Substances of Very High Concern - Borates

Statement on Substances of Very High Concern - Borates

This statement concerns the following Rio Tinto Borates’ (RTB) products:

Substance RTB Product
Boric acid Boric acid MG
(EC 233-139-2) Optibor®
  Solubor® DF (also contains disodium tetraborate)
  Polybor® DF (also contains disodium tetraborate)
Disodium tetraborate    Borax decahydrate
(EC 215-540-4) Dehybor®
  Granubor® Natur
Diboron trioxide Boric oxide
(EC 215-125-8)  
Disodium octaborate Polybor®
(EC 234-541-0) Solubor®

Boric acid, disodium tetraborate, diboron trioxide and disodium octaborate are themselves included in the REACH Candidate List of Substances of Very High Concern (SVHC).

All of the RTB products listed above are derived from naturally occurring mineral and inorganic chemical sources, and are produced in a simple aqueous process. As a consequence of their natural origin, cadmium can be present as one of the metal impurities in extremely small quantities. Cadmium was included in the Candidate List in June 2013. We regularly analyse for cadmium and other metals: cadmium is reported as being present at <0.1ppm. The remaining substances listed on the Candidate List are neither used in our production processes, nor occur naturally with our ores and, whilst we do not specifically test for their presence, we do not expect them to be present in our final packaged product.

These RTB substances – boric acid, sodium tetraborates, diboron trioxide and disodium octaborate – are often used as intermediates to produce other Rio Tinto Borates products (e.g. Firebrake), and other new substances, such as glass and frits. Often, their boron content is described in terms of percentage B2O3 in the RTB product or new substance compositions. The percentage B2O3 described in these compositions is an industry-wide convention, and does not imply that B2O3, or diboron trioxide, exists as a detectable substance in these new products or substances. Thus, it is important to distinguish between the percentage B2O3 describing the composition and the substance diboron trioxide itself. Within the context of REACH, it is the substance diboron trioxide which has been identified as an SVHC, and not the percentage B2O3.

Therefore, before taking any action, identification of the product placed on the market should be confirmed and a check made to see that the use has been covered within our REACH registration dossiers for these substances. For a full list go to:

Inclusion of boric acid, disodium tetraborate, diboron trioxide and disodium octaborate on the Candidate List does not automatically trigger inclusion on the Authorisation list (Annex XIV), nor any market restrictions. It does trigger certain communication requirements and these are explained on ECHA’s website.


October 2018

U.S. Borax, part of Rio Tinto, is a global leader in the supply and science of borates—naturally-occurring minerals containing boron and other elements. We are 1,000 people serving 500 customers with more than 1,700 delivery locations globally. We supply 30% of the world’s need for refined borates from our world-class mine in Boron, California, about 100 miles east of Los Angeles.  Learn more about Rio Tinto

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