N,N'-diphenylguanidine monohydrochloride

Endpoint summary

Description of key information

Based on the results of an acute oral toxicity study with the test item according to OECD 423 the oral LD50 was determined to be: 50 mg/kg bw < LD50 > 300 mg/kg bw in female rats.

Based on the results of an acute dermal toxicity study with a structural analogue substance (CAS 102 -06 -7) the dermal LD50 with the test item is considered to be > 2000 mg/kg bw.

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:

2010-08-10 to 2011-01-10

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)

Version / remarks:

2001

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.1 tris (Acute Oral Toxicity - Acute Toxic Class Method)

Version / remarks:

2008

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

acute toxic class method

Limit test:

no

Species:

rat

Strain:

Wistar

Sex:

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
- Females nulliparous and non-pregnant: yes
- Age at study initiation: 10 weeks
- Weight at study initiation: 177.8 - 198.5 g
- Fasting period before study: overnight before administration
- Housing: in groups of three
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: 8 days

ENVIRONMENTAL CONDITIONS
- Temperature: 22 +/- 3 °C
- Humidity: 30 - 70 %
- Air changes: 10-15 per hr
- Photoperiod: 12 / 12 hrs dark / hrs light

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 0.2 g/mL, 0.03 g/mL or 0.005 g/mL
- Justification for choice of vehicle: recommended by guideline

MAXIMUM DOSE VOLUME APPLIED: 10 mL/kg bw

DOSAGE PREPARATION:
The dose formulations were prepared shortly before each dosing occasion using a magnetic stirrer and a spatula as homogenizers. The test item was first ground with a pestle and mortar and was weighed into a tared glass beaker on a suitable precision balance and the vehicle was added (weight:volume). The mixture was heated to 40 °C to dissolve the test item and was then allowed to cool to room temperature before oral administration. Homogeneity of the test item in the vehicle was maintained during administration using a magnetic stirrer.

Doses:

50, 300, 2000 mg/kg bw

No. of animals per sex per dose:

3 females per group

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing:
Mortality: Daily during acclimatization. Once before treatment and within the first 30 minutes and at approximately 1, 2, 3 and 5 hours after treatment on test day 1 (in common with the clinical signs). Twice daily during days 2 – 15.
Clinical signs: Daily during acclimatization and treatment. Additionally, within the first 30 minutes (after 45 min for group 3) and at approximately 1, 2, 3 and 5 hours after administration on test day 1.
Body Weight: On test days 1 (prior to administration), 8 and 15.
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight

Statistics:

No statistical analysis was performed.

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

> 50 - < 300 mg/kg bw

Based on:

test mat.

Mortality:

All animals, which were treated at the dose of 2000 mg/kg bw or 300 mg/kg bw, died spontaneously within the first 35 minutes after administration. One out of six animals dosed at 50 mg/kg bw had to be killed in extremis approximately 1 hour after administration due to the relevant clinical signs observed, including severely weakened condition, severely swaying and abnormal gait, unconsciousness, moderately decreased activity, prostration, hunched posture, ptosis of both eyes and severely laboured breathing. The other five animals treated at the dose of 50 mg/kg bw survived until the end of the study.

Clinical signs:

Clinical signs were observed in all three animals dosed at 2000 mg/kg bw shortly after the test item administration and before death occurred (approximately 10 minutes after dosing). They consisted of convulsion, ventral recumbency and laboured breathing. Clinical signs were observed in all three animals dosed at 300 mg/kg bw approximately 15 minutes after test item administration. They consisted of tremor in two animals, ventral recumbency and laboured breathing in all three animals before death occurred in all three animals (20 or 35 minutes after dosing). Clinical signs were observed in four animals dosed at 50 mg/kg bw within approximately 0.5 to 5 hours after treatment on day 1, including slightly to moderately weakened condition, slightly to moderately abnormal and swaying gait, slightly to moderately decreased activity, abnormal posture, prostration, hunched posture, slightly to moderately laboured breathing, collapsing, dragging of both hindlegs and slightly ruffled fur. The slightly ruffled fur persisted in one animal up to day 2. No clinical signs were recorded in one animal dosed at 50 mg/kg throughout the entire observation period.

Body weight:

The body weight of the surviving animals was within the range commonly recorded for this strain and age.

