 – < 9 µm
Flammable solid 2
Flammable solid
Tungsten Powder ≥ 9 µm
Not classified
None
Tungsten Blue Oxide
Not classified
None
Tungsten Carbide
Not classified
None
Tungsten Disulphide
Not classified
None
Tungsten Trioxide
Not classified
None
Regulations
ITIA HSE Committee monitors national and international regulations and proposals that may impact the tungsten industry, particularly in member company countries.
Where appropriate, ITIA works closely with regulatory agencies by providing information and comments to assist in the development of reasonable measures to protect health and the environment.
Examples of some of the regulatory programmes ITIA monitors include occupational exposure limits, acceptable levels in environmental media, risk assessments, and chemical control laws applicable to tungsten.
How ITIA can help
Searchable HSE literature database
ITIA has produced a Database with easy access to the literature on tungsten and its compounds in biology and the environment and is the first port of call for those seeking information on tungsten in biology, health and ecological effects, occurrence and concentrations in the environment, and potential beneficial applications for tungsten in medicine and environmental protection.
Copyright images courtesy of: V Mittenzwei