Aluminium tri-sec-butanolate

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1999

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Data source

Reference

Reference Type:

publication

Title:

Identification of Metal Allergens in the Local Lymph Node Assay.

Author:

Basketter et al.

Year:

1999

Bibliographic source:

Am J Contact Dermatitis 1999; 10(4): 207-212.

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

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

Deviations:

yes

Remarks:

:

GLP compliance:

no

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

Aluminium chloride hexahydrate

EC Number:

917-806-1

IUPAC Name:

Aluminium chloride hexahydrate

Details on test material:

- Name of test material (as cited in study report): AlCl3.6H2O
- Analytical purity: no data

In vivo test system

Test animals

Species:

mouse

Strain:

CBA

Sex:

not specified

Details on test animals and environmental conditions:

Species and strain: mouse, 4 CBA/Ca
Source: Harlan Olac, Bicester, UK.
Justification of species and strain: Mouse is the preferred animal for this test (OECD TG#429)
Sex: not stated
Body weight range at the beginning of the study: not stated
Age at testing: 7 to 12 weeks
No further details mentioned

Study design: in vivo (LLNA)

Vehicle:

other: petrolatum

Concentration:

5.0%, 10.0%, and 25.0%

No. of animals per dose:

4

Details on study design:

Two days after the last exposure, the mice were injected with 250 µL of phosphate buffered saline (PBS) containing 20 µCi of tritiated thymidine (from Amersham International, Amersham, UK). Five hours later, the mice were killed, draining lymph nodes excised and a single-cell suspension of the pooled lymph node samples was prepared.

The lymph node cell suspension was washed in excess PBS, precipitated with 5% trichloroacetic acid (TCA) at 4 ºC for 18 hours. After resuspension in TCA, β-scintillation counting was used to measure tritium incorporation.

The method used to kill the animals was not reported.

Observations:
Proliferation of cells in the lymph nodes.

- A positive result was defined as a threefold or greater proliferation than in the concurrent vehicle treated controls.

Positive control substance(s):

other: positive results were seen for metal salts of gold, beryllium, cobalt, mercury, platinum and tin that were tested in parallel

Statistics:

NA

Results and discussion

Positive control results:

positive responses were noted

In vivo (LLNA)

Results

Results 1

Key result

Parameter:

SI

Value:

>= 0.7 - <= 0.8

Test group / Remarks:

5% 0.8; 10% 0.8; 25% 0.7

Results 2

Parameter:

EC3

Remarks on result:

not determinable

Remarks:

all values SI values < 3

Any other information on results incl. tables

The results for aluminium chloride hexahydrate were negative. There was no information on the irritancy of the tested concentration from a pre-test

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Aluminium chloride hexahydrate did not show sensitizing potential under the conditions used in this assay.

Executive summary:

Basketter et al. (1999) investigated the allergenic potential of 13 metal salts including aluminium chloride hexahydrate (99% purity) in the Local Lymph Node Assay (LLNA). Groups of 4 CBA/Ca mice (7 to 12 weeks of age) were treated with 25 μL of substance or with an equal volume of the vehicle alone, on the dorsum of both ears. The mice were treated once daily for 3 days. Two days later, the mice were injected with 250 μL of phosphate buffered saline (PBS) with 20 μCi of tritiated thymidine (2 Ci mmol^-l). The mice were killed 5 hours later and a single-cell suspension of lymph node cells was prepared by mechanical disaggregation. A substance was considered a skin sensitizer the proliferation in the lymph nodes of treated mice was 3-fold or greater than that in the concurrent vehicle-treated controls. Aluminium chloride hexahydrate administered in petrolatum (vehicle) at test concentrations of 5.0%, 10.0% and 25.0% did not induce a lymph node proliferation response compared to concurrent vehicle-treated controls, and therefore the response was judged as negative. The results of this study add to the weight of evidence for a low sensitisation potential of aluminium 3+ cations.