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Toxicological information

Acute Toxicity: dermal

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Administrative data

Endpoint:
acute toxicity: dermal
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
4 (not assignable)
Rationale for reliability incl. deficiencies:
secondary literature
Cross-reference
Reason / purpose:
reference to same study
Reference
Endpoint:
acute toxicity: dermal
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
supporting study
Reliability:
4 (not assignable)
Rationale for reliability incl. deficiencies:
secondary literature
Justification for type of information:
ANALOGUE APPROACH

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
This read-across is based on the hypothesis that source substances and target substance have similar physical-chemical properties and (eco)toxicological properties because they are either stereoisomers of the target substance, are hydrolysed to the same substance or their chemical structure differs only by an additional double bond. This prediction is supported by data on the substances themselves.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
The target substance, L-Citronellol, is a mono-constituent substance (EC No. 231-415-7, CAS no. 7540-51-4 consisting of a C8 carbon backbone, methyl substituents at C3 and C7, one double bond and a hydroxyl group. The substance is optically active, comprising a single, pure enantiomeric laevo form.

The source substance, DL-Citronellol, is a mono-constituent substance (EC No. 203-375-0, CAS no. 106-22-9, consisting of a C8 carbon backbone, methyl substituents at C3 and C7, one double bond and a hydroxyl group. The substance is an equimolar mixture of two optical isomers (enantiomers).

The source substance, citronellyl acetate, is a mono-constituent substance (EC No. 205-775-0, CAS no. 150-84-5) consisting of a C8 carbon backbone, methyl substituents at C3 and C7, one double bond and an acetate group.

The source substance, geraniol and it’s isomer, consist of a C8 carbon backbone, methyl substituents at C3 and C7, two double bonds and a hydroxyl group. The only difference between the isomers is the position of the first double bond.

The source substance, geraniol and nerol, is a multi-constituent substance of E/Z isomers (EC No. 906-125-5). The constituents consist of a C8 carbon backbone, methyl substituents at C3 and C7, two double bonds and a hydroxyl group.

The source substance, geraniol, is a mono-constituent substance (EC No. 203-377-1, CAS no. 106-24-1), consisting of a C8 carbon backbone, methyl substituents at C3 and C7, two double bonds and a hydroxyl group. Geraniol is a pure form of the E-isomer.

The source substance, nerol, is a mono-constituent substance (EC No. 203-378-7, CAS no. 106-25-2), consisting of a C8 carbon backbone, methyl substituents at C3 and C7, two double bonds and a hydroxyl group. Nerol is a pure form of the Z-isomer.
The source and target substances are both of high purity with a low concentration of impurities.

3. ANALOGUE APPROACH JUSTIFICATION
The read across hypothesis is based on structural similarity where the source substances only differ in the enantiomeric ratio or an additional double bond. Another source substance is expected to be hydrolysed to the same structure as the target substance.
In a non-chiral environment the target and source chemical DL-Citronellol will have identical properties, but in the chiral environment of living organisms the enantiomers may possess different carcinogenicity and teratogenicity (in a chiral environment, stereoisomers might experience selective absorption, protein binding, transport, enzyme interactions and metabolism, receptor interactions, and DNA binding). All endpoints read-across from DL-Citronellol are considered to be acceptable for this substance assuming that 50% of the target compound is available in the test material.
The source substance citronellyl acetate is read-across from as part of a weight of evidence approach in the repeated dose toxicity endpoint. As this substance is hydrolysed to Citronellol within 2 hours, this read-across endpoint is acceptable in the weight of evidence approach used.
The source substances geraniol, nerol and the reaction mass of geraniol/nerol differ from the target substance only by an additional double bond at C2. These structures are considered to represent a worst case scenario due to the additional potential reactive feature of the second double bond. The genotoxicity, repeated dose and reproductive toxicity endpoints read-across from these substances are therefore acceptable as a worst case assumption.

4. DATA MATRIX
Please refer to the data matrix included in the read-across justification document attached in Section 13.2.
Reason / purpose:
read-across source
Related information:
Composition 1
Reference:
Composition 0
Qualifier:
no guideline followed
Principles of method if other than guideline:
acute dermal toxicity study carried out in 1973.
GLP compliance:
not specified
Test type:
standard acute method
Limit test:
no
Test material information:
Composition 1
Species:
rabbit
Strain:
not specified
Sex:
not specified
Type of coverage:
not specified
Vehicle:
not specified
Duration of exposure:
no data
Doses:
1250, 2500, 5000 mg/kg bw
No. of animals per sex per dose:
5
Control animals:
not specified
Key result
Sex:
not specified
Dose descriptor:
LD50
Effect level:
2 650 mg/kg bw
95% CL:
>= 1 780 - <= 3 520
Mortality:
5000 mg/kg bw: 5/5
2500 mg/kg bw: 2/5
1250 mg/kg bw: 0/5
Clinical signs:
5000 mg/kg bw: ataxia and pupillary dilation
2500 mg/kg bw: ataxia in 4 animals
1250 mg/kg bw: 2 animals were weak and unable to stand
Interpretation of results:
Category 5 based on GHS criteria
Conclusions:
According to this study, the substance cannot be classified by the CLP classification.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1973
Report Date:
1973

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
acute dermal toxicity study carried out in 1973.
GLP compliance:
not specified
Test type:
standard acute method
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent

Test animals

Species:
rabbit
Strain:
not specified
Sex:
not specified

Administration / exposure

Type of coverage:
not specified
Vehicle:
not specified
Duration of exposure:
no data
Doses:
1250, 2500, 5000 mg/kg bw
No. of animals per sex per dose:
5
Control animals:
not specified

Results and discussion

Effect levels
Key result
Sex:
not specified
Dose descriptor:
LD50
Effect level:
2 650 mg/kg bw
95% CL:
>= 1 780 - <= 3 520
Mortality:
5000 mg/kg bw: 5/5
2500 mg/kg bw: 2/5
1250 mg/kg bw: 0/5
Clinical signs:
5000 mg/kg bw: ataxia and pupillary dilation
2500 mg/kg bw: ataxia in 4 animals
1250 mg/kg bw: 2 animals were weak and unable to stand

Applicant's summary and conclusion

Interpretation of results:
Category 5 based on GHS criteria
Conclusions:
According to this study, the substance cannot be classified by the CLP classification.