Estrone

Endpoint summary

Description of key information

A registration of estrone was already submitted earlier and is public available on the ECHA website. Chapter 7, which is still valid from today's perspective, was amended to fulfill the current information requirements. Consequently the migrated data (IUCLID 5 to IUCLID 6) was kept unchanged and only modified if there was a need for further information and/or to pass the technical completeness check (TCC).

Skin sensitisation

To determine the skin-sensitizing properties of estrone the mouse local lymph node assay was performed on mice according to OECD guideline 429. The main study was conducted with the following test substance concentrations: 10%, 25% and 50%.

All animals treated with 25 and 50% showed slight irritation of the ears, but this had no toxicological significant effect on the activity of the lymph nodes. The mean DPM/animal values were 283 (vehicle control), 449 (10%), 470 (25%) and 268 (50%). The SI values calculated were 1.6 (10%), 1.7 (25%) and 0.9 (50%). Since there was no indication that the test substance elicits an SI above or equal to 3 when tested up to 50%, estrone was considered not to be a skin sensitizer.

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Dec 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)

Qualifier:

according to guideline

Guideline:

EU Method B.42 (Skin Sensitisation: Local Lymph Node Assay)

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.2600 (Skin Sensitisation)

GLP compliance:

yes (incl. QA statement)

Type of study:

mouse local lymph node assay (LLNA)

Specific details on test material used for the study:

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
The test substance formulations (w/w) were prepared within 4 hours prior to each treatment. No adjustment was made for specific gravity of the vehicle. Homogeneity was obtained to visually acceptable levels. The formulations were stirtred with magnetic stirrer immediately prior to dosing.

Species:

mouse

Strain:

other: CBA/J

Sex:

female

Vehicle:

propylene glycol

Concentration:

Pre-Screen test: 25% and 50%
Main test: 10%, 25% and 50%

No. of animals per dose:

Pre-Screen test: 2
Main Test: 5

Parameter:

SI

Remarks on result:

other: Mean Stimulation Index values were: vehicle control: 1.0 10%: 1.6 25%: 1.7 50%: 0.9

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: Mean DPM/animal values were: vehicle control: 283 10%: 449 25%: 470 50%: 268

No mortalities occurred, no symptoms of systemic toxicity, no changes in body weights and body weight gain were observed.

A slight irritation (grade 1) of the ears was seen in all animals treated with 25 and 50%, but this was considered not to have a toxicologically significant effect on the activity of the nodes. No oedema were observed.

All auricular lymph nodes were considered normal in size, no macroscopic abnormalities of the surrounding area were noted in any of the animals.

Interpretation of results:

not sensitising

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

not skin sensitizing

Executive summary:

To determine the skin-sensitizing properties of estrone the mouse local lymph node assay was performed on mice according to OECD guideline 429. The main study was conducted with the following test substance concentrations: 10%, 25% and 50%.

All animals treated with 25 and 50% showed slight irritation of the ears, but this had no toxicological significant effect on the activity of the lymph nodes. The mean DPM/animal values were 283 (vehicle control), 449 (10%), 470 (25%) and 268 (50%). The SI values calculated were 1.6 (10%), 1.7 (25%) and 0.9 (50%). Since there was no indication that the test substance elicits an SI above or equal to 3 when tested up to 50%, estrone was considered not to be a skin sensitizer.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Based on the study results a classification according to Regulation (EC) No. 1272/2008 (CLP) is not required.