Sodium 3,5,5-trimethylhexanoate

Eye irritation

Administrative data

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2016

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 437 (Bovine Corneal Opacity and Permeability Test Method for Identifying i) Chemicals Inducing Serious Eye Damage and ii) Chemicals Not Requiring Classification for Eye Irritation or Serious Eye Damage)

Deviations:

no

Test guideline 2

Qualifier:

equivalent or similar to guideline

Guideline:

EU method B.47 (Bovine corneal opacity and permeability test method for identifying ocular corrosives and severe irritants)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Potassium 3,5,5-trimethylhexanoate

EC Number:

299-890-3

EC Name:

Potassium 3,5,5-trimethylhexanoate

Cas Number:

93918-10-6

Molecular formula:

C9H18O2.K

IUPAC Name:

potassium 3,5,5-trimethylhexanoate

Test material form:

solid: crystalline

Details on test material:

Name: Potassium 3,5,5-trimethylhexanoate
CAS No.: 93918-10-6
Batch No.: PURS151015
Purity: 99.4%
Physical State: solid
Colour: white
Molecular Weight: 196.33 g/mol
Storage Conditions: room temperature
Re-certification Date: 14 October 2016

Specific details on test material used for the study:

Name: Potassium 3,5,5-trimethylhexanoate
CAS No.: 93918-10-6
Batch No.: PURS151015
Purity: 99.4%
Physical State: solid
Colour: white
Molecular Weight: 196.33 g/mol
Storage Conditions: room temperature
Re-certification Date: 14 October 2016

Test animals / tissue source

Species:

cattle

Strain:

not specified

Details on test animals or tissues and environmental conditions:

The assay uses isolated corneas obtained as a by-product from animals freshly slaughtered at the abattoir A. Moksel AG, Buchloe, Germany. On the test day, fresh eyes were collected from the slaughterhouse and were transported in HBSS containing Pen/Strep on ice to the laboratories. Immediately after arrival of the eyes, cornea preparation was initiated. The eyes were carefully examined for defects and any defective eyes were discarded. The tissue surrounding the eyeball was carefully pulled away and the cornea was excised leaving a 2 to 3 mm rim of sclera. The isolated corneas were stored in a petri dish containing HBSS.

Test system

Vehicle:

physiological saline

Controls:

yes, concurrent vehicle

yes, concurrent positive control

yes, concurrent negative control

Amount / concentration applied:

The test item was suspended with physiological saline 0.9% NaCl to gain a 20% concentration.

Duration of treatment / exposure:

750 µL of the test item preparation or the control substance was introduced into the anterior chamber (closed-chamber method). After 4 hours ± 5 minutes incubation at 32 +- 1 °C either the test substance or the control substance was removed and the epithelium washed at least three times with MEM (containing phenol red). Once the medium was free of test substance, the cornea was finally rinsed with complete RPMI (without phenol red). The anterior chamber was refilled with complete RPMI and an illuminance measurement was performed.
After the illuminance measurement was performed, the medium was removed from both chambers of the holder. The posterior chamber was refilled with fresh complete RPMI. 1 mL of a 5 mg/mL sodium fluorescein solution was added to the anterior chamber and the corneas were incubated for 90 minutes at 32 +- 1 °C. Then the medium from the posterior chamber was removed and its optical density at 490 nm (OD490) was determined, using a spectrophotometer (Jenway 6405 UV/VIS).

Number of animals or in vitro replicates:

3 corneas for the test item
3 corneas as negative controls treated with physiological saline 0.9% NaCl
3 corneas as positive control treated with imidazole 20% in physiological saline 0.9% NaCl

Results and discussion

In vitro

Results

Irritation parameter:

in vitro irritation score

Run / experiment:

1

Value:

239.46

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

positive indication of irritation

Any other information on results incl. tables

The eye irritancy potential of Potassium 3,5,5-trimethylhexanoate was investigated in the bovine corneal opacity and permeability assay. The test item was suspended with physiological saline 0.9% NaCl to gain a 20% concentration.

The in vitro irritation score obtained with the positive control fell within the two standard deviations of the current historical mean and therefore this assay is considered to be valid. The negative control responses resulted in opacity and permeability values that are less than the established upper limits for background bovine corneas treated with the respective negative control.

For the test item the following mean in vitro irritation score was calculated: 239.46

For the positive control the following mean in vitro irritation score was calculated: 106.03

For the positive control the following mean in vitro irritation score was calculated: 1.14

Applicant's summary and conclusion

Interpretation of results:

Category 1 (irreversible effects on the eye) based on GHS criteria

Conclusions:

According to the evaluation criteria the test item Potassium 3,5,5-trimethylhexanoate is classified into UN GHS Category 1.

Executive summary:

The eye irritancy potential of Potassium 3,5,5-trimethylhexanoate was investigated in the bovine corneal opacity and permeability assay. The test item was suspended with physiological saline 0.9% NaCl (see 10.3) to gain a 20% concentration. The following mean in vitro irritation score was calculated: 239.46

Therefore the test item was classified into UN GHS Category 1. The in vitro irritation score obtained with the positive control fell within the two standard deviations of the current historical mean and therefore this assay is considered to be valid.

The negative control responses resulted in opacity and permeability values that are less than the established upper limits for background bovine corneas treated with the respective negative control.