1,6-hexanediyl-bis(2-(2-(1-ethylpentyl)-3-oxazolidinyl)ethyl)carbamate

Endpoint summary

Description of key information

Under the conditions investigated the test substance showed a sensitizing potential to skin.

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:

from 1992-05-05 to 1992-06-05

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 12th May 1981

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.6 (Skin Sensitisation)

Version / remarks:

19.9.1984

Deviations:

no

GLP compliance:

yes

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

Test was performed before the LLNA guideline was available.

Species:

guinea pig

Strain:

other: Bor:DHPW

Sex:

male

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Versuchstierzucht Winkelmann, Borchen/Kreis Paderborn
- Other: Animals of this strain were used at Bayer AG for toxicological studies for years. The health of the animals was checked regularly and randomly regarding the most important specific infectious agents. Results of these investigations are archived at Bayer AG.
The sensitivity of the guinea pig strain was checked regularly. The correspondent documents were archived at Bayer AG.
- Strain: Bor: DHPW (SPF)
- Number of animals: 54
- Age at study initiation: 5 - 8 weeks
- Weight at study initiation: 351 g (average), 301 - 397 g
- Housing: Makrolon cages type IV, 5 animals per cage. Bedding: wood granulate.
- Health: Only healthy animals were used in the study. Animals were not treated with anti-infective.
- Diet: "Altromin 3020 - Haltungsdiät für Meerschweinchen". Feed was offered ad libitum.
- Water: drinking water (ad libitum), in each cage two 750 mL flasks made of polycarbonate were installed with drinking water.
- Acclimation period: 7 days

ENVIRONMENTAL CONDITIONS
- Temperature: 21 ± 1.5 °C
- Humidity: 40 - 70 %
- Air changes: ca. 12 - 15 changes per hour
- Photoperiod: 12 hours (6:00 am - 18:00 pm) artificial illumination

Route:

intradermal and epicutaneous

Vehicle:

propylene glycol

Concentration / amount:

Main test:
- intradermal induction: 5 %
- epicutaneous induction: 100 %
- 1. challenge: 100 % (epicutaneous)
- 2. challenge: 50 % and 5 % (epicutaneous)

Route:

epicutaneous, open

Vehicle:

propylene glycol

Concentration / amount:

Main test:
- intradermal induction: 5 %
- epicutaneous induction: 100 %
- 1. challenge: 100 % (epicutaneous)
- 2. challenge: 50 % and 5 % (epicutaneous)

No. of animals per dose:

Main test:
3 animal groups: 20 animals for the test substance, and two control groups with each 10 animals. The second control group was prepared for a further second challenge, if needed.

Details on study design:

RANGE FINDING TESTS:
- dose finding for intradermal induction:
A volume of 0.1 mL of the following test substance concentration were injected intradermal in an animal: 0 %, 1 %, 2.5 %, 5 %. There areas of the injections were assessed after 24 and 48 h: after 24 and 48 h: 0 - 5 % white area with red border, diameter ca. 0.8 cm
- dose finding for topic induction:
Using 4 animals 5 concentrations (6 %, 12.5 %, 25 %, 50 %, 100 %) were checked. Each animal got 4 patches each impregnated with 0.5 mL test substance formulation (occlusive conditions) for 24 h. After exposure test substance residues were washed with sterile physiologic salt solution. The skin around the treated areas was clipped. The skin reactions (skin reddening and formation of edemas) after 48 and 72 h after application were assessed.
No signs of skin reddening or formation of edemas were observed for all test substance concentrations.
- dose finding for challenge:
Using 5 animals 4 concentrations (12 %, 25 %, 50 %, 100 %) were checked. Each animal got 4 patches each impreganated with 0.5 mL test substance formulation (occlusive conditions) for 24 h. After exposure test substance residues were washed with sterile physiologic salt solution. The skaround the treated areas was clipped. The skin reactions (skin reddening and formation of edemas) after 48 and 72 h after application were assessed.
No signs of skin reddening or formation of edemas were observed for all test substance concentrations.

