Disodium 3,3'-[sulphonylbis[p-phenyleneazo(5-imino-3-methyl-1H-pyrazole-4,1-diyl)]]bis(benzenesulphonate)

Endpoint summary

Description of key information

Acute oral toxicity, LD50: > 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:

From the 26th of April to the 19th of May, 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Test conducted according to an internationally accepted test guideline.

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1100 (Acute Oral Toxicity)

GLP compliance:

yes (incl. QA statement)

Test type:

acute toxic class method

Species:

rat

Strain:

Sprague-Dawley

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
Species and strain: Rat, Hsd: Sprague Dawley SD
Sex: Females (nulliparous and non-pregnant)
Age and weight at order: 6-7 weeks old; 150-174 grams
Supplier: Envigo RMS srl, San Pietro al Natisone (UD), Italy
Date of arrival: 07 April 2016
Weight range at arrival: 153.2-162.3 grams
Acclimatisation period: At least 5 days
Veterinary health check: During acclimatisation period

ENVIRONMENTAL CONDITIONS
Animals per cage: 3 during the study; up to 5 during acclimatisation
Housing: Polisulphone solid bottomed cages measuring 59.5×38×20 cm with nesting material provided into suitable bedding bags
Cage control: Daily inspected and changed as necessary (at least 3 times/week)
Water: Drinking water supplied to each cage via a water bottle
Water: supply ad libitum
Diet: 4 RF 18 (Mucedola S.r.l., Via G. Galilei, 4, 20019, Settimo Milanese (MI) Italy)
Diet supply: ad libitum throughout the study except for the dosing procedure
Room: lighting Artificial (fluorescent tubes), daily light/dark cycle of 12/12 hours
Air: changes Approximately 15 to 20 air changes per hour
Temperature range: 22 °C ± 2 °C
Relative humidity range: 55 % ± 15 %
Selection/Allocation
Random at arrival. The body weight of each individual was within 20% of the group’s mean. Animals were unequivocally numbered within the study.
The animal number together with the study number ensured a unique animal numbering for any study employing computerised data collection. The computer system used in this study was Pristima version 6.3.2.
Animal identification
Animals were permanently identified, following arrival, by a combination of ear notch (units) and tattoo on the hind feet. Animals were identified by odd numbers.

Fasting procedure
Food was removed from the cages overnight prior to dosing (Day -1) and was made available approximately 4 hours after dosing.

Route of administration:

oral: gavage

Vehicle:

CMC (carboxymethyl cellulose)

Remarks:

0.5%

Details on oral exposure:

A first group of 3 female animals was dosed at a level of 2000 mg/kg (Step 1).
A second sub-group, similarly composed, was then dosed at the same dose level (Step 2).
No further doses were investigated since the objective of the study had been achieved (no mortality).

Frequency of treatment
Animals were dosed once only on Day 1.

Dose calculation
On the day of dosing (Day 1), the amount of the formulated test item to be administered was
calculated for each fasted animal according to body weight.

Dosing method
The formulated test item was administered, by gavage, at a dose volume of 10mL/kg using a
plastic feeding tube attached to a graded syringe.

Doses:

2000 mg/kg

No. of animals per sex per dose:

3 female per group

Details on study design:

TREATMENT (mg/kg)
2000 in terms of test item corrected for purity (77.1%)
Rat Numbers Females (odd)
7, 9, 11 (Group 2 - Step 1)
19, 21, 23 (Group 4 - Step 2)

OBSERVATION
Mortality and morbidity
Throughout the study all animals were checked twice daily.
Clinical signs
Animals were observed for clinical signs as indicated below:
– Day of dosing
· Session 1: on dosing
· Session 2: approximately 0.5 hour after dosing
· Session 3: approximately 2 hours after dosing
· Session 4: approximately 4 hours after dosing
– Daily thereafter for a total of 14 days (Session 1).

Body weight
All animals were weighed at allocation to the study (Day -1), on the day of dosing (Day 1) and on Days 2, 8 and 15.
Body weight change calculated for Days 2, 8 and 15 of the dosing phase was relevant to Day 1 of the phase.

TERMINAL STUDY
Termination
All animals were sacrificed on Day 15.
Euthanasia method
Animals were sacrificed by carbon dioxide narcosis.
Necropsy procedure
Necropsy was carried out on all animals (gross necropsy examination for both external and
internal abnormalities, with particular attention to the gastro-intestinal tract).

Sex:

female

Dose descriptor:

LD0

Effect level:

> 2 000 mg/kg bw

Based on:

act. ingr.

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

act. ingr.

Mortality:

No mortality occurred in all animals on Day 2 of study, in the first group of animals initially dosed at 2000 mg/kg (Group 2, Step 1).
No death occurred and no clinical signs were observed in the further group of 3 females dosed at the same dose level (Group 4, Step 2).

Clinical signs:

A yellow staining on the tail was observed in all animals on Day 2 of study, in the first group of animals initially dosed at 2000 mg/kg (Group 2, Step 1).

Body weight:

Changes in body weight observed during the study were within the expected range for this strain and age of animals.

Gross pathology:

No abnormalities were observed at necropsy examination performed on all animals dosed at 2000mg/kg (Groups 2 and 4) at the end of the observation period, with the exception of one animal (no. 19, Group 4) that showed red staining on the dorsum.

Interpretation of results:

not classified

Remarks:

Classification criteria according to the CLP Regulation 1272/2008 and its amendments

Conclusions:

No toxic effects at one dose, in rats: 2000 mg/kg.

Executive summary:

Method

The acute toxicity of the substance was investigated following a single oral administration to the Sprague Dawley rat followed by a 14-day observation period, according to OECD 423, in GLP.

A first group of 3 female animals was initially dosed at 2000 mg/kg (Step 1).

A second group of 3 female animals was then dosed at the same dose level (Step 2).

Observations

No mortality occurred. The only finding observed was yellow staining on tail in all animals on Day 2 of the study.

No death occurred and no clinical signs were noted.

Body weight changes recorded during the study were within the expected range for this strain and age of animals. No abnormalities were observed at necropsy examination performed at the end of the observation period on animals of both groups, with the exception of animal no. 19 (Group 4), that showed red staining on the dorsum.

Conclusion

These results indicate that the test item did not induce toxic effects in the rat following oral administration of a single dose at a level of 2000 mg/kg. The lack of mortality demonstrates the acute toxicity expected (ATE) to be greater than 2000 mg/kg body weight.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 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

The acute toxicity of the substance was investigated following a single oral administration to the Sprague Dawley rat followed by a 14-day observation period, according to OECD 423, in GLP..

Results indicate that the test item did not induce toxic effects in the rat following oral administration of a single dose at a level of 2000 mg/kg. The lack of mortality demonstrates the acute toxicity expected (ATE) to be greater than 2000 mg/kg body weight.

Justification for classification or non-classification

Acute oral toxicity

According to the CLP Regulation 1272/2008/EC, 3.1.2.1 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 shown in Table 3.1.1:

Oral (mg/kg body weight)

Category 1: LD50 ≤ 5

Category 2: 5 <LD50 ≤ 50

Category 3: 50 < LD50 ≤ 300

Category 4: 300 < LD50 ≤ 2 000

The oral LD50 values are > 2000 mg/kg/body weight.

The substance is not classified for oral toxicity because it doesn't meet the classification criteria of the CLP regulation n.1272/2008.