Aluminium lanthanum trioxide

Endpoint summary

Description of key information

Key studies demonstrate a lack of skin sensitisation potential: Data are read-across based on grouping of substances, i.e. aluminium oxide, lanthanum oxide and aluminium lanthanum trioxide, based on inertness and similar solubility or lack thereof. Aluminium oxide and lanthanum oxide tested negative (i.e. not sensitising) in sensitisation studies according to Magnusson and Kligman (OECD 406). Positive human experience with aluminium lanthanum trioxide substance has not been reported.Based on read-across (see category approach), it is assumed that aluminium lanthanum trioxide does not possess a skin sensitisation potential.

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Reference 1

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Study period:

2005-10-24 to 2005-12-27

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

The solubility of aluminium lanthanum trioxide (AlLaO3) is low since dissolution of AlLaO3 in water resulted in La concentrations < 0.01 mg/L and Al concentrations < 0.03 mg/L after 34 days. The dissolution of AlLaO3 in water results in Al (3+) (=Al(H2O)6 (3+)) ions and La (3+) ions. Thus, the toxicological moieties of concern are aluminium and lanthanum ions. Thus, in the assessment of toxicity, data available for different aluminium and lanthanum substances are read-across since aluminium and lanthanum ions determine the toxicological potential of aluminium lanthanum trioxide, i.e. are the common toxicological moieties of concern. The effects of the substance aluminium lanthanum trioxide with regard to skin sensitisation are predicted to be equal to the effects of Al (3+) ions and La (3+) ions.

Qualifier:

according to guideline

Guideline:

EU Method B.6 (Skin Sensitisation)

Version / remarks:

1996

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Version / remarks:

1992

Deviations:

no

GLP compliance:

yes

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

A reliable guinea pig maximisation study has been performed, which would not justify conducting an additional LLNA due to animal welfare.

Specific details on test material used for the study:

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
Storage condition of test material : at room temperature (20 ± 5 °C), light protected

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS:
- Source: Charles River Deutschland GmbH
- Age at study initiation: 5 - 6 weeks
- Weight at study initiation: 336 - 392 g
- Housing: individually in Makrolon type-4 cages with standard softwood bedding
- Diet: pelleted standard Provimi Kliba 3418, ad libitum
- Water: community tap water from Füllinsdorf, ad libitum
- Acclimation period: 13 days

ENVIRONMENTAL CONDITIONS
- Temperature: 22 ± 3 °C
- Humidity: 30 - 70 %
- Air changes: 10 - 15 per hr
- Photoperiod: 12 hrs dark / 12 hrs light

Route:

intradermal

Vehicle:

other: PEG 300

Concentration / amount:

15 % or 25 % (w/w) of the test item

Day(s)/duration:

Day 1

Route:

epicutaneous, occlusive

Vehicle:

other: PEG 300

Concentration / amount:

50 % (w/w) of the test item

Day(s)/duration:

day 8 (duration: 48 hours)

Adequacy of induction:

other: pretreated with 10 % SDS

No.:

#1

Route:

epicutaneous, occlusive

Vehicle:

other: PEG 300

Concentration / amount:

50 % (w/w) of the test item

Day(s)/duration:

day 22 (duration: 24 hours)

No. of animals per dose:

15 (main study: 5 in control group, 10 in test group), 3 (pretest)

Details on study design:

* RANGE FINDING TEST:
>>> INTRADERMAL INJECTIONS:
One guinea pig was intradermally injected into the clipped flank at concentrations of B = 25 % and C = 15 % (w/w) of the test item in PEG 300. Due to the high viscosity of the application dilution and the obstacle caused by the tissues, it was not technically possible to inject the liquid dilution at concentration of A = 50 % (w/w) into the intra-cellular space.
Dermal reactions were assessed approximately 24 hours later.
Based on the results, the test item concentration of 25 % was selected for intradermal induction in the main study. However, due to the high viscosity of the test item preparation, the two first animals of the test group could not be applied successfully (only partial application) intracutaneously with the test item concentration of 25 % (w/w) in PEG 300. Therefore, the next lower concentration of 15 % (w/w) tested in the pretest was selected.

