Crotonaldehyde

Endpoint summary

Description of key information

Oral gavage (90 days) resulted in irritancy related effects at 5 mg/kg bw and above in rats.   Nasal lesions in the form of acute irritation were observed in females at the 5 mg/kg bw.  
Oral feed in rats (14 days) did not result in any systemic or irritancy effects at the highest dose tested (175 mg/kg bw).  

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Endpoint conclusion

Dose descriptor:

NOAEL

5 mg/kg bw/day

Additional information

Oral gavage (90 days) resulted in irritancy related effects at 5 mg/kg bw and above in rats. Nasal lesions in the form of acute irritation were observed in females at the 5 mg/kg bw. The stomach related effects are attributable to the irritancy potential of crotonaldehyde and are not considered to be systemic effects. The nasal lesions in the form of acute inflammation are more difficult to interpret. Being that the dose was oral gavage the animals would not have been exposed to crotonaldehyde via inhalation (as they would be from food or water adminsitration). It is possible that this is also a local or irritancy effect but without the full study it is not conclusive. Therefore the NOAEL for systemic toxicity (oral, repeated dose ) is 5 mg/kg bw day.

Oral feed in rats (14 days) did not result in any systemic or irritancy effects at the highest dose tested. The NOAEL in this study was 175 mg/kg bw. This study is not of the duration or quality of the oral gavage study.

There are no usable studies to determine a NOAEL/LOAEL for inhalation. The Voronin study repeatedly cited is an abstract only and the findings are not supported in any other study. Not enough data available to judge the applicability of the results. Crotonaldehdye is a highly irritating substance and in acute inhalation study excitation was seen noted often (excitation as in running around the cage, jumping - more than likely due to the irriation rather than any systemic / stimulatory effect). The change in hemoglobin levels is not reported in any other study with crotonaldehyde. This effect could also be attributed to the irritant potential of crotonaldehyde. No gross pathology or histology is available to confirm or explain this finding. No organ weights or other clinical parameters were reported in the abstract. This study is not valid for obtaining any inhalation parameters for crotonaldehyde.

Repeated dose toxicity: via oral route - systemic effects (target organ) respiratory: nose

Justification for classification or non-classification

According to criteria in reguldation (EC) No. 1272/2008, as well as the requirements of Annex VI thereof, the substance is classified as STOT RE Cat 2.