Barium chloride

Endpoint summary

Description of key information

Acute oral toxicity: LD50 ≥ 100 till ≤ 300 mg/kg bw.
Acute dermal toxicity: derogation statement included; according to SIAR 2008 an LD50 > 2000 mg/kg was stated in the NIAR report 2008
Acute inhalation toxicity: LC50 > 1 mg/L.

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Quality of whole database:

GLP guideline study of 2010

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Additional information

Acute oral toxicity
There are three reliable studies for acute oral toxicity testing (Müller, 1983, Borzelleca, 1988 and Tardiff, 1980). All studies were used in a weight of evidence approach. The study performed by Müller, 1983 results in an LD₅₀of 645 mg BaCl₂/kg bw (male/female), the study performed by Borzelleca in 1988 leads to an LD50 >100 and <300 mg/kg bw. whereas the study conducted by Tardiff 1980 results in an LD50 of 300 mg/kg bw.

Acute dermal toxicity

Testing for acute toxicity of barium dichloride via the dermal route is not required according the criteria laid down in Annex VIII, point 8.5 of REACH (see IUCLID section 7.2.3).

However, according to the SIAR 27 prepared for barium dichloride, an acute dermal toxicity study on barium dichloride was conducted according to OECD 402, in compliance with GLP. In this study, the dermal LD50 was greater than 2000 mg BaCl2/kg bw in rats. Nevertheless, primary data could not be made available by the registrant.

Acute inhalation toxicity
There is only one study on acute toxicity via inhalation available. This study was performed with a limit concentration of 1.1 mg/L barium dichloride dihydrate which relates to a concentration of 0.94 mg/L barium dichloride. Exposure to 1.1 mg/L of barium chloride dihydrate resulted in significant signs of toxicity (mortality of one male, severe and persisting clinical signs) indicating that significant mortality could be expected at the next higher exposure level of 5 mg/L. Due to animal welfare reasons, it was therefore decided not to expose animals to a higher concentration. Instead, since according to regulation (EC) 1272/2008 the threshold value for LC50 is >= 1 mg/L, it can reasonably be stated that the LC50 of barium dichloride is > 1 mg/L.

According to the Regualtion (EC) No 1272/2008 on classification, labelling and packaging of substances and mixtures, barium chloride dihydrate should be classified as Category 4 and should be labelled as H332: Harmful if inhaled.

Also, according to 67/548/EC and subsequent regulations, barium chloride dihydrate is classified as harmful by inhalation

Justification for classification or non-classification

Acute oral toxicity
There are three reliable studies for acute oral toxicity testing (Müller, 1983, Borzelleca, 1988 and Tardiff, 1980). All studies were used in a weight of evidence approach. The study performed by Müller, 1983 results in an LD₅₀of 645 mg BaCl₂/kg bw (male/female), the study performed by Borzelleca in 1988 leads to an LD50 >100 and <300 mg/kg bw whereas the study conducted by Tardiff 1980 results in an LD₅₀of 300 mg/kg bw. Despite the fact that Müller derived an LD₅₀> 300 mg BaCl₂/kg bw. there are two studies result in an LD₅₀<300 mg BaCl2/kg. Taken into consideration too that BaCl2 is legally classified as toxic via ingestion (Regulation (EC) 1272/2008 Annex VI; Index-no: 056-004-00-8 / ATP inserted: 22 / ATP last update 25) the registrant proposes C&L of barium dichloride as "acute tox 3"; H301 (toxic if swallowed) according to GHS.

Specific target organ toxicant (STOT) – single exposure: oral

The classification criteria according to regulation (EC) 1272/2008 as specific target organ toxicant (STOT) – single exposure, oral are not met since no reversible or irreversible adverse health effects were observed immediately or delayed after exposure and no effects were observed at the guidance value, oral for a Category 1 classification of 300 mg/kg bw and at the guidance value, oral for a Category 2 classification of 2000 mg/kg bw in addition to this effects which were responsible for the death of the animals. No classification required.

Acute dermal toxicity
According to the SIAR 27 prepared for barium dichloride, an acute dermal toxicity study on barium dichloride was conducted according to OECD 402, in compliance with GLP. In this study, the dermal LD50 was greater than 2000 mg BaCl2/kg bw in rats. It should be noted here that the primary data could not be made available by the registrant but using the secondary information no classification according to regulation (EC) 1272/2008 will be necessary for barium dichloride.

Acute inhalation toxicity

There is only one study on acute toxicity via inhalation available. This study was performed with a limit concentration of 1.1 mg/L barium dichloride dihydrate which relates to a concentration of 0.94 mg/L barium dichloride.Exposure to 1.1 mg/L of barium chloride dihydrate resulted in significant signs of toxicity (mortality of one male, severe and persisting clinical signs) indicating that significant mortality could be expected at the next higher exposure level of 5 mg/L. Due to animal welfare reasons, it was therefore decided not to expose animals to a higher concentration. Instead, since according to regulation (EC) 1272/2008 the threshold value for LC50is >= 1 mg/L, it can reasonably be stated that the LC50 of barium dichloride is > 1 mg/L and therefore a classification and labelling of barium dichloride as "acute tox. 4"; H332 (harmful via inhalation) according to regulation (EC) 1272/2008 will be necessary for barium dichloride.

Specific target organ toxicant (STOT) – single exposure: inhalation
The classification criteria according to regulation (EC) 1272/2008 as specific target organ toxicant (STOT) – single exposure, inhalation are not met since no reversible or irreversible adverse health effects were observed immediately or delayed after exposure and no effects were observed at the guidance value, inhalation for a Category 1 classification of <= 1 mg/L/4h and at the guidance value, inhalation for a Category 2 <= 5 mg/L/4h - > 1 mg/L/4h. No additional classification required.