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 concentrations. Several of these studies are on-going. As with all metals, appropriate care must be exercised when processing and using tungsten and tungsten substances. 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:
|Ammonium Metatungstate||Acute oral toxicity 4||Harmful if swallowed|
|Ammonium Paratungstate||Not classified||None|
|Sodium Tungstate||Acute oral toxicity 4||Harmful if swallowed|
|Tungsten Powder (0.6-0.9µm)|| - Flammable solid 1
- Self-heating 2
| - Flammable solid
- Self-heating in large quantities; may catch fire
|Tungsten Powder <1.0µm||Flammable solid 1||Flammable solid|
|Tungsten Powder 1.0-1.5µm||Flammable solid 2||Flammable solid|
|Tungsten Powder >1.5µm||Not classified||None|
|Tungsten Blue Oxide||Not classified||None|
|Tungsten Carbide||Not classified||None|
|Tungsten Trioxide||Not classified||None|
Since tungsten products in the form of articles are very hard and abrasion resistant, they can be used safely by consumers as there is very limited potential for tungsten exposure.
Tungsten is a strategic metal and, as such, sustainability of tungsten resources is critical. Scrap recycling is an important factor in the world’s tungsten supply. Due to its high tungsten content by comparison to ore, tungsten scrap is a valuable raw material It is estimated that today some 35% is recycled and the tungsten processing industry is able to treat almost every kind of tungsten-containing scrap and waste to recover tungsten and, if present, other valuable constituents. In addition, by-products generated during tungsten production, such as ammonia, are routinely recycled.
Tungsten compounds are used in several applications that provide environmental benefits. For example, various tungsten species are used to prepare catalysts for use in the petrochemical industry. These catalysts serve to improve the yields of highly desirable components in gasoline and reduce environmentally harmful by-products, such as sulfur and nitrogen compounds. More recently tungsten compounds have found increasing use as a catalyst for the reduction of nitrogen oxide emissions from exhaust gases. Tungsten compounds also have potential clean energy applications such as photovoltaic cells and fuel cell technologies. For more information on Tungsten for a Cleaner Environment, see ITIA Newsletters - June 2004 and December 2004.
ITIA members are encouraged to login the ITIA Members' Area and find more details on the ITIA HSE Work Programme webpages and HSE literature database.