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Description of key information

No skin sensitisation study with cerium neodecanoate is available, thus the skin sensitisation potential will be addressed with existing data on the individual moieties cerium and neodecanoate.

Cerium neodecanoate is not expected to show signs of dermal sensitisation, since the two moieties cerium and neodecanoate have not shown any skin sensitisation potential in experimental testing.

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Referenceopen allclose all

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
experimental study
Adequacy of study:
weight of evidence
Study period:
27 February 2013 - 30 April 2013
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
Well performed study following the OECD guideline 406, EU Method B.6 and US EPA OPPTS 870.2600 with no major deviations. Minor variations from the target relative humidity and temperature ranges were observed during the study. These deviations were considered to have no impact on the animal health and in the study.
Qualifier:
according to guideline
Guideline:
OECD Guideline 406 (Skin Sensitisation)
Deviations:
no
Qualifier:
according to guideline
Guideline:
EU Method B.6 (Skin Sensitisation)
Deviations:
no
Qualifier:
according to guideline
Guideline:
EPA OPPTS 870.2600 (Skin Sensitisation)
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Type of study:
guinea pig maximisation test
Justification for non-LLNA method:
Since the LLNA is the preferred method for new in vivo testing, the use of the standard guinea pig tests to obtain new data on the skin sensitisation potential of a substance will be acceptable only in exceptional circumstances and will require scientific justification. However, existing data of good quality that were generated before 10 May 2017, or for which the study was initiated before 10 May 2017, and derived from such tests are acceptable; and if these tests provide clear results that are adequate for classification, even when a conclusion on potency (Cat. 1A or not) cannot be drawn, they will preclude the need for further in vivo testing.
Species:
guinea pig
Strain:
other: LAL/HA/BR
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, 5 weeks
- Weight at study initiation: 274 – 379 g
- Housing: macrolon cages size IV with laboratory bedding. 5 animals/cage to allow socialization.
- Diet (e.g. ad libitum): CuniFort Diet for Rabbits (Bonafarm-Bábolna Takarmány Ltd.) ad libitum. This diet is classified as being suitable for guinea pigs and used by the breeder/supplier, animals were fully adapted to this diet on arrival.
- Water (e.g. ad libitum): Animals received tap water from municipal supply containing 50 mg/100 mL ascorbic acid, ad libitum.
- Acclimation period: 7 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18.0 – 23.2 °C
- Humidity (%): 22 – 47%
- Air changes (per hr): 15-20 air exchange/hour
- Photoperiod (hrs dark / hrs light): 12 hours daily from 6 a.m. to 6 p.m. (artificial light)

IN-LIFE DATES: From: 27 February 2013 To: 07 April 2013
Route:
intradermal and epicutaneous
Vehicle:
physiological saline
Remarks:
NaCl 0.9%
Concentration / amount:
MAIN STUDY
- Intra-dermal induction exposure: 0.01% (w/v)
- Dermal induction exposure: 100% (w/v)
- Challenge exposure: 100% (w/v) as highest non-irritant concentration; 50% (w/v) as safeguard concentration
Route:
epicutaneous, occlusive
Vehicle:
physiological saline
Remarks:
NaCl 0.9%
Concentration / amount:
MAIN STUDY
- Intra-dermal induction exposure: 0.01% (w/v)
- Dermal induction exposure: 100% (w/v)
- Challenge exposure: 100% (w/v) as highest non-irritant concentration; 50% (w/v) as safeguard concentration
No. of animals per dose:
MAIN STUDY
- Intra-dermal and dermal induction exposure: 10 in control group and 20 in test group.
- Challenge exposure:
Control group: 5 (Left flank) - 5 (Right flank)
Test group: 10 (Left flank: 100 % test substance) - 10 (Right flank: 50 % test substance)
Details on study design:
RANGE FINDING TESTS:
- Intra-dermal injection: 0.01, 0.1, 0.5, 1, 2.5 and 5 % (w/v) concentrations were used for intra-dermal injection. 0.1 mL was injected per concentration into the hair free skin of the flanks. Each concentration was injected in duplicate. Local effects (for erythema and oedema, any other observations of changes to the skin) were examined and scored 1, 24, 48 and 72 hours after treatment.

