1,4-dichloro-2-nitrobenzene

Endpoint summary

Description of key information

Skin irritation:

The dermal irritation potential of chemical 1,4-dichloro-2-nitrobenzene (CAS No. 89-61-2) was assessed in various in- vitro and in-vivo experimental studies. Based on the available key data, it can be concluded that the test chemical 1,4-dichloro-2-nitrobenzene is able to cause skin irritation and considered as irritant. Comparing the above annotations with the criteria of CLP regulation, it can be classified under the category 2 as per the CLP regulation.

 

Eye irritation:

The ocular irritation potential of chemical 1,4-dichloro-2-nitrobenzene (CAS No. 89-61-2) was assessed in various in- vitro and in-vivo experimental studies. Based on the available key data, it can be concluded that the test chemical 1,4-dichloro-2-nitrobenzene is able to cause eye irritation and considered as irritant. Comparing the above annotations with the criteria of CLP regulation, 1,4-dichloro-2-nitrobenzene (CAS No. 89-61-2) can be classified under the category 2 as per the CLP regulation.  

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

secondary literature

Justification for type of information:

Data is from secondary source

Qualifier:

according to guideline

Guideline:

other: as below

Principles of method if other than guideline:

Skin irritation test of chemical 2,5-Dichloronitrobenzene was conducted on rabbit according to standard draize test.

GLP compliance:

no

Species:

rabbit

Strain:

not specified

Type of coverage:

not specified

Preparation of test site:

not specified

Vehicle:

not specified

Controls:

not specified

Amount / concentration applied:

500 mg

Duration of treatment / exposure:

24 hours

Observation period:

no data

Number of animals:

no data

Details on study design:

The test was performed according to standard draize procedure.

Irritation parameter:

overall irritation score

Basis:

mean

Time point:

other: 24 hrs

Reversibility:

no data

Remarks on result:

other: mildly

Interpretation of results:

irritating

Conclusions:

The test was performed according to standard draize procedure.

Executive summary:

Skin irritation test was conducted according to standard draize procedure for chemical 2,5-Dichloronitrobenzene.The test chemical was exposed to rabbit skin with dose concentration of 500 mg for 24-hrs.

 

Mild irritating effects were observed on skin of rabbit when exposed to test chemical 2,5-Dichloronitrobenzene for 24-hrs.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

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

Justification for type of information:

Data is from experimental study report.

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)

Principles of method if other than guideline:

The purpose of this study was to assess potential for the test article to be ocular irritants. The ocular irritation potential of a test article may be predicted by measurement of its cytotoxic effect, as reflected in the (MTT) assay, in the MatTek EpiOcular™ model

GLP compliance:

no

Specific details on test material used for the study:

RADIOLABELLING INFORMATION (Not applicable)
- Radiochemical purity: N/A
- Specific activity: N/A
- Locations of the label: N/A
- Expiration date of radiochemical substance: N/A

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Room temperature / Fridge storage
- Stability under test conditions: No data available
- Solubility and stability of the test substance in the solvent/vehicle: No data available
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium: No data available

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: The test article tested as provided neat (undiluted).
- Preliminary purification step (if any): No data available
- Final dilution of a dissolved solid, stock liquid or gel: No data available
- Final preparation of a solid: No data available

FORM AS APPLIED IN THE TEST:solid

Species:

human

Strain:

other: Not applicable

Details on test animals or tissues and environmental conditions:

- Description of the cell system used:
The normal human-derived keratinocytes were cultured at the air-liquid interface in a chemically defined medium on a permeable polycarbonate insert (surface 0.5 cm2). They were cultured in chemically defined serum free medium to form a multi-layered epithelium similar to that found in native corneal mucosa. Each lot of tissues was Quality Assured by MatTek according to specific QC standards including: histology, tissue viability (MTT mean optical density), reproducibility (SD) and tissue thickness.

