Cyclohexane, 1,3-bis(isocyanatomethyl)-

Endpoint summary

Description of key information

In an acute oral toxicity test, the oral LD50 of 1,4-H6XDI was found to be > 300 mg/kg bw and < 2000 mg/kg bw. This result is read across to 1,3-H6XDI. In an acute oral toxicity study with mice the LD50 was found to be between 520.8 and 625 mg/kg body weight. In an oral acute toxicity study, the LD50 of 1,3-H6XDI was found to be > 1600 mg/kg bw and < 2500 mg/ kg bw in  male and female rats.

In an acute inhalation toxicity, conducted equivalent to OECD 403, the LC50 of 1,3-H6XDI was found to be > 0.147 mg/L and < 0.239 mg/L.

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:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

The rationale to read across the data is attached in Section 13.

Reason / purpose for cross-reference:

read-across source

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

> 300 - < 2 000 mg/kg bw

Based on:

test mat.

Mortality:

Two animals died on the second day after dosing at 2000 mg/ kg bw. No other mortality occurred.

Clinical signs:

At 2000 mg/ kg bw, decrease in spontaneous movement was noted on day 1. For the surviving animals, this resolved after 3 days.
At 300 mg/ kg bw, no clinical signs were noted.

Body weight:

At 2000 mg/kg bw, weight decrease was noted in all animals. The surviving animal showed body weight decrease until day 3 after administration, but showed largely regular body weight gain thereafter. The body weight gain in animals dosed at 300 mg/kg bw was slightly low on the day following administration, but the rats showed largely regular body weight development thereafter.

Gross pathology:

No abnormalities in external appearance or in organs/ tissues in the cephalic, thoracic or abdominal regions were noted.

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

In an acute oral toxicity test, the oral LD50 of 1,4-H6XDI was found to be > 300 mg/kg bw and < 2000 mg/kg bw. This result is read across to 1,3-H6XDI.

Executive summary:

An acute oral toxicity test was performed according to OECD guideline 423 and GLP principles. Three female rats were exposed to 2000 mg 1,4 -H6XDI/ kg bw, which resulted in mortality of two rats on day 2. Decrease in spontaneous movement on day 1 was the only clinical sign observed in this group. The surviving animals showed decreased body weight, but regained body weight from day 4. Two groups of 3 females were exposed to 300 mg/kg bw in a step-wise manner. No mortality occurred, no clinical signs were noted. Slight depression in body weight gain was noted on the first day after administration, but this was resolved the next day. No abnormalities in external appearance or in organs/ tissues in the cephalic, thoracic or abdominal regions were noted. Based on these results, the oral LD50 of 1,4-H6XDI was found to be > 300 mg/kg bw. This result is read across to 1,3-H6XDI.

Reference 2

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

January - February 1971

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline followed

Principles of method if other than guideline:

H6XDI was orally administered to male mice at 6 test animals per test dose (434, 520.8, 625, 750, 900 mg/kg body weight). Clinical signs and mortality were observed over a period of 7 days.

GLP compliance:

no

Test type:

standard acute method

Limit test:

no

Species:

mouse

Strain:

other: ICR/JCL

Sex:

male

Details on test animals or test system and environmental conditions:

- Source: Not specified
- Age at study initiation: 4 weeks old
- Weight at study initiation: 16.5 - 27 g
- Housing: Group housing of 6 animals per cage
- Diet: Free access to diet (CE-2, CLEA Japan, Inc.)
- Water: Free access to tap water.


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 23 ± 2
- Humidity (%): 55 ± 5

No further details available.

Route of administration:

oral: gavage

Vehicle:

other: 5% gum arabic solution

Details on oral exposure:

Frequency: single dose

MAXIMUM DOSE VOLUME APPLIED:
20 mL/kg body weight

Doses:

434 mg/kg body weight
520.8 mg/kg body weight
625 mg/kg body weight
750 mg/kg body weight
900 mg/kg body weight

No. of animals per sex per dose:

6 males

Control animals:

no

Details on study design:

- Duration of observation period following administration: 7 days .
- Frequency of observations: continuously until 4 hours after treatment and thereafter once a day.
- Necropsy of survivors performed: yes, immediately after dead or on the 8th day after iniation.

