Carbonic acid, compound with 2-aminoethanol (1:2)

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

The study was performed between 14 December 2010 and 21 January 2011

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline 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

GLP compliance:

yes

Type of study:

Buehler test

Justification for non-LLNA method:

The LLNA does not need to be conducted becuase adequate data from a Buehler study are available

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

female

Details on test animals and environmental conditions:

Breeder: Harlan Laboratories B.V., Kreuzelweg 53, 5961 NM / The Netherlands

Number of Animals for Main Study / Irritation Screen: 30 females / 3 females (nulliparous and nonpregnant).
Challenge: 20 test animals
10 control animals
Irritation Screens: 3 animals

Age at Delivery / Acclimatization Start: 3 to 4 weeks

Body Weight at Delivery / Acclimatization Start: Test and control animals: 304 to 331 g, Animals used for irritation screen: 319 to 333 g.

Identification: By individual ear tattoo

Randomization: Randomly selected by hand at time of delivery. No computer randomization.

Acclimatization: Under laboratory conditions after health examination. Seven days for the control and test group. However, contrary to the test group the control group remained untreated during the 3 induction weeks. One day for the animals used in the irritation screen for induction and challenge. Only animals without any visible signs of illness were used for the study.

Accomodation: In groups of up to 10 animals in stainless steel cages with standard softwood bedding (‘Lignocel’ J. Rettenmaier&Söhne GmbH&CoKG, 73494 Rosenberg / Germany, imported by Provimi Kliba AG, 4303 Kaiseraugst / Switzerland).

Diet: Teklad Global Guinea pig diet 2040C (batch nos. 24/10 and 81/10 provided by Provimi Kliba AG, 4303 Kaiseraugst / Switzerland), ad libitum.A haystick 4642, batch number 80/09 (Provimi Kliba AG, 4303 Kaiseraugst / Switzerland) was also provided for environmental enrichment.

Standard Laboratory Conditions: Air-conditioned with ranges for room temperature 22 ± 3 °C, relative humidity 30-70% and approximately 10-15 air changes per hour. Room temperature and humidity were monitored continuously. 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.

Water: Community tap water from Füllinsdorf, ad libitum.

Route:

epicutaneous, occlusive

Vehicle:

water

Concentration / amount:

Irritation screen: 25, 15, 10 and 5% in purified water
3-week induction: 50% in water (selected by default)
Challenge: 10% in purified water

Route:

epicutaneous, occlusive

Vehicle:

water

Concentration / amount:

Irritation screen: 25, 15, 10 and 5% in purified water
3-week induction: 50% in water (selected by default)
Challenge: 10% in purified water

No. of animals per dose:

irritation screen: 3 animals
3-week induction: 20 test animals, the 10 control animals remained untreated
Challenge: the 20 test animals previously induced and the 10 control animals

Details on study design:

IRRITATION SCREEN:

The irritation screen was performed during the acclimatization period of the animals to be used in the main study.
The test item concentrations described below were selected during a preliminary solubility testing which was performed before the study initiation date.
The fur was removed from both flanks of the animals.
Four different concentrations (25, 15, 10 and 55 in purifed water9 were used on each of 3 irritation screen animal for a 6-hour exposure period.
The allocation of the different test item dilutions to the sites on the three animals was alternated in order to minimize site-to-site variation in responsiveness.
The test item skin area of the animals were depilated approximately 21 hours after the patches had been removed, using an approved depilatory cream (VEET Cream, Reckitt & Colman AG, 4123 Allschwil / Switzerland). The depilatory cream was placed on the patch sites and surrounding areas, and left on for up to 3-5 minutes. It was then thoroughly washed off with a stream of warm, running water. The animals were then dried with a disposable towel, and returned to their cages.
The grading method was performed 24 ± 2 hours after removal of the patches and repeated 24 ± 2 hours later (48-hour grades) .
The scoring system was performed by visual assessment of erythema, oedema and other clinical changes in skin conditions. They were assessed as follows:

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

Grading of all animals was done by positioning each animal under true-light (Philips Master TLS HE 28 W/840).

Clinical signs, bodyweight and mortality data were recorded.

The highest concentration applied during the irritation screen was 25% (1 part of test item and 3 parts of purified water). As slight skin irritation was observed in 2 out of 3 irritation screen animals when treated at the test item concentration of 25% in purified water while the third animal was devoid of any skin irritation, the concentration of 25% seemed to be too low to ensure the sensitization of the test animals sufficiently. Therefore, the concentration of 50% in purified water was selected by default without performing any second epidermal irritation screen. This concentration demonstrated its slight and non-adverse irritating potential through the 3-week induction.

The concentration of 10% in purified water was selected as being the maximum tested non-irritant concentration, suitable for the challenge exposure.

MAIN STUDY:
Name of test method:
Contact Hypersensitivity in Albino Guinea Pigs, Buehler Test. The purpose of this skin sensitization study was to determine if the test item under the conditions described in the study plan and this report, causes an increased reaction in the skin of guinea pigs at challenge when compared to appropriate controls.

Criteria used to consider a positive response:
Regulation (EC) No 1272/2008 of the European Parliament and of the Council of 16 December 2008 on classification, labeling and packaging of substances and mixtures, amending and repealing Directives 67/548/EEC and 1999/45/EC, and amending Regulation (EC) No 1907/2006. According to the cited classification criteria “For a non-adjuvant guinea pig test method a response of at least 15% of the animals is considered positive”.

