Hexamethylene diisocyanate, oligomers, reaction products with Bis-(Trimethoxysilylpropyl)amine

Endpoint summary

Description of key information

Acute oral toxicity: > 2000 mg/kg bw

Read across:

Acute oral toxicity: > 2000 mg/kg bw (Bioassay, 2012)

Acute inhalation toxicity: LC50 = 5.031mg /L (BASF, 2012)

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Reference 1

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)

GLP compliance:

yes (incl. QA statement)

Test type:

acute toxic class method

Limit test:

yes

Specific details on test material used for the study:

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Room temperature

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Wiga GmbH, Germany
- Females (if applicable) nulliparous and non-pregnant: yes
- Age at study initiation: approx. 10weeks
- Weight at study initiation: animals of comparable weight
- Fasting period before study: at least 16 h before administration
- Housing: Makrolon cage, type III
- Diet (e.g. ad libitum): VRF1(P); SDS Special Diets Services, 67122 Altrip, Germany, ad libitum
- Water (e.g. ad libitum): Tap water ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 3
- Humidity (%): 30-70
- Air changes (per hr): approx. 10
- Photoperiod (hrs dark / hrs light): 12 /12

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

MAXIMUM DOSE VOLUME APPLIED: 1.75 mL/kg bw

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

6

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days (first administration group, 15 days (second administration group)
- Frequency of observations and weighing: Individual body weights shortly before administration, weekly thereafter and on the last day of observation. Clinical signs for each animal were recorded several times on the day of administration and at least once during each workday thereafter. A check for dead or moribund animals was made at least once each workday.
- Necropsy of survivors performed: yes

Statistics:

Calculations were performed using Microsoft Excel 2010 and checked with a calculator.

Sex:

female

Dose descriptor:

LD50

Effect level:

>= 2 000 mg/kg bw

Based on:

test mat.

Mortality:

No mortality occurred in both test groups.

Clinical signs:

other: In the first test group impaired general state and piloerection were observed in all animals from hour 2 or 3 until hour 5 or study day 1. In the second test group impaired general state and piloerection were observed in all animals from hour 4 until hour

Gross pathology:

There were no macroscopic pathological findings in any animal sacrificed at the end of the observation period.

Interpretation of results:

GHS criteria not met

Conclusions:

Under the conditions of this study the median lethal dose of the test item after oral administration was found to be greater than 2000 mg/kg bw in rats.

Executive summary:

In an acute oral toxicity study performed according to the Acute Toxic Class Method, a dose of 2000 mg/kg bw of the undiluted test item were administered by gavage to two test groups of three fasted Wistar rats each (2000 mg/kg bw in 6 females). No mortality occurred. Impaired general state and piloerection was noted in all animals. The body weights of the animals increased within the normal range throughout the study period with two exceptions. The body weights of two animals of the second administration group increased normally during the first observation week but nearly stagnated during the second week. This effect is observed at times in the rat strain used, because in the required age range the female animals have already reached the phase of slow growth. There were no macroscopic pathological findings in any animal sacrificed at the end of observation period (6 females).

 The acute oral LD₅₀was calculated to be higher than 2000 mg/kg bw.

Reference 2

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

2011

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)

GLP compliance:

yes (incl. QA statement)

Test type:

acute toxic class method

Limit test:

yes

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Wiga GmbH
- Age at study initiation: 9-10 weeks
- Weight at study initiation: 172 +/- 20%
- Fasting period before study: at least 16 hrs before test item administration
- Housing: single housing
- Diet: VRF1(P); SDS Special Diets Services ad libitum
- Water: Tap water ad libitum:
- Acclimation period: 5 days before the beginning of the experimental phase

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22°C ± 3°C
- Humidity (%): 30-70%
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

oral: gavage

Vehicle:

olive oil

Remarks:

Ph.Eur.

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 20g/100 mL
- Amount of vehicle (if gavage): 10 mL/kg
- Justification for choice of vehicle: Good homogeneity in olive oil Ph.Eur.

Doses:

2000 mg/kg (two times; limit test)

No. of animals per sex per dose:

3+3

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: before administration (day 0), weekly thereafter and on the last day of observation.
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

No mortality occurred.

Clinical signs:

other: No clinical signs were observed during clinical examination.

