Barium 3,5,5-trimethylhexanoate

Endpoint summary

Description of key information

No acute toxicity studies with barium bis(3,5,5-trimethylhexanoate) are available, thus the acute toxicity will be addressed with existing data on the dissociation products barium and 3,5,5-trimethylhexanoic acid. According to the read-across assessment framework (RAAF), neodecanoic acid will be considered in place of 3,5,5-trimethylhexanoic acid.

Three studies with the assessment entity barium are available and used in a weight of evidence approach resulting in a LD50>100 and <300 mg/kg bw. Barium salts ((EC) No 1272/2008; Index No. 056-002-00-7) are legally binding classified for acute toxicity (oral and inhalation toxicity) category 4. A dermal study with barium dichloride, showed a LD50 value of greater than 2000 mg/kg bw. Neodecanoic acid, as representative of 3,5,5-trimethylhexanoic acid, has not shown signs of acute oral or acute dermal toxicity in experimental testing (LD50 > 2000mg/kg).

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Additional information

No acute toxicity studies with barium bis(3,5,5-trimethylhexanoate) are available, thus the acute toxicity will be addressed with existing data on the dissociation products barium and 3,5,5-trimethylhexanoic acid. According to the read-across assessment framework (RAAF), neodecanoic acid will be considered in place of 3,5,5-trimethylhexanoic acid.

Barium

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 LD50 of 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 

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.

 

Neodecanoic acid

Acute oral toxicity

Male and female rats were gavaged with neodecanoic acid at concentrations of 1, 1.5, 2, 3, or 4 ml/kg to assess acute oral toxicity.  All animals that died during the study did so within 3 days of exposure. Signs of toxicity included lethargy, hypothermia, piloerection, dyspnea, and ataxia. Based on these results, it is concluded that the LD50 is approximately 2.27 ml/kg (2066 mg/kg). 

 

Acute dermal toxicity

In a study that assessed acute dermal toxicity, male and female rats were exposed to 4 ml/kg (3640 mg/kg) neodecanoic acid via an occluded dermal patch for 24 hours. After 24 hours, the patch was removed, and clinical observations were made once daily for 9 days. There were no deaths observed in this study and there were no signs of a toxicity response.  It is concluded that the LD50 is greater than 3640 mg/kg. 

 

Barium bis(3,5,5-triemthylhexanoate)

Signs of acute dermal toxicity are not expected for barium bis(3,5,5-trimethylhexanoate), since the two assessment entities barium and neodecanoic acid have not shown signs of acute dermal toxicity in experimental testing (both LD50 > 2000mg/kg)

Three acute oral toxicity studies with the assessment entity barium are available and used in a weight of evidence approach resulting in a LD50>100 and <300 mg/kg bw. The assessment entity neodecanoic acid, as representative of 3,5,5-trimetylhexnnoic acid, has not shown signs of acute oral toxicity in experimental testing (LD50 > 2000mg/kg). The calculated acute oral toxicity for barium bis(3,5,5-trimethylhexanoate) as category 4 for acute oral toxicity is in line with the legally binding harmonised classification of barium salts ((EC) No 1272/2008; Index No. 056-002-00-7). For further information on the toxicity of the assessment entities, please refer to the relevant sections in the IUCLID and CSR.

Justification for classification or non-classification

The calculated oral LD50 for barium bis(3,5,5-trimethylhexanoate) is LD50 ≥ 330 mg/ kg bw, hence the substance is classified in accordance with the legally binding classification for acute toxicity category 4 (oral and inhalation toxicity) of barium salts ((EC) No 1272/2008; Index No. 056-002-00-7).

The calculated dermal LD50 for barium bis(3,5,5-trimethylhexanoate) is > 2000mg/kg, thus the substance is not to be classified according to regulation (EC) 1272/2008 for acute dermal toxicity.