TREATMENT PREPARATION AND ADMINISTRATION:
The test item and vehicle were placed into a glass beaker on a tared Mettler balance and weight/weight dilutions were prepared using a magnetic stirrer and a spatula as homogenizers. The preparations were made immediately prior to each dosing. Homogeneity of the test item preparation was maintained during treatment using a magnetic stirrer.
Dose concentrations were in terms of material as supplied by the Sponsor.
1) Induction / Performed on Test Days 1, 8 and 15
The fur was clipped from the left shoulder of each test animal and the patches applied, over a period of 3 weeks. Each animal received one patch per week with the test item at 50% in purified water which remained in place for approximately 6 hours each. The repeated application was performed at the same site. The interval between exposures was one week. The control animals remained untreated.
After the last induction exposure the test animals were left untreated for 2 weeks before the challenge.
Any gross skin reactions were recorded without depilation.
The grading method was performed 24 ± 2 hours after removal of the patches.

The scoring system was performed by visual assessment of erythema, oedema and other clinical changes in skin conditions. They were assessed as follows:

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

Grading of all animals was done by positioning each animal under true-light (Philips Master TLS HE 28 W/840).

Clinical signs, bodyweight and mortality data were recorded.

Within the three weeks of induction, discrete/patchy erythema was observed in all test animals after treatment with the test item at 50% in purified water. A slightly higher severity of skin reaction (moderate/confluent erythema) was observed in one animal during the reading of the second induction week. The first and second inductions also included local findings such as crusts and skin desquamation.

2) Challenge / Performed on Test Day 29
The animals previously exposed during the induction period (i.e. test group) as well as the previously untreated control animals were challenged two weeks after the last induction exposure using the test item at 10% in purified water. The fur was clipped from the left posterior quadrant of the side and back of the animals. Patch sites for challenge are indicated below. The exposure period was 6 hours on a naive skin site.

The test item skin area of the animals were depilated approximately 21 hours after the patches had been removed, as described in the irritation screen.
The grading method was performed 24 ± 2 hours after removal of the patches and repeated 24 ± 2 hours later (48-hour grades) .
The scoring system was performed by visual assessment of erythema, oedema and other clinical changes in skin conditions. They were assessed as follows:

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

Grading of all animals was done by positioning each animal under true-light (Philips Master TLS HE 28 W/840).

Clinical signs, bodyweight and mortality data were recorded.

No skin reactions were observed in the control and test animals treated with the test item at 10% in purified water.

POSITIVE CONTROL
The sensitivity and reliability of the experimental system employed was assessed at least twice a year by use of substances such as alpha-hexylcinnamaldehyde or 2 mercaptobenzothiazole which are recommended by the Commission Regulation (EC) No 440/2008, B.6 or OECD 406 guidelines and are known to have moderate skin sensitization properties in the guinea pig. The results from the most recent positive control test (Harlan Laboratories Study D06002, performed from 14-Sep-2010 to 10-Nov-2010) confirm alpha-hexylcinnamaldehyde as skin sensitizer, as it produced allergic contact dermatitis in >15% of the test animals.

Positive control substance(s):

yes

Remarks:

alpha-hexylcinnamaldehyde

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

10% in purified water

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

No clinical signs

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 10% in purified water. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: No clinical signs.

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

10% in purified water

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

No clinical signs

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 10% in purified water. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: No clinical signs.

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

10% in purified water

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

No clinical signs

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 10% in purified water. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: No clinical signs.

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

10% in purifed water

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

No clinical signs

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 10% in purifed water. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: No clinical signs.

Reading:

1st reading

Hours after challenge:

24

Group:

positive control

Dose level:

5% in PEG 300

No. with + reactions:

7

Total no. in group:

20

Clinical observations:

No clinical signs

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: positive control. Dose level: 5% in PEG 300. No with. + reactions: 7.0. Total no. in groups: 20.0. Clinical observations: No clinical signs.

Reading:

2nd reading

Hours after challenge:

48

Group:

positive control

Dose level:

5% in PEG 300

No. with + reactions:

5

Total no. in group:

20

Clinical observations:

No clinical signs

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: positive control. Dose level: 5% in PEG 300. No with. + reactions: 5.0. Total no. in groups: 20.0. Clinical observations: No clinical signs.

Interpretation of results:

GHS criteria not met

Remarks:

Criteria used for interpretation of results: EU

Conclusions:

Based on the above mentioned findings in a non-adjuvant sensitization test in guinea pigs and in accordance to Regulation (EC) No 1272/2008, MEACarbamate does not have to be classified and labelled as a skin sensitizer.

Executive summary:

General

 

The purpose of this skin sensitizing study was to assess the possible allergenic potential of MEA Carbamate when administered topically to albino Dunkin Hartley guinea pigs.

 

For this purpose the “Buehler Test” modified by Ritz, H.L. and Buehler, E.V. (1980) was used. Twenty female animals of the test group were treated topically with MEA Carbamate at 50% in purified water once a week for a 3-week induction phase. Two weeks after the final induction application the animals were challenged with the same test item as used for induction, at a concentration of 10% MEA Carbamate in purified water.

 

The ten animals of the control group were not treated during the induction. They were challenged with MEA Carbamate at 10% in purified water.

  

Results

 

None of the control and test animals were observed with skin reactions after the challenge treatment with the highest tested non-irritating concentration of MEA Carbamate at 10% in purified water.

Conclusion

Based on the above mentioned findings in a non-adjuvant sensitization test in guinea pigs and in accordance to Regulation (EC) No 1272/2008, MEA Carbamate does not have to be classified and labelled as a skin sensitizer.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

Migrated from Short description of key information:
Contact hypersensitivity has been assessed negative in a Buehler test.

Justification for selection of skin sensitisation endpoint:
Reliable study performed on the registered substance.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Data are available from an in vivo assessment of contact hypersensitivity in albino Guinea Pigs, which indicate that this substance is not a skin sensitiser, and therefore classification is not warranted.