1,1'-(benzene-1,3-diyldimethanediyl)bis(1H-pyrrole-2,5-dione)

Endpoint summary

Description of key information

- skin irritation: not irritating, study conducted according to OECD 439, GLP

- eye irritation: not corrosive, IVIS: 7.28, study conducted according to OECD 437, GLP

- eye irritation: QSAR estimation with ToxTree decision tree approach, no alerts for eye irritation

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2017-05-03 to 2017-10-06

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 439 (In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method)

Version / remarks:

28 July 2015

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Cell source:

other: Reconstructed human epidermis tissue containing normal human keratinocytes

Justification for test system used:

This test uses the EpiDerm™ reconstructed human epidermis model (MatTek) which consists of normal human epidermal keratinocytes (NHEK) and therefore represents in vitro the target organ of the species of interest and closely mimics the biochemical and physiological properties of the upper parts of the human, i.e. the epidermis.

Vehicle:

unchanged (no vehicle)

Details on test system:

RECONSTRUCTED HUMAN EPIDERMIS (RHE) TISSUE
- Model used: EpiDerm™ reconstructed human epidermis model
- Tissue batch number(s): Lot No.: 25813, 25829, 25838
- Date of initiation of testing: 2017-05-17

TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment / exposure: 37°C for 35 min and room temperature for 25 min
- Temperature of post-treatment incubation (if applicable): 37°C

REMOVAL OF TEST MATERIAL AND CONTROLS
-Volume and number of washing steps: the inserts were washed at least 15 times with DPBS

MTT DYE USED TO MEASURE TISSUE VIABILITY AFTER TREATMENT / EXPOSURE
- MTT concentration: 1 mg/mL
- Incubation time: 3 h
- Wavelength: 570 nm
- Filter bandwidth: a filter band pass of maximum ± 30 nm without reference wavelength

FUNCTIONAL MODEL CONDITIONS WITH REFERENCE TO HISTORICAL DATA
- Viability: MTT QC assay, 4 h, n = 3; Acceptance criteria: OD (540-570 nm) [1.0 - 3.0], Result (batch: 25813): 1.563 ± 0.022, (batch: 25829) 1.857 ± 0.107, (batch: 25838) 2.403 ± 0.238
- Barrier function: ET-50 assay, 100µL 1%Triton X-100, 4 time-points, n = 3, MTT assay; Acceptance criteria: ET-50 [4.77 - 8.72]; Result (batch: 25813): 5.38 h, (batch: 25829) 5.4 h, (batch: 25838) 5.36 h
- Contamination:HIV-1, Hepatitis B, Hepatitis C, Bacteria, yeast, and other fungi: not detected

NUMBER OF REPLICATE TISSUES: triplicate

CONTROL TISSUES USED IN CASE OF MTT DIRECT INTERFERENCE
- Fresh tissues / killed tissues:
To check the non-specific MTT-reducing capability of the test item 25 mg of the test item was mixed per 1 mL MTT medium and incubated for 60 min at 37 ± 1 °C in the incubator. If the mixture turns blue/purple, the test item is presumed to have reduced MTT and the part of absorption due to the non-specific reduction of MTT (NSMTT) was determined by using killed tissues. For quantitative correction of results, two killed tissues were treated with 25 mg of the test item (KT) and two killed tissues were left untreated as a control (KU), respectively. NSMTT was then calculated relative to the negative control of living tissues (NK) according to the following formula:
NSMTT [%] = [(OD KT - OD KU )/OD NK ] * 100
If the test item is classified as non-irritant and if non-specific MTT reduction is ≤ 30% relative to the negative control of living epidermis, the true MTT metabolic conversion (TOD TT ) of the test item treated living tissues TM was corrected according to the following formula:
TOD TT = OD TM – (OD KT – OD KU )
To check the colouring potential of the test item 25 mg of the test item was mixed per 300 µL aqua dest. and per 300 µL isopropanol each in a transparent recipient and incubated at 37 ± 1°C for 60 min. If the test item is classified as non-irritant and colouring is detected by unaided eye-assessment, and the chemical in water and/or isopropanol absorbs light in the range of 570 ± 30 nm, the test item was checked for its tissue-colouring potential. For quantitative correction of results, the test was performed using two additional living tissues treated with 25 mg of the test item (TVT). The non-specific colour
of additional viable tissues (NSC living ) was then calculated according to the following formula:
NSC living [%] = [OD TVT /OD NK ]*100
If NSC living is ≤ 5% relative to the negative control of living epidermis, no correction of the results is necessary.
If NSC living is > 5% and ≤ 30% relative to the negative control of living epidermis, the true MTT metabolic conversion (TOD TT ) was corrected according to the following formula:
TOD TT = OD TM – OD TVT
For test items which are classified as non-irritant and which act as non-specific MTT-reducers and show non-specific colouring of living tissues, a third control for non-specific colour in killed tissues (NSC killed ) was performed to avoid a possible double-correction for colour interference. Therefore, two killed tissues were treated with 25 mg of the test item (TKT). The non-specific colour of additional viable tissues (NSC killed ) was then calculated according to the following formula:
NSC killed [%] = [OD TKT /OD NK ]*100
The true tissue viability was then calculated as the percent tissue viability obtained with living tissues minus NSMTT minus NSC living plus NSC killed .
If the coloured test material or MTT reducing substance is classified as “irritant” i.e. mean tissue viability is < 50%, the correction procedures are not necessary.


