2-[[4-[(2-cyanoethyl)ethylamino]phenyl]azo]-5-nitrobenzonitrile

Endpoint summary

Description of key information

Oral LD50 (male and female) > 5000 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:

October from 05 to 31, 1990

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 401 (Acute Oral Toxicity)

Version / remarks:

1981

GLP compliance:

yes

Test type:

acute toxic class 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: Bantin & Kingman Ltd., Grimston, Aldborough, Hull, U.K.
- Age at study initiation: approximately five to eight weeks old.
- Weight at study initiation: males weighed 134 - 141 g and the females 129 - 152 g.
- Fasting period before study: overnight fast immediately before dosing.
- Housing: animals were housed in groups of up to five by sex in solid-floor polypropylene cages with sawdust bedding.
- Diet: Rat and Mouse Expanded Diet No. 1, Special Diet Services Limited, ad libitum.
- Water: drinking water, ad libitum.
- Acclimation period: at least five days.

ENVIRONMENTAL CONDITIONS
- Temperature: 21 - 24 °C
- Relative humidity: 49 - 65 %
- Air changes: approximately 15 changes per hour.
- Photoperiod: 12 hours light and 12 hours darkness.

Route of administration:

oral: gavage

Vehicle:

arachis oil

Details on oral exposure:

- Concentration: 250 mg/ml
- Dose volume: 10 ml/kg x 2

Doses:

5000 mg/kg bw

No. of animals per sex per dose:

Five males and five females

Details on study design:

MAIN STUDY
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: deaths and overt signs of toxicity were recorded 30 min, 1, 2 and 4 hours after dosing and subsequently once daily for 14 days. Individual bodyweights were recorded on the day of treatment (day 0) and on days 7 and 14.
- Necropsy of survivors performed: at the end of the study the animals were killed by cervical dislocation and subjected to gross necropsy examination for any macroscopic abnormalities. The procedure consisted of opening the abdominal and thoracic cavities and examining all major organs. The macroscopic appearance of abnormal organs if present was recorded. No tissues were retained.

RANGE-FINDING STUDY
- Concentrations: 200, 2000, 5000 mg/kg bw
- Number of animals per dose: 1 male and 1 female.
- Administration: animals treated with 2000 and 200 mg/kg were dosed once only by gavage using a metal cannula attached to a graduated syringe. Due to the nature of the test material, animals in the 5000 mg/kg dose group received two doses with an interval of one hour between the doses.

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 5 000 mg/kg bw

Based on:

test mat.

Remarks on result:

not determinable due to absence of adverse toxic effects

Mortality:

No deaths occurred.

Clinical signs:

No signs of systemic toxicity were noted during the study.

Body weight:

All animals showed expected gain in bodyweight during the study.

Gross pathology:

No abnormalities were noted at necropsy of animals killed at the end of the study.

Interpretation of results:

other: not classified, according to the CLP Regulatin (EC) No 1272/2008

Conclusions:

LD50 (male and female) > 5000 mg/kg bw

Executive summary:

A study was performed to assess the acute oral toxicity of the test material in the Sprague-Dawley strain rat. The method used followed that described in the OECD Guidelines for Testing of Chemicals (1981) No. 401. Following a range-finding study, a group of ten fasted animals (five males and five females) was given a single oral dose of test material preparation, administered as a suspension in arachis oil B.P. at a dose level of 5000 mg/kg bodyweight.

There were no deaths. No signs of systemic toxicity were noted during the study. All animals showed expected gain in bodyweight during the study. No abnormalities were noted at necropsy of animals killed at the end of the study.

Conclusion

LD50 (male and female) > 5000 mg/kg bw

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

5 000 mg/kg bw

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

ACUTE ORAL TOXICITY

A study was performed to assess the acute oral toxicity of the test material in the Sprague-Dawley strain rat. The method used followed that described in the OECD Guidelines 401. Following a range-finding study, a group of five males and five females was given a single oral dose of test material preparation, administered as a suspension in arachis oil B.P. at a dose level of 5000 mg/kg bw. There were no deaths. No signs of systemic toxicity were noted during the study. All animals showed expected gain in bodyweight during the study. No abnormalities were noted at necropsy of animals killed at the end of the study.

ACUTE INHALATION TOXICITY

No acute toxicity studies by inhalation route are available on Disperse Red 073. Nevertheless, because of the physical state of the substance inhalation is not an appropriate route of exposure. The vapour pressure of the substance is estimated to be negligible; the particle size distribution showed that the 99.75 % of particles have a diameter higher than 45 µm; thus, Disperse Red 073 is characterized by particles not-respirable. This consideration, together with the consideration that the substance is manufactured and handled with suitable risk management measures and with the suitable personal protective equipments, lets to consider the possible absorption of the substance by inhalation route as negligible.

ACUTE DERMAL TOXICITY

No acute toxicity studies by dermal route are available on Disperse Red 073. Nevertheless, the possible absorption rate of the substance by dermal route is not expected to be significant.

The Commission Regulation (EU) 2016/863, amending Annexes VII and VIII to REACH Regulation (EC) No 1907/2006, it is explained that recent scientific analysis of available data from in vivo acute toxicity studies have shown that substances that are not toxic via the oral route may be expected with high certainty to be also non-toxic via the dermal route. Therefore, testing those substances via the dermal route does not provide essential information for their safety assessment. The amendment is the consequence of studies and scientific debates. In particular, the 15^th Meeting of Competent Authorities for REACH and CLP (CARACAL, 2014) concluded that the avoidance of a dermal route test is justified for substances that have shown no toxicity in acute oral toxicity test up to the limit dose of 2000 mg/kg bw.

In the oral acute toxicity tests no signs of systemic toxicity were recorded. The substance is expected to be not a skin sensitizer: the sensitisation potential investigation conducted with Similar Substance 01 in Local Lymph Node Assay (LLNA), did not identify any test item-related systemic clinical signs. No reason of concern is raised on the basis of the skin/eye irritation investigations.

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 5000 mg/kg bw, 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).

Dermal and inhalation exposure is unlikely and no investigation is required.

In conclusion, the test substance does not meet the criteria to be classified for oral acute toxicity, according to the CLP Regulation (EC) No 1272/2008.