4-[[2-methoxy-4-[(4-nitrophenyl)azo]phenyl]azo]phenol

Endpoint summary

Description of key information

A study was conducted to determine the acute oral toxicity of the test substance to rats. Female SPF Wistar rats were administered a single dose of the test substance as a liquid dispersion (20% purity) via gavage. Rats were not fed from 16 h pre-test to 2 h post-application. There were 10 rats per group, exposed to nominal concentrations of 1250, 2500, 4000, 6300 and 10000 mg/kg bw (equivalent to 250, 500, 800, 1260 and 2000 mg a.i./L). The animals were then observed during 14 days for mortality and clinical signs. Bodyweights were recorded weekly. Moribund rats were dissected and evaluated macroscopically. The same procedure was carried out for all remaining rats at the end of the study. Directly after gavage, a yellow discoloration of the urine was observed. Moribund animals showed irregular breathing and disturbance of their balance. At test end, no macroscopic lesions were found except for a rusty brown discoloration in the stomach and intestine. Bodyweight data results were not discussed. Under the study conditions, the LC50 was determined to be 4529 mg/kg bw, equivalent to 905 mg a.i./kg bw (Hollander, 1986).

In another study, female (Hoe WISKf (SPF71)) rats were administered a single dose of the test substance as a liquid dispersion (48% purity) via gavage. Rats were not fed from 16 h pre-test to 2 h post-application. There were 10 rats per group, exposed to nominal concentrations of 1000, 2000, 2800, 4000, 5000 and 6300 mg/kg bw (equivalent to 480, 960, 1344, 1920, 2400 and 3024 mg a.i./L). The animals were then observed during 14 days for mortality and clinical signs. Bodyweights were recorded weekly. Moribund rats were dissected and evaluated macroscopically. The same procedure was carried out for all remaining rats at the end of the study. Moribund animals showed passivity, hyporeflexia, narrowed eyelids, spasmodic and noisy breathing, swelling of the head ('lion head') and brown discoloured urine and stools. Macroscopic evaluation revealed gastrointestinal tract diffuse red and full with test substance, discolored adrenal gland and yellow colored abdomen and fat tissues. There were no further clinical signs at doses up to 4000 mg/kg bw after 72 h and at 5000 mg/kg bw after 8 days. No macroscopic findings were recorded in surviving animals at test end. Under the study conditions, the LC50 was determined to be 3050 mg/kg bw, equivalent to 1525 mg a.i./kg bw (Mayer, 1982).

The acute toxicity of Disperse Orange 29 following dermal administration of a single dose to the rat was investigated according to OECD test guideline 402. For that purpose, a single dose of 2000 mg/kg body weight was administered to a group of 5 male and 5 female animals for 24 hours. After 14 days of observation, all animals were killed and subjected to necropsy examination.

No mortality occurred and no signs of toxicity were observed in male or female animals during the observation period. The body weight changes observed during the study were within the expected range for this species and age of animals.

No abnormalities either general or at the treated site were found at necropsy in the animals at termination of the study. These results indicate that the test item, Disperse Orange 29, has no toxic effect on the rat following dermal exposure over a 24 hour period at a level of 2000mg/kg body weight. The lack of mortality demonstrates the LD50 to be greater than 2000 mg/kg body weight.

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Reference 1

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From March 25, 1976 to April 22, 1976

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Principles of method if other than guideline:

Female SPF Wistar rats were administered a single dose of the test substance as a liquid dispersion (20% purity) via gavage. Rats were not fed from 16 h pre-test to 2 h post-application. There were 10 rats per group, exposed to nominal concentrations of 1250, 2500, 4000, 6300 and 10000 mg/kg bw (equivalent to 250, 500, 800, 1260 and 2000 mg a.i./L). The animals were then observed during 14 days for mortality and clinical signs. Bodyweights were recorded weekly. Moribund rats were dissected and evaluated macroscopically. The same procedure was carried out for all remaining rats at the end of the study.

GLP compliance:

no

Test type:

standard acute method

Limit test:

no

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

Body weight: 80 - 115g

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Doses:

1250, 2500, 4000, 6300, 10000 mg/kg (concentration (%): 25)

No. of animals per sex per dose:

10

Control animals:

no

Details on study design:

Post - observation: 14 days

Statistics:

Probit analysis

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

4 529 mg/kg bw

Based on:

test mat.

95% CL:

ca. 3 511 - ca. 5 843

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

905 mg/kg bw

Based on:

act. ingr.

Remarks:

20% test substance purity

95% CL:

ca. 702 - ca. 1 169

Mortality:

Doses (mg/kg bw):
- 1250: 0/10
- 2500: 2/10
- 4000: 5/10
- 6300: 5/10
- 10000: 10/10

Clinical signs:

other: Directly after gavage, a yellow discoloration of the urine was observed. Moribund animals showed irregular breathing and disturbance of their balance.

