5,5'-sulfonylbis(2-benzofuran-1,3-dione)

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:

2015-02-04 to 2015-03-28

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Version / remarks:

adopted 1992-07-17

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.6 (Skin Sensitisation)

Version / remarks:

, 2008

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

signed 2014-05-14

Type of study:

guinea pig maximisation test

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

male

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories, Research Models and Services, Germany GmbH, Sandhofer Weg 7, 97633 Sulzfeld
Germany
- Age at study initiation: 29 days
- Weight at study initiation: 289 - 354 g (excluding positive control group); positive control group: 297 – 338 g
- Housing: kept in groups of 5 in MAKROLON cages (MZK 80/25); granulated textured wood was used as bedding material in the cages
- Diet (ad libitum): commercial diet, ssniff® Ms-H V2233 (ssniff Spezialdiäten GmbH, 59494 Soest, Germany)
- Water (ad libitum): tap water
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature: 20°C ± 3°C (maximum range)
- Humidity: 55% ± 15% (maximum range)
- Photoperiod (hrs dark / hrs light): 12/12

Route:

intradermal and epicutaneous

Vehicle:

corn oil

Concentration / amount:

Intracutaneous induction: 10% of test item
Topical induction: 75% of test item
Challenge: 75% of test item

Route:

epicutaneous, occlusive

Vehicle:

corn oil

Concentration / amount:

Intracutaneous induction: 10% of test item
Topical induction: 75% of test item
Challenge: 75% of test item

No. of animals per dose:

Treatment group: 20 male guinea pigs
Vehicle control group: 10 male guinea pigs
Positive control group: 20 male guinea pigs

Details on study design:

RANGE FINDING TESTS:
Eight animals were used for the preliminary test: 6 animals for the topical administration and 2 animals for the intracutaneous administration.
Six concentrations of the test material were tested by intracutaneous injection employing a 72-hour observation period: 0.01, 0.1, 0.5, 1, 5 or 10% suspensions in corn oil. Furthermore, six concentrations of the test material were tested by topical application to the shaved skin: 1, 5, 10, 25, 50 and 75% suspensions in corn oil (48-hour or 24-hour exposure).

Results:
- intracutaneous injection: no skin reactions were observed up to the concentration of 1%. The concentration of 5% revealed a discrete or patchy erythemal 24 and 48 hours after start of exposure. A concentration of 10% revealed a moderate and confluent erythema 24 hours and a discrete or patchy erythema 48 and 72 hours after start of exposure.
- topical application: no skin reactions were observed at any concentration and any duration of exposure.

Hence, it was decided to use a 10% suspension for the 1st (intracutaneous) induction stage, a 75% suspension for the 2nd (topical) induction stage and for the challenge in the main study.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 2 (intradermal and topical exposure)
- Site: shoulder region
- Frequency of applications: three intradermal injections (0.1 mL) were given once (day 0) and one week later (day 7) the same site was treated with a topical application (75% suspension of the test item). One day before the topical application was conducted (day 6), the fur was shaved from the application area and the exposed skin was coated with 0.5 mL sodium lauryl sulfate 10% in vaseline in order to induce local irritation, since a 75% concentration of the test material in corn oil was non-irritating in the 48-hour exposure to the skin of the test animals in the preliminary experiment.
- Duration: topical application lasted 48 hours
- Concentrations:
Test animals:
Intradermal injection:
i) Freund's complete adjuvant (diluted 1:1 with 0.9% NaCl)
ii) 10% suspension of the test item in corn oil
iii) 10% suspension of the test item in corn oil in a 1 + 1 mixture (v/v) Freund's complete adjuvant/physiological saline
Topical application:
75% suspension of the test item in corn oil

Control animals:
Intradermal injection:
i) Freund's Complete Adjuvant plus distilled water in the ratio 1:1.
ii) corn oil
iii) corn oil in a 1 + 1 mixture (v/v) Freund's complete adjuvant/physiological saline
Topical application:
corn oil was applied

- Evaluation (hr after induction): skin reaction results of the first induction expousre were evaluated at 24 and 48 hours, of the second induction at 48 and 72 hours after start of exposure

B. CHALLENGE EXPOSURE (procedure for test animals and control animals)
- No. of exposures: 1 (topical application two weeks (day 21) after topical induction)
- Exposure period: 24 hours
- Site: flank region
- Concentrations: 75% suspension of the test item in corn oil (left flank) and vehicle (right flank)
- Evaluation (hr after challenge): 24 and 48 hours after the end of exposure (days 23 and 24); skin reaction were evaluated using the Magnusson and Kligman grading scale

OTHER OBSERVATIONS:
- Mortality: daily during the observation period
- Clinical signs: daily during the observation period
- Body weight: at start of study and at study termination
The body weight was analysed statistically using STUDENT's t-test (p ≤ 0.01).
- Pathology: no necropsy was performed.

