Disodium oxybis[methylbenzenesulphonate]

Skin sensitisation

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:

other: Guideline study and GLP

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2012

Report date:

2012

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)

GLP compliance:

yes

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

Disodium oxybis[methylbenzenesulphonate]

EC Number:

277-242-0

EC Name:

Disodium oxybis[methylbenzenesulphonate]

Cas Number:

73037-34-0

Molecular formula:

C14H12Na2O7S2

IUPAC Name:

disodium oxybis(methylbenzenesulfonate)

Test material form:

solid

Details on test material:

Active content reported: 90-95 %

In vivo test system

Test animals

Species:

mouse

Strain:

CBA

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Age at study initiation: 8-9 weeks
- Housing: in groups of 5
- Diet ad libitum
- Water ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22
- Humidity (%): 55
- Air changes (per hr): 10
- Photoperiod (hrs dark / hrs light): 12/12

Study design: in vivo (LLNA)

Vehicle:

other: aceton:olive oil = 4:1

Concentration:

6.25 %, 12.5 %, 25 %

No. of animals per dose:

5

Details on study design:

Topical application:
Each mouse was treated by topical application of the selected solution to the endire dorsal surface of each ear, once daily on 3 consecutive days.

Administration of 3H-Methyl-thymidine:
5 days after the first topical application all mice were dosed with 3H-Methyl-thymidine diluted to a working concentraion of 80 µCi/ml, by intravenous injection.

Preparation of cell suspension:
Approcimately 5 hours after the injection all mice were sacificed. The draining "auricular lymph nodes" were excised, and individually pooled for each animal (2 lymph nodes/animal) and collected in phosphate buffered saline . A single cell suspension of pooled lymph node cells was prepared by gentle mechanical disaggregation through a polyamide gauze and washed repeatedly.

Determination of Incorporated 3H-Methyl-thymidine:
The 3H-Methyl-thymidine incorporation was measured in a ß-counter for each animal.

Positive control substance(s):

other: p-phenylene diamine (CAS No. 106-50-3)

Statistics:

The proliferative response of lymph node cells was expressed as the number of radioactive disintergations per minute per lymph node (DPM/NODE) and as the rate of 3H-methyl thymidine incorporation into lymph cells of test group animals relative to that recorded of control group animals (STIMULATION INDEX). Before DPM/NODE values were determined, background values were subtracted.
EC3 values, calculated concentrations which induce stimulation indices of 3 are determined by linear interpolation between two points of stimulation index axis. One above and one below the stimulation index of 3. If all measured points are above or below the stimulation index of 3 no EC3 value can be stated.
A substance is regarded as a sensitiser in the LLNA if at least one concentration of the test item results in a 3-fold or greater increase in 3H-methyl thymidine incorporation into lymph node cells of the test group relative to that recorded for the lymph nodes of control group animals (Stimulation Index equal or greater than 3.0).

Results and discussion

Positive control results:

Mean Stimulation index of p-phenylene diamine in this assay is 9.0

In vivo (LLNA)

Results

Results 1

Parameter:

SI

Remarks on result:

other: None of the 3 concentrations of the test item reached the stimulation index of 3. 6.25% : 1.1 12.5 % : 1.3 25 % : 1.0

Results 2

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: 6.25 % : 885.1 DPM 12.5 % : 1007.3 DPM 25 %: : 817.8 DPM

Any other information on results incl. tables

All animals survived througout the test period without showing any clinical signs.

All animals showed the expected body weight development.

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information

Executive summary:

In a Local Lymph Node Assay according to OECD TG 429 and GLP ditolylether disufonic acid disodium salt, isomer mixture dissolved in acetone/olive oil (4:1) was tested for skin sensitizing effects at concentrations of 6.25%, 12.5% and 25%. The EC3 value (derived by linear interpolation) could not be calculated as the stimulation indices of all concentrations were below 3 (6.25%: 1.1, 12.5%: 1.3, 25%: 1.0).

Consequently, according to OECD TG 429 ditolylether disufonic acid disodium salt, isomer mixture is expected to have no sensitizing properties and therefore should not be regarded as a dermal sensitizer.