2-(4-(diethylaminopropylcarbamoyl)phenylazo)-3-oxo-N-(2,3-dihydro-2-oxobenzimidazol-5-yl)butyramide

Endpoint summary

Description of key information

In order to assess the sensitizing potential a Maximization-Test according to OECD 406 was performed in 15 (10 test and 5 control) female pirbright white guinea pigs. After the first challenge procedure 4/10 and after the second challenge procedure 6/10 test animals showed skin reactions. Based on this result the test item has to be classified as skin sensitiser Cat. 1A.

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:

Sept - Nov 1989

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Version / remarks:

Adopted 12 May 1981

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.6 (Skin Sensitisation)

Version / remarks:

Version 25. Apr. 1984

Deviations:

no

GLP compliance:

yes

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

The substance has been tested according to the OECD Guideline 406, Guinea pig Maximization Study before the LLNA test model was selected to be the preferred test system under the REACH Regulation.

Species:

guinea pig

Strain:

Pirbright-Hartley

Remarks:

pirbright-White

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Hoechst AG, Kastengrund, SPF breed
- Weight at study initiation: 262 - 346 g
- Housing: in groups of 5 animals, macrolon type 4 cages in fully air-conditioned room
- Diet (e.g. ad libitum): Altromin 3112 maintenance diet - guinea pigs (Altromin GmbH, Lage/Lippe), ad libitum
- Water (e.g. ad libitum): tao water from water dispenser, ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22+/- 3°C
- Humidity (%): 50 +/- 20%
- Photoperiod (hrs dark / hrs light): 12/12
- IN-LIFE DATES:
From: 26.09. To: 03.11.1989

Route:

intradermal

Vehicle:

paraffin oil

Concentration / amount:

1% - intradermal

Day(s)/duration:

n.a.

Adequacy of induction:

highest concentration used causing mild-to-moderate skin irritation and well-tolerated systemically

Route:

epicutaneous, occlusive

Vehicle:

petrolatum

Concentration / amount:

25% - epicutaneous

Day(s)/duration:

2

Adequacy of induction:

highest concentration used causing mild-to-moderate skin irritation and well-tolerated systemically

No.:

#1

Route:

epicutaneous, occlusive

Vehicle:

petrolatum

Concentration / amount:

5%

Day(s)/duration:

1

Adequacy of challenge:

highest non-irritant concentration

No.:

#2

Route:

epicutaneous, occlusive

Vehicle:

petrolatum

Concentration / amount:

5%

Day(s)/duration:

1

Adequacy of challenge:

highest non-irritant concentration

No. of animals per dose:

test group: 10
control group: 5

Details on study design:

1. Induction
- intradermal injections / performed on test day 1
An area of dorsal skin from the scapular region (approx. 4 x 6 cm) was clipped free of hair. Three pairs of intradermal injections (0.1 mL/site) were made at the border of a 2 x 4 cm area in the clipped region as follows:
Test Group:
a) 1:1 (v/v) mixture of Freund´s Complete Adjuvant and physiological saline
b) The test item at 1% in paraffin
c) The test item at 1% in a 1:1 (v/v) mixture of Freund´s Complete Adjuvant and physiological saline
Control Group:
a) 1:1 (v/v) mixture of Freund´s Complete Adjuvant and physiological saline
b) paraffin
c) 1:1 (w/w) mixture of paraffin in 1:1 (v/v) mixture of Freund´s Complete Adjuvant and physiological saline

- epidermal applications / performed on test day 8
One week after the injections, a 2 x 4 cm patch of flter paper was treated with 0.5 g of the test item (25% in petrolatum) and placed over the injection sites of the test animals. The patch was covered with an occlusive foil and firmly secured by an elastic plaster wrapped around the trunk of the animal and secured with impervious adhesive tape. The occlusive dressings were left in place for 48 hours. The epidermal application procedure described ensured intensive contact of the test item.
The guinea pigs of the control group were treated as described above with petrolatum only.


2. Challenge / performed on test day 22 and 29
The test and control guinea pigs were challenged twice after the epidermal induction aplication and were treated in the same way.
Hair was clipped and shaved from a 5 x 5 cm area on the left (1. challenge) and right (2. challenge) flank of each guinea pig just prior to the application. A 2 x 4 cm patch of flter paper was treated with 0.5 g of the test item (5% in petrolatum) and placed over the clipped sites of the test animals. The patch was covered with an occlusive foil and firmly secured by an elastic plaster wrapped around the trunk of the animal and secured with impervious adhesive tape. The occlusive dressings were left in place for 24 hours.
24 hours after removal of the dressing the test sites treated with the test item were depilated as described in the epidermal pretest.
The reaction sites were assessed 24 and 48 hours after removal of the bandage for erythema and edema according to the method of Magnusson and Kligman.

Challenge controls:

Challenge / performed on test day 22 and 29
The test and control guinea pigs were challenged twice after the epidermal induction aplication and were treated in the same way.
Hair was clipped and shaved from a 5 x 5 cm area on the left (1. challenge) and right (2. challenge) flank of each guinea pig just prior to the application. A 2 x 4 cm patch of flter paper was treated with 0.5 g of the test item (5% in petrolatum) and placed over the clipped sites of the test animals. The patch was covered with an occlusive foil and firmly secured by an elastic plaster wrapped around the trunk of the animal and secured with impervious adhesive tape. The occlusive dressings were left in place for 24 hours.
24 hours after removal of the dressing the test sites treated with the test item were depilated as described in the epidermal pretest.
The reaction sites were assessed 24 and 48 hours after removal of the bandage for erythema and edema according to the method of Magnusson and Kligman.

