Chromate(2-), [2,4-dihydro-4-[(2-hydroxy-4-nitrophenyl)azo]-5-methyl-2-phenyl-3H-pyrazol-3-onato(2-)][3-[(4,5-dihydro-3-methyl-5-oxo-1-phenyl-1H-pyrazol-4-yl)azo]-2-hydroxy-5-nitrobenzenesulfonato(3-)]-, disodium

Endpoint summary

Description of key information

The oral LD50 for the substance was considered to be 1717 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:

no data

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)

Deviations:

no

Principles of method if other than guideline:

not applicable

GLP compliance:

no

Test type:

standard acute method

Limit test:

no

Species:

rat

Strain:

other: Tif: RAIf (SPF)

Sex:

male/female

Details on test animals or test system and environmental conditions:

Healthy random bred animals raised on the premises of the testing laboratory were used for the study. They were kept at a room temperature of 22±1 °C, at a relative humidity of 55±5 % and on a 10 h light cycle day. They received ad libitum rat food - NAFAG, Gossau SG - and water. Prior to treatment the animals were adapted to our laboratories for a minimum of 4 d and the initial body weight ranged from 160 to 180 g. During the treatment and observation period the animals were housed in groups of 5 in Macrolon cages (type 3). Animals were fasted overnight before treatment.

Route of administration:

oral: gavage

Vehicle:

polyethylene glycol

Remarks:

(PEG 400)

Details on oral exposure:

The test substance was suspended with PEG 400. Before treatment the suspension was homogeneously dispersed with an Ultra-Turrax and during treatment it was kept stable with a magnetic stirrer. The concentrations of the test substance in the vehicle were 5, 10, 10, and 30 % which correspond to the dose levels of 600, 1000, 2150 and 4640 mg/kg bw respectively.

Doses:

600, 1000, 2150 and 4640 mg/kg bw

No. of animals per sex per dose:

5/sex/dose

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 d
- Frequency of observations: Animals observed for mortality at 1, 24, and 48 h and weekly thereafter.
- Necropsy of survivors performed: Yes, animals were submitted at random to a necropsy whenever they died, survivors at the end of the observation period.
- Other examinations performed: clinical signs

Statistics:

LD50 including 95 % confidence limits were calculated by the logit model.

Preliminary study:

not applicable

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

1 717 mg/kg bw

Based on:

test mat.

95% CL:

1 271 - 2 433

Sex:

male/female

Dose descriptor:

LD50

Effect level:

1 408 mg/kg bw

Based on:

act. ingr.

Mortality:

A dose dependent increase in the rate of mortality was observed. No mortality was noted at the lowest dose, 2 and 6 deaths were noted in the two subsequent intermediate dose levels respectively and the highest mortality of 10 animals was recorded at the highest dose level.

Clinical signs:

other: Within 2 h after treatment the animals in all dosage groups showed dyspnoea, curved position, diarrhoea and ruffled fur. With the exception of the animals in the lowest dose level, sedation was also observed. Diarrhoea became more accentuated as the dose

Gross pathology:

No test substance related gross organ changes were observed.

Other findings:

none

none

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

The oral LD50 of the test substance was found to be 1717 (1271-2433) mg/kg bw (i.e. ca. 1408 mg a.i./kg bw)

Executive summary:

A study was conducted to evaluate the acute oral toxicity of the test substance (at ca. 82 % purity) following a method comparable to OECD Guideline 401. Four groups of fasted Tif: RAI rats (5/sex/dose) received the test substance at 0, 600, 1000, 2150 and 4640 mg/kg bw once by oral intubation. Animals were observed for mortality and clinical signs for a period of 14 d. At the end of this period, animals were sacrificed and autopsied. No mortality was noted at the lowest dose, 2/10 and 6/10 animals died in the two subsequent intermediate dose levels and mortality of 10/10 animals was recorded at the highest dose level. All the animals across dose groups showed sedation (except lowest dose level), dyspnoea, curved position, diarrhoea and ruffled fur within 2 h of test substance administration. Diarrhoea became more pronounced with increment in dose. The surviving animals recovered within 9 -12 d. Under the study conditions, the oral LD50 of the test substance was found to be 1717 (1271-2433) mg/kg bw (i.e. ca. 1408 mg a.i./kg bw).

