Registration Dossier

Administrative data

Description of key information

One study is available for acute oral toxicity (k_Müller_1983_BaS) conducted with barium sulfide in accordance with OECD 401. An LD50 of 307 mg/kg bw has been calculated for males/females. The LD50 for males is 336 mg/kg bw and for females an LD50 of 275 mg/kg bw. has been calculated (see attachment in the IUCLID robust study summary 7.2.1). 

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion
Endpoint conclusion:
adverse effect observed
Dose descriptor:
LD50
Value:
214 mg/kg bw
Quality of whole database:
One guideline study is performed using barium sulfide as test substance, the study is rated with RL2 (reliable with restrictions)

Acute toxicity: via inhalation route

Endpoint conclusion
Endpoint conclusion:
no study available

Acute toxicity: via dermal route

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

The analytical grade of barium sulfide used for acute oral toxicity testing is given by the study sponsor with ca. 75% BaS. Other compounds/impurities (i.e., Ca and Mg minerals) are assumed to be non harmful/toxic if swallowed on a worst case basis. According to Regulation (EC) 1272/2008 chapter 3.1.3.6 the acute toxicity of mixtures could be estimated based on the following formula:

100 / ATE(mix) = Sum(n) C(i) / ATE(i)

Ci = concentration of ingredient i

i= the individual ingredient from 1 to n

n= the number of ingredients

 

Hence, for a test substance with 100% BaS an LD50 of 214 mg/kg bw can be calculated. Therefore, the study conducted by Müller, V (1983) with barium sulfide with a purity of 75% BaS is fully valid for C&L of barium sulfide as defined in section 1.2 of this registration dossier.


Justification for selection of acute toxicity – oral endpoint
One study conducted with barium sulfide is used as fully valid key study to cover the endpoint on acute oral toxicity.

Justification for classification or non-classification

According to Regulation (EC) 1272/2008 the most sensitive species should be chosen for the purposes of the Chemical Safety Assessment. Since data is available for males and females, and females are more sensitive than males, the LD50 value for females was used for classification.

Hence, the substance has to be classified as toxic if swallowed (H301) due to the fact that mortality was observed at dose levels of < 300 mg/kg bw (LD50 female: 214 mg BaS/kg bw; purity: 100% BaS).

According to 67/548/EEC barium sulfide has to be classified as harmful if swallowed (LD50 >200 and < 2000 mg/kg bw) and labelled with Xn; R22.