Registration Dossier

Administrative data

Endpoint:
skin sensitisation: in vivo (LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2007/03/19 - 2007/05/30
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: This study followed the procedures indicated by the OECD Guidelines for Testing of Chemicals, Updated Guideline 429: Skin Sensitisation: Local Lymph Node Assay (adopted 24 April 2002).

Data source

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

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)
GLP compliance:
yes (incl. certificate)
Type of study:
mouse local lymph node assay (LLNA)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Purity: 100.3 %

In vivo test system

Test animals

Species:
mouse
Strain:
CBA
Sex:
female
Details on test animals and environmental conditions:
temperature: 22 +/- 3°C
relative humidity: 30-70%
artificial light: 6.00 a.m. - 6.00 p.m.

Study design: in vivo (LLNA)

Vehicle:
other: ethanol/water (30/70, v/v)
Concentration:
12.5, 25, or 50 %
No. of animals per dose:
5
Details on study design:
Three groups each of 5 mice were treated with 12.5, 25, or 50 % Dihydroxyacetone by topical application at the dorsum of each ear lobe (left and right) on three consecutive days. A control group of 5 mice was treated with the vehicle only. The highest test item concentrations could be achieved using ethanol/water (30/70, v/v), which, therefore, was used as the vehicle.
Positive control substance(s):
hexyl cinnamic aldehyde (CAS No 101-86-0)
Statistics:
The mean values and standard deviations were calculated in the body weight tables.
The Dunnett-Test (ANOVA) was conducted to assess whether the difference of DPM per animal is statistically significant between test item groups and negative control (vehicle) group. A statistical analysis of the earthickness before and after treatment with the test item was also conducted.

Results and discussion

Positive control results:
The validation-(positive control experiment was performed with a-Hexylcinnamaldehyde in acetone:olive oil (4+1) using CBA/CaOIaHsd mice.
Disintegrations per minute (DPM) of 1005.4, 3108.1, and 6130.7 were determined with the positive control at concentrations of 5, 10, and 25 %, respectively.

In vivo (LLNA)

Resultsopen allclose all
Parameter:
SI
Remarks on result:
other: Stimulation indices (S.I.) of 1.04, 1.16, and 0.77 were determined with DHA at concentrations of 12.5, 25, and 50 % in ethanol/water (30/70, v/v), respectively.
Parameter:
other: disintegrations per minute (DPM)
Remarks on result:
other: Disintegrations per minute (DPM) of 570.9,639.0, and 422.6 were determined with DHA at concentrations of 12.5, 25, and 50 % in ethanol/water (30/70, v/v), respectively.

Applicant's summary and conclusion

Interpretation of results:
not sensitising
Remarks:
Migrated information
Conclusions:
Dihydroxyacetone was not a skin sensitiser under the described conditions.
Executive summary:

In the study the test item dihydroxyacetone dissolved in ethanol/water (30/70, v/v) was assessed for its possible contact allergenic potential. For this purpose a local lymph node assay was performed using test item concentrations of 12.5, 25, and 50%. The animals did not show any clinical signs during the course of the study and no cases of mortality were observed. In this study Stimulation Indices (S.l.) of 1.04, 1.16, and 0.77 were determined with the test item at concentrations of 12.5, 25, and 50% in ethanol/water (30/70, v/v), respectively. Dihydroxyacetone was not a skin sensitiser in this assay.