Estr-4-ene-3,17-dione

Endpoint summary

Description of key information

In the OECD TG 406 study (Buehler method), the skin sensitisation rate of Norandrostendione in guinea pigs was 5% (Lihui, 2020).

 

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:

26 December 2019 - 16 April 2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

The additional test in skin sensitisation was performed based on the Guidance on Environmental Management Registration of New Chemical Substances (Order No. 12 of the MEE of the P.R. China). The in vivo test was the accepted method of the toxicological endpoint skin sensitisation at the time for a New Chemical Substance Registration in China.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Qualifier:

according to guideline

Guideline:

other: State Ministry of Environmental Protection of the People’s Republic of China. Guidelines of Chemical Testing (HJ/T 153-2004) Appendix A 406 Skin Sensitisation Test

GLP compliance:

yes (incl. QA statement)

Type of study:

Buehler test

Justification for non-LLNA method:

A valid Buehler test conducted comparable to guideline with acceptable restrictions is available, which is reliable with restrictions and adequate for classification and labelling purposes. Potency estimation is not mandatory when existing guideline and GLP conforming data are available, which were conducted before the new annex of the REACH Regulation entered into force. For this reason and for reasons of animal welfare no additional LLNA was conducted.

Species:

guinea pig

Strain:

Hartley

Sex:

male

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Liaoning Changsheng Biotechnology Co., Ltd.
- Age at study initiation: Five weeks (at grouping)
- Weight at study initiation: 332.09-394.71 g (at grouping)
- Housing: Two to six guinea pigs/cage
- Diet (e.g. ad libitum): guinea pig maintenance feed (batch nos.: 19101381 and 20011081), Liaoning Changsheng Biotechnology Co., Ltd., ad libitum
- Water (e.g. ad libitum): drinking water, ad libitum
- Acclimation period: 7 d
- Indication of any skin lesions: no

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20.00-24.00 °C
- Humidity (%): 40.73-70.00%
- Photoperiod (hrs dark / hrs light): 12/12

Vehicle:

other: 80% ethanol

Concentration / amount:

0.200 g test sample and 0.2 mL induction medium

Day(s)/duration:

day 0, day 7, day 14

Adequacy of induction:

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

No.:

#1

Route:

epicutaneous, semiocclusive

Vehicle:

other: acetone

Concentration / amount:

0.2 mL 50% test sample solution

Day(s)/duration:

day 28, 6 h exposure

Adequacy of challenge:

highest non-irritant concentration

No. of animals per dose:

20 (test group), 10 (control group)

Details on study design:

RANGE FINDING TESTS:
In the pre-test, the skin at the site exposed to 0.200 g test sample and 0.2 mL induction medium exhibited mild erythema. There were no abnormalities of the skin at the site exposed to 0.2 mL 50% test substance solution, 0.2 mL 25% test substance solution, and 0.2 mL 12.5% test substance solution (Table 1). Therefore, 0.200 g (±1%) test sample and 0.2 mL induction medium were selected for the induction exposure and 0.2 mL 50% test sample solution was selected for the challenge exposure.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 3
- Exposure period: day 0, day 7, day 14
- Test groups: 0.200 g (±1%) test sample was weighed and applied to the dressing filter paper. 0.2 mL induction medium was aspirated to moisten the test sample.
- Control group: Test sample was not used, other operations were the same as the test group.
- Site: left side of the back
- Duration: 6 h


B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: day 28
- Exposure period: 6 h
- Test and control groups: 0.2 mL 50% test sample solution was aspirated and applied to the dressing filter paper
- Site: right side of the back
- Evaluation (hr after challenge): 24 hours and 48 hours after the dressing was removed

Positive control substance(s):

yes

Remarks:

2-mercaptobenzothiazole

Positive control results:

2-mercaptobenzothiazole was used as the positive control substance to carry out the reliability check using test methodology from this test. Start date was 24 May 2019 and completion date was 27 June 2019.
0.2 mL 50% 2-mercaptobenzothiazole solution (medium: 80% ethanol) was used for the induction exposure. 0.2 mL 2.5% 2-mercaptobenzothiazole solution (medium: acetone) was used for the challenge induction. The skin sensitisation rate was 30%, confirming that the methodology used in this test and animal sensitivity were valid.

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

50%

No. with + reactions:

0

Total no. in group:

10

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

50%

No. with + reactions:

0

Total no. in group:

10

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

50%

No. with + reactions:

1

Total no. in group:

20

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

50%

No. with + reactions:

0

Total no. in group:

20

Reading:

other: not specified

Hours after challenge:

24

Group:

positive control

Dose level:

2.5% 2-mercaptobenzothiazole solution (medium: acetone) (challenge)

Remarks on result:

positive indication of skin sensitisation

Remarks:

30% skin sensitisation rate

Clinical observation: No abnormalities were seen in any animals in the test period.

