Sodium ascorbate

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

12/2009 - 02/2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.42 (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

Test material information

Constituent 1

Reference substance name:

Sodium ascorbate

EC Number:

205-126-1

EC Name:

Sodium ascorbate

Cas Number:

134-03-2

Molecular formula:

C6H8O6.Na

IUPAC Name:

sodium ascorbate

Specific details on test material used for the study:

CAS number: 134-03-2

In vivo test system

Test animals

Species:

mouse

Strain:

CBA

Sex:

female

Study design: in vivo (LLNA)

Vehicle:

other: Ethanol/ water 30/70

Concentration:

5%, 10% or 25% (w/v) in ethanol/water (30/70)

No. of animals per dose:

4

Positive control substance(s):

hexyl cinnamic aldehyde (CAS No 101-86-0)

Results and discussion

Positive control results:

A calculation of the EC3 value was performed resulting in an EC3 value of 11.6% for the positive control substance.

In vivo (LLNA)

Results

Results 1

Parameter:

SI

Value:

< 3

Test group / Remarks:

5 %

Results 2

Parameter:

SI

Value:

< 3

Test group / Remarks:

10 %

Results 3

Parameter:

SI

Value:

< 3

Test group / Remarks:

25 %

Results 4

Key result

Parameter:

EC3

Value:

< 3

Remarks on result:

other: A calculation of the EC3 value was not performed because no test concentrations produced a S.I. of 3 or higher.

Any other information on results incl. tables

No deaths occurred during the study period. Neither clinical signs on the ears of the animals nor systemic findings were observed during the study period.

The body weights of the animals, recorded at the start of acclimatisation, prior to the first application and prior to sacrifice, were within the range commonly recorded for animals of the strain and age.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The test item was not a skin sensitizer in this assay

Executive summary:

The skin sensitising potential of Sodium Ascorbate Crystalline was examined in an OECD 429 guideline study under GLP conditions. Three groups of four female mice each were treated daily with the test item at concentrations of 5%, 10% and 25% (w/v) in ethanol/water (30/70) by topical application to the dorsum of each ear lobe for three consecutive days. A control group of four female mice was treated with the vehicle ethanol/water (30/70) only. Five days after the first topical application the mice were injected intravenously into a tail vein with radio-labelled thymidine (3H-methyl thymidine, 3HTdR). Approximately five hours after intravenous injection, the mice were sacrificed, the draining auricular lymph nodes were excised and pooled per group. Single cell suspensions of lymph node cells were prepared from pooled lymph nodes which were subsequently washed and incubated with trichloroacetic acid overnight. The proliferative capacity of pooled lymph node cells was determined by the incorporation of 3HTdR measured in a ß-scintillation counter. All treated animals survived the scheduled study period. Neither clinical signs on the ears of the animals nor systemic findings were observed during the study period. The Stimulation Index (S.I.) was 11.6% for the positive control substance and less than 3% for any of the test item concentrations (Harlan, 2010).

Hence, the EC3 value was not reached even with the highest test substance concentration of 25%. Sodium ascorbate is therefore not a skin sensitizer and the GHS criteria for classification are not met.