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Toxicological information

Skin irritation / corrosion

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Administrative data

Endpoint:
skin irritation: in vivo
Type of information:
experimental study
Adequacy of study:
key study
Study period:
15-Feb-2005 to 15-Apr-2005
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2005
Report date:
2005

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
EU Method B.4 (Acute Toxicity: Dermal Irritation / Corrosion)
Version / remarks:
Commission Directive 2004/73/EC, B.4. “Acute Toxicity: Dermal Irritation/Corrosion”, April 29, 2004.
Qualifier:
according to guideline
Guideline:
OECD Guideline 404 (Acute Dermal Irritation / Corrosion)
Version / remarks:
adopted April 24, 2002
GLP compliance:
yes (incl. QA statement)

Test material

Constituent 1
Reference substance name:
2,2',2''-nitrilotriethanol
EC Number:
203-049-8
EC Name:
2,2',2''-nitrilotriethanol
Cas Number:
102-71-6
Molecular formula:
C6H15NO3
IUPAC Name:
2,2',2''-nitrilotriethanol
Constituent 2
Reference substance name:
2-(2-aminoethoxy)ethanol
EC Number:
213-195-4
EC Name:
2-(2-aminoethoxy)ethanol
Cas Number:
929-06-6
Molecular formula:
C4H11NO2
IUPAC Name:
2-(2-aminoethoxy)ethanol
Constituent 3
Reference substance name:
Heptanoic acid
EC Number:
203-838-7
EC Name:
Heptanoic acid
Cas Number:
111-14-8
Molecular formula:
C7H14O2
IUPAC Name:
heptanoic acid
Constituent 4
Reference substance name:
Isooctanoic acid
EC Number:
246-617-0
EC Name:
Isooctanoic acid
Cas Number:
25103-52-0
Molecular formula:
C8H16O2
IUPAC Name:
isooctanoic acid
Constituent 5
Reference substance name:
Water
EC Number:
231-791-2
EC Name:
Water
Cas Number:
7732-18-5
Molecular formula:
H2O
IUPAC Name:
water
Test material form:
liquid

Test animals

Species:
rabbit
Strain:
New Zealand White
Details on test animals or test system and environmental conditions:
New Zealand White Rabbit, SPF
Recognized by the international guidelines as the recommended test system.
Source: Charles River Laboratories France, BP 0109, F-69592 L’Arbresle.
Number of animals per test: 3 (Animals of both sexes were used).
Age at treatment: 11 weeks (male and females).
Identification: By unique cage number and corresponding ear number.
Acclimatization: Under laboratory conditions after health examination. Only animals without any visual signs of illness were used for the study.
Allocation: Male No. 1, Female Nos. 2 and 3.

Conditions: Standard Laboratory Conditions: Air-conditioned with ranges for room temperature 17 23 °C, relative humidity 30-70 % and approximately 10 15 air changes per hour. Room temperature and humidity were monitored continuously and values outside of these ranges may have occasionally occurred, usually following room cleaning. These transient variations are considered not to have any influence on the study and, therefore, these data are not reported but are retained at RCC. The animals were provided with an automatically controlled light cycle of 12 hours light and 12 hours dark. Music was played during the daytime light period.

Accommodation : Individually in stainless steel cages equipped with feed hoppers and drinking water bowls. Wood blocks (RCC Ltd, Füllinsdorf) and haysticks 4642 (batch no. 38/04, Provimi Kliba AG) were provided for gnawing.

Diet: Pelleted standard Provimi Kliba 3418 rabbit maintenance diet ad libitum (batch nos. 68/04 and 93/04) provided by Provimi Kliba AG, CH-4303 Kaiseraugst. Results of analysis for contami¬nants are archived at RCC Ltd.

Water: Community tap water from Füllinsdorf, ad libitum. Results of bacteriological, chemical and contaminant analyses are ar-chived at RCC Ltd.

Test system

Type of coverage:
semiocclusive
Preparation of test site:
clipped
Vehicle:
unchanged (no vehicle)
Amount / concentration applied:
TEST ITEM PREPARATION:
0.5 mL (per animal) of the test item was measured with a syringe and applied undiluted.
The pH of the test item was measured by the Sponsor and was found to between 9 and 9.5.
According to Commission Directive 2004/73/EC, B.4. and OECD Guidelines 404, a test item needs not to be tested if the pH-value is less than 2 or greater than 11.5, owing to its predictable corrosive properties.
Duration of treatment / exposure:
The duration of treatment was 4 hours.
Observation period:
Observation of local findings: Throughout 7 days after treatment.
Viability/Mortality: Daily from acclimatization of the animals to the termination of test.
Clinical signs: Daily from acclimatization of the animals to the termination of test.
Body weights: At start of acclimatization, on the day of application and at termination of observation.
Number of animals:
three animals
Details on study design:
TREATMENT:
Four to five days before treatment, the left flank was (or both flanks were) clipped with an electric clipper, exposing an area of approximately 100 cm2 (10 cm x 10 cm). The skin of the animals was examined one day before treatment, and regrown fur of all animals was clipped again. Due to strong hair growth, the right flank of animal no. 1 was clipped as well.
Animals with overt signs of skin injury or marked irritation which may have interfered with the interpretation of the results were not used in the test.
On the day of treatment, 0.5 mL of the test item was placed on a surgical gauze patch (2.5 cm x 2.5 cm). This gauze patch was applied to the intact skin of the clipped area. The patch was covered with a semi-occlusive dressing. The dressing was wrapped around the abdomen and anchored with tape.
The duration of treatment was 4 hours. Then the dressing was removed and the skin was flushed with lukewarm tap water to clean the application site so that any reactions (erythema) were clearly visible at that time.
As it was suspected that the test item might produce irritancy, a single animal (one female) was treated first. As neither a corrosive effect nor a severe irritant effect was observed after the 4-hour exposure, the test was completed using the two remaining animals for an exposure period of four hours.

