Registration Dossier
Registration Dossier
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EC number: 200-158-2 | CAS number: 52-90-4
Endpoint summary
Administrative data
Key value for chemical safety assessment
Effects on fertility
Link to relevant study records
- Endpoint:
- toxicity to reproduction
- Data waiving:
- study scientifically not necessary / other information available
- Justification for data waiving:
- other:
- Reproductive effects observed:
- not specified
Reference
Effect on fertility: via oral route
- Endpoint conclusion:
- no adverse effect observed
Effect on fertility: via inhalation route
- Endpoint conclusion:
- no study available
Effect on fertility: via dermal route
- Endpoint conclusion:
- no study available
Additional information
IUCLID section 7.8.1:
L-Cystine (and L-Cysteine respectively) is an amino acid that is required for normal functioning of humans. The substance is of low toxicological activity and subject to homeostasis. Therefore, reprotoxic effects are not expected for L-Cystine and no test is required for this substance. There is sufficient weight of evidence for the absence of reprotoxic effects. A screening for reproductive toxicity (REACH Annex VIII No. 8.7.1) as well as any study on reproductive toxicity as REACH Annex IX no. 8.7 are not to be conducted in accordance with REACH Annex XI no. 1.2. and for reasons of animal welfare: "Where sufficient weight of evidence for the presence or absence of a particular dangerous property is available, further testing on vertebrate animals for this property shall be omitted..."
IUCLID section 7.8.2:
L-Cystine (and L-Cysteine respectively) is an amino acid that is required for normal functioning of humans. The substance is of low toxicological activity and subject to homeostasis. Therefore, reprotoxic effects are not expected for L-Cystine and no test is required for this substance. There is sufficient weight of evidence for the absence of reprotoxic effects. A screening for reproductive toxicity (REACH Annex VIII No. 8.7.1) as well as any study on reproductive toxicity as REACH Annex IX no. 8.7 are not to be conducted in accordance with REACH Annex XI no. 1.2. and for reasons of animal welfare: "Where sufficient weight of evidence for the presence or absence of a particular dangerous property is available, further testing on vertebrate animals for this property shall be omitted..."
Short description of key information:
Waiver: L-Cystine (and L-Cysteine respectively) showed no effects on the reproductive organs in general repeated dose toxicity studies. There have been numerous studies in experimental animals in which diets containing excess or inadequate levels of specific amino acids have been investigate. However these have been designed to investigate nutritional and/or metabolic consequences and not the possible adverse effects at high doses. It can be stated that amino acids are generally quickly absorbed and utilised in the mammal metabolism. Excess amino acid can be degraded, utilised as synthetic starting material for endogenous substances or as energy and excreted via effective metabolic pathways and will not accumulate.
There is sufficient weight of evidence for the absence of reprotoxic effects. A screening for reproductive toxicity (REACH Annex VIII No. 8.7.1) as well as any study on reproductive toxicity as REACH Annex IX no. 8.7 are not to be conducted in accordance with REACH Annex XI no. 1.2. and for reasons of animal welfare: "Where sufficient weight of evidence for the presence or absence of a particular dangerous property is available, further testing on vertebrate animals for this property shall be omitted..."
Effects on developmental toxicity
Description of key information
Waiver: L-Cystine (and L-Cysteine respectively) showed no effects on the reproductive organs in general repeated dose toxicity studies. There have been numerous studies in experimental animals in which diets containing excess or inadequate levels of specific amino acids have been investigated. However these have been designed to investigate nutritional and/or metabolic consequences and not the possible adverse effects at high doses. It can be stated that amino acids are generally quickly absorbed and utilised in the mammal metabolism. Excess amino acid can be degraded, utilised as synthetic starting mate-rial for endogenous substances or as energy and excreted via effective metabolic pathways and will not accumulate.
There is sufficient weight of evidence for the absence of reprotoxic effects. A screening for reproductive toxicity (REACH Annex VIII No. 8.7.1) as well as any study on reproductive toxicity as REACH Annex IX no. 8.7 are not to be conducted in accordance with REACH Annex XI no. 1.2. and for reasons of animal welfare: "Where sufficient weight of evidence for the presence or absence of a particular dangerous property is available, further testing on vertebrate animals for this property shall be omitted..."
Link to relevant study records
- Endpoint:
- developmental toxicity
- Data waiving:
- study scientifically not necessary / other information available
- Justification for data waiving:
- other:
- Abnormalities:
- not specified
- Developmental effects observed:
- not specified
Reference
Effect on developmental toxicity: via oral route
- Endpoint conclusion:
- no adverse effect observed
Effect on developmental toxicity: via inhalation route
- Endpoint conclusion:
- no study available
Effect on developmental toxicity: via dermal route
- Endpoint conclusion:
- no study available
Additional information
IUCLID section 7.8.1:
L-Cystine (and L-Cysteine respectively) is an amino acid that is required for normal functioning of humans. The substance is of low toxicological activity and subject to homeostasis. Therefore, reprotoxic effects are not expected for L-Cystine and no test is required for this substance. There is sufficient weight of evidence for the absence of reprotoxic effects. A screening for reproductive toxicity (REACH Annex VIII No. 8.7.1) as well as any study on reproductive toxicity as REACH Annex IX no. 8.7 are not to be conducted in accordance with REACH Annex XI no. 1.2. and for reasons of animal welfare: "Where sufficient weight of evidence for the presence or absence of a particular dangerous property is available, further testing on vertebrate animals for this property shall be omitted..."
IUCLID section 7.8.2:
L-Cystine (and L-Cysteine respectively) is an amino acid that is required for normal functioning of humans. The substance is of low toxicological activity and subject to homeostasis. Therefore, reprotoxic effects are not expected for L-Cystine and no test is required for this substance. There is sufficient weight of evidence for the absence of reprotoxic effects. A screening for reproductive toxicity (REACH Annex VIII No. 8.7.1) as well as any study on reproductive toxicity as REACH Annex IX no. 8.7 are not to be conducted in accordance with REACH Annex XI no. 1.2. and for reasons of animal welfare: "Where sufficient weight of evidence for the presence or absence of a particular dangerous property is available, further testing on vertebrate animals for this property shall be omitted..."
Justification for classification or non-classification
L-Cysteine does not need to be classified.
Additional information
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.
Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.