MAIN STUDY
INDUCTION EXPOSURE- Intradermal induction:
One day before application back and flank of the animals were clipped. Behind the neck on the left and the right side from the backbone each three injections which were positioned in a line, were conducted. The distance between the injections was 1 - 2 cm.
A volume of 0.1 mL was applied per injection. The animals of the different groups were treated as follows:
- test substance groups:
1. Injections (cranial): Complete adjuvant according to Freund (Difco Lab.) 1:1 diluted with physiologic salt solution (sterile)
2. Injections (meidal): test substance 5 % in propylene glycol formulated
3. Injections (caudal): test substance 5 % in propylene glycol and complete adjuvant according to Freund in equal parts formulated
- control groups:
The animals of the control groups were treated as the animals of the test substance group, but the formulations for the injections 2 and 3 did not contain any test substance, only polypropylene glycol.

INDUCTION EXPOSURE - epicutaneous induction:
One week after the intradermal induction a topic induction was performed. A day before the induction the animals were clipped and were treated with a 10 % formulation of sodium lauryl sulfate in paraffin. Between and in the areas where the injections were done hypo allergenic patches (2x4 cm) were applied and were covered with aluminium foil and additionally were fixed on the skin with Fermo-flextape (Transatalantic GmbH, Schwarzenbach).
The patches were treated as follows:
- test substance groups: 0.5 mL test substance (100 %)
- control groups: 0.5 mL propylene glycol
After exposure for 48 hours residues of test item were washed with physiologic salt solution.

B. CHALLENGE EXPOSURE
Epicutaneous challenge: Challenge was performed 3 - 4 weeks after the intradermal induction.
Animals that were treated as control animals were used as for a dose range finding test for the test substance concentration in the first challenge.
One day before the challenge the animals were clipped on the back and flank. The animals of the test substance group and of the first control group were treated in the course of the first challenge with 100 % test substance which was applied on hypoallergenic patch. The patch was applied on the right flank for 24 h using a Fermoflex-tape. On the right flank an untreated patch was fixed (control).
In the second challenge the animals of the test substance group and the second control group were treated with 50 % and 5 % test substance formulation, respectively, which was applied on a hypo allergenic patch. This patch was fixed with a Fermoflex tape on the left flank for 24 h. The patches with both test substance concentrations were fixed on the animals alternately cranial or caudal. On the right flank two patches which were impregnated with propylene glycol were applied (control). A volume of 0.5 mL was applied. After exposure residues of test item were washed with sterile physiologic salt solution and the skin around the application fields was clipped.

Challenge controls:

Yes, concurrent vehicle during induction exposure.

Positive control substance(s):

no

Reading:

1st reading

Hours after challenge:

48

Group:

test chemical

Dose level:

100 %

No. with + reactions:

8

Total no. in group:

19

Key result

Reading:

1st reading

Hours after challenge:

72

Group:

test chemical

Dose level:

100 %

No. with + reactions:

9

Total no. in group:

19

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

50 %

No. with + reactions:

12

Total no. in group:

19

Key result

Reading:

2nd reading

Hours after challenge:

72

Group:

test chemical

Dose level:

50 %

No. with + reactions:

9

Total no. in group:

19

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

5 %

No. with + reactions:

2

Total no. in group:

19

Key result

Reading:

2nd reading

Hours after challenge:

72

Group:

test chemical

Dose level:

5 %

No. with + reactions:

1

Total no. in group:

19

Reading:

1st reading

Hours after challenge:

48

Group:

negative control

Dose level:

100 %

No. with + reactions:

0

Total no. in group:

19

Key result

Reading:

1st reading

Hours after challenge:

72

Group:

negative control

Dose level:

100 %

No. with + reactions:

0

Total no. in group:

19

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

50 %

No. with + reactions:

0

Total no. in group:

19

Key result

Reading:

2nd reading

Hours after challenge:

72

Group:

negative control

Dose level:

50 %

No. with + reactions:

0

Total no. in group:

19

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

5 %

No. with + reactions:

0

Total no. in group:

19

Key result

Reading:

2nd reading

Hours after challenge:

72

Group:

negative control

Dose level:

5 %

No. with + reactions:

0

Total no. in group:

19

Reading:

1st reading

Hours after challenge:

48

Group:

positive control

Remarks on result:

not measured/tested

Key result

Reading:

2nd reading

Hours after challenge:

72

Group:

positive control

Remarks on result:

not measured/tested

General investigations:

All animals did not show any symptoms. On day 5 one animal of the group was dead. The following autopsy findings were recorded: coagulated blood in chest and abdomen, liver faded.