- Dermal application: 25, 50, 75 and 100% (w/v) concentrations were used for dermal application. Two animals were used per concentration. 0.5 mL was applied onto the clipped and shaved skin of the animals per concentration (occlusive exposure). Time of exposure was 24 hours. Skin effects were scored for erythema and oedema, any other observations of changes to the skin were recorded. Local effects were examined and scored 1, 24, 48 and 72 hours after patch removal.

- Control animals were treated with saline.

MAIN STUDY
A. INDUCTION EXPOSURE

- No. of exposures:
Intra-dermal: A series of three injections was administered on each side of the scapular region of treatment group animals, as follows, resulting in six injections per animal:
2 injections with 0.1 mL of Freund's Complete Adjuvant mixed with physiological saline (1:1) (v/v),
2 injections with 0.1 mL of the test item in saline solution at 0.01% (w/v) concentration,
2 injections with 0.1 mL of test item in 0.01% (w/v), formulated in a 1:1 (v/v) mixture of Freund's Complete Adjuvant and physiological saline.

Dermal: the same inter-scapular region which received the intradermal injections, were used for dermal induction exposure. One dermal application was used.

- Exposure period: time of exposure is not applicable for intra-dermal injection; dermal induction exposure period was 48 hours.

- Test groups: test item in saline

- Control group: The control animals were treated similarly as the test group. However, the vehicle without the test item was used for injections.

- Site: scapular region

- Frequency of applications: not applicable

- Duration: 0-8 d

- Concentrations: same throughout

B. CHALLENGE EXPOSURE

- No. of exposures: one

- Day(s) of challenge: two weeks after the topical induction application, the animals were exposed to a dermal challenge dose (day 22 of treatment)

- Exposure period: 24 hours

- Test groups: 0.5 mL of the test item at 100 % (w/v) concentration in saline (highest non-irritant dose) was applied to the left flank of 10 test animals. The remaining 10 animals were treated with approximately 0.5 mL of the 50 % dilution of the maximum dermal challenge dose (50 % (w/v) in saline as a safeguard dose) to the left flank. The right shaved flank area of all animals was treated with saline.

- Control group: 0.5 mL of the test item at 100 % (w/v) concentration in saline (highest non-irritant dose) was applied to the left flank of 5 control animals. . The remaining 5 animals were treated with approximately 0.5 mL of the 50 % dilution of the maximum dermal challenge dose (50 % (w/v) in saline as a safeguard dose) to the left flank. The right shaved flank area of all animals was treated with saline.

- Site: left and right flank

- Concentrations: 100 % (w/v) as highest non-irritant concentration; 50 % (w/v) as safeguard concentration

- Evaluation (hr after challenge): 24 and 48 hours after the patch removal.