- Test System Identification
All of the EpiOcular™ 3-dimensional human tissues used in this study were identified by the date of arrival and the lot number. Certificate of Analysis for the tissues is included in this report. Tissue plates were appropriately labeled with study information. Bias was not a factor in this test system.
- Justification of the test method and considerations regarding applicability
EpiOcularTM Eye Irritation (OCL) by MatTek In Vitro Life Science Laboratories, Bratislava, Slovakien

The test articles and controls were evaluated for potential ocular irritancy using the EpiOcular™ 3 dimensional human tissue model purchased from MatTek,In Vitro Life Science Lab. (Bratislava, Slovakia).The EpiOcular tissue construct is a nonkeratinized epithelium prepared from normal human keratinocytes (MatTek). It models the cornea epithelium with progressively stratified, but not cornified cells. These cells are not transformed or transfected with genes to induce an extended life span in culture. The “tissue” is prepared in inserts with a porous membrane through which the nutrients pass to the cells. A cell suspension is seeded into the insert in specialized medium. After an initial period of submerged culture, the medium is removed from the top of the tissue so that the epithelial surface is in direct contact with the air. This allows the test material to be directly applied to the epithelial surface in a fashion similar to how the corneal epithelium would be exposed in vivo. Each lot of tissues was Quality Assured by MatTek, Inc. according to specific QC standards including: histology (cell layers), tissue viability (MTT mean optical density) and reproducibility (SD).

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent positive control

yes, concurrent negative control

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 50 mg of solid test chemical
- Concentration (if solution): neat (undiluted)

VEHICLE (no vehicle)
- Amount(s) applied (volume or weight with unit): none
- Concentration (if solution): none
- Lot/batch no. (if required): none
- Purity: none

NEGATIVE CONTROL
- Amount(s) applied (volume or weight): 50 μL
- Concentration (if solution): neat

POSITIVE CONTROL
- Amount(s) applied (volume or weight): 50 μL
- Concentration (if solution): neat

Duration of treatment / exposure:

Tissues were exposed for approximately 6 hrs ± 15 min for solid test articles, and controls, at approximately 37°C, 5% CO2 in a humidified incubator.

Observation period (in vivo):

Not applicable

Duration of post- treatment incubation (in vitro):

Following the washing and post soak, the tissues were rinsed and incubated at approximately 37°C, 5% CO2 in a humidified incubator for a post-exposure recovery time of 18 hours for solid test chemicals and controls

Number of animals or in vitro replicates:

2 tissues were used for test compound and control.

Details on study design:

- Details of the test procedure used
The tissues were exposed to the test article neat (undiluted). EpiOcular™ tissues were purchased from MatTek. Quality control of the tissues was performed by MatTek and the Certificate of Analysis (CoA)
for the tissues is provided and is kept in the study binder. Tissues were exposed for approximately 6 hrs ± 15 min for solid test articles and controls at approximately 37°C, 5% CO2 in a humidified incubator.
After the exposure, the test article was rinsed off the tissues and the tissues were soaked in media for ~25 minutes for solid test articles and controls.Following the washing and post soak, the tissues were rinsed and incubated at approximately 37°C, 5% CO2 in a humidified incubator for a post-exposure recovery time of 18 hours for solid test chemicals and controls.Tissue viability was assessed by 3-(4,5-dimethylthiazol- 2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay.

- MTT Auto reduction and colouring assessment
MTT Pre-test
The test article was assessed for the potential to interfere with the assay. Approximately 50 µL of liquid test article was added to 1 mL of MTT media (~1 mg/mL) and incubated in a humidified incubator at approximately 37°C and approximately 5% CO2 for 3 hours. 50 µL of ultrapure water was used as a negative control.
- Test Article Color Test
Approximately 50 µL of liquid test article was added to 1.0 mL of ultrapure water and 2.0 mL isopropanol and incubated in a humidified incubator at approximately 37°C and approximately 5% CO2 for 2 hours, 04 minutes and 35 seconds. Samples were then added to the wells of a clear 96-well plate and the plate was read on a Thermo Scientific Multiskan FC Microplate Photometer to 570 nm. Test articles that tested positive for excessive coloration (OD >0.08) were assessed on living-tissue controls that were incubated in both culture media and MTT media as well (n=3 for both conditions).

- MTT Assay:
Inserts are removed from the 24-well plate after 3 hrs of incubation and the bottom of the insert is blotted on absorbent material, and then transferred to a pre-labeled 6-well plate containing 1 ml isopropanol in each well so that no isopropanol is flowing into the insert. At the end of the non-submerged extraction inserts and tissues are discarded without piercing and 1 ml of isopropanol is added into each well. The extract solution is mixed and the optical density of the extracted formazan (200 μL/well of a 96-well plate) was determined using Thermo Scientific Multiskan FC Microplate Photometer at 570 nm. Relative cell viability was calculated for each tissue as % of the mean negative control tissues.