Gross pathology:

Conglomerate in the stomach in two animals of the first and in all animals of the second administration group was noted at necropsy on the last day of observation (six females).
Additionally dark spotted small intestine and white granular inclusion in the hypogastric region were observed in the one animal of the second administration group, which lost weight in the second post-exposure week.

Interpretation of results:

GHS criteria not met

Conclusions:

Under the conditions of this study the median lethal dose of the test item after oral administration was found to be greater than 2000 mg/kg bw in rats.

Executive summary:

In an acute oral toxicity study performed according to the Acute Toxic Class method, 2000 mg/kg bw of test item (preparation in olive oil Ph.Eur.) were administered to two test groups of three fasted Wistar rats by gavage. No mortality occurred in all animals. No clinical signs were observed in all animals. The mean body weight of the first test group increased throughout the study period within the normal range. The mean body weight of the second test group increased throughout the study period within the normal range. Only one animal lost weight in the second observation week.

In five out of six animals conglomerate in the stomach were found. In one out of six animals dark spotted small intestine and white granular inclusion in the hypogastric region were observed.

The acute oral LD50 was calculated to be higher than 2000 mg/kg bw.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Quality of whole database:

The qualtity of the database is high.

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Qualifier:

according to guideline

Guideline:

EU Method B.2 (Acute Toxicity (Inhalation))

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1300 (Acute inhalation toxicity)

GLP compliance:

yes (incl. QA statement)

Test type:

standard acute method

Limit test:

no

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan Laboratories B.V., Kreuzelweg 53, 5961 NM Horst, The Netherlands
- Age at study initiation: males: approx. 7 - 8 weeks; females: approx. 9 – 10 weeks
- Weight at study initiation: 189.8 g - 203. g
- Housing: Makrolon cages, type M III (floor area about 800 cm2) (for single housing) or Polysulfon cages (H-Temp [PSU]), floor area about 2065 cm2 (610x435x215 mm); supplied by TECNIPLAST, Hohenpeißenberg, Germany (caged in groups, if the animals were free from clinical signs and findings)
- Number of animals per cage: Single housing or up to 5 animals
- Enrichment: Wooden gnawing blocks (Typ NGM E-022); Abedd ® Lab. and Vet. Service GmbH Vienna, Austria
- Bedding: Dust-free wooden bedding
- Diet (e.g. ad libitum): Kliba-Labordiät (Maus / Ratte Haltung “GLP”), Provimi Kliba SA, Kaiseraugst, Basel, Switzerland, ad libitum
- Water (e.g. ad libitum): Tap water ad libitum
- Acclimation period: at least 5 days before exposure.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 - 24
- Humidity (%): 30 - 70
- Air changes (per hr): 15
- Day / night rhythm: 12 h / 12 h

The room was completely disinfected using a disinfector ("AUTEX", fully automatic, formalinammonia-based terminal disinfector) before the start of the study. The floor and the walls were cleaned once a week with water containing an appropriate disinfectant.

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

nose/head only

Vehicle:

other: anhydrous acetone

Details on inhalation exposure:

SUBSTANCE VEHICLE: anhydrous acetone

GENERATION OF THE INHALATION ATMOSPHERE
- Test-substance preparation: Test group 1: A test-substance dilution of one part anhydrous acetone + seven parts test substance (w/w) was used. Test group 2 and 3: A test-substance dilution of two parts anhydrous acetone + seven parts test substance (w/w) was used.
- Equipment: Two-component atomizer Mod. 970 (stainless steel, Schlick) Magnetic stirrer. Continuous infusion pump Perfusor (Harvard PHD Ultra, Tyco/Healthcare, Kendall, Monojet)
- Generation technique: Liquid aerosols were generated.For each test group the aerosols were produced by continuously pumping amounts of the test substance preparation to a two-component atomizer. Using compressed air, the aerosol was produced with the atomizer inside the exposure system.