After removal of the patches of the second induction (day 9), some animals (animal no. 7, 15, 25, 28, 32) showed wounds in places. On day 10 some animals (animal no. 7, 15, 22, 24, 25, 28, 32, 33, 40) had a crusted skin at the treated areas. These crusts were healed on day 13 (animal no. 22, 24, 28) , on day 14 (animal no. 15) , on day 15 (animal no. 7), on day 16 (animal no. 32, 33, 40), and on day 17 (animal 25).

On day 24 the body weights of the animals of the test substance group and of the first control group were slightly reduced compared to the body weights of the second control group. On day 31 the body weights of the animals of the second control group and of the test item group were reduced and slightly increased, respectively, compared to the body weights recorded on day 24.

Interpretation of results:

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

Conclusions:

Under the conditions investigated the test substance showed a sensitizing potential to skin.

Executive summary:

The test substance was tested in a Guinea Pig Maximization Test according to EU method B.6 and OECD guideline no. 406. The test substance concentrations selected for the main study were based on the results of preliminary skin irritation tests. In the main study, 20 animals were intradermally induced with a test substance concentration of 5 % in propylene glycol. One week later the test substance in its pure form (100 %) was applied epicutaneously on rabbit’s skin. After 48 hours, the test substance was removed with physiological saline. Ten control animals were similarly treated, but with vehicle only. Three to four weeks after the epicutaneous application all animals were challenged with the test substance in its pure form (100 %). The second challenge was performed with 50 % and 5 % of the test substance. Vehicle was used as control.

After the first challenge 63 % of the treated animals showed signs of skin reactions (redness). The skin of the control animals was unaffected. After the second challenge skin reactions were noted in 63 % and 50 % of the animals treated with 50 % and 5 %, respectively. No skin irritation was observed in control animals.

Body weight was reduced in animals of the treatment group and of control animals after challenge with the test substance compared to control group indicating a slightly systemic effect.

Under the conditions of the experiment, the test substance is considered to have a skin sensitising potential.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (sensitising)

Additional information:

Skin sensitization

The test substance was tested in a Guinea Pig Maximization Test according to EU method B.6 and OECD guideline no. 406. The test substance concentrations selected for the main study were based on the results of preliminary skin irritation tests. In the main study, 20 animals were intradermally induced with a test substance concentration of 5 % in propylene glycol. One week later the test substance in its pure form (100 %) was applied epicutaneously on rabbit’s skin. After 48 hours, the test substance was removed with physiological saline. Ten control animals were similarly treated, but with vehicle only. Three to four weeks after the epicutaneous application all animals were challenged with the test substance in its pure form (100 %). The second challenge was performed with 50 % and 5 % of the test substance. Vehicle was used as control.

After the first challenge 63 % of the treated animals showed signs of skin reactions (redness). The skin of the control animals was unaffected. After the second challenge skin reactions were noted in 63 % and 50 % of the animals treated with 50 % and 5 %, respectively. No skin irritation was observed in control animals.

Body weight was reduced in animals of the treatment group and of control animals after challenge with the test substance compared to control group indicating a slightly systemic effect.

Under the conditions of the experiment, the test substance is considered to have a skin sensitising potential.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Based on the results of the presented study, the test substance was classified for Skin sensitisation in cat. 1B, H317 (may cause an allergic skin reaction) according to Regulation (EC) No 1272/2008 (CLP), as amended for the 17th time in Regulation (EU) 2021/849.