IRRITATION SCORES:
The skin reaction was assessed according to the numerical scoring system listed in the Commission Directive 2004/73/EC, April 29, 2004, approximately 1, 24, 48 and 72 hours, as well as 7 days after the removal of the dressing, gauze patch and test item.
To allow further examination of the test site animal no. 2 was re-clipped on completion of the 1-hour examination. Animals no. 1 and 3 were re-clipped just after the 72-hour observation.
If evident, corrosive or staining properties of the test item were described and recorded.

TREATMENT OF RESULTS:
Data are summarized in tabular form, showing the irritation scores for erythema and oedema for each individual animal at all observation intervals after patch removal, any lesions, a description of the degree and nature of irritation, corrosion or reversibility, and any other toxic effects observed.
To evaluate the irritation of the test item the mean score was calculated across 3 scoring times (24, 48 and 72 hours after patch removal) for each animal for erythema/eschar grades and for oedema grades, separately. An animal is positive when the mean score is 2 or greater. The test is positive for irritation when at least 2 animals are positive for the same endpoint (erythema/eschar or oedema).

Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
erythema score
Basis:
animal #1
Time point:
24/48/72 h
Score:
1
Irritation parameter:
erythema score
Basis:
animal #2
Time point:
24/48/72 h
Score:
0.33
Irritation parameter:
erythema score
Basis:
animal #3
Time point:
24/48/72 h
Score:
0.33
Irritation parameter:
edema score
Basis:
animal: #1, #2 and #3
Time point:
24/48/72 h
Score:
0
Irritant / corrosive response data:
Well-defined erythema were observed in all three animals at the 1-hour reading and persisted as very slight erythema up to 24-hour observation in two animals or 72-hour examination in one animal.
Very slight swelling was noted in all three animals at the 1-hour observation.
No abnormal findings were observed on the treated skin of any animal 7 days after treatment, the end of the observation time.

Neither alterations of the treated skin were observed nor were corrosive effects evident on the skin.
Other effects:
No clinical signs of systemic toxicity were observed in the animals during the study and no mortality occurred.
No staining produced by the test item of the treated skin was observed.

Any other information on results incl. tables

SKIN IRRITATION SCORES - INDIVIDUAL VALUES

Animal Number Sex Evaluation Interval* Erythema Oedema

1

2

3

M

F

F

1 hour

2

2

2

1

1

1

1

2

3

M

F

F

24 hours

1

1

1

0

0

0

1

2

3

M

F

F

48 hours

1

0

0

0

0

0

1

2

3

M

F

F

72 hours

1

0

0

0

0

0

1

2

3

M

F

F

7 days

0

0

0

0

0

0

* Examinations were performed at the specified times after removal of the dressing.

The body weights of all rabbits were considered to be within the normal range of variability. Body weight in grams:

Animal No. Sex First Day of Acclimatization Day of Treatment Last Day of Observation
1 male 2129 2417 2616
2 female 2043 2221 2588
3 female 2020 2275

2566

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Conclusions:
Based upon the referred classification criteria (Commission Directive 2001/59/EC of August 2001), the test item is considered to be “not irritating” to rabbit skin.
The test item is not considered to be classified for Skin irrititation/corrosion based on GHS criteria (not classified: not irritating / not Skin Irrit. 3).
Executive summary:

The primary skin irritation potential of the test item was investigated according to OECD test guideline no. 404. The test item was applied by topical semi-occlusive application of 0.5 mL to the intact left or right flank of each of three young adult New Zealand White rabbits. The duration of treatment was four hours. The scoring of skin reactions was performed 1, 24, 48 and 72 hours, as well as 7 days after removal of the dressing.

The mean score was calculated across 3 scoring times (24, 48 and 72 hours after patch removal) for each animal for erythema/eschar grades and for oedema grades, separately. The mean erythema/eschar score of the three animals was 1.00, 0.33 and 0.33, respectively and the mean oedema score was 0.00 for all three animals, respectively.

The application of the test item to the skin resulted in mild signs of irritation. These included erythema and oedema. These effects were reversible and were no longer evident 7 days after treatment, the end of the observation period for all animals. The test item caused no staining of the treated skin. No corrosive effects were noted on the treated skin of any animal at any of the measuring intervals and no clinical signs were observed.

Thus, the test item did not induce significant or irreversible damage to the skin.

Based upon the referred classification criteria (Commission Directive 2001/59/EC of August 2001), the test item is considered to be “not irritating” to rabbit skin.

Based on GHS criteria ( Regulation (EC) No 1272/2008 and GHS of the United Nations (ST/SG/AC.10/30) ) the test item is considered to be “not irritating” to rabbit skin.