Registration Dossier
Registration Dossier
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EC number: 200-158-2 | CAS number: 52-90-4
Endpoint summary
Administrative data
Description of key information
In an oral toxicity study for repeated exposure in rats, L-cysteine was administered with doses of 500, 1000, or 2000 mg / kg / day for 28 consecutive days (6 male rats / dose).
The control group was treated with 0.5% of methylcellulose. The toxicological observations showed renal lesions and increase of basophilic tubules in all treated animals.
At 1000 and 2000 mg / kg / day indicative symptoms of focal erosion were observed in the mucosa of the stomach. Finally, an increase in reticulocyte counting was found in rats treated with 2000 mg / kg / day of L-cysteine.
In this study, the NOAEL was estimated <500 mg / kg / day.
Key value for chemical safety assessment
Additional information
Bibliographic source:
Yusuke S, Ryosei S, Yasuhiro M, Takeshi M. Comparisons of L-cysteine and D-cysteine toxicity in 4-week
repeated-dose toxicity studies of rats receiving daily oral administration. Journal of Toxicologic Pathology 2017.
Justification for classification or non-classification
Conclusive but not sufficient for classification
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