NUMBER OF INDEPENDENT TEST SEQUENCES / EXPERIMENTS TO DERIVE FINAL PREDICTION: 4

PREDICTION MODEL / DECISION CRITERIA
- The test substance is considered to be corrosive to skin if the viability after exposure and post-incubation is less than or equal 50%.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 25 µL of sterile DPBS was applied to the epidermal surface in order to improve the contact between the powder and the epidermis. Afterwards, 25 mg (39 mg/cm²) of the test item was applied directly atop the EpiDerm™ tissue using an application spoon avoiding compression of the test item.
The test item was spread to match size of the tissue by gently shaking the inserts or by using a bulb-headed Pasteur pipette.

NEGATIVE CONTROL
- Amount(s) applied (volume or weight): 30 µL DPBS

POSITIVE CONTROL
- Amount(s) applied (volume or weight): 30 µL 5% SDS
- Concentration (if solution): 5%

Duration of treatment / exposure:

35 ± 1 min

Duration of post-treatment incubation (if applicable):

24 ± 2 h

Number of replicates:

triplicates

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

test item, experiment I

Value:

50.1

Vehicle controls validity:

not examined

Negative controls validity:

valid

Positive controls validity:

valid

Remarks:

4.7% tissue viability

Remarks on result:

no indication of irritation

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

test item, experiment II

Value:

96.5

Vehicle controls validity:

not examined

Negative controls validity:

valid

Positive controls validity:

valid

Remarks:

3.9% tissue viability

Remarks on result:

no indication of irritation

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

test item, experiment III

Value:

48.7

Vehicle controls validity:

not examined

Negative controls validity:

valid

Positive controls validity:

valid

Remarks:

3.9% tissue viability

Remarks on result:

other: Standard deviation of Viabilities was not below 18 %

Irritation / corrosion parameter:

other: absolute tissue viability

Run / experiment:

test item, experiment IV

Value:

88.8

Vehicle controls validity:

not examined

Negative controls validity:

valid

Positive controls validity:

valid

Remarks:

4.4% tissue viability

Remarks on result:

no indication of irritation

Other effects / acceptance of results:

- OTHER EFFECTS:
- Direct-MTT reduction: The mixture of 25 mg test item per 1 mL MTT medium showed no reduction of MTT compared to the solvent. The mixture did not turn blue/purple. Therefore, NSMTT equalled 0%.
- Colour interference with MTT: The mixture of 25 mg of the test item per 300 µL aqua dest. and/or per 300 µL isopropanol showed no colouring detectable by unaided eye-assessment. Therefore, NSC equalled 0%.