OTHER:
Time of observations after intra-dermal induction: 24 hours after treatment
Time of observations after dermal induction: 1, 24, 48 and 72 hours after the patch removal
Challenge controls:
No naive control group was used for the challenge exposure.
Positive control substance(s):
no
Remarks:
The sensitivity and reliability of the experimental procedure is assessed twice a year by use of items which are known to have moderate skin sensitisation properties such as 2-Mercaptobenzothiazole
Positive control results:
The sensitivity and reliability of the experimental procedure is assessed twice a year by use of items which are known to have moderate skin sensitisation properties such as 2-Mercaptobenzothiazole. On the basis of the results of the most recent reliability check study (start of experiment: 28 November 2012, date of report: 21 January 2013), the reference item 2-Mercaptobenzothiazole was classified as a skin sensitizer. This demonstrated that the experimental procedure and the test system were appropriate.
Reading:
1st reading
Hours after challenge:
24
Group:
test chemical
Dose level:
100 % (w/v)
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
no
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 100 % (w/v). No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: no.
Reading:
2nd reading
Hours after challenge:
48
Group:
test chemical
Dose level:
100 % (w/v)
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
no
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 100 % (w/v). No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: no.
Reading:
1st reading
Hours after challenge:
24
Group:
negative control
Dose level:
100 % (w/v)
No. with + reactions:
0
Total no. in group:
5
Clinical observations:
no
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 100 % (w/v). No with. + reactions: 0.0. Total no. in groups: 5.0. Clinical observations: no.
Reading:
2nd reading
Hours after challenge:
48
Group:
negative control
Dose level:
100 % (w/v)
No. with + reactions:
0
Total no. in group:
5
Clinical observations:
no
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 100 % (w/v). No with. + reactions: 0.0. Total no. in groups: 5.0. Clinical observations: no.
Reading:
1st reading
Hours after challenge:
24
Group:
test chemical
Dose level:
50% (w/v)
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
no
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 50% (w/v). No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: no.
Reading:
2nd reading
Hours after challenge:
48
Group:
test chemical
Dose level:
50% (w/v)
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
no
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 50% (w/v). No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: no.
Reading:
1st reading
Hours after challenge:
24
Group:
negative control
Dose level:
50% (w/v)
No. with + reactions:
0
Total no. in group:
5
Clinical observations:
no
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 50% (w/v). No with. + reactions: 0.0. Total no. in groups: 5.0. Clinical observations: no.
Reading:
2nd reading
Hours after challenge:
48
Group:
negative control
Dose level:
50% (w/v)
No. with + reactions:
0
Total no. in group:
5
Clinical observations:
no
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 50% (w/v). No with. + reactions: 0.0. Total no. in groups: 5.0. Clinical observations: no.
Group:
positive control
Remarks on result:
other: The sensitivity and reliability of the experimental procedure is assessed twice a year by use of items which are known to have moderate skin sensitisation properties such as 2-Mercaptobenzothiazole

Body weight: there were no notable differences between the test animal group and the control group.

Mortality: there were no moribund or dead animals during the study.

Local / Clinical observations: During the induction period very slight erythema was observed in all test item treated animals, 1 hour after the patch removal. No further local skin effects were observed in either the test group or in the control group. No clinical signs were noted during the study.

Range finding test

- Intra-dermal application: the test item at concentrations of 0.1, 0.5, 1, 2.5 and 5% (w/v) produced focal necrosis from 24 hours after the treatment; therefore these concentrations were not acceptable for the main study. Very slight erythema (score 1) was also observed at 48 hours after the treatment at the treatment site away from the necrotic foci at concentrations of 0.5, 1, 2.5 and 5% (w/v). The concentration of 0.01% (w/v) caused no reaction (scores 0 -0 for erythema and oedema) in the skin of guinea pigs.

- Dermal application: It was found that 0.5 mL of the test item formulations at concentrations of 100, 75 and 50% (w/v) caused very slight erythema (score 1) at 1 hour after patch removal. At concentration of 50 % (w/v) and 24 hours after the patch removal, barely perceptible erythema (score 1) was observed in one of two animal but 0/2 animals at the higher 100% application; this observation was considered to be an individual response and not a clear treatment related response. Concentration of 25% (w/v) produced no reaction (scores 0-0) on the skin of guinea pigs.

