Fatty acids, C16-18, barium salts

Endpoint summary

Description of key information

Fatty acids, C16-18, barium salts is expected to be harmful if swallowed. On other other hand fatty acids, C16-18, barium salts is not expected to show acute toxic effects via the inhalation and dermal route. 

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:

no adverse effect observed

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Additional information

The hazard information on the acute toxicity of fatty acids, C16 -18, barium salts is addressed by specific read-across information on barium stearate. However, since the overall quality of that information is limited, read-across hazard information related to the soluble barium dichloride is included for consistency reasons.

Acute oral toxicity

A highly reliable key study (RL=1 or 2) is not available on the acute oral toxicity of fatty acids, C16 -18, barium salts. Instead data on acute oral toxicity was obtained by read-across to the substance barium distearate. Since also no highly reliable key study (RL=1 or 2) is available for this substance, a weight-of-evidence approach is applied using less reliable data that was obtained from a factual database (RTECS, 1997) and a publication (Schmidt, 1975). Besides the effect levels (LD50), the animal species and the route of exposure, no further information could be obtained from the factual database. The publication showed significant methodological deficiencies. Despite being of low relevance for the hazard assessment and the classification, results for intraperitoneal exposure are also reported for the sake of completeness (please refer for these entries to section 7.2.4 Acute toxicity: other routes):

 

Table: Summary of LD50 values of barium distearate (route of exposure: oral)

Species	LD50 value	Reference
Rat	3400 mg/kg bw	Schmidt (1975)
	2506 mg/kg	RTECS (1997)
Mouse	ca. 7500 mg/kg bw	Schmidt (1975)
	1832 mg/kg	RTECS (1997)
Guinea pig	3600 mg/kg	RTECS (1997)

 

 

Table: Summary of LD50 values of barium distearate (route of exposure: intraperitoneal)

Species	LD50 value	Reference
Rat	1850 mg/kg bw	Schmidt (1975)
Mouse	319 mg/kg	RTECS (1997)

 

Considering the lowest relevant LD50 value of 1832 mg/kg (mouse, oral exposure) barium distearate should be classified as harmful if swallowed (Category 4) according to Regulation (EC) 1272/2008. Considering read-across fatty acids, C16 -18, barium salts should also be classified as harmful if swallowed (Category 4). This is in agreement with the harmonised classification for barium salts (group entry under Index No. 056 -002 -00 -7).

Acute inhalation toxicity

A highly reliable key study (RL=1 or 2) is not available on the acute inhalation toxicity of fatty acids, C16 -18, barium salts. Instead data on acute inhalation toxicity was obtained by read-across to the substance barium distearate. Since also no highly reliable key study (RL=1 or 2) is available for this substance, a weight of evidence approach is applied using less reliable data that was obtained from a factual database (RTECS, 1997) and a publication (Schmidt, 1975). Besides the lethal concentration and the route of exposure, no further information could be obtained from the factual database. The publication Schmidt, 1975 showed significant methodological deficiencies. The lethal concentration values of the two references are given in the table below:

Table: Summary of LC50 values of barium distearate

Species	LC50 value (4 hours)	Reference
Rat	>0.45 mg/L (maximum attainable concentration; LC50 value calculated using Haber's law)	Schmidt, 1975)
Mammals (species unspecified)	> 1241 mg/m^3 (LC value, not clear if LC50)	RTECS (1997)

Assuming that these two lethal concentration values were obtained using the maximum attainable concentration of the test substance, barium distearate should not be classified according to Regulation (EC) 1272/2008. Considering read-across fatty acids C16 -18, barium salts should also not be classified. This is in disagreement with the harmonised classification for barium salts (group entry under Index No. 056 -002 -00 -7), requiring Barium salts to be classified as harmful via inhalation(Category 4). Using a worst case approach, fatty acids, C16 -18, barium salts is also classified as harmful if inhaled (Category 4) due to the lack of reliable data on acute inhalation toxicity of this substance.

Acute dermal toxicity

A highly reliable key study (RL=1 or 2) is not available on the acute dermal toxicity of fatty acids, C16 -18, barium salts. Instead data on acute dermal toxicity was obtained by read-across to the substance barium dichloride. According to the SIAR 27 prepared for barium chloride, an acute dermal toxicity study on barium chloride was conducted according to OECD TG 402, in compliance with GLP. In this study, the dermal LD50 was greater than 2000 mg BaCl2/kg bw in rats. It is note 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 chloride. Using the read-across approach, fatty acids, C16 -18, barium salts should also not be classified as acute toxic via the dermal route.

Justification for selection of acute toxicity – oral endpoint
Weight of evidence information.

Justification for selection of acute toxicity – inhalation endpoint
Weight of evidence information.

Justification for selection of acute toxicity – dermal endpoint
Read-across information.

Justification for classification or non-classification

Acute oral toxicity

Considering the legal classification of barium salts (group entry under Index No. 056 -002 -00 -7) according to Regulation (EC) 1272/2008, fatty acids, C16 -18, barium salts should be classified as harmful if swallowed (Category 4) according to Regulation (EC) 1272/2008 and harmful if swallowed (Xn; R22) according to Directive 67/548 EC, which is also supported by the weight of evidence read-across acute oral toxicity information on barium stearate.

Acute inhalation toxicity

Effect levels for acute intalative toxicity of substance fatty acids, C16-18, zinc salts are above criteria values for classificaton. However, the substance is a barium salt, and thus has to be classified in accordance with tables 3.1 and 3.2 REGULATION (EC) No 1272/2008, Index No: 056-002-7 (barium salts in general) for acute inhalative toxicity (Cat 4/H332; Xn R20) according to Regulation (EC) 1272/2008 and Directive 67/548/EEC, respectively.

Acute dermal toxicity

The acute dermal toxicity for fatty acids, C16 -18, barium salts is believed to be > 2000mg/kg bw, since both constituents have shown no sign of acute dermal toxicity. Hence the substance is not to be classified according to regulation (EC) 1272/2008 or according to directive 67/548/EEC for acute dermal toxicity.