Statistics:

Litchfield and Wilcoxon's method.

Key result

Sex:

male

Dose descriptor:

LD50

Effect level:

>= 520.8 - <= 625 mg/kg bw

Based on:

test mat.

Sex:

male

Dose descriptor:

other: Calculated LD50

Effect level:

570 mg/kg bw

Based on:

test mat.

95% CL:

>= 483 - <= 673

Mortality:

0/6 - dose 434 mg/kg body weight
2/6 - dose 520.8 mg/kg body weight
4/6 - dose 625 mg/kg body weight
5/6 - dose 750 mg/kg body weight
5/6 - dose 900 mg/kg body weight

All deaths occurred <16 hours post administration with exception of 1 mouse (900 mg/kg body weight) that died on the second day of observation.

Clinical signs:

Initial signs of slight excitement were soon followed by decreased locomotor activity and respiratory depression. Surviving animals returned to normal 24 hours after treatment.

Body weight:

Not measured.

Gross pathology:

A slight swelling, hyperemia and hemorrhage were noted during autopsy in the gastric mucosa of the animals that died within 2 days post administration.
Animals that were killed showed no abnormalities during autopsy.

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

In an acute oral toxicity study with mice the LD50 was found to be between 520.8 and 625 mg/kg body weight. Therefore H6XDI is classifed as category 4 according to the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) of the United Nations (2015) (including all amendments) and according to Regulation (EC) No 1272/2008 on classification, labelling and packaging of items and mixtures (including all amendments).

Reference 3

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

10 September 1981 - 8 October 1981

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

GLP compliance:

no

Test type:

standard acute method

Limit test:

no

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River U.K. Limited, Margate, Kent, England
- Age at study initiation: 4-6 weeks
- Weight at study initiation: 96-131 g
- Fasting period before study: yes (21 hours prior and 3 hours post-dosing)
- Housing: in groups, in metal cages with wire mesh floors
- Diet: ad libitum, standard laboratory diet (Laboratory Diet no. 1, Spratt's Ltd., Barking, Essex, England)
- Water: ad libitum
- Acclimation period: minimum 6 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20±2
- Humidity (%): 43-66
- Air changes (per hr): appr. 15
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 10 September 1981 To: 8 October 1981

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 20% w/v
- Amount of vehicle (if gavage): The dose volume was varied to achieve the necessary dosage levels (no further details given)

MAXIMUM DOSE VOLUME APPLIED: 20 mL/kg (corresponds to a dose of 4000 mg/kg bw)

Doses:

500 and 2000 mg/kg bw (preliminary study); 1000, 1600, 2500 and 4000 mg/kg bw.

No. of animals per sex per dose:

2 (preliminary study), 5 (main study)

Control animals:

yes

Details on study design:

- Duration of observation period following administration: 5 days (preliminary study); 14 days (main study)
- Frequency of observations and weighing: animals were observed soon after dosing, then at regular intervals for the remainder of day 1. On subsequent days the animals were observed at least once. Clinical signs were recorded at each observation (recorded without time-point of observations). Weighing was done at days 1, 8 and 15.
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight

Statistics:

The acute oral median LD50 to rats was calculated using the method of: Finney (1971) Probit Analysis (3rd Edition) Cambridge University Press).

Preliminary study:

No mortality was seen in animals dosed at 500 mg/kg bw. At 2000 mg/ kg bw two females died, both dosed males survived. Time of death was less than 46 and less than 70 hours after dosing, respectively.

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 1 600 - <= 2 500 mg/kg bw

Based on:

test mat.

Remarks on result:

other: The LD50 was calculated to be 1900 mg/kg bw (1600 - 2300 mg/kg bw)

Mortality:

No animals died when dosed up to 1000 mg/kg bw.
At 1600 mg/ kg bw, one male and one female died. At higher doses, all males died. One female survived at 2500 mg/kg bw, all females dosed at 4000 mg/kg bw died.
Mortalities occurred within 19 hours and 67 hours of dosing.

