Registration Dossier
Registration Dossier
Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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.
Use of this information is subject to copyright laws and may require the permission of the owner of the information, as described in the ECHA Legal Notice.
EC number: 204-468-9 | CAS number: 121-43-7
Sediment toxicity
Administrative data
Link to relevant study record(s)
Description of key information
No sediment toxicity data are available for trimethyl borate since the compound rapidly hydrolyzes in water with a half-life of less than 1 second to form methanol and boric acid. Methanol is much less toxic to sediment organisms compared to boric acid. Therefore, sediment toxicity data for boric acid was used. Three studies are available for boric acid. The geometric mean for two sediment studies was calculated, and converted to account for the boron content in trimethy borate.
Key value for chemical safety assessment
- EC10, LC10 or NOEC for freshwater sediment:
- 792 mg/kg sediment dw
Additional information
The study is not technically feasible because the test substance hydrolyzes in water with a half-life of less than 1 second to form methanol and boric acid. Methanol is much less toxic to environmental organisms compared to boric acid. Therefore, sediment toxicity data compiled on boric acid was used. The endpoints included in the dossier under environmental hazard assessment were reported from studies on the ecotoxicity of boron and various compounds, such as boric acid (H3BO3), anhydrous sodium tetraborate (Na2B4O7), and hydrated sodium tetraborates (Na2B4O7.xH2O). All endpoints were converted to concentrations of elemental boron (B) using the relative molar mass and then converted to C3H9BO3 for this IUCLID. A 2011 chronic sediment toxicity study was designated a key study for exposure of boric acid toChironomus riparius,in which the organisms were exposed to spiked sediment (the most relevant route of exposure for this sediment-dwelling organism) and reported a NOEC for mortality, developmental rate and emergence rate of 37.7 mg B/kg sediment. An additional study using the same route of exposure was available and reported a NOEC of 180 mg B/kg sediment for mortality and emergence rate. Because these studies were similar exposures using similar guidelines, the geometric mean was calculated as 82.4 mg B/kg sediment to serve as the most conservative estimate of the NOEC for sediment exposure. When converted for the boron content of the compound, this equals a concentration of 792 mg/kg for trimethyl borate. A third study was available but not included in the calculation as it was not considered as relevant because the route of exposure was via spiked water.
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.
Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.