Gross pathology:

No macroscopic lesions were found except for a rusty brown discoloration in the stomach and intestine.

Executive summary:

A study was conducted to determine the acute oral toxicity of the test substance to rats. Female SPF Wistar rats were administered a single dose of the test substance as a liquid dispersion (20% purity) via gavage. Rats were not fed from 16 h pre-test to 2 h post-application. There were 10 rats per group, exposed to nominal concentrations of 1250, 2500, 4000, 6300 and 10000 mg/kg bw (equivalent to 250, 500, 800, 1260 and 2000 mg a.i./L). The animals were then observed during 14 days for mortality and clinical signs. Bodyweights were recorded weekly. Moribund rats were dissected and evaluated macroscopically. The same procedure was carried out for all remaining rats at the end of the study. Directly after gavage, a yellow discoloration of the urine was observed. Moribund animals showed irregular breathing and disturbance of their balance. At test end, no macroscopic lesions were found except for a rusty brown discoloration in the stomach and intestine. Bodyweight data results were not discussed. Under the study conditions, the LC50 was determined to be 4529 mg/kg bw, equivalent to 905 mg a.i./kg bw (Hollander, 1986).

Reference 2

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From September 16, 1982 to December 02, 1982

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Principles of method if other than guideline:

Female Wistar rats (Hoe WISKf (SPF71)) were administered a single dose of the test substance as a liquid dispersion (48% purity) via gavage. Rats were not fed from 16 h pre-test to 2 h post-application. There were 10 rats per group, exposed to nominal concentrations of 1000, 2000, 2800, 4000, 5000 and 6300 mg/kg bw (equivalent to 480, 960, 1344, 1920, 2400 and 3024 mg a.i./L). The animals were then observed during 14 days for mortality and clinical signs. Bodyweights were recorded weekly. Moribund rats were dissected and evaluated macroscopically. The same procedure was carried out for all remaining rats at the end of the study.

GLP compliance:

no

Test type:

standard acute method

Limit test:

no

Species:

rat

Strain:

other: Hoe WISKf (SPF71)

Sex:

female

Details on test animals or test system and environmental conditions:

Body weight: 172 - 210 g

Route of administration:

oral: gavage

Vehicle:

water

Doses:

Nominal: 1000, 2000, 2800, 4000, 5000 and 6300 mg/kg bw, equivalent to 480, 960, 1344, 1920, 2400 and 3024 mg a.i./L (48% purity)

No. of animals per sex per dose:

10

Control animals:

no

Details on study design:

Post-observation period: 14 days

Statistics:

Probit analysis

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

3 050 mg/kg bw

Based on:

test mat.

95% CL:

ca. 2 330 - ca. 3 830

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

1 525 mg/kg bw

Based on:

act. ingr.

Remarks:

48% test substance purity

95% CL:

ca. 1 118 - ca. 1 838

Mortality:

Doses (mg/kg bw):
- 1000: 0/10
- 2000 and 2800: 3/10
- 4000: 9/10
- 5000 and 6300: 9/10
Animals died during the first 4 days post - application

Clinical signs:

other: Passivity, hyporeflexia, narrowed eyelids, spasmodic and noisy breathing, swelling of the head ('lion head') and brown discoloured urine and stools.

Gross pathology:

Moribund animals: gastrointestinal tract diffuse red and full with test substance, discolored adrenal gland and yellow colored abdomen and fat tissues.
At test end: no notable macroscopic observations.

Conclusions:

Under the study conditions, the LD50 of the test substance in rats was determined to be 3050 mg/kg bw, corresponding to 1525 mg/a.i./kg bw based on a purity of 48%.

Executive summary:

A study was conducted to determine the acute oral toxicity of the test substance to rats. Female (Hoe WISKf (SPF71)) rats were administered a single dose of the test substance as a liquid dispersion (48% purity) via gavage. Rats were not fed from 16 h pre-test to 2 h post-application. There were 10 rats per group, exposed to nominal concentrations of 1000, 2000, 2800, 4000, 5000 and 6300 mg/kg bw (equivalent to 480, 960, 1344, 1920, 2400 and 3024 mg a.i./L). The animals were then observed during 14 days for mortality and clinical signs. Bodyweights were recorded weekly. Moribund rats were dissected and evaluated macroscopically. The same procedure was carried out for all remaining rats at the end of the study. Moribund animals showed passivity, hyporeflexia, narrowed eyelids, spasmodic and noisy breathing, swelling of the head ('lion head') and brown discoloured urine and stools. Macroscopic evaluation revealed gastrointestinal tract diffuse red and full with test substance, discolored adrenal gland and yellow colored abdomen and fat tissues. There were no further clinical signs at doses up to 4000 mg/kg bw after 72 h and at 5000 mg/kg bw after 8 days. No macroscopic findings were recorded in surviving animals at test end. Under the study conditions, the LC50 was determined to be 3050 mg/kg bw, equivalent to 1525 mg a.i./kg bw (Mayer, 1982).