Clinical signs:

Substance-related observations included abnormal body carriage and gait (hunched posture and waddling for all dosed animals). Furthermore, dose-related lethargy was seen, diarrhoea, ptosis, and pallor of extremities. Diuresis was seen in 2 animals at 1600 mg/kg bw and 4 rats at the highest dose. Furthermore decreased respiratory rate was seen in 4, 8 and 5 rats dosed at respectively 1600 mg/kg bw, 2500 mg/kg bw and 4000 mg/kg bw. Recovery of the surviving animals, as judged by external appearance and behaviour, was apparently complete by day 8.

Body weight:

Body weight gain at the end of the observation period was not affected by test substance exposure in females. Exposed males showed decreased body weight gain at 1000 and 1600 mg/kg bw during the first week of observation only.

Gross pathology:

Autopsy of animals that died shortly after dosing revealed congestion or haemorrhage of the lungs and pallor of the liver, spleen and kidneys. These observations were accompanied by congestion of the blood vessels of the stomach in one female at 1600 mg/kg, one male and four females at 2500 mg/kg bw and one male at 4000 mg/kg bw. The blood vessels of the small intestine were congested in one male and one female dosed at 2500 mg/kg bw. Terminal autopsy findings were within normal limits.

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

In an oral acute toxicity study, the LD50 of 1,3-H6XDI was found to be > 1600 mg/kg bw and < 2500 mg/ kg bw in male and female rats.

Executive summary:

An oral acute toxicity study was performed with 1,3 -H6XDI with male and female rats. No animals died when dosed up to 1000 mg/kg bw. At 1600 mg/ kg bw, one male and one female died. At higher doses, all males died. One female survived at 2500 mg/kg bw, all females dosed at 4000 mg/kg bw died. Substance-related observations included abnormal body carriage and gait (hunched posture and waddling for all dosed animals). Furthermore, dose-related lethargy was seen, diarrhoea, ptosis, and pallor of extremities. Diuresis was seen in 2 animals at 1600 mg/kg bw and 4 rats at the highest dose. Furthermore decreased respiratory rate was seen in 4, 8 and 5 rats dosed at respectively 1600 mg/kg bw, 2500 mg/kg bw and 4000 mg/kg bw. Recovery of the surviving animals, as judged by external appearance and behaviour, was apparently complete by day 8. Body weight gain at the end of the observation period was not affected by test substance exposure in females. Exposed males showed decreased body weight gain at 1000 and 1600 mg/kg bw during first week of observation only. Autopsy of animals that died shortly after dosing revealed congestion or haemorrhage of the lungs, pallor of the liver, spleen and kidneys and incidences of congestion of the blood vessels of the stomach. No abnormalities were found in the surviving animals. Based on these findings, the LD50 of 1,3-H6XDI was found to be > 1600 mg/kg bw and < 2500 mg/kg bw in rats. The substance is therefore classified cat. 4 according to Regulation EC 1272/2008.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

300 mg/kg bw

Quality of whole database:

Reliable studies are used.

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:

01JAN1980 - 06MAR1980

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

The study is well-documented, sufficient concentrations were tested and the test substance concentration was verified. The study was conducted equivalant to OECD guideline, but not following GLP principles.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

GLP compliance:

no

Test type:

acute toxic class method

Limit test:

no

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River UK, Manston Road, Margate, Kent
- Age at study initiation: 6-8 weeks
- Weight at study initiation: 155 - 202g
- Fasting period before study: no
- Housing: 5 male or 5 female rats/ cage, polypropylene cages with detachable wire mesh tops and floors, suspended on a movable rack (except during 4 hour exposure and 48 hour post exposure when rats were hold in a ventilated cabinet)
- Diet: Spratt's Laboratory Diet I, measured amount
- Water: tap water, ad libitum
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18.4 - 24.3
- Humidity (%): 31.1 - 42.9

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

whole body

Vehicle:

air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: whole body exposure chambers
- Exposure chamber volume: 0.13m3
- Source and rate of air: clean, dry air (compressed and oil-free)
- System of generating aerosols: an aerosol generator mixed clean dry air at a rate of 30 litres/ minute with the test substance at a flow rate between 0.15 and 0.021 mL per minute
- Method of particle size determination: samples were drawn by a May multistage liquid impinger with 0.04M dibenzylamine solution
- Temperature in chambers(°C): 20.3 - 25.4