Gross pathology:

Macroscopic findings were recorded at the unscheduled necropsy of three animals dosed at 2000 mg/kg bw and three animals dosed at 300 mg/kg bw as well as one animal dosed at 50 mg/kg bw, including lungs discolored in light red and a gray white stomach distended with gas (7 animals); a gray white ileum distended with gas (6 animals); reddish duodenum and jejunum, both distended with gas and a reddish ileum hemorrhage (1 animal).

Interpretation of results:

Category 3 based on GHS criteria

Conclusions:

The median lethal dose of the test item after single oral administration to female rats, observed over a period of 14 days, is: 50 mg/kg body weight < LD50 (female rat) < 300 mg/kg body weight.

Executive summary:

Four groups, each consisting of three female RccHan:WIST (SPF) rats, were treated with the test item by single oral gavage administration at a dosage of 2000 mg/kg, 300 mg/kg or 50 mg/kg body weight. The test item was formulated in purified water at a concentration of 0.2 g/mL, 0.03 g/mL or 0.005 g/mL and administered at a dosing volume of 10 mL/kg. The animals were examined daily during the acclimatization period and mortality, viability and clinical signs were recorded. All animals were examined for clinical signs before treatment, within the first 30 minutes and approximately 1, 2, 3 and 5 hours after treatment on day 1 and once daily during test days 2-15. Mortality/viability was recorded before treatment, within the first 30 minutes and approximately 1, 2, 3 and 5 hours after administration on test day 1 (with the clinical signs) and twice daily during days 2-15. Body weights were recorded on day 1 (prior to administration) and on days 8 and 15. All animals were necropsied and examined macroscopically. All animals, which were treated at the dose of 2000 mg/kg or 300 mg/kg, died spontaneously within the first 35 minutes after administration. One out of six animals dosed at 50 mg/kg had to be killed in extremis approximately 1 hour after administration due to the relevant clinical signs observed, including severely weakened condition, severely swaying and abnormal gait, unconsciousness, moderately decreased activity, prostration, hunched posture, ptosis of both eyes and severely laboured breathing. The other five animals treated at the dose of 50 mg/kg survived until the end of the study. Clinical signs were observed in all three animals dosed at 2000 mg/kg shortly after the test item administration and before death occurred (approximately 10 minutes after dosing). They consisted of convulsion, ventral recumbency and laboured breathing. Clinical signs were observed in all three animals dosed at 300 mg/kg approximately 15 minutes after test item administration. They consisted of tremor in two animals, ventral recumbency and laboured breathing in all three animals before death occurred in all three animals (20 or 35 minutes after dosing). Clinical signs were observed in four animals dosed at 50 mg/kg within approximately 0.5 to 5 hours after treatment on day 1, including slightly to moderately weakened condition, slightly to moderately abnormal and swaying gait, slightly to moderately decreased activity, abnormal posture, prostration, hunched posture, slightly to moderately laboured breathing, collapsing, dragging of both hindlegs and slightly ruffled fur. The slightly ruffled fur persisted in one animal up to day 2. No clinical signs were recorded in one animal dosed at 50 mg/kg throughout the entire observation period. The body weight of the animals was within the range commonly recorded for this strain and age. Macroscopic findings were recorded at the unscheduled necropsy of three animals dosed at 2000 mg/kg and three animals dosed at 300 mg/kg as well as one animal dosed at 50 mg/kg, including lungs discolored in light red and a gray white stomach distended with gas (7 animals); a gray white ileum distended with gas (6 animals); reddish duodenum and jejunum both distended with gas and a reddish ileum hemorrhage (1 animal). The median lethal dose of the test item after single oral administration to female rats, observed over a period of 14 days, is:

50 mg/kg body weight < LD50 (female rat) < 300 mg/kg body weight.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Quality of whole database:

GLP and guideline study.

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

discriminating dose

Value:

2 000 mg/kg bw

Quality of whole database:

GLP and guideline study of a read-across substance.

