[2-[4-(dihexylamino)-2-methylbenzylidene]benzo[b]thien-3(2H)-ylidene]malononitrile S,S-dioxide

Endpoint summary

Description of key information

Oral LD50 (female) > 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:

September from 05th to 21st, 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

17th December 2001

Deviations:

no

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: Toxi Coop ZRT, Budapest, Hungary.
- Females: nulliparous and non pregnant animals.
- Age at study initiation: young adult rat, 8 weeks old in first and second step.
- Weight at study initiation: 197 - 214 g first step; 217 - 220 g second step.
- Fasting period before study: the day before treatment the animals were fasted.
- Housing: 3 animals per cage, Type III polypropylene/polycarbonate.
- Diet: animals received ssniff® SM R/M-Z+H complete diet for rats and mice produced by ssniff Spezialdiäten GmbH, ad libitum.
- Water: tap water from municipal supply, as for human consumption from bottle, ad libitum.
- Acclimation period: 5 days in first step and 6 days in second step.
- Animal health: only healthy animals were used for the study. Health status was certified by the study director.

ENVIRONMENTAL CONDITIONS
- Temperature: 22 ± 3 °C
- Relative humidity: 30 - 70 %
- Air changes: above 10 air exchanges/hour by central air-condition system.
- Photoperiod: 12 light hours daily, from 6.00 a.m. to 6.00 p.m.

Route of administration:

oral: gavage

Vehicle:

vegetable oil

Remarks:

Helianthi annui oleum raffinatum

Details on oral exposure:

- Treatment volume: concentration of formulations was adjusted to maintain a treatment volume of 10 ml/kg bw.
- Test concentration: 200 mg/ml.
- Correction factor: 1.18
- Formulation: formulations were prepared just before the administration and were stirred continuously during the treatment.
- Proocedure: stepwise procedure with the use of 2000 mg/kg bw as the starting dose.

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

3 animals per group

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations: animals were observed individually after dosing at least once during the first 30 minutes, then 1 h, 2 h, 3 h, 4 h after the treatment and twice each day for 14 days thereafter. Individual observations were performed on the skin and fur, eyes and mucous membranes and also respiratory, circulatory, autonomic and central nervous system, somatomotor activity and behaviour pattern. Particular attention was directed to observation of tremors, convulsions, salivation, diarrhoea, lethargy, sleep and coma.
- Frequency of weighing: body weights were recorded on day 0 (just before the treatment), on day 7 and on day 15 with a precision of 1 g.
- Necropsy of survivors performed: necropsy on Day 15. At the end of the observation period all rats were sacrificed under isofluran anaesthesia. After examination of the external appearance, the cranial, thoracic and abdominal cavities were opened and the appearance of the tissues and organs was observed, and any abnormality was recorded with details of its location, colour, shape and size.

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Remarks on result:

not determinable due to absence of adverse toxic effects

Mortality:

No death occurred at 2000 mg/kg bw single oral dose of test item. All female rats in step 1 and step 2 survived until the end of the 14-day observation period.

Clinical signs:

In group 1 treated with 2000 mg/kg bw dose blue anus and bedding (3 cases of 57 observations) were detected on Day 1. These alterations were observed in all animals and in both cages (score +1).
In group 2 treated with 2000 mg/kg bw dose blue anus and bedding (3 cases of 57 observations) were detected on Day 1. These alterations were observed in all animals and in both cages (score +1).

Body weight:

The mean body weight of animals treated with 2000 mg/kg bw dose corresponded to their species and age throughout the study.

Gross pathology:

All animals treated with 2000 mg/kg bw dose survived until the scheduled necropsy on Day 15.
Internal necropsy finding as pale kidneys was observed in three animals of group 2. This alteration could not be related to the test item toxic effect, but was regarded an individual variation. Most likely the observation is a congenital anomaly. No pathological changes were found related to the effect of the test item during the macroscopic examination of animals treated with 2000 mg/kg bw dose.

Interpretation of results:

other: not classified, according to the CLP Regulation (EC) 1272/2008

Conclusions:

LD50 (female) > 2000 mg/kg bw

Executive summary:

The acute toxic class method was carried out involving a stepwise procedure with the use of 2000 mg/kg bw as the starting dose in three female rats. No animal died in the first step at 2000 mg/kg bw dose level, so treatment with 2000 mg/kg bw was repeated on further three female rats. No animal died in the second step, too, so the test was finished, the stopping criteria of OECD Guideline No. 423 (presented in Appendix VII) were met.

Animals were weighed, observed for lethality and toxic symptoms for 14 days after the treatment. Gross pathological examination was carried out 15th day after the treatment.

No lethality was noted at single oral dose of 2000 mg/kg bw. In first step, blue anus and bedding were observed on Day 1. It was connected with the physical property of test item. No systemic clinical symptoms were observed on the day of the treatment and during the 14-day observation period, the general state and behaviour of experimental animals were normal.

In second step, blue anus and bedding observed on Day 1. It was connected with the physical property of test item. No systemic clinical symptoms were observed on the day of the treatment and during the 14-day observation period, the general state and behaviour of experimental animals were normal.

The body weight development was undisturbed in all animals.

All organs of the animals treated with 2000 mg/kg bw proved to be free of treatment related gross pathological changes.

Conclusion

LD50 (female) > 2000 mg/kg bw

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Additional information

ORAL ACUTE TOXICITY

The acute toxic class method was carried out involving a stepwise procedure with the use of 2000 mg/kg bw as the starting dose in three female rats. No animal died in the first step at 2000 mg/kg bw dose level, so treatment with 2000 mg/kg bw was repeated on further three female rats. No animal died in the second step, too, so the test was finished, the stopping criteria of OECD Guideline No. 423 (presented in Appendix VII) were met. Animals were weighed, observed for lethality and toxic symptoms for 14 days after the treatment. Gross pathological examination was carried out 15th day after the treatment. No lethality was noted at single oral dose of 2000 mg/kg bw. In first step, blue anus and bedding were observed on Day 1. It was connected with the physical property of test item. No systemic clinical symptoms were observed on the day of the treatment and during the 14-day observation period, the general state and behaviour of experimental animals were normal.

In second step, blue anus and bedding observed on Day 1. It was connected with the physical property of test item. No systemic clinical symptoms were observed on the day of the treatment and during the 14-day observation period, the general state and behaviour of experimental animals were normal.

The body weight development was undisturbed in all animals.

All organs of the animals treated with 2000 mg/kg bw proved to be free of treatment related gross pathological changes.

Justification for classification or non-classification

According to the CLP Regulation (EC) No 1272/2008, 3.1 Acute toxicity section, substances can be allocated to one of four toxicity categories based on acute toxicity by the oral, dermal or inhalation route according to the numeric criteria. Acute toxicity values are expressed as (approximate) LD50 (oral, dermal) or LC50 (inhalation) values or as acute toxicity estimates (ATE).

The oral LD50 value was established to be greater than 2000 mg/kg body weight, therefore the test substance is out of any classification limit for acute oral toxicity (oral acute toxicity category 4: 300 < ATE ≤ 2000 mg/kg bw).

In conclusion, the test substance is non classified for oral acute toxicity, according to the CLP Regulation (EC) No 1272/2008.