Magnesium neodecanoate

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2018-02-05 to 2018-03-13

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Version / remarks:

2015-07-28

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

signed 2015-06-05

Test material

Test material information

Constituent 1

Reference substance name:

Magnesium neodecanoate

EC Number:

260-742-8

EC Name:

Magnesium neodecanoate

Cas Number:

57453-97-1

IUPAC Name:

magnesium neodecanoate

Test material form:

solid

Details on test material:

- State of aggregation: solid

Specific details on test material used for the study:

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: dry; < 30 °C

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Deutschland, 97633 Sulzfeld, Germany
- Age at study initiation: approx 41 and 43 weeks old
- Weight at study initiation: 3.9 – 4.3 kg
- Housing: individually housed in ABS-plastic or Noryl rabbit cages, floor 4200 cm2
- Diet (ad libitum): autoclaved hay and Altromin 2123 maintenance diet for rabbits, rich in crude fibre
- Water (ad libitum): tap water
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature: 18 ± 3 °C
- Relative humidity: 55 ± 10 %
- Air changes: at least 10 x / hour
- Photoperiod (hrs dark / hrs light): 12/12

Test system

Type of coverage:

semiocclusive

Preparation of test site:

clipped

Vehicle:

unchanged (no vehicle)

Controls:

no

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5 g of the test item
The test item was applied directly without moistening, due to the sticky and hydrophobic nature of the test item. The test item was evely distributed on the skin and a good test item contact with the skin was given.

Duration of treatment / exposure:

initial animal: 3 minutes, 1 hour and 4 hours
confirmatory animal: 4 hours

Observation period:

Initial animal: 14 days
Confirmatory animal: 21 days

Number of animals:

2 male rabbits

Details on study design:

TEST SITE
- Area of exposure/Type of wrap if used: approx. 24 hours before the test, the fur was removed from the dorsal area of the trunk by using an electric clipper. The test item was applied to a small area (approx. 6 cm²) of skin on one side of the dorsal area and covered with a gauze patch, which was held in place with a non-irritating tape. The untreated other side served as control. The test item was applied to the patch first and then applied to the skin. The patch was fixed with a semi-occlusive dressing. The limits of the application site were marked with an ink marker.

INITIAL AND CONFIRMATORY TESTING
Initially, a single animal test was employed. Up to three test patches were applied sequentially to the animal. The first patch was removed after three minutes. No serious skin reaction was observed, so a second patch was applied at a different site and removed after one hour. The observations at this stage indicated that exposure can humanely be allowed to extend to four hours, so a third patch was applied and removed after four hours, and the response was graded. No corrosive effect was observed after the last patch was removed, so the animal was observed for 14 days.

The results of the initial test indicate the test item is not corrosive to the skin using the procedure described. In order to confirm the irritant response, one additional animal was treated with one patch for an exposure period of 4 hours. According to OECD 404, section 17, treatment of a third animal can be omitted when animal no. 1 and 2 exhibit the same response. Furthermore, according to the classification directives the results of two animals were sufficient for classification of the test item. Moreover, as the test item showed no signs of corrosion in two animals, it is considered that adding a third animal would not change the outcome of the study

REMOVAL OF TEST SUBSTANCE
- Washing: at the end of the exposure period, the residual test item was not removed.

OBSERVATION TIME POINTS
- initial animal: immediatley and 1 hour, 24, 48 and 72 hours after patch removal
- confirmatory animal: 1 hour, 24, 48 and 72 hours after patch removal

SCORING SYSTEM: according to the Draize scale
In addition, all local effects such as hyperplasia, scaling, discolouration, fissures and scabs were also recorded.

FURTHER OBSERVATIONS
- body weights: prior to the administration and at the end of the observation period
- any systemic effects were also recorded.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

mean

Remarks:

animal #1

Time point:

24/48/72 h

Score:

2

Max. score:

4

Reversibility:

not fully reversible within: 14 days

Results 2

Irritation parameter:

edema score

Basis:

mean

Remarks:

animal #1

Time point:

24/48/72 h

Score:

0.67

Max. score:

4

Reversibility:

fully reversible within: 72 hours

Results 3

Irritation parameter:

erythema score

Basis:

mean

Remarks:

animal #2

Time point:

24/48/72 h

Score:

2

Max. score:

4

Reversibility:

not fully reversible within: 21 days

Results 4

Irritation parameter:

edema score

Basis:

mean

Remarks:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

4

Irritant / corrosive response data:

- initial animal: the examination of the test site immediately and 1 hour after the patch removal revealed slight erythema (grade 1). Furthermore, moderate erythema (grade 2) was observed 24, 48 and 72 hours and up to day 7 after patch removal as well as on days 12 to 14 after patch removal. Slight erythema (grade 1) was observed on day 8 to day 11 after patch removal. Lastly, slight oedema (grade 1) was observed on 24 and 48 hours after patch removal.
No adverse changes apart from the reactions described above were observed at the skin sites.

- confirmatory animal: the examination of the test site 1 hour after the patch removal revealed slight erythema (grade 1). Furthermore, moderate erythema (grade 2) was observed 24, 48 and 72 hours and up to day 4 after patch removal. Lastly, slight erythema (grade 1) was observed on day 5 to day 21 after patch removal.
The animal showed scaling at the application site from day 9 to day 15.

Other effects:

- body weight: there were no significant body weight changes during the observation period
- clinical signs: no mortality was observed.

Applicant's summary and conclusion

Interpretation of results:

Category 2 (irritant) based on GHS criteria

Conclusions:

The test item is irritating to the skin.
According to the Regulation (EC) No 1272/2008 and subsequent amendments and corrections, the test item is irritating to the skin (Category 2; H315).