Dimethyl 2-nitroterephthalate

Eye irritation

Administrative data

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:

other: Well performed GLP and OECD guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2012

Report date:

2012

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: OECD Guideline for Testing of Chemicals 437: Bovine Corneal Opacity and Permeability Test Method for Identifying Ocular Corrosives and Severe Irritants (September, 2009)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Dimethyl 2-nitroterephthalate

EC Number:

226-134-1

EC Name:

Dimethyl 2-nitroterephthalate

Cas Number:

5292-45-5

Molecular formula:

C10H9NO6

IUPAC Name:

dimethyl 2-nitroterephthalate

Details on test material:

- Name of test material (as cited in study report): Nitro DMT

Test system

Vehicle:

physiological saline

Amount / concentration applied:

A 20% (w/v) suspenion of the test item in physiological saline was prepared. Each 0.75 mL of the suspension were applied to three bovine corneas.

Duration of treatment / exposure:

The corneas were exposed to the test item suspension for 240 minutes.

Details on study design:

Three bovine corneas were exposed to each 0.75 mL of a 20% (w/v) suspension of the test item in physiological saline for 240 minutes. After treatment the test item suspension was rinsed off the corneas and the corneas' opactity was determined. In a second step the permeability of the corneas was determined photometrically after 90 minutes treatment with fluorescein solution.

Results and discussion

In vivo

Results

Irritation parameter:

other: In vitro Irritation Score = (opacity value – opacity value mean negative control) + (15 x corrected OD490 value)

Basis:

other: bovine corneae

Remarks on result:

other: In vitro Irritation Score, Threshold for Corrosive / Severe irritant: ≥ 55.1, In vitro Irritation Score found: 1.78, Conclusion: not corrosive / not severe irritant

Irritant / corrosive response data:

Relative to the negative control, the test item Nitro DMT did not cause any increase of the corneal opacity or permeability. The calculated mean in vitro irritation score was 1.78. According to OECD 437 the test item is classified as not corrosive / not severe irritant to the eye.

Any other information on results incl. tables

Results after 240 Minutes Incubation Time

Test Group	Opacity value = Difference (t240-t0) of Opacity		Permeability at 490 nm (OD490)		In vitro Score	Mean in vitro irritation score	Proposedin vitro Irritation Scale
		Mean		Mean
Negative Control	1	1.670	0.108	0.078	2.62	2.84	Non corrosive / non severe irritant
	2		0.073		3.10
	2		0.053		2.80
Positive Control	264.33*		- 0.020*		264.03	217.33	Corrosive / severe irritant
	178.33*		0.001*		178.35
	209.33*		0.019*		209.62
Nitro DMT	- 0.67*		0.000*		- 0.67	1.78	Non corrosive / non severe irritant
	2.33*		0.108*		3.95
	2.33*		- 0.019*		2.05

*corrected values

Applicant's summary and conclusion

Interpretation of results:

other: not corrosive / not severe irritant to the eye

Remarks:

Criteria used for interpretation of results: expert judgment

Conclusions:

Under the experimental conditions reported, the test item Nitro DMT is not corrosive / not severely irritating to the eye (CLP/EPA/GHS (Cat 1)).

Executive summary:

This in vitro study was performed to assess the corneal irritation and damage potential of Nitro DMT by means of the BCOP assay using fresh bovine corneas according to OECD TG 437.

Prior to the application 808.80 mg of the test item were suspended in 4.04 mL saline (20% (w/v)) using ultrasonic technique for five minutes.

After a first opacity measurement of the fresh bovine corneae (t₀), the 20% (w/v) suspension in saline (0.9% (w/v) NaCl in deionised water) of the test item Nitro DMT, the positive, and the negative controls were applied to corneas and incubated for 240 minutes at 32 ± 1 °C in complete medium. Since the test item could not be suspended homogeneously, each 0.75 mL of the so prepared stock was distributed to each cornea. Thereby it was taken care of that the corneas were evenly covered with the test item. After the incubation phase the test item, the positive, and the negative controls were each rinsed from the corneas and opacity was measured again (t₂₄₀).

After the opacity measurements permeability of the corneas 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 (saline) neither an increase of opacity nor permeability of the corneas could be observed (mean in vitro irritation score 2.84).

The positive control (10% (w/v) Benzalkonium chloride in saline) showed clear opacity effects (mean in vitro irritation score 217.33) corresponding to a classification as corrosive /severe irritant to the eye (CLP/EPA/GHS (Cat 1)).

Relative to the negative control, the test item Nitro DMT did not cause any increase of the corneal opacity or permeability. The calculated mean in vitro irritation score was 1.78. According to OECD 437 the test item is classified as not corrosive / not severe irritant to the eye.