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Toxicological information

Skin sensitisation

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Administrative data

Endpoint:
skin sensitisation: in vivo (LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2007
Report date:
2007

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)
Version / remarks:
adopted 24 April 2002
GLP compliance:
yes
Type of study:
mouse local lymph node assay (LLNA)

Test material

Constituent 1
Reference substance name:
methyl tetradecanoate, chloro
Molecular formula:
C13H26Cl4COOCH3 and C13H25Cl5COOCH3 (primary isomers based on product weight of 35-40% Cl by weight)
IUPAC Name:
methyl tetradecanoate, chloro
Constituent 2
Reference substance name:
Methyl octadecanoate, chloro
Molecular formula:
C17H30Cl4COOCH3, C17H29Cl5COOCH3 , and C17H28Cl6COOCH3 (primary isomers based on 35-40% Cl by weight)
IUPAC Name:
Methyl octadecanoate, chloro
Constituent 3
Reference substance name:
Methyl hexadecanoate, chloro
Molecular formula:
C15H28Cl4COOCH3 and C15H27Cl5COOCH3 (primary isomers based on 35-40% Cl by weight)
IUPAC Name:
Methyl hexadecanoate, chloro
Test material form:
liquid
Details on test material:
This is a UVCB substance developed from the chlorination of fatty acid methyl esters.

In vivo test system

Test animals

Species:
mouse
Strain:
CBA/Ca
Remarks:
CBA/CaOlaHsd
Sex:
female
Details on test animals and environmental conditions:
Only nulliparous and non-pregnant female mice were used. Age 7-8 weeks at the beginning of acclimatisation.

Single caging. The animals were distributed into the test groups at random and identified by cage number.

Environment:
temperature 22 ± 3°C
relative humidity 30-70%
artificial light 6.00 a.m. - 6.00 p.m.

Study design: in vivo (LLNA)

Vehicle:
acetone/olive oil (4:1 v/v)
Concentration:
0, 25, 50, 100%
No. of animals per dose:
4 females
Details on study design:
Each test group of mice was treated by topical (epidermal) application to the dorsal surface of each ear lobe (left and right) with different test item concentrations of 25, 50, and 100% (w/v) in acetone:olive oil (4+1 ). The application volume, 25 μI, was spread over the entire dorsal surface (0 ~ 8 mm) of each ear lobe once daily for three consecutive days. A further group of mice was treated with an equivalent volume of the relevant vehicle alone (control animals).

Five days after the first topical application, all mice were administered with 250 μI of 81.7 μCi/ml 3HTdR (corresponds to 20.4 μCi 3HTdR per mouse) by intravenous injection via a tail vein. The draining lymph nodes were rapidly excised and pooled per group (8 nodes per group). Single cell suspensions (in phosphate buffered saline) of pooled lymph node cells were prepared by gentle mechanical disaggregation through stainless steel gauze (200 μm mesh size). After washing two times with phosphate buffered saline (approx. 10 ml) the lymph node cells were resuspended in 5 % trichloroacetic acid (approx. 3 ml) and
incubated at approximately +4 °C for at least 18 hours for precipitation of macromolecules. The precipitates were then resuspended in 5 % trichloroacetic acid (1 ml) and transferred to plastic scintillation vials with 10 ml of 'Ultima Gold' scintillation liquid and thoroughly mixed.

The level of 3HTdR incorporation was then measured on a beta-scintillation counter. Similarly, background 3HTdR levels were also measured in two 1 ml-aliquots of 5 % trichloroacetic acid. The beta-scintillation counter expresses 3HTdR incorporation as the number of radioactive disintegrations per minute (DPM).

The proliferative response of lymph node cells is expressed as the number of radioactive disintegrations per minute per lymph node (DPM/node) and as the ratio of 3HTdR incorporated into lymph node cells of test lymph nodes relative to that recorded for control lymph nodes (stimulation index). Before DPM/node values were determined, mean scintillation-background DPM was subtracted from test and control raw data.
Positive control substance(s):
not specified

Results and discussion

In vivo (LLNA)

Resultsopen allclose all
Key result
Parameter:
SI
Value:
1.26
Test group / Remarks:
25% Concentration
Key result
Parameter:
SI
Value:
2.31
Test group / Remarks:
50% Concentration
Key result
Parameter:
SI
Value:
1.82
Test group / Remarks:
100% Concentration

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Conclusions:
In this study Stimulation Indices (S.1.) of 1.26, 2.31, and 1.82 were determined with the test item at concentrations of 25, 50, and 100% in acetone: olive oil (4+1 ), respectively. The EC3 value could not be calculated, since all SI's are below 3.

The test item is not a skin sensitizer.
Executive summary:

In the study the C16 and C18 chlorinated methyl esters were dissolved in acetone: olive oil (4+1) was assessed for

possible contact allergenic potential. For this purpose a local lymph node assay was performed using test item concentrations of 25, 50, and 100%.

The animals did not show any clinical signs during the course of the study and cases of mortality were not observed.

In this study Stimulation Indices (S.1.) of 1.26, 2.31, and 1.82 were determined with the test item at concentrations of 25, 50, and 100% in acetone: olive oil (4+1 ), respectively. The EC3 value could not be calculated, since all SI's are below 3.

The test item is not a skin sensitizer.