ACCEPTANCE OF RESULTS:
- Acceptance criteria met for negative control: yes
- Acceptance criteria met for positive control: yes
- Acceptance criteria met for variability between replicate measurements: yes, except for Experiment III
- Range of historical values if different from the ones specified in the test guideline:
Mean Relative viability [%] Positive Control: 3.9 ± 1.9 (n = 27), Mean OD 570 ± 30 nm NK = 1.831 ± 0.357 (n = 27)
Acceptance criteria: Mean OD 570 nm Negative Control: ≥ 0.8 and ≤ 2.8, Mean Relative viability [%] Positive Control ≤ 20, Standard deviation of viability of replicate tissues of all dose groups ≤ 18% (except Experiment III)

Table 1: Mean Absorbance of the test material, Relative Viability [%] Positive Control and SD Viability [%]

Group	Exp. I	Exp. II	Exp. III	Exp. IV
Mean Absorbance 570 nm	0.999	1.451	0.730	1.556
Relative Viability [%] Positive Control	4.7	3.9	3.9	4.4
SD Viability [%]	0.2-14.4	0.7-6.4	0.4-38.3	0.1-6.8

Interpretation of results:

GHS criteria not met

Conclusions:

In the present study conducted according to OECD guideline 439 the test material m-Xylylenebismaleimide was applied to the reconstituted three-dimensional human skin model EpiDerm™(MatTek) for 60 min followed by a 42 h post-incubation period and immediate determination of cytotoxic effects via MTT reduction assay. There were no indications for skin irritation and all acceptance criteris were fulfiled, thus, the substance does not need to be classified according to Regulation (EC) 1272/2008 (CLP) and the Globally Harmonized System for Classification and Labelling of Chemicals (GHS).

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Reference

Reference 1

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2017-04-03 to 2017-05-29

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

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)

Version / remarks:

adopted 26 July, 2013

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Species:

cattle

Strain:

not specified

Details on test animals or tissues and environmental conditions:

SOURCE OF COLLECTED EYES
- Storage, temperature and transport conditions of ocular tissue (e.g. transport time, transport media and temperature, and other conditions):
On the test day, fresh eyes were collected from the slaughterhouse and were transported in HBSS containing 1% Pen/Strep on ice to the laboratories. Immediately after arrival of the eyes, cornea preparation was initiated.

- Time interval prior to initiating testing:
At least 1 hour

- indication of any existing defects or lesions in ocular tissue samples:
Before the corneae were mounted in corneal holders with the endothelial side against the O-ring of the posterior chamber, they had been visually examined for defects and any defective cornea had been discarded.

- Indication of any antibiotics used:
1% Penicilin/Streptomycin

Vehicle:

physiological saline

Controls:

yes, concurrent vehicle

yes, concurrent positive control

Amount / concentration applied:

TEST MATERIAL
- Concentration (if solution): 20% solution in physiological saline

VEHICLE

- Concentration (if solution): 0.9% NaCl physiological saline

Duration of treatment / exposure:

4 h at 32°C

Duration of post- treatment incubation (in vitro):

90 min at 32°C

Number of animals or in vitro replicates:

each 3 corneae were used for the test item, the positive control and the negative control

Details on study design:

SELECTION AND PREPARATION OF CORNEAE
Isolated corneae were obtained as a by-product from animals freshly slaughtered at an abattoir. Fresh eyes were collected from the slaughterhouse and transported in HBSS containing Pen/Strep on ice to the laboratories. Immediately after arrival of the eyes, cornea preparation was initiated.
The tissue surrounding the eyeball was carefully pulled away and the cornea will be excised leaving a 2 to 3 mm rim of sclera. The isolated corneae will be stored in a petri dish containing HBSS. Before mounting the corneae in corneal holders with the endothelial side against the O-ring ofthe posterior chamber, they were visually examined for defects and any defective cornea were discarded.

QUALITY CHECK OF THE ISOLATED CORNEAS
The eyes were visually checked for any defects of the cornea.

NUMBER OF REPLICATES
3

SOLVENT CONTROL USED (if applicable)
yes, pyhsiological saline

POSITIVE CONTROL USED
20% imidazole

APPLICATION DOSE AND EXPOSURE TIME
20% solution of the test item was applied and the corneae incubated for 4 h at 32°C

TREATMENT METHOD:
The eyes were incubated applying the closed chamber method.

POST-INCUBATION PERIOD:
No.

REMOVAL OF TEST SUBSTANCE
- Number of washing steps after exposure period:
The eyes were washed at least three times

- POST-EXPOSURE INCUBATION:
Yes. 90 min at 32°C.