Interpretation of results:
not sensitising
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
Under the conditions of the present assay the test item Cerium trichloride was shown to have no sensitisation potential and classified as a non-sensitizer, according to current EU-regulations.
Endpoint:
skin sensitisation: in vivo (LLNA)
Type of information:
experimental study
Adequacy of study:
weight of evidence
Study period:
30 October 2012-14 November 2012
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Well documented GLP study performed according to OECD Guideline 429 and EU Method B42. The study has been scored Klimish 2 to reflect the ambiguity of the results (expert judgment).
Qualifier:
according to guideline
Guideline:
OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)
Deviations:
no
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)
Species:
mouse
Strain:
other: CBA/CaOlaHsd
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Harlan Laboratories
- Age at study initiation: 8-12 weeks
- Weight at study initiation: 15-23 g
- Housing: Individually housed in suspended solid-floor polypropylene cages with softwood flakes
- Diet (e.g. ad libitum): ad libitum 2014C Teklad Global Rodent diet
- Water (e.g. ad libitum): ad libitum tap water
- Acclimation period: At least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-25 degrees C
- Humidity (%): 30-70%
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12

Vehicle:
other: ethanol/water 7:3
Concentration:
Range-finding test: 50%. This concentration was selected as maximum concentration suitable for dosing in solubility trials.
Main test: 10, 25 and 50%. These concentrations were selected as, at 50%, no excessive irritation was noted.
No. of animals per dose:
Range-finding test: 1
Main test: 4
Details on study design:
RANGE FINDING TESTS:
- Compound solubility: the solubility of the test item in different vehicles was determined on the basis of maximising the concentration and solubility whilst producing a solution/suspension suitable for application. The vehicles tested were: acetone/olive oil (4:1), dimethyl formamide, butanone, dimethyl sulphoxide, acetone and ethanol/distilled water (7:3). The concentration tested was 50% (0.5 g test iem + 0.5 g vehicle).
- Irritation: excessive ear thickness (> 25%)
- Lymph node proliferation response: Ratio of 3HTdR incorporation relative to control.

MAIN STUDY
- Criteria used to consider a positive response: Threefold or greater increase in 3HTdR incorporation relative to control.

TREATMENT PREPARATION AND ADMINISTRATION:
-25 uL test item to dorsal ear surface days 1, 2, and 3
-Day 6; injection via tail vein of 25 µL PBS containing 3H-methyl thymadine (80 µCi/mL, specific activity 2.0 Ci/mmol), total 20µCi per mouse.
-Asphixiation by carbon dioxide 5 hours after 3HTdR injection.
-Auricular lymph nodes excised, drained and pooled for each group, and 1 mL PBS added to pool.
-Cells disaggregated through 200 mesh stainless gauze, rinsed w/4mL of PBS into a petri dish.
-Suspension was transferred to a centrifuge tube w/rinse, pelleted and resuspended twice in PBS.
-Pellet resuspended in 3 mL 5% TCA.
- After 18 hours at 4 degrees C; precipitates recovered by centrifugation and resuspended in 1 mL TCA and transferred to scintillation vial.
- Disintegrations per minute counted with Beckman LS6500 system
Positive control substance(s):
hexyl cinnamic aldehyde (CAS No 101-86-0)
Positive control results:
DPM: 67009.02
Desintegrations per minute: 94581.61 dpm/min
Stimulation Index: 11.79
Parameter:
other: disintegrations per minute (DPM)
Remarks on result:
other: Vehicle-9024.63 dpm Test item: 10%-19147.17 dpm 25%-40083.18 dpm 50%- 38746.54 dpm
Parameter:
SI
Value:
2.12
Test group / Remarks:
10 %
Remarks on result:
other: Vehicle-na Test item: 10%-2.12 25%-4.44 50%- 4.29
Parameter:
SI
Value:
4.44
Test group / Remarks:
25 %
Remarks on result:
other: Vehicle-na Test item: 10%-2.12 25%-4.44 50%- 4.29
Parameter:
SI
Value:
4.29
Test group / Remarks:
50 %
Remarks on result:
other: Vehicle-na Test item: 10%-2.12 25%-4.44 50%- 4.29

Main study - Observations

- Clinical Observations: there were no deaths. No signs of systemic toxicity were noted in the test or control animals during the test.

- Body weights: bodyweight changes of test animals were comparable to corresponding control (vehicle) animals.

