1,1'-(4-methyl-1,3-phenylene)bis-1H-pyrrole-2,5-dione

Endpoint summary

Description of key information

- Acute oral toxicity: LD50(rat, m/f) > 2000 mg/kg bw; OECD TG 401; RL1; GLP

- Acute inhalation toxicity: LC50(rat, m/f) = 0.09 mg/L; OECD TG 403; RL1; GLP

- Acute dermal toxicity: LD50(rat, m/f) > 2000 mg/kg bw; OECD TG 402; RL1; GLP

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1989-10-24 to 1990-01-24

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Version / remarks:

adopted Feb 1987

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.1 (Acute Toxicity (Oral))

Version / remarks:

adopted Mar 1984

Deviations:

no

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: 9 weeks (males), 11 weeks (females)
- Weight at study initiation: 192-209 g (males), 172-183 g (females)
- Fasting period before study: 12-18 h
- Housing: Groups of five animals in Makrolon type-3 cages with standard softwood bedding ("Lignocel", Schill AG, CH-4132 Muttenz).
- Diet: Pelleted standard Kliba 343, Batch 55/89 rat maintenance diet ("Kliba", Klingentalmuehle AG, CH-4303 Kaiseraugst), ad libitum.
- Water: Community tap water, ad libitum
- Acclimation period: 1 week

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3
- Humidity (%): 40-70
- Air changes (per hr): 10-15
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

oral: gavage

Vehicle:

water

Remarks:

bi-distilled

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 200 mg/mL
- Amount of vehicle (if gavage): 10 mL/kg bw

MAXIMUM DOSE VOLUME APPLIED: 10 mL/kg bw

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing:
Mortality/Viability: four times on Day 1 and daily thereafter until Day 15
Body Weights: on Day 1 (pre-administration), 8 and 15
Clinical Signs: four times during Day 1 and daily thereafter until Day 15
- Necropsy of survivors performed: yes

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

No mortality occurred up to the end of the 14-day observation period.

Clinical signs:

Hunched posture was observed in one male on Day 1 after treatment. Ruffled fur was observed in 3 males between Day 1 and 6 and in 2 females between Day 1 and 3. No clinical signs were observed in males and females from Day 7 and 4, respectively, until the end of the study.

Body weight:

The body weight gain of the animals was not affected by the test article treatment throughout the entire study period.

Gross pathology:

Macroscopical findings were limited to one male animal showing pale discolouration of the lungs and clay-coloured left lateral lobe of the liver. No abnormalities were observed in the remaining males and in any females.

Interpretation of results:

GHS criteria not met

Conclusions:

The oral LD50 in male and female Wistar rats was determined to be greater than 2000 mg/kg bw. There were no treatment-related deaths and no abnormal changes in body weight. Clinical signs (hunched posture and ruffled fur) were observed in a few males and were fully reversible by study Day 7. Macroscopical findings (pale discolouration of the lungs and clay-coloured left lateral lobe of the liver) were limited to one male animal.
Based on the study results, the substance does not fulfil the criteria for classification in accordance with Regulation (EC) 1272/2008 (CLP) and the Globally Harmonized System of Classification and Labelling of Chemicals (GHS), and is thus considered to be not acutely toxic by the oral route.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

discriminating dose

Value:

2 000 mg/kg bw

Quality of whole database:

Since the study was performed according to OECD TG 401 and GLP the results are considered to be valid enough to fulfil the registration requirements of Annex VII of Regulation (EC) No 1907/2006.

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1989-11-23 to 1989-12-27

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Version / remarks:

12 May 1981

Deviations:

no

GLP compliance:

no

Test type:

traditional method

Limit test:

no

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: 8-9 weeks
- Weight at study initiation: male: 267 ± 19.1 g; females: 190 ± 8.2 g
- Housing: groups of five animals in cages type D III of Becker, without beedding
- Diet (e.g. ad libitum): ad libitum during the post exposure period, Kliba rat/mouse laboratory diet 24-343-4 10 mm pellets, Klingentalmühle AG, CH-4303 Kaiseraugst Switzerland
- Water (e.g. ad libitum): ad libitum

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-24
- Humidity (%): 30-70
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

nose/head only

Vehicle:

air

Mass median aerodynamic diameter (MMAD):

> 1.8 - <= 3.1 µm

Geometric standard deviation (GSD):

>= 3 - <= 3.7

Remark on MMAD/GSD:

The MMAD and the GSD was calculated from the results of the particle size analysis which was performed for each test group.