>>> EPIDERMAL APPLICATION:
4 patches of filter paper were saturated with the test item at D = 50 % (technically the highest possible concentration to be applied sufficiently), E = 25 %, F = 15 % and G = 10 % (w/w) in PEG 300 and applied to the clipped and shaved flanks of 2 guinea pigs. The patches were covered by a strip of aluminum foil and firmly secured by elastic plaster wrapped around the trunk and covered with impervious adhesive tape.
21 hours after removal of the dressing the application site was depilated in order to visualize any resulting erythema.
3 hours later (48 hours from the epidermal application) the skin reaction was observed and recorded. After this observation a second observation (approximately 72 hours from the epidermal application) was made and once again recorded.
Based on the results obtained the concentration selected for induction and challenge in the main study was 50 % (w/w).


* MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 2
- Type of epicutaneous induction: occlusive
- SLS application: yes (0.5 mL at 10% w/w)
- Exposure period: on D1 (intradermal) and D8 (epidermal, 48-hr exposure)
- Test groups:
>>> Intradermal induction:
1) 1:1 (v/v) mixture of Freund's Complete Adjuvant and physiological saline
2) The test item at 25 % or 15 % (w/w) in PEG 300
3) The test item at 25 % or 15 % (w/w) in a 1:1 (v/v) mixture of Freund's Complete Adjuvant and physiological saline
>>> Epidermal application: test item at 50 % (w/w) in PEG 300
- Control group:
>>> Intradermal induction:
1) 1:1 (v/v) mixture of Freund's Complete Adjuvant and physiological saline
2) PEG 300
3) 1:1 (w/w) mixture of PEG 300 in a 1:1 (v/v) mixture of Freund's Complete Adjuvant and physiological saline
>>> Epidermal application: PEG 300 only
- Site: dorsal skin of the scapular region
- Frequency of applications: not applicable
- Duration: 8 days (duration of the induction phase)
- Concentrations: 15 or 25 % w/w by intradermal injection, 50 % by epidermal application

B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day of challenge: day 22
- Exposure period: 24 hours
- Test groups: test item in the vehicle only (+ vehicle only in the other flank)
- Control group: test item in the vehicle only (+ vehicle only in the other flank)
- Site: left (test item) and right (vehicle) flanks
- Concentrations: 50% (w/w)
- Evaluation: 48 hr after the beginning of the challenge

- Statistics: descriptive statistics were calculated for body weights. No inferential statistics were used.

Challenge controls:

Please refer to the field "Details on study design" above.

Positive control substance(s):

yes

Remarks:

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

Positive control results:

hexyl cinnamic aldehyde was tested in the same conditions as described above. Based on the findings, hexyl cinnamic aldehyde at 1% in PEG 300 was considered as a skin sensitizer.
The positive control was not included in the study, but put in an other report , as regularly control.

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

50 % of the test item

No. with + reactions:

0

Total no. in group:

5

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

50%

No. with + reactions:

0

Total no. in group:

10

Reading:

1st reading

Hours after challenge:

24

Group:

positive control

Dose level:

1% of the postive control

No. with + reactions:

4

Total no. in group:

10

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

50% of the test item

No. with + reactions:

0

Total no. in group:

5

Clinical observations:

In the control group, no skin reactions were observed in the animals when treated with either PEG 300 only or when treated with the test item at 50 % (w/w) in PEG 300.

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

50% of the test item

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

No mortality, no sign of systemic toxicity and no effect on body weight were observed during the study. In the test group, no skin reactions were observed in the animals when treated with either PEG 300 or the test item at 50 % (w/w) in PEG 300.

Reading:

2nd reading

Hours after challenge:

48

Group:

positive control

Dose level:

1% of the positive control

No. with + reactions:

1

Total no. in group:

10

Interpretation of results:

GHS criteria not met

Conclusions:

The substance is not a skin sensitiser.
According to Regulation (EC) No 1272/2008 and subsequent adaptations, the substance does not require classification as skin sensitiser.