EXPOSURE
Head-nose inhalation system INA 20 (glass-steel construction, BASF SE, volume V ≈ 55 L): the animals were restrained in glass tubes and their snouts projected into the inhalation system. The homogenous distribution of test substance atmosphere/s in this inhalation system has been verified with model aerosols. Central air conditioning system provides cold air of about 15°C. This cold air will pass through an activated charcoal filter, be adjusted to room temperature of 20 to 24°C and pass through a second particle filter (H13 (HEPA) Camfil Farr, Germany). The so generated conditioned air is used to generate inhalation atmospheres.
Compressed air is produced by an oil-free compressor (HT 6, Josef Mehrer GmbH & Co KG, Germany). For this purpose, air is filtered by an inlet air strainer and introduced into the compressor. After passed through an second ultra filter (SMF 5/3, 108 mm, Donalson), the compressed air (15 bar) is stored in a storage of 1500 or 5000 L. The compressed air is conducted to the labs via pipes, where the pressure is reduced to 6 bar. In the lab, the compressed air can be taken as required.
The exhaust air is filtered and conducted into the exhaust air of the building. The exposure system was located inside an exhaust cabin in an air-conditioned laboratory. During each exposure, the following parameters were recorded four times at about 1-hour intervals: Supply air flows (compressed air) (from a central air-conditioning system): 1.5 m³/h. The flows were adjusted and continuously measured with a flowmeter (Yokogawa); Exhaust air flows: 1.35 m³/h. The flows were adjusted and continuously measured with a flowmeter (Yokogawa).
The lower amounts of exhaust air, which were adjusted by means of a separate exhaust air system, achieved positive pressures inside the exposure systems. This ensured that the mixtures of test substance and air were not diluted with laboratory air in the breathing zones of the animals. Air changes of about 27 times per hour can be calculated by dividing the supply air flows by the volume of the inhalation systems. The animals were exposed to the inhalation atmosphere for 4 hours plus equilibration time of the inhalation systems (t99 about 10 min). No surveillance of the oxygen content in the inhalation system was performed. The air change was judged to be sufficient to prevent oxygen depletion by the breathing of the animals, and the concentration of the test substance used could not have a substantial influence on oxygen partial pressure.
Temperatures: The temperatures in the inhalation system were measured continuously with a digital thermometer.
Humidities: The humidities in the inhalation system were measured with a dielectric probe (Testo).

ANALYTICAL INVESTIGATIONS
- The nominal concentrations were calculated from the amounts of test substance dosed and the supply air flows.
- Gravimetric measurement of the inhalation atmosphere concentration: In technical trials it was shown, that the test substance was quantitatively recovered, when the preparation was dried on gravimetric filters. Vacuum pump (Millipore); Sampling devices: Filtration equipment with probe, internal diameter: 7 mm, (Millipore); Filter: MN 85/90 BF (d = 47 mm); Equipment: Balance Mettler AT 250; Sampling position: immediately adjacent to the animals' noses at a separate spare port; Sampling flow: 3 L/min; Sampling velocity: 1.25 m/s; Sampling frequency: 4 samples at about hourly intervals; Test group:Sample volume (L) 1:30, 2:12, 3:6
In technical trials it was shown, that the test substance was quantitatively recovered, when the preparation was dried on gravimetric filters. Preweighed filters were placed into the filtration equipment. By means of the vacuum pump metered volumes of the aerosol were drawn through the filter. For each sample the aerosol 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 atmospheres. Mean and standard deviation were calculated for each concentration from the results of the individual measurements.
- Particle size analyses: Equipment: Stack Sampler Mark III (Andersen); Vacuum pump (Millipore); Sampling probe (internal diameter 6.9 mm); Limiting orifice 3 L/min; Balance: Sartorius M3P and Sartorius LC 1201S
Before sampling, the impactor stages were assembled with preweighed glass-fiber collecting discs and equipped with a backup particle filter. The impactor was connected to the vacuum pump, and for each test group samples were taken from the breathing zone of the animals according to the following tables. Sampling occurred 30 minutes (or later) after the beginning of the exposure. After sampling the impactor was taken apart. The collecting discs and the backup particle filter were re-weighed. Test group:Number of samples:Sample volume (L), 1:2:30, 2:2:12, 3:2:6
- The feed used in the study was assayed for chemical as well as for microbiological contaminants. In view of the aim and duration of the study, the contaminants occurring in commercial feed should not influence the results. Deviations from these specifications that might have had any adverse effect on the results are reported in the results section.
- Analysis of drinking water: The drinking water is regularly assayed for chemical contaminants both by the municipal authorities of Frankenthal and by the Environmental Analytics Water/Steam Monitoring of BASF SE as well as for bacteria by a contract laboratory. The Drinking Water Regulation will serve as the guideline for maximum tolerable contaminants.
- The bedding and enrichment are regularly assayed for contaminants (chlorinated hydrocarbons and heavy metals). On the basis of the analytical findings the bedding was found to be suitable.