METHODS FOR MEASURED ENDPOINTS:
- Corneal opacity:
Corneal opacity was measured using an opacitometer (BASF-OP3.0, Duratec)

- Corneal permeability:
passage of sodium fluorescein dye measured with the aid of UV/VIS spectrophotometry (OD490)

- Others (e.g, pertinent visual observations, histopathology):
Beside illuminance measurement the corneae were observed visually and pertinent observations were recorded

SCORING SYSTEM:
In Vitro Irritancy Score (IVIS)

DECISION CRITERIA:
The following IVIS cut-off values for identifying test substances as inducing serious eye damage (UN GHS Category 1) and test substances not requiring classification for eye irritation or serious eye damage (UN GHS No Category) were used:
IVIS UN GHS
≤ 3 No Category
>3; ≤ 55 No prediction can be made
> 55 Category 1

Irritation parameter:

in vitro irritation score

Run / experiment:

mean IVIS of three experiments

Value:

7.28

Vehicle controls validity:

valid

Remarks:

IVIS 0.59

Negative controls validity:

not examined

Positive controls validity:

valid

Remarks:

IVIS 121.72

Other effects / acceptance of results:

OTHER EFFECTS:
- Visible damage on test system:
No

DEMONSTRATION OF TECHNICAL PROFICIENCY:
The BCOP assay is considered to be valid if the in vitro irritation score obtained with the positive control falls within the two standard deviations of the current historical mean.

ACCEPTANCE OF RESULTS:
- Acceptance criteria met for negative control: The negative control responses should result in opacity and permeability values that are less than the established upper limits (Mean VaIue + 2 x Standard Deviation = 2.89) for background bovine corneae treated with the respective negative control. Mean in vitro score = 0.59.

- Acceptance criteria met for positive control:
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. Mean in vitro score = 121.72.


Historical mean IVIS of the positive control:
Mean value (MV): 125.72
Standard deviation (SD): 18.54
MV-2 x SD: 88.65
MV+2 x SD: 162.80
Number of Replicates providing Historical Mean: 21

Historical mean IVIS of the negative control:
Mean value (MV): 1.27
Standard deviation (SD): 0.81
MV-2 x SD: -0.34
MV+2 x SD: 2.89
Number of Replicates providing Historical Mean: 21

Table 1: Opacity

Cornea No.	Test Item	Initial Opacity	Final Opacity	Change of Opacity Value	Corrected Opacity Value
1 2 3 MV	Negative Control	2.20 2.01 2.08 2.10	3.09 2.05 2.12 2.42	0.89 0.04 0.04 0.32
4 5 6 MV	Positive Control	3.20 3.16 3.05 3.14	94.43 96.42 92.88 94.58	91.23 93.25 89.84 91.44	90.91 92.93 89.52 91.12
7 8 9 MV	Test Item	0.98 2.85 0.88 1 .57	7.10 8.37 10.45 8.64	6.12 5.52 9.57 7.07	5.80 5.19 9.25 6.75

MV: mean value

Table 2: Permeability

Cornea No.	Test Item	OD490	Corrected OD490 Value
1 2 3 MV	Negative Control	0.009 0.009 0.036 0.018
4 5 6 MV	Positive Control	1 .435 2.415 2.325 2.058	1.417 2.397 2.307 2.040
7 8 9 MV	Test Item	0.022 0.037 0.101 0.053	0.004 0.019 0.083 0.035

MV: mean value

Table 3: In Vitro Irritation Score

Cornea No.	Test Item	Corrected Opacity	Corrected OD490 Value
1 2 3 MV	Negative Control	0.89 0.04 0.04 0.32	0.009 0.009 0.036 0.018	0.59
4 5 6 MV	Pos itive Control	90.91 92.93 89.52 91.12	1 .417 2.397 2.307 2.040	121.72
7 8 9 MV	Test Item	5.80 5.19 9.25 6.75	0.004 0.019 0.083 0.035	7.28

MV: mean value

Interpretation of results:

Category 2 (irritating to eyes) based on GHS criteria

Conclusions:

In the present study the treatment of bovine corneae with m-Xylylenebismaleimide for 4h at 32°C resulted in a mean IVIS of 7.28. There were signs of opacity in of the treated corneae after 4 h exposure and the corneae showed a yellowish colouration. However, in accordance with OECD Testguideline 437 (adopted July 26, 2013) the following cut-off values for classification according to GHS criteria the IVIS must be < 3 for no classification and > 55 to idenify a substance as inducing serious eye damage (UN GHS Category 1). All values between the afore mentioned values do not provide conclusive results, thus, no prediction can be made for the test item.
Due to the lack of further information, m-Xylylenebismaleimide is classified in Category 2 'causes serious eye irritation' according to Regulation EC No 1272/2008 (CLP) and the Globally Harmonized System for Classification and Labelling of Chemicals (GHS) for precautionary reasons.