Executive summary:

The sensitisation potential of Lanthane oxide was evaluated on Dunkin-Hartley guinea pigs according to the maximisation method of Magnusson and Kligman, described in EU method B.6, and in compliance with Good Laboratory Practice.

Ten test and five control guinea pigs were included in this study. Induction was carried out as the following:

- on day one, animals were injected by the intracutaneous route with Lanthane oxide (15 and 25% % w/w in PEG 300) +/- Freund Complete Adjuvant (treated group) or with PEG 300 +/- Freund Complete Adjuvant (control group) or with Freund Complete Adjuvant alone (both groups);

- on day 7, the same region received a topical application of sodium lauryl sulfate (10 % w/w in paraffinum perliquidum) in order to induce local irritation;

- on day 8, a 48-hour topical occlusive application was performed with Lanthane oxide at 50 % w/w in PEG 300 (test animals) or the vehicle (controls).

- on day 22, the control and test animals were challenged by a cutaneous application of the test substance at 50 % w/w in PEG 300 to the left flank. The right flank served as control and received the vehicle only. The test substance and the vehicle were maintained under an occlusive dressing for 24 hours.

Skin reactions (erythema and oedema) were evaluated approximately 24 and 48 hours after removal of the dressing.

No clinical signs and no deaths related to treatment were noted during the study.

After the challenge application, at the 24-hour and 48-hour readings, no cutaneous reactions were noted.

In this study, Lanthane oxide is not a dermal sensitizer.

Reference 2

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

supporting study

Study period:

From 23 November 2009 to 18 December 2009; preliminary dose range finding study was from 16 November 2009 to 21 November 2009

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

GLP - Guideline study. According to the ECHA guidance document “Practical guide 6: How to report read-across and categories (March 2010)”, the reliability was changed from RL1 to RL2 to reflect the fact that this study was conducted on a read-across substance.

Justification for type of information:

The solubility of aluminium lanthanum trioxide (AlLaO3) is low since dissolution of AlLaO3 in water resulted in La concentrations < 0.01 mg/L and Al concentrations < 0.03 mg/L after 34 days. The dissolution of AlLaO3 in water results in Al (3+) (=Al(H2O)6 (3+)) ions and La (3+) ions. Thus, the toxicological moieties of concern are aluminium and lanthanum ions. Thus, in the assessment of toxicity, data available for different aluminium and lanthanum substances are read-across since aluminium and lanthanum ions determine the toxicological potential of aluminium lanthanum trioxide, i.e. are the common toxicological moieties of concern. The effects of the substance aluminium lanthanum trioxide with regard to skin sensitisation are predicted to be equal to the effects of Al (3+) ions and La (3+) ions.

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.2600 (Skin Sensitisation)

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: Commission Regulation (EC) No 440/2008 of 30 May 2008; B.6

GLP compliance:

yes

Type of study:

guinea pig maximisation test

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

male

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: LAB-ÁLL Bt. Budapest, 1174 Hunyadi u. 7.
- Age at study initiation: young adult
- Weight at study initiation: 307-315 g
- Housing: The animals were housed in macrolon cages, size III (42Χ42Χ19 cm). Two or three animals were kept in each cage.
- Diet (e.g. ad libitum): PURINA Base – Lap gr. diet for rabbits produced by AGRIBRANDS Europe Hungary PLC, H-5300 Karcag, Madarasi road, Hungary, ad libitum. The composition of the diet was provided in Appendix 8 of the report.
- Water (e.g. ad libitum): Animals were provided ad libitum with tap water from the municipal supply as for human consumption, containing 50 mg/100 ml ascorbic acid. The water was routinely analyzed and was considered not to contain contaminants that could affect the purpose or integrity of the study.
- Acclimation period: Animals were allowed to acclimate for 6-7 days
- Other:
- Bedding: The bedding used was Lignocel 3-4 Fasern (produced by J. Rettenmaier & Söhne GmbH+CO.KG, D-73494 Rosenberg, Germany).
- Animal health: Only animals in acceptable health condition were used for the test as certified by the veterinarian
- Identification: The animals were individually marked using ear punching and the cages were also marked with individual identity cards.
- Randomization: Animals were randomly assigned to treatment groups with verification that the actual body weights showed an “acceptable homogeneity and variability among the groups”.