TEST ATMOSPHERE
- Samples taken from breathing zone: yes (5 samples/ exposure from the exposure chamber to determine test substance concentration and 2 samples to determine particle size distribution)
- Brief description of analytical method used: HPLC (samples were drawn through a gas absorption trap (jet impinger type) with 0.04M dibenzylamine in 1,2 dichloroethane)

The mean concentration and standard deviation of the mean concentration of each group was as follows:
72.7 mg/m3 (10.50)
114.7 mg/m3 (26.59)
147.1 mg/m3 (31.47)
239.1 mg/m3 (21.00)
531.6 mg/m3 (75.37)

The mean percentage by weight of respirable particles (aerodynamic diameter <5.5µm was 88.1% (3.94%).

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Concentrations:

72.7, 114.7, 147.1, 239.1 and 531.6 mg/m3

No. of animals per sex per dose:

5

Control animals:

yes

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations: continuously during exposure and at least twice daily during the observation period
- Frequency of weighing: daily
- Necropsy of survivors performed: yes, gross macroscopy, lung weight was determined (lungs, livers and kidneys collected for possible microscopic examination)
- Other examinations performed: amount of food and water consumed by cage was measured daily

Statistics:

LD50 calculated by log probit method (Miller and Tainter, Proc. Soc. Exp. Biol. Med. 57 (2), 1944, pp 261 - 264).
The standard error was calculated from the formula: S.E. of LC50 = 2s/√(2N)
2s = estimated increment in concentration of the test substance between probits 4.0 and 6.0 corresponding to 16% and 84% mortality and N is the total number of rats in groups with mortality between 6.7% and 93.3%.

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 147.1 - < 239.1 mg/m³ air (analytical)

Based on:

test mat.

Exp. duration:

4 h

Remarks on result:

other: calculated LD 50 = 189.9 mg/m3 (standard error = 34.9 mg/m3)

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 0.147 - < 0.239 mg/L air (analytical)

Based on:

test mat.

Exp. duration:

4 h

Mortality:

No mortality was seen in the control group. At 72.7 mg/m3 one male died 48 hours after exposure, and one female died 8 days after exposure. At 114.7 mg/m3, one male died at 5 hours after exposure. All rats survived exposure to 147.1 mg/m3. At 239.1 mg/m3, 9/10 rats died (2 rats during exposure, 2 rats died within 1 hour after exposure, the other 3 between 36 and 48 hours after exposure, one male rat surrvived) and at the highest concentration all rats died (during or immediately after exposure).

Clinical signs:

other: No clinical signs were seen in the control group during or after exposure. During exposure, rats exposed to 72.7 mg/m3 showed salivation and hunched posture. At higher concentrations salivation, lacrimation, hunched or prone posture, peripheral vasodilat

Body weight:

At 72.7 and 114.7 mg/m3 marked decrease in group mean bodyweight was noted in the first 3 days after exposure, subsequent body weight gain was comparable to that of the control rats. Surviving rats at 147.1 mg/m3 also showed decrease in body weight gain during first three days after exposure, after this body weight gain was lower than that of the control rats for a further 3 days. The surviving male at 239.1 mg/m3 showed decreased body weight gain during first 5 days after exposure.

Gross pathology:

Gross pathology of rats that died as a result of exposure revealed haemorrhage, oedema and areas of hepatisation in the lung and distended gas filled stomachs at 72.7 and 114.7 mg/m3. At 147.1 mg/m3, scattered dark red foci or small area's of consolidation in the lungs of 4 rats were seen. Areas of hepatisation were also seen in the lungs of 2 rats exposed at 72.7 mg/m3 killed at the end of the observation period. A 7 mm diameter hemispherical lesion was observed on the liver of one male. At 239.1 mg/m3, oedema. Hepatisation affecting large areas of the lung and distended gas filled stomachs were seen in rats that died as a result of exposure. Findings for the rat that survived were small areas of hepatisation and a few scattered dark red foci in the lung. the adrenals of this rat were pale and enlarged. At the highest dose, oedema and hepatisation affecting large areas of the lung were seen in all rats.