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER
DESCRIPTION
- Exposure apparatus: Head-nose inhalation system INA 20 (glass-steel construction. BASF Aktiengesellschaft, volume V =55 L): the animals were restrained in tubes and their snouts projected into the inhalation chamber.
- Exposure chamber volume: 55 L
- Method of holding animals in test chamber: the animals were restrained in tubes and their snouts projected into the inhalation chamber.
- Source and rate of air: compressed air and dilution were set to: 1,500 [1/h]
- Method of conditioning air: The dilution air was conditioned via a central air-conditioning system
- System of generating particulates/aerosols: A dust aerosol was generated by means of an solid, particle generator [brush generator, Technical University of Karlsruhe/BASF] (test group 1) and a dosing-wheel dust generator (Gericke/BASF) (test groups 2, 3, 4).
- Method of particle size determination: At the beginning of the test in test group 1 or 30 min earliest after beginning of the test in test groups 2-4 one sample was taken for the particle size analysis. Before the sampling, the impactor was equipped with glass-fiber collecting discs and a backup particle filter. The impactor was connected to the pump and the test apparatus, and one sample (9-720L) was taken. The impactor was taken apart, and the collecting discs and the backup particle filter were weighed. The contents of the pre-impactor as well as the amounts of the material adsorbed on the walls of the impactor and in the sampling probe (wall losses) were also determined quantitatively.
- Treatment of exhaust air: By means of an exhaust air system the pressure ratios in the inhalation system were adjusted in such a way that the amount of exhaust air was about 10% lower (excess pressure). This ensured that the mixture of test substance and air was not diluted with laboratory air in the breathing zones of the animals.
- Temperature: 19-25 °C

TEST ATMOSPHERE
- Brief description of analytical method used: Gravimetric determination of the inhalation atmosphere concentration: The preweighed filter was placed into the filtration equipment, By means of a vacuum compressed air pump volume of the dust aerosol was drawn through the filter. The dust concentration in mg/L was calculated from the difference between the preweight of the filter and the weight of the filter after sampling, with reference to the sample volume of the inhalation atmosphere. The concentrations were corrected for the amount of the additive.
- Samples taken from breathing zone: yes

VEHICLE
- Composition of vehicle (if applicable):The test substance was mixed with 1%[w/w] Aerosil
- Justification of choice of vehicle: The vehicle was chosen in order to achieve a more uniform dust concentration in air.

Analytical verification of test atmosphere concentrations:

yes

Remarks:

Gravimetric determination of the inhalation atmosphere concentration

Duration of exposure:

4 h

Concentrations:

Nominal concentration: 0.016, 0.13, 0.52, 5.0 mg/L

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days for the test groups 2-4 and 16 days for the test group 1.
- Frequency of observations and weighing: Body weight was determined before the test, after 7 days and at the end of the observation period. Clinical findings were recorded several times during exposure and at least once on each workday in the observation period. Mortality was checked daily.
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight, gross necropsy

Statistics:

The statistical evaluation of the dose-response relationship was carried out using FORTRAN program AKPROZ. Depending on the data of the dose-relationship obtained by way of experiment, this program is used to estimate the LC50 or to perform a Probit analysis. Estimation of the LC50 will produce types LC50 greater, LC50 about, or LC50 smaller. If the reults are Type LC50 greater or LC50 smaller, an additional binominal test will be carried out, to verify these statements statistically, if necessary. The calculation of the particle size distribution was carried out on the basis of mathematical methods for evaluating particle measurements (DIN 66141: Darstellung von Korngrößenverteilungen, DIN 66161: Partikelgrößenanalyse)

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

ca. 0.09 mg/L air

Based on:

test mat.