- Evaluation of Test Article in the cell Models
1. Cell System:
Upon receipt, the MatTek EpiOcular™ tissue cultures were placed in 1.0 mL of fresh Maintenance medium (in a 6-well plate) for 60 minutes. After the 60 minutes incubation, the Maintenance medium was exchanged with fresh medium and the tissues were incubated overnight (16-24 hrs) at approximately 37°C, approximately 5% CO2 in a humidified incubator.
2. Control and Test Article Exposures:
20 µL of calcium and magnesium free DPBS was added to each tissue and the tissues placed back into the incubator for 30 minutes. The controls and the test article will be applied topically to tissues by pipette.2 tissues will be used per test compound and control.
a)Controls: 50 µL of negative control sterile ultrapure water and positive control methyl acetate were added to the tissues. The tissues were placed into the ~37°C humidified incubator with 5% CO2 for the approximately 30 minute exposure time.
b)Test Article: When a solid was tested, 50 mg of the solid were added to the tissues. The tissues were placed into the ~37°C humidified incubator with 5% CO2 for the approximately 6 hrs ± 15 min.
3. Post exposure treatment:
After the exposure, the tissues were rinsed 20 times with sterile of DPBS to remove test material. The apical surface was gently blotted with a cotton swab and cultures were immediately transferred to a 12-well plate containing 5 mL of media per well. Tissues exposed to liquid test articles (and the respective control) were incubated, submerged in the media for ~12 minutes at room temperature.For liquid test articles, tissues, Tissuses were then transferred to 6-well plates containing 1.0 mL fresh Maintenance medium per well and incubated for a post-exposure recovery period for 2 hours at approximately 37 degC, 5% CO2 in a humidified incubator.
- Doses of test chemical and control substances used
Test Article:
When a solid was tested, 6 hours of the solid were added to the tissues. The tissues were placed into the ~37°C humidified incubator with 5% CO2 for the approximately 6 hrs ± 15 min.
Controls: 50 µL of negative control sterile ultrapure water, positive control methyl acetate were added to the tissues. The tissues were placed into the ~37°C humidified incubator with 5% CO2 for the approximately 30 minute exposure time.

- Duration and temperature of exposure, post-exposure immersion and post-exposure incubation periods:
Tissues were exposed for approximately 6 hours for solid test articles and controls, at approximately37°C, 5% CO2 in a humidified incubator.
Following the post soak, the tissues were rinsed and incubated at approximately 37°C, 5% CO2 in a humidified incubator for a post-exposure recovery time totaling 18 hours for solid test articles and controls.

- Justification for the use of a different negative control than ultrapure H2O (Not applicable)
- Justification for the use of a different positive control than neat methyl acetate (Not applicable)
- Number of tissue replicates used per test chemical and controls: 2 tissues were used for test compound and control.
- Description of the method used to quantify MTT formazan
The blue formazan salt was extracted by placing the tissue insterts in 1 mL isopropanol in a 6-well plate. The extraction for solid exposed tissues was 3 hrs incubation. After an addition of 1 ml isopropanol and mixing, the optical density of the extracted formazan (200μL/well of a 96-well plate) was determined using a Thermo Scientific Multiskan FC Microplate Photometer at 570 nm.

