3,5-diiodothyronine

Endpoint summary

Description of key information

A study on the eye irritating potential according to OECD 492 was conducted. The substance was found to be not eye irritating. Thus the substance can be considered to be not skin irritating as well and no study has to be conducted.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin irritation: in vitro / ex vivo

Data waiving:

other justification

Justification for data waiving:

other:

Justification for type of information:

A study on the eye irritating potential according to OECD 492 was conducted. The substance was found to be not eye irritating. Thus the substance can be considered to be not skin irritating as well and no study has to be conducted.

Endpoint conclusion

Endpoint conclusion:

no study available

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 492 (Reconstructed Human Cornea-like Epithelium (RhCE) Test Method for Identifying Chemicals Not Requiring Classification and Labelling for Eye Irritation or Serious Eye Damage)

GLP compliance:

yes (incl. QA statement)

Controls:

yes, concurrent positive control

yes, concurrent negative control

Amount / concentration applied:

Two replicates were tested with 51.4 mg and 49.6 mg of the substance, respectively.

Duration of treatment / exposure:

After dosing the last tissue, all plates were transferred into the incubator for 6 hours at 37 ± 1 °C, 5 ± 1 % CO2 and 80 – 100 % relative humidity.

Duration of post- treatment incubation (in vitro):

At the end of exposure time, the inserts were removed from the plates in one-minute-intervals using sterile forceps and rinsed immediately. The inserts were thoroughly rinsed with DPBS. Then, the tissues were immediately transferred into 5 mL of assay medium in pre-labelled 12-well plate for 25 minutes post soak at room temperature.
After that, each insert was blotted on absorbent material and transferred into a pre-labelled 6-well plate, containing 1 mL assay medium. For post-treatment incubation, the tissues were incubated for 18 hours at 37 ± 1 °C, 5 ± 1 % CO2 and 80 – 100 % relative humidity.

Number of animals or in vitro replicates:

Two replicates were tested.

Irritation parameter:

in vitro irritation score

Remarks:

% viability

Run / experiment:

Tissue 1

Value:

93.3

Negative controls validity:

valid

Positive controls validity:

valid

Irritation parameter:

in vitro irritation score

Remarks:

% viability

Run / experiment:

Tissue 2

Value:

96.8

Negative controls validity:

valid

Positive controls validity:

valid

Irritation parameter:

in vitro irritation score

Remarks:

% viability

Run / experiment:

mean value

Value:

95

Negative controls validity:

valid

Positive controls validity:

valid

The % viability values of the positive control were:

40.7 % (tissue 1), 35.7 % (tissue 2) and 38.2 % (mean value), respectively.

Interpretation of results:

GHS criteria not met

Conclusions:

Under the conditions of the test, L-Tyrosine, O-(4-hydroxyphenyl)-3,5-diiodo- is consid-ered non-eye irritant in the EpiOcularTM Eye Irritation Test.
After treatment with the test item, the mean value of relative tissue viability was reduced to 95.0 %. This value is above the threshold for eye irritation potential (≤ 60%).
All validity criteria were met. The criterion for optical density of the negative control was fulfilled: The OD value was 2.0 (> 0.8 and < 2.5).
The positive control induced a decrease in tissue viability as compared to the negative control to 38.2%. Variation within the replicates of the controls and the test item was ac-ceptable (< 20%).
For these reasons, the result of the test is considered valid.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)