Exp. duration:

4 h

Sex:

male

Dose descriptor:

LC50

Effect level:

> 0.016 - < 0.13 mg/L air

Based on:

test mat.

Exp. duration:

4 h

Remarks on result:

other: The statistical reliability for the male rats is 95 %.

Sex:

female

Dose descriptor:

LC50

Effect level:

ca. 0.13 mg/L air

Based on:

test mat.

Exp. duration:

4 h

Mortality:

Test group 1: No deaths occurred until the end of the observation period.
Test group 2: 5 males and 2 females died on the day of exposure.
Test group 3: 3 males and 4 females died on the day of exposure and 2 males and 1 female died on observation day 1.
Test group 4: 5 males and 5 females died on the day of exposure.

Clinical signs:

other: Test group 1: All animals showed accelerated respiration during the exposure time. From day 1 after exposure until the end of the 16 days observation period no further clinical signs were reported. Test group 2: During the exposure time and the first 2 ob

Body weight:

The body weight gain of males and females of test group 1 was retarded, for males in observation week 1 and for females in observation week 2. However, the male animals in test group 1 regained body weight during the second week and was adjusted to normal. Body weight gain in test group 2 could only be detected in female rats and was not affected by the treatment as compared to a historical control collective. The body weights of test groups 3 and 4 were not recorded during the observation period due to premature death of the animals.

Gross pathology:

At the end of the obsevation period (14 days test groups 2, 3, 4; 16 days test group 1) the surviving animals were sacrificed with CO2 and were subjected to gross-pathological examination like all other animals which had died before.
Findings in animals that died spontaneously: Lungs: marked hyperemia with edema and/ or with emphysema; Thorax: hydrothorax in some animals. Findings in the sacrificed animals: None.

Table 1: concentration measurements

Sample No	Analytical concentration [mg/L]
Test group 1
13	0.018
14	0.017
15	0.016
16	0.014
Mean	0.0163
Mean corrected for 1% additive	0.0161
Mean (rounded)	0.016
Standard deviation of the mean	±0.0017
Nominal concentration	0.021
Test group 2
9	0.17
10	0.13
11	0.13
12	0.12
Mean	0.138
Mean corrected for 1% additive	0.134
Mean (rounded)	0.13
Standard deviation of the mean	±0.022
Nominal concentration	5.77
Test group 3
5	0.54
6	0.53
7	0.56
8	0.48
Mean	0.528
Mean corrected for 1% additive	0.518
Mean (rounded)	0.52
Standard deviation of the mean	±0.034
Nominal concentration	15.5
Test group 4
1	5.25
2	5.35
3	5.11
4	4.68
Mean	5.10
Mean corrected for 1% additive	5.049
Mean (rounded)	5.0
Standard deviation of the mean	±0.30
Nominal concentration	28.1

Interpretation of results:

Category 2 based on GHS criteria

Conclusions:

In the present study conducted according to OECD guideline 403, GLP, 5 female and 5 male Wistar rats were exposed to 0.016, 0.13, 0.52, 5.0 mg/L of the test substance using a head-nose inhalation system for 4h. The animals were observed for further 14 days in test group 2-4 and for 16 days in test group 1. In test group 2, 3 and 4, three female, two male and 1 female and five male and five female animals died after exposure, respectively. In test group 3 all animals were dead at the end of observation day 1. The combined LC50 for male and female rats was estimated to be 0.09 mg/L air. Based on the study results, the test material fulfils the criteria for classification as acute toxicity by inhalation Category 2 in accordance with Regulation (EC) 1272/2008 (CLP) and the Globally Harmonized System of Classification and Labelling of Chemicals (GHS), and is thus considered to be fatal if inhaled.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LC50

Value:

90 mg/m³

Quality of whole database:

Since the study was performed according to OECD TG 403 and GLP the results are considered to be valid enough to fulfil the registration requirements of Annex VII of Regulation (EC) No 1907/2006.

