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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Description of key information

  • Acute oral toxicity: LD50: 7 mg sodium selenite /kg bw for rats dosed with sodium selenite by gavage.
  • Acute inhalation toxicity: LC50 (4 h) > 0.052 and ≤ 0.51 mg sodium selenate /L, for Wistar rats exposed to sodium selenate, according to OECD 403 (Acute inhalation toxicity), GLP compliant

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion
Endpoint conclusion:
adverse effect observed
Dose descriptor:
7 mg/kg bw
Quality of whole database:
Literature data of good quality (Klimisch 2).

Acute toxicity: via inhalation route

Endpoint conclusion
Endpoint conclusion:
adverse effect observed
Dose descriptor:
52 mg/m³ air
Quality of whole database:
GLP study of hight quality (Klimisch 1)

Acute toxicity: via dermal route

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

For acute oral toxicity a reliable study on rats dosed with sodium selenite by gavage is available, which stated a LD50 of 7 mg sodium selenite /kg. Acute toxicity after inhalation is derived from a reliable study on rats using disodium selenate as testing substance with a LC50 (4 h) of above 0.052 up to 0.51 mg sodium selenate /L.

All Selenium compounds (organic and inorganic), do share the very same metabolic fate in that after their resorption reduction to the selenide moiety [Se2-] takes place which is the single common precursor for its further metabolic conversion (Ohta and Suzuki (2008)). From this follows, that data for disodium selenite fits also for the toxicological assessment of sodium selenate.

Moreover, the water solubility, as prerequisite of the bioavailability of such inorganic substances, is comparable for sodium selenate and sodium selenite:

water solubility of sodium selenite: 800 -900 g/L

water solubility of disodium selenate: 585 g/L

No data are available for the dermal route, hower dermal is not considered to be the major route of exposure for sodium selenate. Furthermore, the physicochemical and toxicological properties do not suggest potential for significant rate of absorption through the skin.

No data gaps were identified. The available data are adequate for risk assessment and classification and labelling purposes.

Justification for selection of acute toxicity – oral endpoint
The key study is of good quality (Klimisch 2).

Justification for selection of acute toxicity – inhalation endpoint
The key study is of high quality (Klimisch 1)

Justification for classification or non-classification

Selenium compounds are subject to legal binding classification. Based on harmonised classification, CLP Regulation (EC) No 1272/2008, Annex VI, table 3.1 Selenium has to be classified and labelled as follows:

Acute Tox. 3* - H301: Toxic if swallowed.

Acute Tox. 3* - H331: Toxic if inhaled

This classification is a minimum classification which needs to be reevaluated on basis of acutal data set.

According to the CLP Regulation (EU GHS Regulation (EC) No 1272/2008) the following classification and labelling is required for sodium selenate, based on acute oral toxicity value of LD50 = 7 mg/kg bw and an acute inhaltion toxicity value of LC50 > 0.052 and ≤ 0.51 mg/L air.

Acute Tox. 2     H300: Fatal if swallowed.

Acute Tox. 2     H330: Fatal if inhaled.