Chenodeoxycholic acid

Endpoint summary

Description of key information

The experimentel oral LD50 in rats is 4000 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:

4 600 mg/kg bw

Quality of whole database:

It was not possible to assess the quality of the literature study because it was not possible to consult the original study report, but the LD50 value was reported by a validated toxicological database (RTECS) and the results of the QSAR study carried out with ACD/Tox Suite confirm that the value of 4000 mg/kg bw is reliable.

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

An experimental oral LD₅₀in rats value is available from literature. The value (LD₅₀: 4000 mg/kg bw) agrees to the predicted oral LD₅₀value in rats, calculated by ACD/Tox Suite (LD₅₀: 2200 mg/kg bw). No values are available for inhalation and dermal routes, and no experimental values have been produced, because not necessary, considering that exposure by these routes is not significant and unlikely. A subcutaneous LD₅₀in rabbits for the similar substance ursodeoxycholic acid is available in literature and according to this value (LD₅₀: > 2000 mg/kg bw) it can be supposed that acute dermal toxicity will be low.

Justification for selection of acute toxicity – oral endpoint
Although it was not possible to assess the quality of the information reported in the study, the oral LD50 value reported for rats is consistent with the predicted value of the QSAR study carried out with ACD/Tox Suite.

Justification for selection of acute toxicity – inhalation endpoint
No experimental data was deemed necessary for dermal route, because skin contact is unlikely and not significant. The substance is only used at industrial sites by trained workers, wearing suitable protective gloves and clothes, under specific risk control measures (as described in the Exposure Scenarios). Moreover, no dermal toxicity is expected on the basis of the available data on subcutaneous acute toxicity in rabbits for a similar substance (ursodeoxycholic acid, LD50 > 2000 mg/kg bw).

Justification for selection of acute toxicity – dermal endpoint
No experimental data was deemed necessary for dermal route, because skin contact is unlikely and not significant. The substance
is only used at industrial sites by trained workers, wearing suitable protective gloves and clothes, under specific risk control
measures (as described in the Exposure Scenarios). Moreover, no dermal toxicity is expercted on the basis of the available data on subcutaneous acute toxicity in rabbits for a similar substance (ursodeoxycholic acid, LD50 > 2000 mg/kg bw).

Justification for classification or non-classification

In conclusion, basing on the available toxicological information, no classification for acute toxicity by oral, inhalation and dermal routes is deemed necessary for chenodeoxycholic acid, according to Regulation 1272/2008/EU.