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

1 717 mg/kg bw

Quality of whole database:

Good quality study conducted according to acceptable methodology

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

Two studies on oral toxicity are availble:

In the first study acute oral toxicity of the test substance (at ca. 75 % purity) was evaluated following a method comparable to OECD Guideline 401. Four groups of fasted Tif: RAI rats (5/sex/dose) received the test substance at 1670, 2780, 3590 and 4640 mg/kg bw once by oral intubation. All the animals were observed for mortality and clinical signs for a period of 14 d.No mortality was noted at the lowest dose, 1/10 and 2/10 animals died in the two subsequent intermediate dose levels and mortality of 5/10 animals was recorded at the highest dose level. All the animals across dose groups showed sedation, dyspnoea, curved position, diarrhoea and ruffled fur within 2 h of test substance administration. Diarrhoea became more pronounced with increment in dose. The surviving animals recovered within 9 d. No test substance-related macroscopic changes were observed. Under the study conditions, the LD50 value of the test substance was 4706 (3602-6149) mg/kg bw (i.e. ca. 3530 mg a.i./kg bw).

In the second study, the acute oral toxicity of the test substance (at ca. 82 % purity) was evaluated following a method comparable to OECD Guideline 401. Four groups of fasted Tif: RAI rats (5/sex/dose) received the test substance at 0, 600, 1000, 2150 and 4640 mg/kg bw once by oral intubation. Animals were observed for mortality and clinical signs for a period of 14 d. At the end of this period, animals were sacrificed and autopsied. No mortality was noted at the lowest dose, 2/10 and 6/10 animals died in the two subsequent intermediate dose levels and mortality of 10/10 animals was recorded at the highest dose level. All the animals across dose groups showed sedation (except lowest dose level), dyspnoea, curved position, diarrhoea and ruffled fur within 2 h of test substance administration. Diarrhoea became more pronounced with increment in dose. The surviving animals recovered within 9 -12 d. Under the study conditions, the oral LD50 of the test substance was found to be 1717 (1271-2433) mg/kg bw (i.e. ca. 1408 mg a.i./kg bw).

Justification for selection of acute toxicity – oral endpoint
Two acute oral studies were conducted on rats using two different preparations of the test substance. In the first study, the LD50 value of the test substance was 4706 (3602-6149) mg/kg bw with a test item purity of 75 %. In the second study, the oral LD50 of the test substance was found to be 1717 (1271-2433) mg/kg bw with a test item purity of 82 %. As both studies were of similar quality (Klimisch 2), the lowest value was selected as the key value.

 

Acute toxicity: inhalation

The test substance has very low vapor pressure and high melting point (>260 °C), so the potential for the generation of inhalable forms is low. The low partition coefficient of -0.68 at 20 °C again point to poor absorption across the respiratory tract. The substance was found to have high water solubility (135 g/L), hence the inhaled dust may be retained within the mucus of the respiratory tract, thereby limiting absorption. Also the use of this substance will not result in aerosols, particles or droplets of an inhalable size, so exposure to humans via the inhalatory route will be unlikely to occur. Taking into consideration all above argumants, acute inhalation toxicity test was considered scientifically not neccessary.

 

Acute toxicity: dermal

Currently no study to assess acute dermal toxicity of Acid Red 315 is available. However, the molecular weight of the substance is 803.6 g/mol, which indicates the substance being too large for dermal absorption. Further, high water solubility (135 g/L) and low partition coefficient (-0.68 at 20 °C), indicate the substance may be too hydrophilic to cross the lipid rich environment of the stratum corneum. Hence, the dermal uptake for the substance is expected to be low. Absence of systemic toxicity in skin irritation as well as sensitization studies, further supports the conclusion that low toxicity is expected on acute dermal exposure of the target chemical and testing by the dermal route was considered scientifically not necessary.

Justification for classification or non-classification

Based on the available data (oral LD50= 1717 mg/kg bw), Acid Red 315 needs to be classsified as Acute Oral Toxicity Category 4 (H302) according to CLP (Regulation (EC) No 1272/2008 Of The European Parliament And Of The Council) as implementation of UN-GHS in the EU.