5',5'''-[ethylenebis(p-phenyleneazo)]bis[1',2'-dihydro-6'-hydroxy-4'-methyl-2'-oxo-1,3'-bipyridinium] dilactate

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:

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

Adequacy of study:

key study

Study period:

From 10th January to 14th February, 1991

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Justification for type of information:

The test substance is the acid form of the substance under registration; justification for Read Across is detailed in the IUCLID section 13.

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Version / remarks:

1981

Qualifier:

according to guideline

Guideline:

EU Method B.1 (Acute Toxicity (Oral))

GLP compliance:

yes (incl. QA statement)

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 (UK) Ltd., Manston, Kent, U.K.
- Age at study initiation: five to eight weeks old.
- Weight at study initiation: males weighed 150 - 162 g and the females 141 - 151 g.
- Fasting period before study: overnight fast immediately before dosing and for approximately two hours after dosing.
- Housing: animals were housed in groups of five by sex in solid-floor polypropylene cages with sawdust bedding.
- Diet: Rat and Mouse Expanded Diet No. 1, Special Diet Services Limited, Witham, Essex, U.K., ad libitum.
- Water: ad libitum.
- Acclimation period: minimum acclimatisation period of at least five days.

ENVIRONMENTAL CONDITIONS
- Temperature: 17 - 21 °C. On occasions the temperature was below the lower limit specified in the protocol (19 °C). This did not affect the purpose or integrity of the study.
- Relative humidity: 38 - 52 %
- Air changes: approximately 15 changes per hour.
- Photoperiod: the lighting was controlled by a time switch to give 12 hours continuous light and 12 hours darkness.

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

TEST ITEM PREPARATION
For the purpose of the study, the test material was freshly prepared, as required, as a suspension at the appropriate concentration in distilled water. Homogeneity was assured by the use of a Silverson Homogeniser.
The composition and stability of the test material and the stability of the preparations were not determined.

DOSAGE MAIN STUDY
- Concentration: 500 mg/l
- Volume: 10 ml/kg

DOSAGES RANGE-FINDING STUDY
- Concentration: 500, 200, 20, 2.5 mg/l
- Volume: 10 ml/kg

Doses:

MAIN STUDY: 5000 mg/kg bw
RANGE-FINDING STUDY: 5000, 2000, 20, 25 mg/kg

No. of animals per sex per dose:

MAIN STUDY: 5 males and 5 females per dose per group.
RANGE-FINDING STUDY: 1 male and 1 female per dose per group.

Details on study design:

MAIN STUDY
- Duration of observation period following administration: deaths and overt signs of toxicity were recorded at 0.5, 1, 2 and 4 hours after dosing and then daily for 14 days.
- Frequency of observations and weighing: 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 animals were killed by cervical dislocation and subjected to gross pathological examination. This consisted of an external examination and opening of the abdominal and thoracic cavities. The appearance of any macroscopic abnormalities was recorded. No tissues were retained.

RANGE-FINDING STUDY
- Aim: a range-finding study was performed using pre-selected dose levels to determine the highest dose that caused no deaths.
- Substance administration: all animals were dosed once only by gavage using a metal cannula attached to a graduated syringe. The volume administered to each animal was calculated according to its fasted bodyweight at the time of dosing.
- Observations: deaths and overt signs of toxicity were recorded at 0.5, 1, 2 and 4 hours after dosing and then daily for five days. Individual bodyweights were recorded on the day of dosing to allow calculation of individual treatment volumes. No necropsies were performed.
- Results: the results of the range-finding study indicated that the acute oral median lethal dose of the test material was greater than 5000 mg/kg bw. Based on this information, a dose level of 5000 mg/kg bodyweight was selected for the main study.

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 5 000 mg/kg bw

Based on:

test mat.

Mortality:

MAIN STUDY
No deaths were recorded.

RANGE-FINDING STUDY
No deaths occurred.

Clinical signs:

MAIN STUDY
No signs of systemic toxicity were noted during the study. Brown coloured staining of the fur was commonly noted during the study.

RANGE-FINDING STUDY
Signs of systemic toxicity noted in the male treated with 5000 mg/kg were gasping respiration, noisy respiration, hunched posture, red/brown stains around mouth, lethargy and decreased respiratory rate.
There were no clinical signs of toxicity noted in the female treated with 5000 mg/kg or animals treated with 2000, 200 or 25 mg/kg

Body weight:

MAIN STUDY
AII animals showed expected gain in bodyweight during the study.

Gross pathology:

MAIN STUDY
No abnormalities were noted at necropsy.

Interpretation of results:

other: not classified, according to the CLP Regulation (EC 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 guideline 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, as a suspension in distilled water at a dose level of 5000 mg/kg bodyweight. The animals were observed for fourteen days after the day of dosing and were then killed for gross pathological examination. 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. The acute oral median lethal dose Sprague-Dawley strain rat was found to be higher than 5000 mg/kg bw.

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 TOXICITY - ORAL ROUTE

There are no information about the oral acute toxicity potential of Basic Yellow 094, thus the available information on the structural analogue Similar Substance 01 have been taken into consideration. Similar Substance 01 is the acid form of Basic Yellow 094; the read across approach can be considered as appropriate and suitable to assess the property under investigation (details about the approach are reported into the IUCLID section 13).

A study was performed to assess the acute oral toxicity of the Similar Substance 01 in the Sprague-Dawley strain rat. The method used followed that described in the OECD guideline 401. Following a range-finding study, a group of five males and five females was given a single oral dose of test material, as a suspension in distilled water 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.

ACUTE TOXICITY, INHALATION ROUTE

No acute toxicity studies by inhalation route are available on Basic Yellow 094.

Nevertheless, because of the physical state and the trade forms of the substance under registration, inhalation is not an appropriate route of exposure. Acute toxicity results for the other exposure routes indicate no concern.

ACUTE TOXICITY, DERMAL ROUTE

The inhalation and the skin contact of Basic Yellow 094 are unlikely.

Extend of percutaneous absorption of a substance depends largely on the physical and chemical properties of the substance itself. In particular, factors like the degree of ionization, molecular size and water and lipid solubilities influence penetration through the skin. Considering the molecular size and the hydrophilic character of Basic Yellow 094, dermal route is not expected to be the main absorption route.

Moreover, in the oral acute toxicity test as well as in studies with dermal exposure, no signs of systemic toxicity were recorded.

Justification for classification or non-classification

According to the CLP Regulation (EC 1272/2008), 3.1 Acute toxicity section, substances can be allocated to one of four toxicity categories based on acute toxicity by 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 body weight, thus 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, thus no acute toxicity value is available and no further investigation is required.

 

In conclusion, the test substance is non classified for oral acute toxicity, according to the CLP Regulation (EC 1272/2008).