Other findings:

Food and water consumption:
At 72.7, 114.7 and 147.1 mg/m3 food and water consumption was reduced to 25-30% of normal for 3 days following exposure. Normal food and water consumption resumed over the next 2-3 days.
The surviving male at 239.1 mg/m3 consumed little or no food during 5 days after exposure. Water consumption was 10-15% of normal consumption.

Lung weight to body weight ratio:
Within normal limits for surviving rats; high values for animals that died early in the study.

Interpretation of results:

Category 2 based on GHS criteria

Conclusions:

In an acute inhalation toxicity, conducted equivalent to OECD 403, the LD50 of 1,3-H6XDI was found to be > 0.147 mg/L and < 0.239 mg/L.

Executive summary:

An acute inhalation toxicity was performed equivalent to OECD 403 with 1,3H6XDI. Five male and female rats were exposed to aerosols for 4 hours (whole body exposure) and followed for 14 days. Mortality was 0, 2, 1, 0, 9 and 10 rats at 0, 72.7, 114.7, 147.1, 239.1 and 531.6 mg/m3. The time of death correlated with exposure concentration. During exposure, rats showed salivation, lacrimation, hunched or prone posture, peripheral vasodilation and laboured breathing (gasping at two highest doses). The rapidity of onset of these reactions was related to the exposure level. During observation period, laboured breathing and rales were observed in all exposed animals. Brown staining (or dark red discharge) around snouts and peripheral vasodilation was observed in all rats 3 days post exposure. Persistence of the observations was dependent on exposure concentration. Dose-dependent decrease in body weight gain was noted during first 3 to 5 days after exposure. Subsequent body weight gain was comparable to that of the control rats for rats dosed at 72.7 and 114.7 mg/m3, but for rats dosed higher body weight gain remained lower, or further decreased (at 239.1 mg/m3). Gross macroscopy revealed substance related effects in the lungs (oedema and hepatisation, dose-dependent severity). As the LD50 of 1,3-H6XDI was found to be > 147.1 mg/m3 and < 239 mg/m3, which correlates to > 0.147 mg/L and < 0.239 mg/L, 1,3H6XDI is classified as category 2 for inhalation toxicity according to Regulation EC 1272/2008.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LC50

Value:

147.1 mg/m³

Quality of whole database:

A reliable study is used.

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:

10SEP1981 - 19OCT1981

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study performed equivalent to OECD guidance. Study performed with substance analogue (maximum Klimisch score = 2).The rationale to read across these data is attached in section 13.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Principles of method if other than guideline:

The test item was held on the skin with an impermeable covering. This can be considered worst case.

GLP compliance:

no

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River U.K. Limited, Margate, Kent England
- Age at study initiation: 6-8 weeks
- Weight at study initiation: 191 - 234g
- Housing: Individuall, in metal cages with wire mesh floors
- Diet: ad libitum, standard rodent diet (Laboratory Diet No. 1, Spratt's Limited, Barking, Essex, England)
- Water: ad libitum
- Acclimation period: at least 3 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22.5±2.5
- Humidity (%): 31-57
- Air changes (per hr): Appr. 15
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 10SEP1981 To: 19OCT1981

Type of coverage:

occlusive

Vehicle:

other: as supplied (main study) or as 20% suspension in corn oil (preliminary study)

Details on dermal exposure:

TEST SITE
- area of exposure: appr. 10% of total body surface
- % coverage: 100% of test site
- Type of wrap if used: Application site was covered with aluminium foil which was held in place with impermeable dressing encircled firmly around the trunk (occlusive coverage)

REMOVAL OF TEST SUBSTANCE
- Washing: yes, with warm water (40-50°C), blotted dry with absorbent paper
- Time after start of exposure: 24 hours

TEST MATERIAL
- Amount applied (volume or weight with unit): maximum volume = 4.54 mL/ kg bw (density = 1.101 g/mL).
- Constant volume or concentration used: no

Duration of exposure:

24 hours

Doses:

0.1 and 0.5 mg/kg bw (preliminary study);
0.5, 2.0 and 5.0 g/kg bw (main study).