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Remarks on duration:

+ about 10 min equilibration time of the inhalation systems

Concentrations:

1.257, 2.869 and 5.134 mg/L

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

EXPERIMENTAL PROCEDURE
Observation period: At least 14 days.
Feed and Water: twice a day on workdays and once daily on weekends and public holidays.
Body weight determination: once during the acclimatization period, shortly before exposure (day 0) and at least on days 1, 3 and 7, and before the sacrifice of the animals at the end of the observation period.
Signs: Detailed clinical observations were recorded for each animal separately several times during exposure and at least once daily on the pre-exposure day and during the observation period.
Mortality: twice each workday and once on Saturdays, Sundays and on public holidays.
Pathology: At the end of the observation period the surviving animals were killed with CO2-inhalation in a chamber with increasing concentration over time, and were subjected to gross-pathological examination as well as the animal which died or were killed in a moribund state before. To clarify the gross-pathological findings, selected organs of individual animals were examined histopathologically. Each moribund animal, which most probably would have died on account of the toxic effects of the test substance was killed during the observation period according to the German Animal Protection Law (BGBL I, 22 Aug 1986).

Statistics:

By the data the LC50 was calculated by Probit analysis (FINNEY, D.J. (1971): "Probit Analysis" Cambridge University Press). For results of the type ”LC50 greater than”, ”LC50 approx.”, or ”LC50 smaller than”, the binomial test was used for statistical evaluation.
The calculation of the particle size distribution was carried out in the inhalation laboratory on the basis of mathematical methods for evaluating particle measurements, according to DIN 66141 and DIN 66161.

Sex:

male/female

Dose descriptor:

LC50

Effect level:

5.031 mg/L air (analytical)

Based on:

test mat.

Exp. duration:

4 h

Mortality:

Test group 1 (1.257 mg/L): No lethality was observed in male and female animals during the study period of 14 days.
Test group 2 (2.869 mg/L): No lethality was observed in male and female animals during the study period of 14 days.
Test group 3 (5.134 mg/L): Three of five female animals but no males died or were killed in a moribund state during the post exposure observation period.
(one female was found dead: in-life day 1; one female was sacrificed moribund: in-life day 1; one female was sacrificed moribund: in-life day 6)

Clinical signs:

other: Clinical signs of toxicity in animals exposed to 1.257 mg/L comprised accelerated and abdominal respiration, respiration sounds, colorless discharge and red encrusted nose, piloerection and substance contaminated. These various findings were observed from

Body weight:

Test group 1 (1.257 mg/L): the mean body weights of the animals decreased during the first post exposure observation day and increased from study day 3 onward.
Test group 2 (2.869 mg/L): the mean body weights of the animals decreased during the first post exposure observation day and increased from study day 3 onward.
Test group 3 (5.134 mg/L): the mean body weights of the male animals decreased during the first post exposure observation day and increased from study day 3 onward. The mean body weights of the female animals decreased during the first few post exposure observations days and increased from study day 7 onward.

Gross pathology:

No gross pathological abnormalities were noted during the necropsy at the termination of the post exposure observation period in animals exposed to 1.257 mg/L and 2.869 mg/L. In anaimals exposed to 5.134 mg/L of the one female animal that was found dead on study day 1, dark-red discoloration in all lung lobes, edema and red encrusted nose were noted during necropsy. Necropsy findings of the one female animal that were killed in a moribund state on study day 1 comprised dark-red discoloration in all lung lobes, edema of the lung and. Necropsy findings of the one female animal that were killed in a moribund state on study day 6 comprised at the edge of the right cranial lung lobe a focus, red encrusted nose, alopecia on the left nose region and substance contaminated fur. The remaining animals showed no gross pathological abnormalities during the necropsy at the termination of the post exposure observation period.

The following clinical signs and findings were observed during (up to 4 hours) and after exposure (> 4 hours).

