Use of this information is subject to copyright laws and may require the permission of the owner of the information, as described in the ECHA Legal Notice.
EC number: 244-492-7
CAS number: 21645-51-2
Preliminary dose range finding study (2 animals per concentration)
- Intra-dermal treatment: Scores 0 for erythema (0-E) and 0 for oedema (0-O) for both animals for all the tested concentrations (5.0%, 1.0%, 0.1%, 0.01%) at 1, 24, 48 and 72 hours after exposure
- Dermal treatment: 1 hour after the application of 100% concentration, scores 1-E 0-O were recorded for both animals; scores 0-E and 0-0 were recorded for both animals at this concentration 24, 48 and 72 hours after the patch removal. Scores 0-E and 0-0 were recorded for both animals at concentrations 25%, 50% and 75% 1, 24, 48 and 72 hours after the patch removal
Intra-dermal induction exposure: no visible changes were observed in any animal in either test or control group 24 hours after the treatment
“The detailed description of FCA [Freund’s complete adjuvant] treatments is not announced in the report, as these FCA effects are well known.”
Dermal induction exposure:
- Control group: no visible changes were observed in any animal 1, 24, 48 and 72 hours after the patch removal.
- Test group. “Very slight erythema” was observed in one animal 1 hour after the patch removal. No visible changes were observed in this animal 24, 48 or 72 hours after the patch removal. No visible changes were observed in the other nine animals at 1, 24, 48 or 72 hours after the patch removal
Skin sensitisation score 0 was recorded on left and right side of all control and tested animals 24 and 48 hours after the patch removal.
Dermal response scores after the challenge exposure (Appendix 5)
Test animals Control animals
24 h 48 h 24 h 48 h
number of positive/ 0/10 0/10 0/5 0/5
number of tested
All health effects/lesions/outcome examined:
Individual data on body weight (with group means) were provided in the report. There were no notable differences in body weight between the test and the control groups.
No overt signs of an adverse clinical response to treatment were observed during the course of the study.
There was no mortality during the study
Positive control results
In the test group, 10 animals were treated with the reference item. Challenge with the test item 2-Mercaptobenzothiazoleresulted in a positive response in 50 % of the test animals sensitized previously. No visible changes were found in the control animals. The net score value was 0.50.On the basis of the results of the reliability check study, the test item was classified as a skin sensitizer. This demonstrated that the reliability checking for this method was successful.
This study was performed in Guinea pigs (Dunkin Hartley (LAL/HA/BR) using the Magnusson and Kligman method (LAB Research Inc., 2010). The study design was based on OECD TG # 406 (17 July 1992), Commission Regulations (EC) No 440/2008 of 30 May 2008; B.6; and the US EPA OPPTS 870.2600 (EPA 712-C-03-197, March 2003). Methylcellulose (1%), selected based on results from a Preliminary Compatibility Test, was used as the vehicle in this study. Based on the preliminary dose range finding study, 1% (w/v) was used for a first induction stage by intradermal administration. This consisted of three injections to both left and right flanks: an injection with 0.10 mL of Freund's Complete Adjuvant mixed with physiological saline (1:1 v/v); an injection with 0.10 mL of the test item in 1% methylcellulose at the selected concentration; and an injection with 0.10 mL of test item at the appropriate concentration in a 1:1 (v/v) mixture of Freund's Adjuvant and physiological saline. The animals in the control group received three similar injections to each side with the omission of the test item. Again based on the results of a dose range finding study, 100% (w/v) was used for a second induction stage by dermal application. 0.5 mL of the suspension was applied with occlusion for 48 hours. Two weeks after the last induction exposure, two concentrations were used for the occlusive epicutaneous challenge exposure: 0.5 mL of 75% (w/v) suspension was applied to the left flank of the animals and 0.5 mL of 37.5% (w/v) suspension was applied to the right flank. The test item was applied to the flanks of the test and control animals using a 5x5 cm sterile gauze patch saturated with the test item. The patches remained in place, occluded, for 24 hours. After patch removal, residual test item was removed with a swab and observations were made at 24 and 48 hours. No irritation effects (scored according to Draize, 1977) were observed during the dose-range finding study or the induction exposures. In the test group, no positive responses were observed in the treated animal (n=10) with either the 75% (w/v) or 37.5% (w/v) formulations. No positive responses were observed on challenge exposure in the control animals (n=5). In summary, the Guinea-Pig Maximisation test was used to determine the skin sensitisation potential of the test item, aluminium hydroxide. Challenge with the test item produced no positive responses in the previously sensitized test animals or in the control animals. The incidence rate was 0% and the net score 0.00. Thus, it was shown that, under the conditions of this test, aluminium hydroxide had no detectable sensitisation potential and does not meet EU criteria for classification for sensitisation.
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.
Welcome to the ECHA website. This site is not fully supported in Internet Explorer 7 (and earlier versions). Please upgrade your Internet Explorer to a newer version.
Do not show this message again