ENVIRONMENTAL CONDITIONS
- Temperature (°C): The temperate was maintained at 20±3C
- Humidity (%): and the relative humidity 30-70%
- Air changes (per hr): Air flow allowed 15-20 air exchanges/hour.
- Photoperiod (hrs dark / hrs light): Artificial light was used 12 hours daily from 6 a.m. to 6 p.m.

Route:

intradermal and epicutaneous

Vehicle:

other: The vehicle used was 1 % Methylcellulose in Humaqua. This vehicle was selected based on results from a Preliminary Compatibility Test. The methyl cellulose (1%) was obtained from Molar Chemicals Ltd (Batch #: K93935287). The Humaqua was manufactured by

Concentration / amount:

Justification for selected concentrations: The selected concentrations were based on the results of a preliminary dose range finding study:

Preliminary dose range finding study:
Two animals were used per concentration:
- For intra-dermal application, concentrations 5.0, 1.0, 0.1 and 0.01% (w/v) were tested (volume 0.1 ml); none produced skin reactions.
- For dermal application, 25% and 50% (for 24 hours), 75% and 100 % (for 48 hours) w/v concentrations were tested (volume 0.5 ml). Concentrations 25, 50 and 75 % (w/v) produced no skin reaction (scores 0-0) and 100% w/v concentration produced slight erythema (score 1-1).

The next concentrations were considered for the main study for:
Induction exposure:
- Intra-dermal – 1% (w/v) was used.
- Dermal – 100% (w/v) was used.

Challenge exposure:
- 75% (w/v) concentration and its 50% dilution (37.5% concentration - as a safeguard dose) were used.

Route:

epicutaneous, occlusive

Vehicle:

other: The vehicle used was 1 % Methylcellulose in Humaqua. This vehicle was selected based on results from a Preliminary Compatibility Test. The methyl cellulose (1%) was obtained from Molar Chemicals Ltd (Batch #: K93935287). The Humaqua was manufactured by

Concentration / amount:

Justification for selected concentrations: The selected concentrations were based on the results of a preliminary dose range finding study:

Preliminary dose range finding study:
Two animals were used per concentration:
- For intra-dermal application, concentrations 5.0, 1.0, 0.1 and 0.01% (w/v) were tested (volume 0.1 ml); none produced skin reactions.
- For dermal application, 25% and 50% (for 24 hours), 75% and 100 % (for 48 hours) w/v concentrations were tested (volume 0.5 ml). Concentrations 25, 50 and 75 % (w/v) produced no skin reaction (scores 0-0) and 100% w/v concentration produced slight erythema (score 1-1).

The next concentrations were considered for the main study for:
Induction exposure:
- Intra-dermal – 1% (w/v) was used.
- Dermal – 100% (w/v) was used.

Challenge exposure:
- 75% (w/v) concentration and its 50% dilution (37.5% concentration - as a safeguard dose) were used.

No. of animals per dose:

Test groups: 10 animals
Control group: 5 animals

Details on study design:

About 24 hours before the induction treatments, 5 x 5 cm on the scapular region of the animals was clipped free of hair and shaved.

Intra-dermal induction exposure
The animals in the test groups received three injections to each side:
- 1 injection with 0.10 ml of Freund's Complete Adjuvant mixed with physiological saline (1:1 v/v),
- 1 injection with 0.10 ml of the test item in 1 % Methylcellulose at the selected concentration,
- 1 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 were treated similarly with the omission of the test item from the injections to each side:
- 1 injection with 0.1 ml mix of Freund's Complete Adjuvant and physiological saline (1:1 v/v)
- 1 injection with 0.1 ml of 1 % Methylcellulose
- 1 injection with 0.1 ml of 50 w/v% formulation of the vehicle in a 1:1 mixture (v/v) Freund's Adjuvant and physiological saline.

