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Eye irritation

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Administrative data

eye irritation: in vitro / ex vivo
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference Type:
study report
Report date:

Materials and methods

Test guideline
according to guideline
OECD Guideline 437 (Bovine Corneal Opacity and Permeability Test Method for Identifying Ocular Corrosives and Severe Irritants)
Principles of method if other than guideline:
Additional the test methods are compatible to Bovine Corneal Opacity and Permeability (BCOP) Assay, SOP of Microbiological Associates Ltd., UK, Procedure Details, April 1997.
GLP compliance:
yes (incl. QA statement)

Test material


Test animals / tissue source

other: bovine eyes
Details on test animals or tissues and environmental conditions:
Freshly isolated bovine cornea (at least 9 month old donor cattle) from Schlachthof Bensheim, Germany

Test system

unchanged (no vehicle)
yes, concurrent positive control
yes, concurrent negative control
Amount / concentration applied:
Test item or negative or positive control is applied undiluted at a volume of 0.75 mL on the surface of the corneae.
Duration of treatment / exposure:
Incubation time: 10 min
Duration of post- treatment incubation (in vitro):
After the test item or control items, respectively, were rinsed off from the application side with saline, the corneae were incubated at 32 ± 1 °C for further two hours in a vertical position, followed by a second opacity reading.
Number of animals or in vitro replicates:
Number of Corneae:
Negative Control: 3
Positive Control: 3
Test Item: 3
Details on study design:
This in vitro study was performed to assess the corneal damage potential of Di-(iso)-pentyl terephthalate (DPT) by means of the BCOP assay using fresh bovine corneae.
The corneae were distributed as follows:

Negative Control (0.9% w/v NaCl): 3 corneae

Positive Control (2-Ethoxyethanol): 3 corneae

Test Item (DPT): 3 corneae

After a first opacity measurement of the fresh bovine corneae (t0), the neat test item Di-(iso)-pentyl terephthalate (DPT), the positive, and the negative controls were applied to corneae and incubated for 10 minutes at 32 ± 1 °C. The posterior chamber contained incubation medium. After the incubation phase the test item, the positive, and the negative controls were each rinsed from the corneae. Further, the corneae were incubated for another 120 minutes at 32 ± 1 °C in incubation medium, and opacity was measured a second time (t130).
After the opacity measurements permeability (OD490 value) of the corneae was determined by measuring spectrophotometrically the transfer of sodium fluorescein after incubation in a horizontal position for 90 minutes at 32 ± 1 °C.

At the end, an In vitro Irritancy Score (IVIS) is calcuted:
The following formula is used to determine the IVIS of the positive control and the test item:
IVIS = (opacity value – opacity value mean negative control) + (15 x corrected OD490 value)
The mean IVIS value of each treated group is calculated from the IVIS values.
Depending on the score obtained, the test item is classified into the following category according to OECD guideline 437:

≤ 3: No Category (according to GHS)
> 3; < 55: No prediction can be made
≥ 55: Serious eye damaging according to CLP/EPA/GHS (Cat 1)

Results and discussion

In vitro

Irritation parameter:
in vitro irritation score
Run / experiment:
DPT (Test item)
Vehicle controls validity:
not applicable
Negative controls validity:
Positive controls validity:
Remarks on result:
other: No serious eye damaging
Other effects / acceptance of results:


- Acceptance criteria met for negative control: The negative control responses result in opacity and permeability values that are less than the established upper limits for background opacity and permeability values for bovine corneae treated with the respective negative control.

- Acceptance criteria met for positive control: the positive control gives an IVIS that falls within two standard deviations of the current historical mean (updated every three months).

- Range of historical values if different from the ones specified in the test guideline:
Positive Control Negative Control
Mean IVIS 72.53 1.131
Standard Deviation 18.62 0.76
Range of IVIS 3.59 - 153.20 0.00 - 2.84

Any other information on results incl. tables

After the opacity measurements permeability of the corneae was determined by measuring spectrophotometrically the transfer of sodium fluorescein after incubation in a horizontal position for 90 minutes at 32 ± 1 °C. With the negative control (0.9% (w/v) NaCl solution in deionised water) neither an increase of opacity nor permeability of the corneae could be observed. The positive control (2-Ethoxyethanol) showed clear opacity and distinctive permeability of the corneae corresponding to a classification as serious eye damaging (CLP/EPA/GHS (Cat 1)). Relative to the negative control, the test item Di-(iso)-pentyl terephthalate (DPT) caused a slight increase of the corneal opacity, but permeability effects did not occur. The calculated mean in vitro irritancy score was 4.73. According to OECD 437 (see table in chapter 3.10.3) the test item is not classified as serious eye damaging (CLP/EPA/GHS (Cat 1), but the test item’s hazard for eye damaging cannot be predicted.

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
In conclusion, according to the current study and under the experimental conditions reported, Di-(iso)-pentyl terephthalate (DPT) is not serious eye damaging, but a prediction for the damage hazard cannot be made (GHS).