Body weight: All animals gained weight in the test period

Skin response: At the induction stage, there were no visible abnormalities of the skin at the exposure site for the animals in the control group. In the test group, 18 animals exhibited mild erythema of the skin at the exposure site.
At the challenge stage, there were no visible abnormalities of the skin at the exposure site for the animals in the control group. In the test group, one animal (animal no.: 1711) exhibited discrete erythema of the skin at the exposure site.

Conclusions:

Under the conditions of this test, based on observations and the evaluation system used, the skin sensitisation rate in guinea pigs was 5%.

Executive summary:

This test was carried out with reference to Chemical Test Methods - Health Effects Volume 406-Skin Sensitisation Test (second edition) which is comparable to OECD Guideline 406 (Buehler method). Using guinea pig as the test animal, a local occlusive dressing method was used to measure potential sensitisation in guinea pigs from repeated exposure to Norandrostendione.

0.200 g (± 1%) test sample and 0.2 mL induction medium were used to carry out induction exposure, and 0.2 mL 50% test sample solution was used to carry out the challenge exposure. For the 20 guinea pigs in the test group, an area of fur at the left side of the back was shaved and exposed to 0.200 g (± 1%) test sample and 0.2 mL induction medium dose. Exposure was once weekly for three continuous weeks (induction exposure). With the exception that they were not treated with the test sample, the same operating methods were used for the 10 guinea pigs in the control group. Two weeks after the third induction exposure, 0.2 mL 50% test sample solution was used at the area of shaved fur at the right side of the back of the guinea pigs in the test group and the control group to carry out the challenge exposure.
In the induction exposure, skin respons e at the exposure site was observed and recorded at approximately one hour, 24 hours, and 48 hours after the dressing was removed. In the challenge exposure, skin response at the exposure site was observed and recorded at approximately 24 hours and 48 hours after the dressing was removed.
At the induction stage, there were no visible abnormalities of the skin at the exposure area for the animals in the control group. 18 animals in the test group exhibited mild erythema of the skin at the exposure site. At the challenge stage, the animals in the control group exhibited no visible abnormalities of the skin at the exposure site. One animal in the test group (animal no.: 1711) exhibited discrete erythema of the skin at the exposure site. The skin sensitisation rate of the animals in the control group was 0% while the skin sensitisation rate of the animals in the test group was 5%. All of the animals gained weight during the test and no anomalous symptoms were observed (not including skin reactions at the exposure site).
Under the conditions of this test, based on observations and the evaluation system used, the skin sensitisation rate of the test item in guinea pigs was 5%. According to EU GHS, no classification is required.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

This test was carried out with reference to Chemical Test Methods - Health Effects Volume 406-Skin Sensitisation Test (second edition) which is comparable to OECD Guideline 406 (Buehler method). Using guinea pig as the test animal, a local occlusive dressing method was used to measure potential sensitisation in guinea pigs from repeated exposure to Norandrostendione.

0.200 g (± 1%) test sample and 0.2 mL induction medium were used to carry out induction exposure, and 0.2 mL 50% test sample solution was used to carry out the challenge exposure. For the 20 guinea pigs in the test group, an area of fur at the left side of the back was shaved and exposed to 0.200 g (± 1%) test sample and 0.2 mL induction medium dose. Exposure was once weekly for three continuous weeks (induction exposure). With the exception that they were not treated with the test sample, the same operating methods were used for the 10 guinea pigs in the control group. Two weeks after the third induction exposure, 0.2 mL 50% test sample solution was used at the area of shaved fur at the right side of the back of the guinea pigs in the test group and the control group to carry out the challenge exposure.
In the induction exposure, skin response at the exposure site was observed and recorded at approximately one hour, 24 hours, and 48 hours after the dressing was removed. In the challenge exposure, skin response at the exposure site was observed and recorded at approximately 24 hours and 48 hours after the dressing was removed.
At the induction stage, there were no visible abnormalities of the skin at the exposure area for the animals in the control group. 18 animals in the test group exhibited mild erythema of the skin at the exposure site. At the challenge stage, the animals in the control group exhibited no visible abnormalities of the skin at the exposure site. One animal in the test group (animal no.: 1711) exhibited discrete erythema of the skin at the exposure site. The skin sensitisation rate of the animals in the control group was 0% while the skin sensitisation rate of the animals in the test group was 5%. All of the animals gained weight during the test and no anomalous symptoms were observed (not including skin reactions at the exposure site).
Under the conditions of this test, based on observations and the evaluation system used, the skin sensitisation rate of the test item in guinea pigs was 5%. According to EU GHS, no classification is required (Lihui, 2020).

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

No classification required for skin sensitisation according to Regulation (EC) No. 1272/2008 (CLP).