Dermal induction exposure
For dermal induction exposure, the animals in the test group were treated with 0.5mL of 100% concentration of the test item. The control group was treated with 0.5mL of vehicle.

To apply the solutions, the exposed areas were covered for 48 hours with 4 layers of porous gauze pads soaked in the formulations and fully occlusive foil. After removal of the patch, a swab was used to remove the remaining test item.

Challenge exposure
Timing: two weeks after the dermal induction exposure and 3 weeks after the intra-dermal induction exposure
Details: Twenty-four hours before the treatment a 6x8cm area on each flank of the animals had the hair clipped and was shaved. The test item was applied to the left flank of the test and control animals using a 5x5 cm sterile gauze patch saturated with the test item (75 % (w/v) concentration). Right flank areas of all animals were treated with a 50 % dilution of the dermal challenge dose (i.e., 37.5 % w/v concentration). The volumes applied were approximately 0.5 ml and the patches remained in place, occluded, for 24 hours. After patch removal, residual test item was removed with a swab.

Observations:
Body weights were recorded at the beginning and at the end of the experiment
Mortality was monitored daily from delivery of the animals to the termination of the test
Clinical signs were monitored daily during the test.

Skin reactions:
- In the preliminary dose range finding study, irritation was observed at 1, 24, 48 and 72 hours after the patch removal;
- Intra-dermal induction exposure: 24 hours after the treatment
- Dermal induction exposure: 1, 24, 48 and 72 hours after the patch removal
- For the challenge exposure, observations were made 24 and 48 hours after the patch removal

Scoring of skin reactions:
Dermal irritation (preliminary dose range finding study and induction dermal exposure) was evaluated according to scoring system by Draize (1977):
A. Erythema and eschar formation
- No erythema 0
- Very slight erythema (barely perceptible) 1
- Well defined erythema 2
- Moderate to severe Erythema 3
- Severe erythema (beet redness) to slight eschar formation (injuries in depth) 4
B. Oedema formation
- No oedema 0
- Very slight oedema (barely perceptible) 1
- Slight oedema (edges of area well defined by definite raising) 2
- Moderate oedema (raised app. 1 mm) 3
- Severe oedema (raised more than 1 mm and extending beyond area of exposure) 4

Classification of skin irritation
0 = non irritant
1 = slightly irritant
2-3 = mildly to moderately irritant
4 = severely irritant

Scoring of skin sensitisation
0 = no visible change
1 = discrete or patchy erythema
2 = moderate and confluent erythema
3 = intense erythema and swelling

The percentage of animals showing positive reactions was calculated for both treatment and control groups. The percentage of control animals responding to the challenge was subtracted from the percentage of responding treatment animals.

Challenge controls:

The “safeguard dose” (50% dilution of the maximum dermal challenge dose (37.5% w/v)) was applied to the right flank area of the animals.

Positive control substance(s):

yes

Remarks:

The sensitivity and reliability of the experimental procedure is assessed in the testing laboratory twice a year. The results of the latest reliability check (described below) do not raise any concerns. hexyl cinnamic aldehyde (CAS No 101-86-0); mercapt

Positive control results:

In the test group, 10 animals were treated with the reference item. Challenge with the test item 2-Mercaptobenzothiazole resulted 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.

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

50 and 75%

No. with + reactions:

0

Total no. in group:

5

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 50 and 75%. No with. + reactions: 0.0. Total no. in groups: 5.0.

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

50 and 75%

No. with + reactions:

0

Total no. in group:

10

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 50 and 75%. No with. + reactions: 0.0. Total no. in groups: 10.0.

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

50 and 75%

No. with + reactions:

0

Total no. in group:

5

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 50 and 75%. No with. + reactions: 0.0. Total no. in groups: 5.0.

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

50 and 75%

No. with + reactions:

0

Total no. in group:

10

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 50 and 75%. No with. + reactions: 0.0. Total no. in groups: 10.0.

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

E-erythema; O-oedema

 

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

 

Challenge exposure:

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:

Body weight

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.