- Ear thickness: there was an overall increase in ear thickness (>25%) in mice treated at 50% on day 6, which contradicted the results of the preliminary study. No increase in ear thickness was noted in any other test or control animals. Very slight erythema was noted in animals treated with the positive control at a concentration of 15% v/v on days 2 and 3.

Main study

- No EC3 calculated.

Interpretation of results:
ambiguous
Remarks:
Migrated information Criteria used for interpretation of results: expert judgment
Conclusions:
At concentrations of 50% and 25%, the stimulation indexes are only slightly higher than the threefold increase in 3HTdR incorporation compared to the control values (4.29 and 4.44 respectively). It was observed that the test item has the potential to cause irritation as shown in the main test animals (50% and 25%). On this basis the test item can not be clearly classified as a sensitiser.
Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Limited study details are provided, preGLP
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 406 (Skin Sensitisation)
GLP compliance:
no
Type of study:
guinea pig maximisation test
Justification for non-LLNA method:
Since the LLNA is the preferred method for new in vivo testing, the use of the standard guinea pig tests to obtain new data on the skin sensitisation potential of a substance will be acceptable only in exceptional circumstances and will require scientific justification. However, existing data of good quality that were generated before 10 May 2017, or for which the study was initiated before 10 May 2017, and derived from such tests are acceptable; and if these tests provide clear results that are adequate for classification, even when a conclusion on potency (Cat. 1A or not) cannot be drawn, they will preclude the need for further in vivo testing.
Species:
guinea pig
Strain:
other: Internal strain, no additional details provided
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Shell Toxicology Laboratory
Route:
intradermal and epicutaneous
Vehicle:
unchanged (no vehicle)
Concentration / amount:
0.1 ml test material in 50:50 Freund's complete adjuvant and corn oil
Route:
epicutaneous, occlusive
Vehicle:
unchanged (no vehicle)
Concentration / amount:
0.1 ml test material in 50:50 Freund's complete adjuvant and corn oil
No. of animals per dose:
5 per sex per dose
Details on study design:
MAIN STUDY
A. INDUCTION EXPOSURE - INTRADERMAL INJECTION
- No. of exposures: 2
- Exposure period: 1 week
- Test groups: single group
- Control group: Freund's complete adjuvant or corn oil
- Site: each side of the midline in the shorn skin of the shoulder region

B. INDUCTION EXPOSURE - TOPICAL APPLICATION
- No. of exposures: 2
- Exposure period: 1 week after intradermal injection
- Test groups: single group
- Control group: Freund's complete adjuvant or corn oil
- Site: each side of the midline in the shorn skin of the shoulder region
- Concentrations: 0.1 ml via occluded patch.

C. CHALLENGE EXPOSURE
- No. of exposures: Single 24 hour exposure
- Day(s) of challenge: 2 weeks after topical application
- Test groups: yes
- Control group: yes
- Site: 3x3 cm area on flank
- Evaluation (hr after challenge): 24 and 48 hours after removal
Reading:
1st reading
Hours after challenge:
24
Group:
test chemical
Dose level:
0.1 ml
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
Not sensitizing
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 0.1 ml. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: Not sensitizing.
Reading:
1st reading
Hours after challenge:
24
Group:
negative control
Remarks on result:
other: results were not presented
Reading:
1st reading
Hours after challenge:
24
Group:
positive control
Remarks on result:
not measured/tested
Interpretation of results:
not sensitising
Remarks:
Migrated information
Conclusions:
Neodecanoic acid is not sensitizing.
Executive summary:

In this study, neodecanoic acid was examined for skin sensitization potential in the guinea pig maximization procedure of Magnusson and Kligman.

 

A preliminary screen was carried out to determine the concentrations of test material to be used for intradermal induction, topical induction, and topical challenge. Two male and female guinea pigs were used for each test concentration.

 

Groups of ten male and ten female guinea pigs were used for the test and a further five males and five females as controls. 