No. of animals per sex per dose:

2 (preliminary study);
5 (main study)

Control animals:

yes

Details on study design:

- Duration of observation period following administration: 5 days (preliminary study) and 14 days (main study)
- Frequency of observations: on day 1 regular observations, at least once daily in following period (animals observed for clinical signs and skin effects)
- Frequency of weighing: day 1, 8 and 15
- Necropsy of survivors performed: yes

Preliminary study:

No mortality occurred in the preliminary study.

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 5 000 mg/kg bw

Based on:

test mat.

Mortality:

No mortality occurred in the main study.

Clinical signs:

Hunched posture and abnormal gait (waddling) were noted for treated animals (resolved by day 5).

Body weight:

Depressed body weight gains compared to controls were seen for treated males in the first week, and for treated females in second week of observation.

Gross pathology:

Terminal autopsy revealed congestion of the subcutaneous blood vessels under the site of application in one treated male and three treated females.

Other findings:

Slight or well-defined oedema, accompanied by dryness and sloughing of the epidermis was observed in all test substance treated animals on second day after removal. A gradual increase in severity of the reactions was observed and "in depth" skin damage was observed in four rats by day 10 and in three further rats by day 12. Well-defined to moderate erythema accompanied by well-defined oedema was seen in the remaining animals.
At termination, "in depth" damage persisted in two animals. Dryness and sloughing of the epidermis, with or without scab formation, was observed in nine treated animals on day 15.

Interpretation of results:

GHS criteria not met

Conclusions:

An acute dermal toxicity study was performed with 1,3-H6XDI. Since no mortality occurred at 5000 mg/kg bw, the LD50 of 1,3-H6XDI can be expected to exceed 5000 mg/kg bw.

Executive summary:

An acute dermal toxicity study was performed comparable to OECD with male and female rats. The test was performed with 1,3-H6XDI. No mortality occurred at 5000 mg/kg bw. Hunched posture and abnormal gait (waddling) were noted for treated animals (resolved by day 5). Depressed body weight gains compared to controls were seen for treated males in the first week, and for treated females in the second week of observation. Slight or well-defined oedema, accompanied by dryness and sloughing of the epidermis was observed in all test substance treated animals on the second day after removal. A gradual increase in severity of the reactions was observed and "in depth" skin damage was observed in four rats by day 10 and in three further rats by day 12. Well-defined to moderate erythema accompanied by well-defined oedema was seen in the remaining animals. Skin effects were also seen at autopsy: one treated male and three treated females were found to have congestion of the subcutaneous blood vessels under the site of application. Based on these data, the LD50 of 1,3-H6XDI can be expected to exceed 5000 mg/kg bw.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

5 000 mg/kg bw

Quality of whole database:

A reliable study is used.

Additional information

Acute oral toxicity:

An acute oral toxicity test was performed according to OECD guideline 423 and GLP principles. Three female rats were exposed to 2000 mg 1,4-H6XDI/ kg bw, which resulted in mortality of two rats on day 2. Decrease in spontaneous movement on day 1 was the only clinical sign observed in this group. The surviving animals showed decreased body weight, but regained body weight from day 4. Two groups of 3 females were exposed to 300 mg/kg bw in a step-wise manner. No mortality occurred, no clinical signs were noted. Slight depression in body weight gain was noted on the first day after administration, but this was resolved the next day. No abnormalities in external appearance or in organs/ tissues in the cephalic, thoracic or abdominal regions were noted. Based on these results, the oral LD50 of 1,4-H6XDI was found to be > 300 mg/kg bw. This result is read across to 1,3-H6XDI.

In an acute oral toxicity study with mice the LD50 was found to be between 520.8 and 625 mg/kg body weight (supporting study).