Acute toxicity: via dermal route

Link to relevant study records

Reference

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1989-10-26 to 1990-01-26

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Version / remarks:

adopted Feb 1987

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.3 (Acute Toxicity (Dermal))

Version / remarks:

adopted Mar 1984

Deviations:

no

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: 10 weeks (males), 12 weeks (females)
- Weight at study initiation: 241-269 g (males), 201-219 g (females)
- Housing: Individually in Makrolon type-2 cages with standard softwood bedding ("Lignocel", Schill AG, CH-4132 Muttenz).
- Diet: Pelleted standard Kliba 343, Batches 55/89 and 60/89 rat maintenance diet ("Kliba", Klingentalmuehle AG, CH-4303 Kaiseraugst), ad libitum.
- Water: Community tap water, ad libitum
- Acclimation period: 1 week

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3
- Humidity (%): 40-70
- Air changes (per hr): 10-15
- Photoperiod (hrs dark / hrs light): 12/12

Type of coverage:

semiocclusive

Vehicle:

water

Remarks:

bi-distilled

Details on dermal exposure:

TEST SITE
- Area of exposure: dorsal skin
- % coverage: 10
- Type of wrap if used: The semi-occlusive dressing was wrapped around the abdomen and fixed with an elastic adhesive bandage.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): The treated skin was washed with lukewarm tap water and dried with disposable paper towels.
- Time after start of exposure: 24 h

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 4 mL/kg bw
- Concentration (if solution): 500 mg/mL
- Constant volume or concentration used: yes

Duration of exposure:

24 h

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

5

Control animals:

not required

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing:
Mortality/Viability: four times on Day 1 and daily thereafter until Day 15
Body Weights: on Day 1 (pre-administration), 8 and 15
Clinical Signs: four times during Day 1 and daily thereafter until Day 15
- Necropsy of survivors performed: yes

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

No mortality occurred up to the end of the 14-day observation period.

Clinical signs:

No clinical signswere observed up to the end of the 14-day observation period.

Body weight:

The body weight gain of the animals was not affected throughout the study by test article treatment.

Gross pathology:

Macroscopical findings were limited to one male animal showing dark red discolouration of the lungs, and one female showing pale discolouration of the lungs. No abnormalities were observed in the remaining male and female animals.

Other findings:

The following local signs were observed on the back of the animals:
2000 mg/kg: males/females - scales, yellow skin.
The rats had recovered from local signs after 8 (males) and 11 (females) observation days.

Interpretation of results:

GHS criteria not met

Conclusions:

The dermal LD50 in male and female Wistar rats was determined to be greater than 2000 mg/kg bw. There were no treatment-related deaths, no clinical signs of systemic toxicity and no abnormal changes in body weight. Local signs (scales, yellow skin) were observed in all animals and were fully reversible by study Day 8 and 11 in males and females, respectively. Macroscopical findings were limited to one male (dark red discolouration of the lungs) and one female (pale discolouration of the lungs).
Based on the study results, the substance does not fulfil the criteria for classification in accordance with Regulation (EC) 1272/2008 (CLP) and the Globally Harmonized System of Classification and Labelling of Chemicals (GHS), and is thus considered to be not acutely toxic by the dermal route.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

discriminating dose

Value:

2 000 mg/kg bw

Quality of whole database:

Since the study was performed according to OECD TG 402 and GLP the results are considered to be valid enough to fulfil the registration requirements of Annex VII of Regulation (EC) No 1907/2006.

