Heptasodium bis[4-hydroxy-5-[(2-hydroxy-1-naphthyl)azo]-3-[(2-hydroxy-3-nitro-5-sulphophenyl)azo]naphthalene-2,7-disulphonato(5-)]cobaltate(7-)

Endpoint summary

Description of key information

LD₅₀ (oral, rat) > 10000 mg/kg bw

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

10 000 mg/kg bw

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

Acute oral toxicity

The acute oral toxicity of the test item was evaluated in an experimental study equivalent to the OECD Guideline 401 (1987). A preliminary study was carried out to establish a dosing regimen: two male and two female Wistar rats were administered 10,000 mg test item/kg bw and monitored for mortality. In the main study, five male and five female Wistar rats were administered 10,000 mg test item/kg bw by oral gavage. Clinical symptoms and mortality were monitored after administration for an observation period of 14 days, thereafter all animals were submitted to necropsy and macroscopic examination.

No mortality was observed among animals in the preliminary study. In the main study, 1 male and 3 females died before the end of the observation period. The male mortality occurred 26 hours after dosing; the female mortalities occurred 5, 5 and 14 hours after dosing. Mean body weights of surviving males and females increased throughout the observation period. The LD₅₀of the test item was found to exceed 10,000 mg test item/kg body weight.

The acute oral toxicity results of Acid Black 076 can be supported by experimental data on Similar Substance 01 and Similar Substance 02.

The acute oral toxicity of Similar Substance 01 was evaluated in an experimental study according to the OECD Guideline 423 (2001). Three female Wistar rats were administered 2000 mg test item/kg bw in a 0.5% solution of CMC and deionised water by oral gavage and monitored for clinical symptoms and mortality for an observation period of 14 days. A second group of 3 female Wistar rats were administered the same dose and monitored in the same way.

No mortality was observed in either test group to the end of the observation period. Impaired general state and piloerection was observed in all animals of the first test group within 3 days of dosing and no animals of the second test group. No macroscopic pathologic abnormalities were observed in any animals. The body weight of the animals in both test groups increased within the normal range throughout the study period with two exceptions in the first test group: in these two animals, the body weights were within the normal range during the first week, but stagnated during the second week. This effect may be attributed to a normal phase of slow growth. Based on these findings, the LD₅₀(oral, rat) of the test item was found to be higher than 2000 mg/kg bw.

The acute oral toxicity of Similar Substance 02 was evaluated in an experimental study according to the OECD Guideline 401 (1987). 5 male and 5 female Wistar rats were administered 2000 mg test item per kg of body weight by oral gavage and monitored for mortality and clinical signs for 14 days. Body weight was observed on days 1, 8 and 15 after administration. At the end of the observation period, all animals were anesthetised by an intraperitoneal injection (equivalent to at least 320 mg sodium pentobarbitone/kg body weight) and sacrificed by exsanguination. The animals were examined macroscopically.

No mortality, clinical signs or macroscopic findings were observed. The rate of body weight gain during the observation period was not affected by treatment with the test item. Based on these findings, the LD₅₀(oral, rat) was found to be higher than 2000 mg/kg bw.

Justification for classification or non-classification

According to the CLP Regulation (EC) No 1272/2008, acute toxicity is defined as “those adverse effects occurring following oral or dermal administration of a single dose of a substance or a mixture, or multiple doses given within 24 hours, or an inhalation exposure of 4 hours”. A substance can be allocated to one of four toxicity categories based on acute toxicity by the oral, dermal or inhalation route. The numeric criteria based on the acute toxicity estimates (ATE) in mg/kg bodyweight are presented in Annex I, Part 3, Table 3.1.1.

Based on acute oral toxicity data > 2000 mg/kg bw, no classification for acute oral toxicity is warranted under the CLP Regulation (EC) No. 1272/2008.