Registration Dossier

Administrative data

Endpoint:
skin sensitisation: in vivo (LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2008-05-20 till 2008-06-11
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: guideline-conform study under GLP without deviations

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2008
Report date:
2008

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Type of study:
mouse local lymph node assay (LLNA)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): SODIUM 2-HYDROXYETHANESULPHONATE
- Physical state: solid, white crystalline
- Analytical purity: => 99%
- Impurities (identity and concentrations): water (0.07%)
- Purity test date: 2008-04-30
- Lot/batch No.: EK 08/116
- Expiration date of the lot/batch: 2010-12-31
- Stability under test conditions: Stable for 730 days in water at room temperature
- Storage condition of test material: At room temperature, moisture protected

In vivo test system

Test animals

Species:
mouse
Strain:
CBA
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Harlan Netherlands
- Age at study initiation: 8 - 12 weeks
- Weight at study initiation: 19.3 +/- 0.7 (Group 1), 20.2 +/- 0.3 (Group 2), 19.5 +/- 0.3 (Group 3), 18.9 +/- 1.2 (Group 4)
- Housing: Single caging. Cage type: Makrolon Type I, with wire mesh top
- Diet (e.g. ad libitum): pelleted standard diet, ad libitum
- Water (e.g. ad libitum): tap water from Rossdorf, ad libitum
- Acclimation period: At least 5 days prior to the start of dosing


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 3°C
- Humidity (%): 30 - 70%
- Photoperiod (hrs dark / hrs light): 12 / 12

Study design: in vivo (LLNA)

Vehicle:
other: ethanol: deionised water (30:70)
Concentration:
10%, 25%, 50%
No. of animals per dose:
5 females per dose
Details on study design:
RANGE FINDING TESTS:
- Compound solubility: The highest test item concentration, which can be technically used was a 50 % solution in ethanol:deionised water (30:70).
With other vehicles used, equivalent concentrations could not be achieved.
- Irritation: performed on two female mice, by topical application of concentrations of 5, 10, 25, and 50 % on one ear each on three consecutive days.
The animals did not show any signs of irritation or systemic toxicity.


MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: Local Lymph Node Assay (LLNA)
- Criteria used to consider a positive response: The sensitivity and reliability of the experimental technique employed was assessed by use of a
substance which is known to have skin sensitisation properties in CBA/CaOlaHsd mice (-Hexylcinnamaldehyde in acetone:olive oil, 4:1 )


TREATMENT PREPARATION AND ADMINISTRATION:
25 µl was spread to the entire dorsal surface of each ear of each mouse once daily for three consecutive days. On day 6 an injection of 250 µl phosphate buffered saline (PBS) containing 78.9 µCi of 3H-methyl thymidine (3H-TdR) was made into the tail vein of each experimental mouse. Five hours
later, the draining Auricular lymph node of each ear was excised into PBS. A single cell suspension of lymph node cells was prepared from each
mouse. After washing two times with phosphate buffered saline the lymph node cells were resuspended in 5 % trichloroacetic acid and incubated at approximately +4 °C for at least 18 hours for precipitation of macromolecules. The precipitates were then resuspended in 5 % trichloroacetic acid
and transferred to plastic scintillation vials. The level of 3HTdR incorporation was then measured on a -scintillation counter.
Positive control substance(s):
hexyl cinnamic aldehyde (CAS No 101-86-0)
Statistics:
No data.

Results and discussion

Positive control results:
The sensitivity and reliability of the experimental technique employed was assessed by use of a substance which is known to have skin sensitisation properties in CBA/CaOlaHsd mice.

In vivo (LLNA)

Resultsopen allclose all
Parameter:
SI
Remarks on result:
other: see Remark
Remarks:
Stimulation Indices (S.I.) of 0.46, 0.48, and 0.56 were determined with the test item at concentrations of 10, 25, 50 % in ethanol:deionised water (30+70), respectively. The EC3 value could not be calculated, since none of the tested concentrations induced an S.I. greater than 3.
Parameter:
other: disintegrations per minute (DPM)
Remarks on result:
other: See table 1

Applicant's summary and conclusion

Interpretation of results:
not sensitising
Remarks:
Migrated information
Conclusions:
The test item Sodium 2-hydroxyethanesulphonate was found to be not a skin sensitiser under the described conditions.
Executive summary:

The sensitization potential was investigated according to OECD Guideline 429.

The test item concentrations choosen for the LLNA test were 10, 25, 50 %.

No deaths occurred during the study period. No symptoms of local toxicity at the ears of the animals and no systemic findings were observed during the study period. The body weight of the animals was within the range commonly recorded for animals of this strain and age.