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

905 mg/kg bw

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Link to relevant study records

Reference

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Start of experimental phase: 23 March 2017 End of experimental phase: 07 April 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Version / remarks:

adopted on 24 February 1987

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.3 (Acute Toxicity (Dermal))

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1200 (Acute Dermal Toxicity)

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: EPA, OPPTS Methods 870.1000 “Acute Toxicity Testing - Background”

Deviations:

no

GLP compliance:

yes

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
Species and strain: Rat, Hsd: Sprague Dawley SD
Sex: Males and females (nulliparous and non-pregnant)
Age: 6 to 8 weeks old
Weight at order: 176 to 200 grams
Supplier: Envigo RMS s.r.l., San Pietro al Natisone (UD), Italy
Breeder: Envigo RMS B.V., Kreuzelweg 53, 5961 NM Horst, Netherlands
Date of arrival: 15March 2017
Weight range at arrival: 188 to 193 grams for males; 189 to 197 grams for females
Acclimatisation period: At least 5 days
Veterinary health check: During acclimatisation period

ENVIRONMENTAL CONDITIONS
Animals per cage: Up to 5 of one sex during acclimatisation; individually caged
during the study
Housing: Clear polysulphone H-Temp solid bottomed cages (Tecniplast Gazzada S.a.r.l., Buguggiate, VA, Italy) measuring 59.5×38×20 cm during acclimatisation period and 42.5×26.6×18.5 cm
during the study 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
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%

Type of coverage:

semiocclusive

Vehicle:

water

Remarks:

pasted with 1.5 mL water

Details on dermal exposure:

TEST SITE
- Area of exposure: Dorsal surface of the trunk
- % coverage: Approximately 10% of body surface
- Type of wrap if used: Adhesive bandage and gauze patch

REMOVAL OF TEST SUBSTANCE
- Washing (if done): Yes, with cotton wool soaked with lukewarm water
- Time after start of exposure: 24 hours

Duration of exposure:

The animals remained in contact with the test item for 24 hours

Doses:

2000 mg/kg body weight

No. of animals per sex per dose:

5 males and 5 females at 2000 mg/kg body weight

Control animals:

not required

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Animals were observed for clinical signs the day of dosing: on dosing, approximately 1 hour after dosing, 2 hours after dosing and 4 hours after dosing, aaily thereafter. All animals were weighed at allocation to the study (Day -1), on the day of dosing (Day 1) and on Days 8 and 15.
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight.

Statistics:

NA

Key result

Sex:

male/female

Dose descriptor:

LD0

Effect level:

>= 2 000 mg/kg bw

Based on:

test mat. (total fraction)

Remarks on result:

no indication of skin irritation up to the relevant limit dose level

Mortality:

No mortality occurred.

Clinical signs:

other: Only black staining at the treated site, due to the colour of the test substance, was observed in all male and female animals from Day 2 up to Day 7. This discolouration recovered from Day 8 up to Day 14 of the observation period.

Gross pathology:

No abnormalities were found at necropsy examination performed on all animals at termination of the study.

Interpretation of results:

GHS criteria not met

Conclusions:

The acute toxicity of Disperse Orange 29 was investigated following dermal administration of a single dose to the rat at 2000mg/kg body weight.
No mortality occurred following dosing and no signs of toxicity were observed during the 14-day observation period.
These results indicate that the test item, Disperse Orange 29, has no toxic effect on the rat following dermal exposure over a 24 hour period at a level of 2000 mg/kg body weight. The lack of mortality demonstrates the LD50 to be greater than 2000mg/kg body weight.
European Directives concerning the classification, packaging and labelling of dangerous substances (Council Regulation (EC) No. 1272/2008 and subsequent revisions) would suggest the following:
Classification No category
Signal word No signal word required
Hazard statement No hazard statement required

Executive summary:

The acute toxicity of Disperse Orange 29 following dermal administration of a single dose to the rat was investigated according to OECD test guideline 402. For that purpose, a single dose of 2000 mg/kg body weight was administered to a group of 5 male and 5 female animals for 24 hours. After 14 days of observation, all animals were killed and subjected to necropsy examination.

No mortality occurred and no signs of toxicity were observed in male or female animals during the observation period. The body weight changes observed during the study were within the expected range for this species and age of animals.

No abnormalities either general or at the treated site were found at necropsy in the animals at termination of the study. These results indicate that the test item, Disperse Orange 29, has no toxic effect on the rat following dermal exposure over a 24 hour period at a level of 2000mg/kg body weight. The lack of mortality demonstrates the LD50 to be greater than 2000 mg/kg body weight.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Justification for classification or non-classification

Based on the results of acute oral toxicity studies in rat, the test substance warrants classification as Acute Tox 4 – H302 : Harmful if swallowed according to CLP (EC 1272/2008) criteria.