Reference 2

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

(Q)SAR

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with limited documentation / justification

Justification for type of information:

1. SOFTWARE
Toxtree (Estimation of Toxic Hazard - A Decision Tree Approach) version 2.6.13

2. MODEL (incl. version number)
2.6.13

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
SMILES: O=C3C=CC(=O)N3Cc1cc(CN2C(=O)C=CC2(=O))ccc1
Melting point: 120°C
Water solubility: silent
log Kow: 1.60
Molecular weight: 296.28 g/mol

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
- Defined endpoint: eye irritation/corrosion (BfR inclusion/exclusion rules)/structural alert

5. APPLICABILITY DOMAIN
- Descriptor domain: According to international risk assessment guidelines, skin corrosion potential excludes further considerations on a similar hazardous potential to eyes, since the chemical has already proved to have corrosive properties. Thus the following effects induced by local contact to skin are also assumed to be predictive of eye damage.

- Structural and mechanistic domains:
The underlying mechanism is based on the published work of (Gerner, Liebsch and Spielman, 2005):
Gerner, I., Liebsch, M., Spielmann, H. (2005). Assessment of the eye irritating properties of chemicals by applying alternatives to the Draize rabbit eye test: the use of QSARs and in vitro tests for the classification of eye irritation. Alternatives to Laboratory Animals 33, 215-237.

- Similarity with analogues in the training set:
Some functional groups contained in the substance can be found in the inclusion rules. However, several other physicochemical properties,i.e. molecular weight, melting point, log Kow and water solubility were entered in order to estimate the eye irritating /corrosion potential. As described in the previous section the provision of physicochemical data improves the prediction.

6. ADEQUACY OF THE RESULT
Although some structural features of the substance were identified by the inclusion rules the substance is not considered to be an irritant or corrosive, because several physicochemical values were entered for the estimation, thus improving the prediction.

Qualifier:

no guideline followed

Principles of method if other than guideline:

Prediction of skin/eye irritation/corrosion based on structural alerts (Toxtree Decision Tree Approach)

GLP compliance:

no

Irritation parameter:

other: skin/eye irritation/corrosion potential by structural alerts

Remarks:

based on BfR rules

Run / experiment:

#1

Vehicle controls validity:

not applicable

Negative controls validity:

not applicable

Positive controls validity:

not applicable

Remarks on result:

no indication of irritation

Remarks:

based on the decision tree approach there is no structural alert for skin/eye irritation/corrosion

Interpretation of results:

GHS criteria not met

Conclusions:

In the present report m-Xylylenebismalimide is considered to be non irritating and not corrosive to the skin and the eyes based on the Toxtree Decision Tree Approach. This result substantiate the assumption that the test item is not corrosive to the eye.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

- skin irritation:

In a dermal irritation study performed in accordance with OECD Guideline 439 (In Vitro Skin Irritation) (adopted July 28, 2015), m-Xylylenebismaleimide was applied to the three-dimensional human epidermis model tissue for an exposure period of 35 ± 1 min in a humidified incubator (37 ± 1°C, 5.0% CO2) and afterwards for 60 ± 1 min under the sterile flow (room temperature), in triplicates.

25 µL of sterile DPBS was applied to the epidermal surface in order to improve the contact between the powder and the epidermis. Afterwards, 25 mg (39 mg/cm²) of the test item was applied directly atop the EpiDerm ™ tissue.

The test item was spread to match the surface of the tissue. After 60 minutes exposure at room temperature, the tissues were washed with phosphate buffered saline to remove any residual test material. The inserts were placed in prepared new 6-well plates containing 0.9 mL pre-warmed fresh assay medium per well and the tissue surface was  dried  using  a  sterile  cotton  tip. The plates were post-incubated at 37 ± 1 °C, 5.0%  CO₂ , humidified to 95%, for 24 ± 2 h. Following this incubation the tissues were transferred to new wells containing 0.9 mL fresh assay medium and incubated for additional 18 ± 2 h.