An oral acute toxicity study was performed with 1,3 -H6XDI with male and female rats. No animals died when dosed up to 1000 mg/kg bw. At 1600 mg/ kg bw, one male and one female died. At higher doses, all males died. One female survived at 2500 mg/kg bw, all females dosed at 4000 mg/kg bw died. Substance-related observations included abnormal body carriage and gait (hunched posture and waddling for all dosed animals). Furthermore, dose-related lethargy was seen, diarrhoea, ptosis, and pallor of extremities. Diuresis was seen in 2 animals at 1600 mg/kg bw and 4 rats at the highest dose. Furthermore decreased respiratory rate was seen in 4, 8 and 5 rats dosed at respectively 1600 mg/kg bw, 2500 mg/kg bw and 4000 mg/kg bw. Recovery of the surviving animals, as judged by external appearance and behaviour, was apparently complete by day 8. Body weight gain at the end of the observation period was not affected by test substance exposure in females. Exposed males showed decreased body weight gain at 1000 and 1600 mg/kg bw during first week of observation only. Autopsy of animals that died shortly after dosing revealed congestion or haemorrhage of the lungs, pallor of the liver, spleen and kidneys and incidences of congestion of the blood vessels of the stomach. No abnormalities were found in the surviving animals. Based on these findings, the LD50 of 1,3-H6XDI was found to be > 1600 mg/kg bw and < 2500 mg/kg bw in rats.

Acute inhalation:

An acute inhalation toxicity was performed equivalent to OECD 403 with 1,3H6XDI. Five male and female rats were exposed to aerosols for 4 hours (whole body exposure) and followed for 14 days.Mortality was 0, 2, 1, 0, 9 and 10 rats at 0, 72.7, 114.7, 147.1, 239.1 and 531.6 mg/m3. The time of death correlated with exposure concentration. During exposure, rats showed salivation, lacrimation, hunched or prone posture, peripheral vasodilation and laboured breathing (gasping at two highest doses). The rapidity of onset of these reactions was related to the exposure level. During observation period, laboured breathing and rales were observed in all exposed animals. Brown staining (or dark red discharge) around snouts and peripheral vasodilation was observed in all rats 3 days post exposure. Persistence of the observations was dependent on exposure concentration. Dose-dependent decrease in body weight gain was noted during first 3 to 5 days after exposure. Subsequent body weight gain was comparable to that of the control rats for rats dosed at 72.7 and 114.7 mg/m3, but for rats dosed higher body weight gain remained lower, or further decreased (at 239.1 mg/m3). Gross macroscopy revealed substance related effects in the lungs (oedema and hepatisation, dose-dependent severity).As the LD50 of 1,3-H6XDI was found to be > 147.1 mg/m3 and < 239 mg/m3, which correlates to > 0.147 mg/L and < 0.239 mg/L, 1,3H6XDI is classified as category 2 for inhalation toxicity according to Regulation EC 1272/2008.

Acute dermal toxicity:

An acute dermal toxicity study was performed comparable to OECD with male and female rats. The test was performed with 1,3-H6XDI. No mortality occurred at 5000 mg/kg bw. Hunched posture and abnormal gait (waddling) were noted for treated animals (resolved by day 5). Depressed body weight gains compared to controls were seen for treated males in the first week, and for treated females in the second week of observation. Slight or well-defined oedema, accompanied by dryness and sloughing of the epidermis was observed in all test substance treated animals on the second day after removal. A gradual increase in severity of the reactions was observed and "in depth" skin damage was observed in four rats by day 10 and in three further rats by day 12. Well-defined to moderate erythema accompanied by well-defined oedema was seen in the remaining animals. Skin effects were also seen at autopsy: one treated male and three treated females were found to have congestion of the subcutaneous blood vessels under the site of application. Based on these data, the LD50 of 1,3-H6XDI can be expected to exceed 5000 mg/kg bw.

Justification for classification or non-classification

The oral LD50 of 1,3-H6XDI was found to be > 300 mg/kg bw and therefore 1,3-H6XDI is classified category 4 for acute oral toxicity according to Regulation EC 1272/2008.

As the LC50 of 1,3-H6XDI was considerd to be > 147.1 mg/m3 and < 239 mg/m3, which correlates to > 0.147 mg/L and < 0.239 mg/L, 1,3-H6XDI is classified as category 2 for inhalation toxicity according to Regulation EC 1272/2008.

1,3-H6XDI is not classified for acute dermal toxicity.