- Description of evaluation criteria used including the justification for the selection of the cut-off point for
the prediction model
Calculations and Statistical Methods
MTT Assay
Blanks:
· The OD mean from all replicates for each plate (ODblank).
Negative Controls (NC):
· The blank corrected value was calculated: ODNC= ODNCraw– ODblank.
· The OD mean per NC tissue was calculated.
· The mean OD for all tissues corresponds to 100% viability.
· The mean, standard deviation (SD), standard error of the mean (SEM) and the percent coefficient of variation (% CV) was calculated.
ODblank= optical density of blank samples (isopropanol alone).
ODNCraw= optical density negative control samples.
ODNC= optical density of negative control samples after background subtraction.
Positive Control (PC):
· Calculate the blank corrected value: ODPC= ODPCraw– ODblank.
· The OD mean per PC tissue was calculated.
· The viability per tissue was calculated: %PC = [ODPC/ mean ODNC] x 100.
· The mean viability for all tissues was calculated: Mean PC = Σ %PC / number of tissues.
· The standard deviation (SD), standard error of the meanthe mean (SEM) and the percent coefficient of variation (% CV) was calculated.
ODPCraw= optical density positive control samples.
ODPC= optical density of positive control samples after background subtraction.
Tested Articles:
· Calculate the blank corrected value ODTT= ODTTraw– ODblank.
· The OD mean per tissue is calculated.
· The viability per tissue is calculated: %TT = [ODTT/ mean ODNC] x 100.
· The mean viability for all tissues is calculated: Mean TT = Σ %TT / number of tissues.
· The standard deviation (SD) and the percent coefficient of variation (% CV)for the controls and the test articles will be calculated.
ODTTraw= optical density test article samples.
ODPC= optical density of test article samples after background subtraction.
Data Correction Procedure for MTT Interfering Compounds
True viability = Viability of treated tissue – Interference from test article = ODtvt – ODkt where ODkt =
(mean ODtkt – mean ODukt).
ODtvt = optical density of treated viable tissue
ODkt = optical density of killed tissues
ODtkt = optical density of treated killed tissue
ODukt = optical density of untreated killed tissue (NC treated tissue)
Data Correction Procedure for Colored Compounds
True viability = Viability of treated tissue incubated in MTT media – Viability of treated tissue incubated in
media without MTT = ODtvt – ODvt.
ODtvt = optical density of treated viable tissue incubated in MTT media
ODvt = optical density of viable tissues incubated in media alone.
Proposed Statistical methods
The mean, standard deviation (SD) and the percent coefficient of variation (% CV) for the controls and the test article will be calculated.
- Evaluation of data
The results of the assay was evaluated and compared to negative control.
Table: Irritancy Prediction
In VitroResults In VivoPrediction
Mean tissue viability ≤60% Irritant (I) – Category 1 or 2
Mean tissue viability >60% Non-irritant (NI) – No Category
- Assay quality controls
- Negative Controls (NC)
The assay is meeting the acceptance criterion if the mean viability of the NC in terms of Optical Density(OD570) of the NC tissues (treated with sterile ultrapure water) in the MTT assay are >0.8 to <2.5. This is an indicator of tissue viability following shipping and conditions under use.
- Positive Controls (PC)
Methyl acetate was used as a PC and tested concurrently with the test article. The assay is meeting the acceptance criteria if the viability of the PC is <50% of the negative control.
- Standard Deviation (SD)
Each test of ocular irritancy potential is predicted from the mean viability determined on 2 single tissues. The assay meets the acceptance criteria if SD calculated from individual percent tissue viabilities of the
replicates is <18% for three replicate tissues.

Irritation parameter:

other: mean % tissue viability

Run / experiment:

Run 1

Value:

22.4

Vehicle controls validity:

not specified

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: Mean of OD is 0.472; Irritating

Other effects / acceptance of results:

The MTT data show the assay quality controls were met.

Interpretation of results:

other: Irritating

Conclusions:

The ocular irritation potential of test article was determined according to the OECD 492 test guideline followed for this study. The mean % tissue viability of test substance 1,4-dichloro-2-nitrobenzene (CAS No. was determined to be 22.4 %. Thus, the test chemical was considered to be irritating to the human eyes.

Executive summary:

The ocular irritation potential of test article was determined according to the OECD 492 test guideline for this study. The MatTek EpiOcular™ model was used to assess the potential ocular irritation of the test articles by determining the viability of the tissues following exposure to the test article via MTT. Tissues were exposed to solid test articles and control for approx.6 hours, followed by a 25 minute post-soak and approximately 18 hours recovery after the post-soak. The viability of each tissue was determined by MTT assay.

The MTT data show the assay quality controls were met, passing the acceptance criteria.

The mean % tissue viability of test substance 1,4-dichloro-2-nitrobenzene was determined to be 22.4 %. Hence, under the experimental test conditions it was concluded that test substance 1,4-dichloro-2-nitrobenzene was considered to be irritating to the human eyes and can thus be classified as ‘’Irritating to eyes in Category 2” as per CLP Regulation.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Skin irritation:

Various studies has been investigated for the test chemical 1,4-dichloro-2-nitrobenzene (CAS No: 89-61-2) to observe the potential for dermal irritation to a greater or lesser extent. The studies are based on in-vitro and in-vivo experiments which have been summarized as below;

 

