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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Additional information

One available study examined the acute toxicity effects of the test substance,disodium disilicate (delta-crystalline)in fish (Danio rerio). The LC50 was determined to be above than 500 mg/L.

The effects ofdisodium disilicate (delta-crystalline)to Algae (Scenedesmus subspicatus) were examined in two growth inhibition test studies. In both studies the NOEC (72 hour) was determined to be 18 mg/L. The EbC50 in both studies were similar (51.6 mg/L and 44.1 mg/L). In the key study higher concentrations were also examined while the pH was adjusted (to 7.6), the obtained NOEC was thereby higher, 100 mg/L.

One study examined the effect of the test substancedisodium disilicate (delta-crystalline)on micro-organisms, by means of measuring the inhibitory effect in respiration (oxygen consumption) of micro-organisms in activated sludge taken from a domestic sewage. The EC50 value obtained in the study was 720 mg/L fordisodium disilicate (delta-crystalline).

The following studies were waived:

In accordance with column 2 of REACH Annex IX, a long-term toxicity test with aquatic invertebrates and a long term toxicity test with fish (required in section 9.1.5 and 9.1.6 respectively) does not need to be conducted in accordance to the chemical safety assessment indicating thatdisodium disilicate (delta-crystalline)needs no further investigation regarding these two kind of studies. The substance is expected to have a low potential for bioaccumulation (log Kow expected3 as the substance is not soluble in octanol).In addition it was shown that disodium disilicate (delta-crystalline) is hydrolysed to water glass in aqueous solution which is identical to silicate. Therefore it can be concluded that disodium disilicate (delta-crystalline) is hydrolytically degraded to a naturally occurring substance which is widespread in nature. In addition the concentration related silicate-release of disodium disilicate (delta-crystalline) is not expected to be significantly higher than natural fluctuations in silicate levels.Thus, based on this assessment a long-term toxicity test is not scientifically justified and not in line with animal welfare.