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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

Endpoint Study Summary:




Test substance

Conc. in environment




Eichhornia crassipes(aquatic plant)


0,4 mg/L (ppm)

> 2,9 - < 6,4

Steady state (21 d). Measured in roots, stems and leafs

Chua H, 1998

Unio praesidens(clam)


200 ppm

30,74 (soft part)

4,3 (shell)

Steady state (5 d)

El-Shinawy, 1987



400 ppm

5,65 (soft part)

1,14 (shell)

Steady state (5 d)

El-Shinawy, 1987

Roccus saxatilus(bass)


0,18 µg/L

< 20


Carpenter JH, 1967

Crassostrea virginica(oyster)


0,18 µg/L



Carpenter JH, 1967

Mya arenaria(clam)



0,18 µg/L



Carpenter JH, 1967


 ·      El-Shinawy et al. reports that cerium is lowest accumulated in the soft part and shell of the clam Unio praesidens in comparison to cobalt or zinc.

·      Carpenter et al. reports a BCF of 1000 for the soft clam Mya arenaria. However, the precarious description of the experiment set up does not allow a reliable interpretation of the results.

·      The results are too divergent to confirm per weight of evidence that “Although cerium may bioaccumulate in aquatic organisms, there is no evidence that it may become magnified along food chains due to the low bioaccumulation factors”. However, in general Ce bioaccumulation seems to be relatively low and the BCF observed for the clam Mya arenaria may not be representative of other bivalves or aquatic organisms.


Observations of the cerium content in natural waters may be of relevance due to the accumulation of cerium radioisotopes. Radioactive cerium enters the marine environment through world wide fallout and effluent discharged from reprocessing of the irradiated fuels (Borkar, 1979). However, this is not an intended use identified in this registration. Cerium is being registered here for alloying purposes. According to the type of articles into which cerium is eventually processed (see uses section) no exposure in the aquatic compartment is expected.

Therefore, “direct and indirect exposure of the aquatic compartment is unlikely" and this endpoint can be waived.