The dermal irritation potential of test article was determined according to the OECD 439 test guideline for this study. The MatTek EpiDerm™ model was used to assess the potential dermal irritation of the test article by determining the viability of the tissues following exposure to the test article via MTT. Tissues were exposed to the test article and controls for ~one hour, followed by a 42 hour post-exposure recovery period. The viability of each tissue was determined by MTT assay. The MTT data show the assay quality controls were met and passed the acceptance of criteria. The Mean % tissue viability compared to negative control (n=3) of the test substance 1,4-dichloro-2-nitrobenzene (CAS No: 89-61-2) was determined to be 108.3 %. Hence, under the current experimental test conditions it was concluded that test substance 1,4-dichloro-2-nitrobenzene (CAS No: 89-61-2) was considered to be not irritating to human skin and can thus be classified as “Not Classified'' as per CLP Regulation.

 

Similar in-vivo skin irritation test from secondary source was conducted according to standard draize procedure for chemical 2,5-Dichloronitrobenzene.The test chemical was exposed to rabbit skin with dose concentration of 500 mg for 24-hrs. Mild irritating effects were observed on skin of rabbit when exposed to test chemical 2,5-Dichloronitrobenzene for 24-hrs.

 

 

In the third in-vivo study skin irritation study was conducted for the test chemical 2, 5-Dichloronitrobenzene on rabbits. The test material was wet with pure 95% ethanol or o-dichlorobenzene and held in contact with the skin by means of cotton pads. 2, 5-Dichloronitrobenzene, wetted with pure ethanol, produced irritation and edema after two hours contact. There was no visible reaction after contact time of one hour, wetted with o-dichlorobenzene, these two compounds had slight action after contact for two hours. When melted and applied to the shaved skin, the compound had no apparent local or systemic effects. The test compound 2, 5-Dichloronitrobenzene is irritating to the skin of rabbit. According to the publication, the test material classifies as a skin irritant.

 

Thus on the basis of experimental key in-vivo study, chemical consider to be irritating to skin and classified in category 2 as per the CLP regulation criteria.

Eye irritation:

Various studies has been investigated for the test chemical 1,4-Dichloro-2-nitrobenzene (CAS No. 89-61-2) to observe the potential for ocular irritation to a greater or lesser extent. The studies are based on in-vitro and in-vivo experiments which have been summarized as below;

 

The ocular irritation potential of test article was determined according to the OECD 492 test guideline for this study. The MatTek EpiOcular™ model was used to assess the potential ocular irritation of the test articles by determining the viability of the tissues following exposure to the test article via MTT. Tissues were exposed to solid test articles and control for approx.6 hours, followed by a 25 minute post-soak and approximately 18 hours recovery after the post-soak. The viability of each tissue was determined by MTT assay. The MTT data show the assay quality controls were met, passing the acceptance criteria. The mean % tissue viability of test substance 1,4-dichloro-2-nitrobenzene was determined to be 22.4 %. Hence, under the experimental test conditions it was concluded that test substance 1,4-dichloro-2-nitrobenzene was considered to be irritating to the human eyes and can thus be classified as ‘’Irritating to eyes in Category 2” as per CLP Regulation.

 

Secondly the in-vivo eye irritation test was conducted according to standard draize procedure for chemical2,5-Dichloronitrobenzene.The test chemical was exposed to eye of the rabbit with dose concentration of 100 mg for 24-hrs. Moderate irritating effects were observed in eye irritation test of chemical 2,5-Dichloronitrobenzene exposed to rabbit eye for 24-hrs.

 

Above studies was supported by the third study from secondary source. Eye irritation study was conducted on rabbits to evaluate the eye irritation potential of the test compound 1,4-dichloro-2-nitrobenzene. The test compound 1,4-dichloro-2-nitrobenzene is moderately irritating to the eyes of rats. According to the effects observed on the eye of rabbit, the test material classifies as an eye irritant.

 

Thus on the basis of experimental key in-vitro and in-vivo study, chemical 1,4-dichloro-2-nitrobenzene consider to be irritating to eye and classified in category 2 as per the CLP regulation criteria.

Justification for classification or non-classification

The skin and eye irritation potential of test chemical 1,4-dichloro-2-nitrobenzene (CAS No. 89-61-2) were observed in various studies. The results obtained from these studies indicate that the chemical is likely to cause skin irritation as well as eye irritation. Hence the test chemical 1,4-dichloro-2-nitrobenzene (CAS No. 89-61-2) can be classified under the category 2 as per the CLP regulation.