 

Induction was accomplished in two stages. 

 

1) Intradermal injection

Two rows of three injections were made, one on each side of the midline in the shorn skin of the shoulder region. 

 

2) Topical application

One week after the intradermal injections, the same area was clipped free from hair. A 4x4 cm patch of filter paper was soaked in a solution of the test material and placed over the injection sites and covered with an occlusive dressing. The dressing was left in place for 48 hours. 

 

The challenge procedure was carried out two weeks after topical induction. Challenge was accomplished by topical application of the test material to the flank of animals via an occluded patch. The challenge lasted 24 hours. 

 

Immediately after the challenge, and then again at 24 and 48 hours later, each animals was examined for signs of skin sensitization.

 

At no point was there any evidence of skin sensitization produced by neodecanoic acid.   

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not sensitising)
Additional information:

Cerium

The skin sensitisation potential of cerium chloride was evaluated by performing an in vivo local lymph node assay. In a range finding study 50% of cerium chloride was selected as maximum concentration suitable for dosing in solubility trials. The main study was performed with 10, 25 and 50% with 4 animals per dose. These concentrations were selected as at 50% no excessive irritation was noted. DPM served as positive control. At concentrations of 50% and 25%, the stimulation indexes are only slightly higher than the threefold increase in 3HTdR incorporation compared to the control values (4.29 and 4.44 respectively). It was observed that the test item has the potential to cause irritation as shown in the main test animals (50% and 25%). On this basis the test item can not be clearly classified as a sensitiser.

 

Thus, for clarification, a guinea pig maximisation test was performed. Intra-dermal injection of 0.01, 0.1, 0.5, 1, 2.5 and 5% cerium chloride as well as dermal application of 25, 50, 75 and 100 % were tested in a range finding study. Based on these results 0.01% cerium chloride were used for the induction exposure. Two weeks after the topical induction application, the animals were exposed to a dermal challenge dose of 100% or 50% (day 22 of treatment) for 24 hours. The control animals were treated similarly as the test group. Body weight, mortality and clinical signs were recorded. Under the conditions of the present assay the test item Cerium chloride was shown to have no sensitisation potential and classified as a non-sensitizer, according to current EU-regulations.

 

Neodecanoate

Neodecanoic acid has been examined for skin sensitization potential in the guinea pig maximization procedure of Magnusson and Kligman. Groups of ten male and ten female guinea pigs were used for the test and a further five males and five females as controls. Induction was accomplished in two stages. 

 1) Intradermal injection: Two rows of three injections were made, one on each side of the midline in the shorn skin of the shoulder region. 2) Topical application: One week after the intradermal injections, the same area was clipped free from hair. A 4x4 cm patch of filter paper was soaked in a solution of the test material and placed over the injection sites and covered with an occlusive dressing. The dressing was left in place for 48 hours. The challenge procedure was carried out two weeks after topical induction. Challenge was accomplished by topical application of the test material to the flank of animals via an occluded patch. The challenge lasted 24 hours. Immediately after the challenge, and then again at 24 and 48 hours later, each animals was examined for signs of skin sensitization. At no point was there any evidence of skin sensitization produced by neodecanoic acid.   

Cerium neodecanoate

Cerium neodecanoate is not expected to show signs of dermal sensitisation, since the two moieties cerium and neodecanoate have not shown any skin sensitisation potential in experimental testing. Thus, cerium neodecanoate is not to be classified according to regulation (EC) 1272/2008 as skin sensitising. Further testing is not required. For further information on the toxicity of the individual assessment entities, please refer to the relevant sections in the IUCLID and CSR.

Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available

Justification for classification or non-classification

Cerium neodecanoate is not expected to show signs of dermal sensitisation, since the two moieties cerium and neodecanoate have not shown any skin sensitisation potential in experimental testing. Thus, cerium neodecanoate is not to be classified according to regulation (EC) 1272/2008 as skin sensitising.