Table 1: Duration of signs (test group 1)

Test group 1 (1.257 mg/L)	Male animals	Female animals
Fur, substance contaminated	d0 – d1	d0 – d1
Nose, colorless discharge	d1 – d5	d1 – d5
Nose, red encrusted	d0 – d4	d0
Respiration, abdominal	d0 – d2	d0 – d4
Respiration, accelerated	h4	h4
Respiration, sounds	d0 – d1	-
Piloerection	d0 – d5	d0 – d4

No clinical signs and findings were observed from study day 6 onwards.

 

Table 2: Duration of signs (test group 2)

Test group 2 (2.869 mg/L)	Male animals	Female animals
Alopecia	-	d6 – d14
Fur, substance contaminated	d0 – d6	d0 – d14
Nose, discharge colorless	d1 – d2	d1 – d2
Nose, red discharge	d1 – d2	-
Nose, red encrusted	d1 – d2	-
Respiration, abdominal	d0 – d2	d0 – d2
Respiration, accelerated	h3 – d2	h3 – d2
Respiration, sounds	-	d0 – d2
Piloerection	d0 – d3	d0 – d2

No clinical signs and findings were observed in the male animals from study day 7 onwards.

The clinical signs and finding were observed in the female animals during the whole study period.

 

Table 3: Duration of signs (test group 3)

Test group 3 (5.134 mg/L)	Male animals	Female animals
Lethality (number of animals)	-	3
Alopecia	d2 – d14	d5 – d14
Eye, red encrusted	-	d0 – d4
Eyelid, closed	-	d1 – d4
Dehydrated general condition	-	d2 – d4
Fur, substance contaminated	d0 – d12	d0 – d6
Gasping	-	d0 – d6
Nose, colorless discharge	d2 – d6	-
Nose, red discharge	-	d1
Nose, red encrusted	d1	d1
Nose, swelling	d0 – d1	d0 – d1
Respiration, abdominal	d0 – d2	d0 – d5
Respiration, accelerated	h1 – h2	h1 – h2; d1 – d2
Respiration, labored	h3 – h4	h3 – h4
Respiration, sounds	-	d2 – d6
Piloerection	d0 – d14	d0 – d7
Poor general condition	-	d1 – d6
Salivation	d0 – d4	d0 – d4
Skin, pale	-	d1

 

The clinical signs and finding were observed during the whole study period.

PATHOLOGY

Necropsy findings:

Table 4: Animals that died or were killed in a moribund state during the study period

Findings	test group 3
Number of animals	3 females
Lung: dark-red discoloration in all lobes	2 females
Lung: Edema	2 females
Lung: at the edge of the right cranial lobe a focus (ᴓ4 mm)	1 female
Nose: red encrusted	3 females
Fur: left nose region alopecia	1 female
Fur: substance contaminated	1 female

 

To further evaluate the macroscopic findings, histopathological examination was carried out of the respiration tract (nasal cavity, larynx, trachea, lung) from female animal no. 609 which was killed in a moribund state on study day 6. The lung showed a minimal to slight diffuse acute congestion and a minimal to slight diffuse alveolar histiocytosis. The nasal cavity showed a slight to moderate multifocal necrotizing and purulent rhinitis with degeneration and regeneration. The larynx and trachea were without findings.

 

Table 5: Necropsy of the animals at termination of the post exposure periods

Findings	test group 1	test group 2	test group 3
Number of animals	5 males + 5 females	5 males + 5 females	5 males + 2 females
Organs without particular findings	5 males + 5 females	5 males + 5 females	5 males + 2 females

 

Interpretation of results:

GHS criteria not met

Conclusions:

Under the conditions of this study the LC50 for male and female rats after liquid aerosol inhalation exposure of the test item was estimated to be 5.031 mg/L for the female animals (analytical concentration).

Executive summary:

To determine the acute inhalation toxicity (single 4-hour exposure, head-nose only) of the test item as a liquid aerosol, a study was performed in male and female Wistar rats according to OECD-Guideline method 403, as well as EC and EPA guidelines. For technical reasons the test substance was sprayed as solution with anhydrous acetone.