Positive control substance(s):

not specified

Remarks:

no data; however, the test substance proved to be a skin sensitiser. Therefore, it is concluded that the test condtions are suffcient for identifaction of senstising properties.

Positive control results:

no data

Key result

Reading:

1st reading

Hours after challenge:

48

Group:

negative control

Dose level:

5%

No. with + reactions:

0

Total no. in group:

5

Clinical observations:

no clinical symptoms

Key result

Reading:

2nd reading

Hours after challenge:

72

Group:

negative control

Dose level:

5%

No. with + reactions:

0

Total no. in group:

5

Clinical observations:

no clinical symptoms

Key result

Reading:

1st reading

Hours after challenge:

48

Group:

test chemical

Dose level:

5%

No. with + reactions:

4

Total no. in group:

10

Clinical observations:

no clinical symptoms

Key result

Reading:

2nd reading

Hours after challenge:

72

Group:

test chemical

Dose level:

5%

No. with + reactions:

4

Total no. in group:

10

Clinical observations:

no clinical symptoms

Key result

Reading:

rechallenge

Hours after challenge:

48

Group:

negative control

Dose level:

5%

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

no clinical symptoms

Key result

Reading:

rechallenge

Hours after challenge:

72

Group:

negative control

Dose level:

5%

No. with + reactions:

0

Total no. in group:

5

Clinical observations:

no clinical symptoms

Key result

Reading:

rechallenge

Hours after challenge:

46

Group:

test chemical

Dose level:

5%

No. with + reactions:

6

Total no. in group:

10

Clinical observations:

no clinical symptoms

Key result

Reading:

rechallenge

Hours after challenge:

72

Group:

test chemical

Dose level:

5%

No. with + reactions:

5

Total no. in group:

10

Clinical observations:

no clinical symptoms

Reading:

1st reading

Hours after challenge:

48

Group:

positive control

Dose level:

5%

No. with + reactions:

0

Total no. in group:

0

Clinical observations:

n.a.

Remarks on result:

not measured/tested

Remarks:

not required since the substance prived to be sensitising

1. Skin effects after intradermal induction - performed on test day 1

The expected and common findings were observed in the control and test group after the different applications using FCA intradermally. These findings consisted of erythema, edema, necrotizing dermatitis, and hardening. In case of test substance application the site were additionally slightly yellow colored.

2. Skin effects after epidermal induction - performed on test day 8

Control group: the FCA treated sites were reddened, swollen and hardened. Furthermore, necrosis was reported.

Test group: Additionally, to effects observed in the control group the treated sites were yellow colored.

3. Skin effects after the challenge - performed on test day 22 and 29

Control group: No skin reactions were observed in the animals when treated with the test item at 5% in petrolatum.The treated sites were sligthly yellow colored.

Test group: Discrete/patchy erythema was observed in 4 animals at the 24- and 48 -hour reading after first challenge and in 6 animals after the second challenge with the test item at 5% in petrolatum. The treated sites were slighlty yellow colored.

4. Viability / Mortality / Macroscopic findings

No mortality observed.

5. Clinical signs, systemic

No signs of systemic toxicity were observed in the animals.

6. Body weights

The body weight of all animals was within the range commonly recorded for animals of this strain and age.

Interpretation of results:

Category 1A (indication of significant skin sensitising potential) based on GHS criteria

Conclusions:

Based on the described findings the test item has to be classified as skin sensistizer.

Executive summary:

In order to assess the sensitizing potential a Maximization-Test was performed in 15 (10 test and 5 control) female pirbright white guinea pigs.

The intradermal induction of sensitizing in the test group was performed in the nuchal region with 1% dilution of the test item in paraffin oil and in an emulsion of Freund´s Complete Adjuvant (FCA)/physiological saline. The epidermal induction of sensitizing was conducted for 48 h under occlusion with the test item at 25% in petrolatum one week after the intradermal induction. The animals of the control group were intradermally induced with paraffin oil and FCA/physiological saline and epidermally induced with petrolatum under occlusion.

Two weeks after epidermal induction the control and test animals were challenged by epidermal application of the test item at 5% in petrolatum under occlusive dressing.

Cutaneous reactions were evaluated at 48 and 72 h after removal of the dressing.

No toxic symptoms were evident in the guinea pigs of the control or test group.

Skin reactions after the 1. challenge procedure:

- after 48 hours:

control animals - 0/5 (5% test item in petrolatum)

test animals - 4/10 (5% test item in petrolatum)

- after 72 hours:

control animals - 0/5 (5% test item in petrolatum)

test animals - 4/10 (5% test item in petrolatum)

Skin reactions after the 2. challenge procedure:

- after 48 hours:

control animals - 0/5 (5% test item in petrolatum)

test animals - 6/10 (5% test item in petrolatum)

- after 72 hours:

control animals - 0/5 (5% test item in petrolatum)

test animals - 5/10 (5% test item in petrolatum)

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (sensitising)

Additional information:

The sensitization potential of Pigmentadditive C was investigated according to OECD Guideline 406. The test item concentrations chosen for the the guinea pig maximisation test were:

- intradermal induction: 1% in pararffin oil

- epicutaneous induction: 25% in petrolatum

- 1./2. challenge: 5% in petrolatum

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Pigmentadditve C showed skin sensitizing properties in the guinea pig maximisation test according to the OECD guideline 406.

With reference to the number of affected animals Pigmentadditive C has to be classified as skin sensitiser cat 1A according to the criteria laid down in the EU Classification Labelling and Packaging Regulation (1272/2008/EC).