Registration Dossier

Data platform availability banner - registered substances factsheets

Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

Key value for chemical safety assessment

Additional information

Justification for read-across

Read-across from magnesium chloride and magnesium chloride hexahydrate to magnesium carbonate is justified on the following basis.


Due to the presence of acid, mainly in the form of hydrochloric acid, in the stomach, magnesium carbonate will be converted into magnesium chloride when orally ingested. Furthermore, magnesium chloride is significantly more soluble than the carbonate salt and therefore represents the worst case in terms of its bioavailability for systemic absorption.

In addition, both salts have been shown to have no acute toxicity and do not exhibit evidence of systemic toxicity when tested at a concentration of 2000 mg/kg bw in acute oral studies.

Magnesium carbonate and magnesium chloride also occur in the natural environment and humans are widely exposed to naturally occurring magnesium carbonate and chloride, e.g. via drinking water and food on a day to day basis. Ingested magnesium, carbonate and chloride ions are actively regulated by the body. Any systemic toxicity is likely to be caused by absorption of the magnesium ion rather than either the carbonate or chloride counterions and hence studies on magnesium salts can be read across from one to the other.

Genotoxicity data

The key studies for in vitro genotoxicity were performed on the analogue substances magnesium chloride and magnesium chloride hexahydrate. The results of an in vitro gene mutation study in bacteria (Ishidate et al, 1984), two in vitro chromosome aberration studies in mammalian cells (Ishidate et al, 1984 and BSL, 2010) and an in vitro gene mutation study in mammalian cells (Oberly et al, 1982) were all negative. As detailed in the read across justification, these studies are directly applicable to magnesium carbonate. Hence magnesium carbonate is not considered to be genotoxic based on the results from in vitro studies.


No in vivo genotoxicity studies are available on either magnesium carbonate or analogue substances. However, testing is not justified based on the negative results obtained in the in vitro studies.

Short description of key information:
Magnesium carbonate is not genotoxic based on read across from analogous substances.

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

The results of an in vitro gene mutation study in bacteria, two in vitro chromosome aberration studies in mammalian cells and an in vitro gene mutation study in mammalian cells on the read-across substances magnesium chloride and mangesium chloride hexahydrate were all negative. It is concluded that magnesium carbonate is not genotoxic and does not warrant classification for mutagenicity under either the DSD or CLP.