The following measured concentrations were tested: 1.257, 2.869 and 5.134 mg/L (analytical concentration). Cascade impactor measurements resulted in particle size distributions with mass median

aerodynamic diameters (MMADs) between 1.6 and 3.8 μm, which are well within the respirable range. No lethality was observed in male and female animals at 1.257 mg/L and 2.869 mg/L. At 5.134 mg/L three of five female animals but no males died or were killed in a moribund state died. Lethality was observed either during exposure, after exposure on study day 1 or on study day 6.

Clinical signs of toxicity in animals exposed to 1.257 mg/L comprised accelerated and abdominal respiration, respiration sounds, colorless discharge and red encrusted nose, piloerection and substance contaminated. These various findings were observed from hour 4 of exposure through to study day 5. No clinical signs and findings were observed from study day 6 onwards. The mean body weights of the animals decreased during the first post exposure observation day and increased from study day 3 onward. No gross pathological abnormalities were noted during the necropsy at the termination of the post exposure observation period.

Clinical signs of toxicity in animals exposed to 2.869 mg/L were similar to those described at lower concentrations. Some more unspecific symptom (e.g. alopecia) was seen. These various findings were observed from hour 3 of exposure. No clinical signs and findings were observed in the male animals from study day 7 onwards. The clinical signs and finding were observed in the female animals during the whole study period. The mean body weights of the animals decreased during the first post exposure observation day and increased from study day 3 onward. No gross pathological abnormalities were noted during the necropsy at the termination of the post exposure observation period.

Clinical signs of toxicity in animals exposed to 5.134 mg/L comprised accelerated and labored respiration, abdominal respiration, gasping, respiration sounds, closed eyelid, red encrusted eye, colorless or red discharge and red encrusted nose, swelling nose, alopecia, dehydrated and poor general condition, salivation, pale of the skin, piloerection and substance contaminated. The mean body weights of the male animals decreased during the first post exposure observation day and increased from study day 3 onward. The mean body weights of the female animals decreased during the first few post exposure observations

days and increased from study day 7 onward. During necropsy of the one female animal that was found dead on study day 1, dark-red discoloration in all lung lobes, edema and red encrusted nose were noted during necropsy. Necropsy findings of the one female animal that were killed in a moribund state on study day 1 comprised dark-red discoloration in all lung lobes, edema of the lung and. Necropsy findings of the one female animal that were killed in a moribund state on study day 6 comprised at the edge of the right cranial lung lobe a focus, red encrusted nose, alopecia on the left nose region and substance contaminated fur. The remaining animals showed no gross pathological abnormalities during the necropsy at the termination of the post exposure observation period.

To further evaluate the macroscopic findings, histopathological examination was carried out of the respiration tract (nasal cavity, larynx, trachea, lung) from female animal no. 609 which was killed in a moribund state on study day 6. The lung showed a minimal to slight diffuse acute congestion and a minimal to slight diffuse alveolar histiocytosis. The nasal cavity showed a slight to moderate multifocal necrotizing and purulent rhinitis with degeneration and regeneration. The larynx and trachea were without findings.

Under the conditions of this study the LC50 for male and female rats after liquid aerosol inhalation exposure of the test item was estimated to be 5.031 mg/L for the female animals (analytical concentration).

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LC50

Value:

5 031 mg/m³ air

Quality of whole database:

The quality of the whole database is high.

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Acute oral toxicity:

In an acute oral toxicity study performed according to the Acute Toxic Class Method, a dose of 2000 mg/kg bw of the undiluted test item were administered by gavage to two test groups of three fasted Wistar rats each (2000 mg/kg bw in 6 females). No mortality occurred. Impaired general state and piloerection was noted in all animals. The body weights of the animals increased within the normal range throughout the study period with two exceptions. The body weights of two animals of the second administration group increased normally during the first observation week but nearly stagnated during the second week. This effect is observed at times in the rat strain used, because in the required age range the female animals have already reached the phase of slow growth. There were no macroscopic pathological findings in any animal sacrificed at the end of observation period (6 females).

The acute oral LD₅₀was calculated to be higher than 2000 mg/kg bw.

In an acute oral toxicity study performed according to the Acute Toxic Class method, 2000 mg/kg bw of the read across substance iGloss Crosslinker (preparation in olive oil Ph.Eur.) were administered to two test groups of three fasted Wistar rats by gavage. No mortality occurred in all animals. No clinical signs were observed in all animals. The mean body weight of the first test group increased throughout the study period within the normal range. The mean body weight of the second test group increased throughout the study period within the normal range. Only one animal lost weight in the second observation week.