Cytotoxicity (irritancy) was expressed as the reduction of mitochondrial dehydrogenase activity measured by formazan production from MTT at the end of the treatment. The positive (5% SDS) and negative (DBPS) control gave responses that were within the acceptance criteria and as such demonstrated the validity of the study.

The relative mean tissue viability obtained after 60 minutes treatment and 42 h post-incubation period with m-Xylylenebismaleimide compared to the negative control tissues was 90% and 88.8% in two independent experiments. Since the mean relative tissue viability for the test substance was above 50%, m-Xylylenebismaleimide is identified to be not irritating.

- eye irritation:

An in vitro study was performed to assess the corneal irritation and damage potential of m-Xylylenebismaleimide (20% in 0.9% NaCl) by means of the BCOP assay using fresh bovine corneae according to OECD guideline 437, adopted 7 September 2009 and EU method B.47, December 2010. The corneae were incubated with the test substance and controls for 4 h ± 5 min at 32 ± 1°C. After rinsing with MEM, the anterior chamber was filled with RPMI (without phenol red) and an illuminance measurement was performed. The test was performed in triplicates. Opacity and permeability were determined. The in vitro irritancy score (IVIS) were calculated as mean opacity value + (15 x mean OD490 value); a substance that induces an IVIS ≥ 55 is defined as a corrosive or severe irritant.

A 20% dilution of the test substance in 0.9% NaCl caused an increase of the corneal opacity and permeability. Furthermore, it was stated in the study report that all three corneae treated with m-Xylylenebismalimide showed yellowish coloration of the tissue .The calculated mean in vitro irritation score was 7.28.

The positive control (imidazole 20%) increased the opacity and permeability of the corneae in both experiments (mean in vitro irritation score 121.72). 

With the negative control (saline) neither an increase of opacity nor permeability of the corneae could be observed in both experiments (mean in vitro irritation score 0.59).

Since the mean in vitro irritancy score of the test substance was < 55 but > 3, a classification for eye irritation of 20% dilution of m-Xylylenebismaleimide in 0.9% NaCl cannot be made with the Bovine Corneal Opacity and Permeability test under the experimental conditions described in this report.

Additionally, a QSAR estimation was performed using the ToxTree decision tree approach. According to the results obtained from this QSAR prediction, irritating effects to the eyes are not expected.

Thus, due to the lack of further information, m-Xylylenebismaleimide is classified in Category 2 'causes serious eye irritation' according to Regulation EC No 1272/2008 (CLP) and the Globally Harmonized System for Classification and Labelling of Chemicals (GHS) for precautionary reasons.

Justification for classification or non-classification

Skin irritation/corrosion:

Based on available, reliable and relevant datam-Xylylenebismaleimide does not need to be classified according to Regulation (EC) No 1272/2008 (CLP) and the Globally Harmonized System for Classification and Labelling of Chemicals (GHS).

Eye irritation/corrosion:

An in vitro study conducted according to OECD TG 437 is available for m-Xylylenebismaleimide which revealed an inconclusive result according to the evaluation criteria of the guideline. The calculated IVIS was > 3 and < 55 (7.28). As mentioned in the ECHA Guidance on information requirements Chapter R.7.a section 7.2.11.2.:"in case inconsistent in vitro results for serious eye damage/eye irritation are obtained, the Weight of Evidence including information on skin irritation (Category 2) may support the classification for eye irritation (Category 2), as a precautionary principle.

A Toxtree prediction for structural alerts was also preformed in order to determine the irritating/corrosive potential of the test item. The BfR exclusion/inclusion rules revealed that no structural alert for skin /eye irritation/corrosion is present in the test item.

Additionally, the study report stated that the corneal tissue showed yellowish colouration, the substance is assumed to produce false positive results not only in the preformed BCOP assay but also in any other in vitro test system which is validated and accepted as test method to fulfil the information requirements of Regulation (EC) No 1907/2006 (REACH) Annex VII. Furthermore, the results from the in vitro skin irritation study conducted according to OECD TG 439 showed no indication for irritation, thereby further substantiating the assumption that the substance may not irritating/corrosive to the eyes and that the inconclusive result originates from rather from colouration of the tissue than from an irritating effect. However, due to the lack of further information the substance is classified in "Category 2: causes serious eye irritation" according to Regulation (EC) No 1272/2008 (CLP) and the Globally Harmonized System for Classification and Labelling of Chemcials (GHS) for precautionary reasons.