Additional information

Acute oral toxicity

In an acute oral toxicity study according to OECD guideline 401, adopted February 1987, 5 female and 5 male Wistar rats, fasted, 9 -11 weeks old were given a single dose of 2000 mg/kg bw 2,4 -Bismaleimidotoluene by gavage and were observed for 15 days. No premature death occurred during the observation period, furthermore, the body weight gain of the animals was not affected by the test article. The following clinical signs were observed: In both sexes: ruffled fur; in males hunched posture. The male rats had recovered after 7 days and the femal rats had recovered after 4 days. After the observation period the animals were sacrificied and macroscopical findings were recorded. The lungs were discolored and showed a pale appearance and the left lobe of the liver was clay-coloured in one male animal. The other animals showed no macroscopical changes. The oral LD50 in male and female Wistar rats was determined to be greater than 2000 mg/kg bw.

Based on the study results, the substance does not fulfil the criteria for classification in accordance with Regulation (EC) 1272/2008 (CLP) and the Globally Harmonized System of Classification and Labelling of Chemicals (GHS), and is thus considered to be not acutely toxic by the oral route.

Acute inhalation toxicity

In an acute inhalation toxicity study according to OECD guideline 403 (adopted May 1981), 5 female and 5 male Wistar rats per group, 8 -9 weeks old, were given 2,4 -Bismaleimodotoluene at doses of 0.016 mg/L, 0.13 mg/L, 0.52 mg/L and at the limit dose of 5 mg/L via an inhalation chamber. The animals were exposed for 4 h. After the exposure period the animals were observed for further 14 days. During the observation time the body weight was checked at the beginning of the observation time, after 7 days and at the end of the experiment. Clinical observations were mader at least once each workday and a check for dead was mase daily during the observation time. At the end of the observation time the surviving animals were sacrificed and subjected to gross pathology.

All of the animals receiving the highest dose died on application day, animals inhaling 0.52 mg/L for 4h died on experimental day one, from the female rats receiving 0.13 mg/L 2,4 -Bismaleimodotoluene for 4 h only 2 survived the experimental time. All animals inhaling the lowest dose survived. For the first 4 h after administration of the substance the animals were observed for any clinical signs. All animals regardless the applied dose of 2,4 -Bismaleimodotoluene showed restlessness and attempted to escape within the first 15 min after application. Almost all animals showed eyelid closure within the first 2h and only a few showed more severe clinical signs like intermittent respiration, whooping respiration, gasping respiration or respiratory sounds. All clinical signs were reversible within the first day after exposure. The female and male rats in group 1 (0.016 mg/L air) showed a retarded body weight gain as compared to the historical control collective, however, this decrease abolished in the second week of the observation time. Due to the occurring mortality the LC50 values were determined as follows: LC50 male/female: 0.09 mg/L; LC50 male: 0.016 to < 0.13 mg/L; LC50 female: 0.13 mg/L.

Acute dermal toxicity

In an acute inhalation toxicity study according to OECD guideline 402 (adopted February 1987), 5 female and 5 male Wistar rats, 10 -12 weeks old, were treated 2,4-Bismaleimodotoluene at a single dose of 2000 mg/kg bw applied to the skin for 24 h. During the observation period of 15 days the mortality, body weights and clinical signs like general behaviour, respiration, motility, body position, motor susceptibility and any changes of the skin, eyes or nose were recorded. At the end of the experimental time all animals underwent necropsy. No premature mortality occurred and no changes in body weight gain were determined. However, in all animals changes of the treated skin (scales and yellow skin) were detected. These effects were reversible occurred at the second day of the observation period and disappeared until at least day 10. The necropsy revealed one animal with some discoloration of the lungs. Due to the slight and fully reversible effects the dermal LD50 of 2,4 -Bismaleimidotoluene is considered to be > 2000 mg/kg bw.

Justification for classification or non-classification

Based on the available relevant and reliable data 2,4 -Bismaleimidotoluene does not need to be classified and labelled according to the CLP Regulation (EC) No 1272/2008 with respect to acute oral and dermal toxicity.

Based on the study results, the substance does fulfil the criteria for classification in accordance with Regulation (EC) 1272/2008 (CLP) and the Globally Harmonized System of Classification and Labelling of Chemicals (GHS), and is thus classified Category 2 (fatal if inhaled) with respect to inhalation toxicity and assigned the hazard statement H330 and the signal word “Danger”.