Challenge controls:

10 male guinea pigs were used as control group.
Challenge dose: 75% suspension of the test item in corn oil

Positive control substance(s):

yes

Remarks:

α-hexyl cinnamic aldehyde (induction exposures: 10% (v/v)) (intradermal exposure) and undiluted (topical exposure); topical challenge exposure: 0.01%.)

Positive control results:

Dunkin-Hartley guinea pigs treated with α-hexyl cinnamic aldehyde in sesame oil exhibited a sensitising reaction in all animals in form of a discrete or patchy erythema or a moderate and confluent erythema 48 hours after start of exposure.

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

75% test item

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

No skin irritation in any animal.

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 75% test item. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: No skin irritation in any animal..

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

75% test item

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

No skin irritation in any animal.

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 75% test item. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: No skin irritation in any animal..

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

75% test item

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

No skin irritation in any animal.

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 75% test item. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: No skin irritation in any animal..

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

75% test item

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

No skin irritation in any animal.

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 75% test item. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: No skin irritation in any animal..

Reading:

1st reading

Hours after challenge:

24

Group:

positive control

Dose level:

0.01% α-hexyl cinnamic aldehyde

No. with + reactions:

20

Total no. in group:

20

Clinical observations:

All animals exhibited a sensitising reaction in form of a discrete or patchy erythema or a moderate and confluent erythema 24 hours after the end of exposure.

Remarks on result:

other: see Remark

Remarks:

Reading: 1st reading. . Hours after challenge: 24.0. Group: positive control. Dose level: 0.01% α-hexyl cinnamic aldehyde. No with. + reactions: 20.0. Total no. in groups: 20.0. Clinical observations: All animals exhibited a sensitising reaction in form of a discrete or patchy erythema or a moderate and confluent erythema 24 hours after the end of exposure..

Reading:

2nd reading

Hours after challenge:

48

Group:

positive control

Dose level:

0.01% α-hexyl cinnamic aldehyde

No. with + reactions:

11

Total no. in group:

20

Clinical observations:

Eleven animals exhibited a sensitising reaction in form of a discrete or patchy erythema 48 hours after the end of exposure.

Remarks on result:

other: see Remark

Remarks:

Reading: 2nd reading. . Hours after challenge: 48.0. Group: positive control. Dose level: 0.01% α-hexyl cinnamic aldehyde. No with. + reactions: 11.0. Total no. in groups: 20.0. Clinical observations: Eleven animals exhibited a sensitising reaction in form of a discrete or patchy erythema 48 hours after the end of exposure..

INDUCTION EXPOSURE:

- intracutaneous induction: 10% suspension of the test item in corn oil revealed a moderate and confluent erythema or discrete or patchy erythema 24 hours and a discrete or patchy erythema 48 hours after administration in all 20 test item-treated animals.

- topical induction: 75% suspension of the test item in corn oil/animal were not irritating to the shaved skin in the preliminary experiment. Hence, in the main study the skin was coated with sodium lauryl sulfate on the day before stage 2 induction in order to induce a local irritation. This treatment resulted in a discrete or patchy erythema 48 to 72 hours after start of exposure in all 30 animals.

CHALLENGE EXPOSURE:

The challenge with 2 mL of a 75% suspension of the test item in corn oil/animal revealed no skin irritation in any animal and, thus, the test item had no sensitising properties.

The vehicle control revealed no skin reactions.

OBSERVATIONS:

- Body weight: body weight gain of the animals treated with the test item was within the range of the vehicle control during the experiment.

- Clinical signs: behaviour remained unchanged during the course of the study.

- Mortality: no animal was found dead or was sacrificed in extremis during the study.

Interpretation of results:

not sensitising

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The test item is not considered to be a skin sensitiser.
According to the EC-Regulation 1272/2008 and subsequent regulations, the test substance is not classified as skin sensitiser.
According to the Directive 67/548/EEC and its subsequent amendments, the test substance is not classified as skin sensitiser.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

A standard Guinea pig maximisation test according to OECD Guideline 406 (1992) ( k_Haferkorn_2015) conducted with the test substance is considered to be reliable without restrictions. The results showed that the test item has no skin sensitisation potential.

An expert statement why a GMPT was performed instead of an LLNA is provided as attachment below.

Migrated from Short description of key information:
Skin sensitisation: not sensitising (OECD 406; GLP compliant)

Justification for selection of skin sensitisation endpoint:
GLP guideline study conducted with the test item

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Skin sensitisation

The test item has no skin sensitisation potential and does not require classification as skin sensitiser according to Directive 67/548/EEC and its subsequent amendments or according to Regulation (EC) No 1272/2008 and subsequent regulations.