 

Clinical observations

No overt signs of an adverse clinical response to treatment were observed during the course of the study.

 

Mortality

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.

Interpretation of results:

not sensitising

Remarks:

Migrated information

Conclusions:

In this study, the Guinea-Pig Maximisation Test was used to determine the skin sensitisation potential of the test item aluminium hydroxide. In summary, the test item produced no positive responses in the previously sensitized test animals or in the control animals. The incidence rate of 0% and the net score 0.00 show that under the conditions of this test, aluminium hydroxide has no sensitisation potential.

Executive summary:

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.

Reference 3

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

weight of evidence

Study period:

1999

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

other: Relevant methodological deficiencies.

Justification for type of information:

The solubility of aluminium lanthanum trioxide (AlLaO3) is low since dissolution of AlLaO3 in water resulted in La concentrations < 0.01 mg/L and Al concentrations < 0.03 mg/L after 34 days. The dissolution of AlLaO3 in water results in Al (3+) (=Al(H2O)6 (3+)) ions and La (3+) ions. Thus, the toxicological moieties of concern are aluminium and lanthanum ions. Thus, in the assessment of toxicity, data available for different aluminium and lanthanum substances are read-across since aluminium and lanthanum ions determine the toxicological potential of aluminium lanthanum trioxide, i.e. are the common toxicological moieties of concern. The effects of the substance aluminium lanthanum trioxide with regard to skin sensitisation are predicted to be equal to the effects of Al (3+) ions and La (3+) ions.

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)

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
Acclimatization: not stated
Animal health: not stated
Housing: not stated
Bedding: not stated
Lighting: not stated
Temperature: not stated
Relative humidity: not stated
Ventilation: not stated
Diet: not stated
Water supply: not stated

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 250µL of phosphate buffered saline (PBS) containing 20µCi 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 4ºC 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: none used

Statistics:

No statistical testing was done.

Positive control results:

Not applicable.

Parameter:

SI

Test group / Remarks:

5 % concentration

Remarks on result:

other: no indication of skin sensitisation

Parameter:

SI

Test group / Remarks:

10 % concentration

Remarks on result:

other: no indication of skin sensitisation

Parameter:

SI

Test group / Remarks:

25 % concentration

Remarks on result:

other: no indication of skin sensitisation

The results for aluminium chloride hexahydrate were negative.

 

Known sensitizers, cobalt and beryllium were positive. 

Nickel, however, did not show positive results in the LLNA.

Interpretation of results:

not sensitising

Remarks:

Migrated information

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. Although this study did not provide sufficient detail in the description of the study and its outcome (Klimisch score 3), the results add to the weight of evidence for a low sensitisation potential of the target substances.

Reference 4

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Remarks:

in vivo

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Acceptable, well documented study which meets basic scientific principles

Justification for type of information:

The solubility of aluminium lanthanum trioxide (AlLaO3) is low since dissolution of AlLaO3 in water resulted in La concentrations < 0.01 mg/L and Al concentrations < 0.03 mg/L after 34 days. The dissolution of AlLaO3 in water results in Al (3+) (=Al(H2O)6 (3+)) ions and La (3+) ions. Thus, the toxicological moieties of concern are aluminium and lanthanum ions. Thus, in the assessment of toxicity, data available for different aluminium and lanthanum substances are read-across since aluminium and lanthanum ions determine the toxicological potential of aluminium lanthanum trioxide, i.e. are the common toxicological moieties of concern. The effects of the substance aluminium lanthanum trioxide with regard to skin sensitisation are predicted to be equal to the effects of Al (3+) ions and La (3+) ions.

Qualifier:

no guideline available

Principles of method if other than guideline:

Landsteiner-Draize Method. No more information.