Additional information

Acute oral toxicity

Four groups, each consisting of three female RccHan:WIST (SPF) rats, were treated with the test item by single oral gavage administration at a dosage of 2000 mg/kg, 300 mg/kg or 50 mg/kg body weight. The test item was formulated in purified water at a concentration of 0.2 g/mL, 0.03 g/mL or 0.005 g/mL and administered at a dosing volume of 10 mL/kg. The animals were examined daily during the acclimatization period and mortality, viability and clinical signs were recorded. All animals were examined for clinical signs before treatment, within the first 30 minutes and approximately 1, 2, 3 and 5 hours after treatment on day 1 and once daily during test days 2-15. Mortality/viability was recorded before treatment, within the first 30 minutes and approximately 1, 2, 3 and 5 hours after administration on test day 1 (with the clinical signs) and twice daily during days 2-15. Body weights were recorded on day 1 (prior to administration) and on days 8 and 15. All animals were necropsied and examined macroscopically. All animals, which were treated at the dose of 2000 mg/kg or 300 mg/kg, died spontaneously within the first 35 minutes after administration. One out of six animals dosed at 50 mg/kg had to be killed in extremis approximately 1 hour after administration due to the relevant clinical signs observed, including severely weakened condition, severely swaying and abnormal gait, unconsciousness, moderately decreased activity, prostration, hunched posture, ptosis of both eyes and severely laboured breathing. The other five animals treated at the dose of 50 mg/kg survived until the end of the study. Clinical signs were observed in all three animals dosed at 2000 mg/kg shortly after the test item administration and before death occurred (approximately 10 minutes after dosing). They consisted of convulsion, ventral recumbency and laboured breathing. Clinical signs were observed in all three animals dosed at 300 mg/kg approximately 15 minutes after test item administration. They consisted of tremor in two animals, ventral recumbency and laboured breathing in all three animals before death occurred in all three animals (20 or 35 minutes after dosing). Clinical signs were observed in four animals dosed at 50 mg/kg within approximately 0.5 to 5 hours after treatment on day 1, including slightly to moderately weakened condition, slightly to moderately abnormal and swaying gait, slightly to moderately decreased activity, abnormal posture, prostration, hunched posture, slightly to moderately laboured breathing, collapsing, dragging of both hindlegs and slightly ruffled fur. The slightly ruffled fur persisted in one animal up to day 2. No clinical signs were recorded in one animal dosed at 50 mg/kg throughout the entire observation period. The body weight of the animals was within the range commonly recorded for this strain and age. Macroscopic findings were recorded at the unscheduled necropsy of three animals dosed at 2000 mg/kg and three animals dosed at 300 mg/kg as well as one animal dosed at 50 mg/kg, including lungs discolored in light red and a gray white stomach distended with gas (7 animals); a gray white ileum distended with gas (6 animals); reddish duodenum and jejunum both distended with gas and a reddish ileum hemorrhage (1 animal). The median lethal dose of the test item after single oral administration to female rats, observed over a period of 14 days, is: 50 mg/kg body weight < LD50 (female rat) < 300 mg/kg body weight.

Acute dermal toxicity with the read-across substance (CAS 102 -06 -7)

The acute dermal toxicity of a structural analogue substance was evaluated in rabbits in a study performed following EU method B. 3 (for read-across justification please refer to attached document in IUCLID Chapter 13). A limit test was performed in which one group of five male and five female rabbits received a single dermal application of DPG at a dose of 2000 mg/kg body weight. Following dosing, the rabbits were observed daily and weighed weekly. A gross necropsy examination was performed on all test animals at the time of death or scheduled euthanasia (day 15). No mortality occurred during the study. The most notable clinical signs were generally limited to transient dermal irritation at the site of test article application. Body weight gain was exhibited by all animals during the study. At necropsy on day 15, the pancreas or pancreatic lymph nodes of 4/10 animals were noted to have an abnormal red discoloration. The cause of this finding could not be determined. No significant internal abnormalities were observed in the remaining animals at necropsy. The acute dermal LD0 of the read-across substance was determined to be greater than 2000 mg/kg in the rabbit.

Justification for classification or non-classification

Classification, Labelling, and Packaging Regulation (EC) No 1272/2008
The available experimental test data are reliable and suitable for classification purposes under Regulation (EC) No 1272/2008. Based on available data on acute oral and dermal toxicity, the test item is classified and labelled as acutely toxic via the oral route Cat. 3 (H301: "Toxic if swallowed") according to Regulation (EC) No 1272/2008 (CLP), as amended for the tenth time in Regulation (EU) No 2017/776.

The test item does not require classifcation as acutely toxic via the dermal route.