In five out of six animals conglomerate in the stomach were found. In one out of six animals dark spotted small intestine and white granular inclusion in the hypogastric region were observed.

The acute oral LD50 was calculated to be higher than 2000 mg/kg bw.

Acute inhalation toxicity:

To determine the acute inhalation toxicity (single 4-hour exposure, head-nose only) of the read across substance, iGloss Crosslinker, as a liquid aerosol, a study was performed in male and female Wistar rats according to OECD-Guideline method 403, as well as EC and EPA guidelines. For technical reasons the test substance was sprayed as solution with anhydrous acetone.

The following measured concentrations were tested: 1.257, 2.869 and 5.134 mg/L (analytical concentration). Cascade impactor measurements resulted in particle size distributions with mass median

aerodynamic diameters (MMADs) between 1.6 and 3.8 μm, which are well within the respirable range. No lethality was observed in male and female animals at 1.257 mg/L and 2.869 mg/L. At 5.134 mg/L three of five female animals but no males died or were killed in a moribund state died. Lethality was observed either during exposure, after exposure on study day 1 or on study day 6.

Clinical signs of toxicity in animals exposed to 1.257 mg/L comprised accelerated and abdominal respiration, respiration sounds, colorless discharge and red encrusted nose, piloerection and substance contaminated. These various findings were observed from hour 4 of exposure through to study day 5. No clinical signs and findings were observed from study day 6 onwards. The mean body weights of the animals decreased during the first post exposure observation day and increased from study day 3 onward. No gross pathological abnormalities were noted during the necropsy at the termination of the post exposure observation period.

Clinical signs of toxicity in animals exposed to 2.869 mg/L were similar to those described at lower concentrations. Some more unspecific symptom (e.g. alopecia) was seen. These various findings were observed from hour 3 of exposure. No clinical signs and findings were observed in the male animals from study day 7 onwards. The clinical signs and finding were observed in the female animals during the whole study period. The mean body weights of the animals decreased during the first post exposure observation day and increased from study day 3 onward. No gross pathological abnormalities were noted during the necropsy at the termination of the post exposure observation period.

Clinical signs of toxicity in animals exposed to 5.134 mg/L comprised accelerated and labored respiration, abdominal respiration, gasping, respiration sounds, closed eyelid, red encrusted eye, colorless or red discharge and red encrusted nose, swelling nose, alopecia, dehydrated and poor general condition, salivation, pale of the skin, piloerection and substance contaminated. The mean body weights of the male animals decreased during the first post exposure observation day and increased from study day 3 onward. The mean body weights of the female animals decreased during the first few post exposure observations

days and increased from study day 7 onward. During necropsy of the one female animal that was found dead on study day 1, dark-red discoloration in all lung lobes, edema and red encrusted nose were noted during necropsy. Necropsy findings of the one female animal that were killed in a moribund state on study day 1 comprised dark-red discoloration in all lung lobes, edema of the lung and. Necropsy findings of the one female animal that were killed in a moribund state on study day 6 comprised at the edge of the right cranial lung lobe a focus, red encrusted nose, alopecia on the left nose region and substance contaminated fur. The remaining animals showed no gross pathological abnormalities during the necropsy at the termination of the post exposure observation period.

To further evaluate the macroscopic findings, histopathological examination was carried out of the respiration tract (nasal cavity, larynx, trachea, lung) from female animal no. 609 which was killed in a moribund state on study day 6. The lung showed a minimal to slight diffuse acute congestion and a minimal to slight diffuse alveolar histiocytosis. The nasal cavity showed a slight to moderate multifocal necrotizing and purulent rhinitis with degeneration and regeneration. The larynx and trachea were without findings.

Under the conditions of this study the LC50 for male and female rats after liquid aerosol inhalation exposure of the read-across substance was estimated to be 5.031 mg/L for the female animals (analytical concentration).

Justification for classification or non-classification

Based on the available acute oral and inhalation toxicity study with the target and the read-across substance, no classification and labeling is required (according to Directive 67/548/EEC and according to CLP).