GLP compliance:

no

Type of study:

other: Landsteiner / Draize method

Species:

guinea pig

Strain:

other: albino SPF

Sex:

male

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Central Institute for the Breeding of laboratory Animals, TNO, Zeist, The Netherlands
- Age at study initiation: young adult
- Weight at study initiation: 276 - 348 g
- Housing: animals were individually housed in suspended stainless steel cages, fitted with wire mesh floors and fronts
- Diet : all animals were fed stock diet (produced by Hope Farms, Woerden, The Netherlands), ad libitum. The composition of the diet and Al content are not provided (not a critical omission).
- Water: tap water ad libitum
- Acclimation period: 3 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 24 ± 1°C
- Humidity (%): 45 ± 5%
- Photoperiod (hrs dark / hrs light): Artificial light was used 12 hours daily from 6 a.m. to 6 p.m.

Randomization: Animals were randomly assigned to 4 treatment groups – two test groups and two control groups with 8 animals in each group.

Route:

intradermal

Vehicle:

other: It was mentioned that both test compounds were administered as aqueous suspensions. No details were available on the preparation of test item for administration, however.

Concentration / amount:

The concentration 33.33% was selected based on the results of a preliminary study that showed that one intra-dermal injection of 0.1 ml of a 33.33% aqueous suspension induced a mild skin reaction. Therefore, a 33.33% dilution was used for the induction and challenge injections.

Route:

intradermal

Vehicle:

other: It was mentioned that both test compounds were administered as aqueous suspensions. No details were available on the preparation of test item for administration, however.

Concentration / amount:

The concentration 33.33% was selected based on the results of a preliminary study that showed that one intra-dermal injection of 0.1 ml of a 33.33% aqueous suspension induced a mild skin reaction. Therefore, a 33.33% dilution was used for the induction and challenge injections.

No. of animals per dose:

Test groups: 8 animals;
Control group: 8 animals.

Details on study design:

RANGE FINDING TESTS:

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 10 intra-dermal injections
- Site: on the right flank within an area of 3 x 4 cm
- Frequency of applications: 3 times weekly for 3 weeks
- Concentrations: During the first injection, each animal received 0.05 ml of the administered solution, in the second to the tenth injections 0.1 ml was administered to each animal
- The injection sites were examined 24 hours after the injection.

B. CHALLENGE EXPOSURE
- Concentrations: 0.05 ml of the 33.33% diluted test sample
- Evaluation (hr after challenge): 2 weeks after the last injection
- The reaction sites were examined 24 hours after the injection.

OTHER:
Observations
Data on body weights, mortality and signs of systemic toxicity during the study are not available.

Skin reactions:
The test compounds caused mild (after 1 to 7 injections in 8 animals) to moderate (after 8 injection in 2 animals, after 9 injection in 4 animals and after 10 injections in 8 animals) skin reactions during the induction period.

Challenge controls:

The control animals were treated at the same time as test animals with 0.05 ml of the 33.33% dilution of the each test sample.

Positive control substance(s):

no

Positive control results:

not applicable

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

33.33%

No. with + reactions:

8

Total no. in group:

8

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 33.33%. No with. + reactions: 8.0. Total no. in groups: 8.0.

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

33.33%

No. with + reactions:

8

Total no. in group:

8

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 33.33%. No with. + reactions: 8.0. Total no. in groups: 8.0.

Reading:

1st reading

Hours after challenge:

24

Group:

positive control

Remarks on result:

not measured/tested

Test groups (8 animals)

AK 43/79

After the challenge dose of AK 43/79, all animals from this group developed a mild skin reaction.

 

AK 44/79

The challenge dose of AK 44/79 provoked mild reaction in 6 animals and moderate reaction in 2 animals.

 

Control group (8 animals)

AK 43/79 (controls)

After the challenge dose of AK 43/79, the control animals showed a mild reaction in 7 and a moderate reaction in 1 animal. 

 

AK 44/79 (controls)

The challenge dose of AK 44/79 provoked 7 mild reactions and 1 moderate reaction.

 

No significant differences were reported between both test compounds and the control animals with respect to the degree and incidence of erythema and oedema.

Individual data are provided in Table 1 and 2 of the report.

 

Table 1. Individual positive reactions (marked with + signs) observed during the induction and challenge period with AK 43/79

Test animals

Control animals

No.

Individual direct reaction

challenge

No.

Reaction to injection at the same time as the challenge

1

2

3

4

5

6

7

8

9

10

2278

+

+

+

+

+

+

+

+

+

++

+

2286

+

2279

+

+

+

+

+

+

+

++

++

++

+

2287

+

2280

+

+

+

+

+

+

+

+

+

++

+

2288

+

2281

+

+

+

+

+

+

+

++

++

++

+

2289

++

2282

+

+

+

+

+

+

+

+

++

++

+

2290

+

2283

+

+

+

+

+

+

+

+

+

++

+

2291

+

2284

+

+

+

+

+

+

+

+

++

++

+

2292

+

2285

+

+

+

+

+

+

+

+

+

++

+

2293

+

2298

+

+

+

+

++

++

++

++

++

+

2306

+

2299

+

+

+

+

+

++

++

++

++

++

+

2307

+

2300

+

+

+

+

+

+

++

+

++

++

++

2308

++

2301

+

+

+

+

+

+

++

++

++

++

+

2309

+

2302

+

+

+

+

+

++

++

++

++

++

+

2310

+

2303

+

+

+

+

+

++

++

++

++

++

+

2311

+

2304

+

+

+

+

+

+

++

++

++

++

+

2312

+

2305

+

+

+

+

+

++

++

++

++

++

++

2313

+

 Degree of reaction: + = mild; ++ = moderate

Interpretation of results:

not sensitising

Remarks:

Migrated information

Conclusions:

Based on the reaction to the challenge dose, it can be concluded that Al oxide AK 43/79 and Aluminium oxide AK 44/79 has no sensitisation potential under the experimental conditions.

Executive summary:

The skin sensitisation potential of two samples aluminium oxide, namely aluminium oxide TBH: AK 43/79 and aluminium oxide TOF: AK 44/79, was assessed in guinea pigs (male albino SPF, 8 animals in each group) using the Landsteiner/Draize method (Central Institute for Nutrition and Food Research, Germany) at the request of Degussa AG, Germany (1979). Both compounds were administered by intra-dermal injections. A 33.3% aqueous suspension was used in both the induction and challenge phases. During the induction phase, the test animals received 10 intra-dermal injections of the test suspension, 3 times per week over a 3 week period. The test suspensions were administered to different shaved spots on the right flank of the animals within an area of 3 x 4 cm. The injected volume was 0.05 mL for the first injection and 1.0 mL for subsequent. The control group received a single injection during this phase. The injection sites were examined 24 hours after the injection and the diameter, colour and thickness of any lesions were used as criteria for the intensity of the reaction. In the induction phase,following 1 to 7 injections of AK 43/79, all animals showed mild reactions. Two animals showed moderate reactions after the 8^th injection, an additional 2 animals showed moderate reactions after the 9^th injection and all 8 animals showed a moderate reaction after the 10^th injection. Data were provided on any skin reactions on the single injection received by the control animals. For AK 44/79, all reactions were mild until after the 6^th injection when 5 animals showed a moderate reaction. All animals showed moderate reactions

after the 7^th to 10^th injections.  Two weeks after the last injection, guinea pigs from both test groups and the control group received the challenge dose in the amount of 0.05 mL per animal. The reaction sites were examined 24 hours after the injection.After the challenge dose of AK 43/79, all animals exposed during the induction period developed a mild skin reaction. A mild reaction was also found in 7 and a moderate reaction in 1 of the animals in the control group. The challenge dose of AK 44/79 provoked a mild reaction in 6 animals and moderate reaction in 2 animals exposed during the induction period. In the control animals, 7 mild reactions and 1 moderate reaction were observed. No significant differences were observed between the test and control animals with respect to the degree and incidence of erythema and oedema. Under the conditions of this test, aluminium oxide AK 43/79 and aluminium oxide AK 44/79 are not skin sensitizers (Landsteiner/Draize test, guinea pig).

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Justification for classification or non-classification

Aluminium lanthanum trioxide does not have a skin sensitisation potential and therefore must not be classified and labelled according to Regulation (EC) 1272/2008 and subsequent adaptations.