1-phenylazo-2-naphthol

Toxicity to reproduction

Administrative data

Endpoint:

reproductive toxicity, other

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Justification for type of information:

Data is from peer-reviewed publication.

Data source

Reference

Reference Type:

publication

Title:

CHRONIC TOXICITY STUDIES ON FOOD COLOURS. PART II. OBSERVATIONS ON THE TOXICITY OF FD & C GREEN NO. 2 (LIGHT GREEN SF YELLOWISH), FD & C ORANGE NO. 2 (ORANGE SS) AND FD & C RED NO. 32 (OIL RED XO) IN RATS.

Author:

M. G. ALLMARK, H. C. GRICE AND W. A. MANNELL

Year:

1956

Bibliographic source:

J. Pharma. Pharmacology; Vol. 8, Pg. no. 417-424, 1956

Materials and methods

Test guideline

Qualifier:

no guideline available

Principles of method if other than guideline:

The reproductive toxicity study was conducted to evaluate the toxic effects of administration of 1-(2,4-dimethylphenylazo)-2-naphthol (Sudan II) in rats for 20 weeks.

GLP compliance:

not specified

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

1-(2,4-dimethylphenylazo)-2-naphthol

EC Number:

221-490-4

EC Name:

1-(2,4-dimethylphenylazo)-2-naphthol

Cas Number:

3118-97-6

Molecular formula:

C18H16N2O

IUPAC Name:

1-[(2,4-dimethylphenyl)diazenyl]-2-naphthol

Test material form:

solid: crystalline

Details on test material:

- Name of test material (as cited in study report):FD&C Red No. 32.
- Molecular formula: C18H16N2O
- Molecular weight : 276.337 g/mol
- Substance type: Organic
- Physical state: Solid
- Smiles : Cc1ccc(N=Nc2c(O)ccc3ccccc23)c(C)c1
- InChI: 1S/C18H16N2O/c1-12-7-9-16(13(2)11-12)19-20-18-15-6-4-3-5-14(15)8-10-17(18)21/h3-11,21H,1-2H3/b20-19+

Specific details on test material used for the study:

- Name of test material (as cited in study report): 1-(2,4-dimethylphenylazo)-2-naphthol (C.I. Solvent orange 7/Sudan II)
- Molecular formula: C18H16N2O
- Molecular weight: 276.337 g/mol
- Substance type: Organic
- Physical state: Solid

Test animals

Species:

rat

Strain:

not specified

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: No data available
- Age at study initiation: 5 to 6 weeks
- Weight at study initiation: No data available
- Fasting period before study: No data available
- Housing: Rats were kept in groups of two in a cage.
- Use of restrainers for preventing ingestion (if dermal): No data available
- Diet (e.g. ad libitum): Diet ad libitum
- Water (e.g. ad libitum): Water ad libitum
- Acclimation period: No data available

ENVIRONMENTAL CONDITIONS
- Temperature (°C): No data available
- Humidity (%):No data available
- Air changes (per hr): No data available
- Photoperiod (hrs dark / hrs light): No data available

IN-LIFE DATES: No data available

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

not specified

Details on exposure:

Not specified.

Details on mating procedure:

Not specified.

Analytical verification of doses or concentrations:

not specified

Details on analytical verification of doses or concentrations:

Not specified.

Duration of treatment / exposure:

20 weeks (More than 4 months)

Frequency of treatment:

Daily

Details on study schedule:

Not specified.

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

0 mg/kg bw/day (nominal)

Doses / concentrations 2

Dose / conc.:

200 mg/kg bw/day (nominal)

Doses / concentrations 3

Dose / conc.:

400 mg/kg bw/day (nominal)

No. of animals per sex per dose:

10 animals/sex/dose in treated group
10 control animals were used for study.

Control animals:

yes, concurrent vehicle

Details on study design:

Not specified.

Positive control:

Not specified.

Examinations

Parental animals: Observations and examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: No data available
- Cage side observations checked in table [No.?] were included: No data available


DETAILED CLINICAL OBSERVATIONS: No data available
- Time schedule: No data available

BODY WEIGHT: Yes
- Time schedule for examinations: Body weight of the test animal was recorded weekly.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Yes, food consumption of the test animal was recorded weekly.
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: No data available


WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No data available
- Time schedule for examinations: No data available


OTHER:
Food efficiency of the test animal was also recorded weekly. For more accurate evaluation of food consumption it would have been preferable to place only one rat in a cage, but this was not possible.

Haematology determinations were made for 20 weeks on groups of male and female rats.
A slight modification of the pyridine-haemochromogen method of Rimington was used and the mean values of the final determinations were made. Blood haemoglobin parameter was examined.

Organs of surviving rats were weighed at the termination of the test. The mean weight in mg/g of body weight was calculated.

Mortality was observed.

Oestrous cyclicity (parental animals):

Not specified

Sperm parameters (parental animals):

Sperm parameters (parent animal)
Parameters examined in [all/P] male parental generations: A detailed examination was made of the haematoxylin-eosin stained paraffinsections of testes.

Litter observations:

Not specified

Postmortem examinations (parental animals):

SACRIFICE
- Male animals: All surviving animals [describe when, e.g. as soon as possible after the last litters in each generation were produced.]: No data available
- Maternal animals: All surviving animals [describe when, e.g. after the last litter of each generation was weaned.]: No data available
- Other: Post-mortem examinations were made where possible on rats which died on test. All surviving rats were killed at the end of the experiments and post-mortem examinations were made.

GROSS NECROPSY
- Gross necropsy consisted of [external and internal examinations including the cervical, thoracic, and abdominal viscera.]: No data available

HISTOPATHOLOGY / ORGAN WEIGHTS
The tissues indicated in Table [#] were prepared for microscopic examination and weighed, respectively: Yes, many of the organs were weighed and prepared for histological examination.
A detailed examination was made of the haematoxylin-eosin stained paraffin sections of a number of organs including lung, heart, liver, spleen, thyroid, pancreas, stomach, small intestine, kidney, urinary bladder, adrenal, testes, ovaries and thymus.

Postmortem examinations (offspring):

Not applicable

Statistics:

Standard deviation was observed.

Reproductive indices:

Not specified

Offspring viability indices:

Not specified

Results and discussion

Results: P0 (first parental generation)

General toxicity (P0)

Clinical signs:

not specified

Dermal irritation (if dermal study):

not specified

Mortality:

mortality observed, treatment-related

Description (incidence):

By the end of 20 weeks, 6 male rats receiving a dose of 200 mg/kg bw/day had died whereas all 10 female rats has survived for 20 weeks.

However, 5 male and 3 female rats receiving a dose of 400 mg/kg bw/day had died by the end of the experiment.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

In a number of cases the body weights of the test animals were less than the controls. In other cases the body weights of test and control animals were about the same.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Food consumption was affected by the test substance at the dose level of 400 mg/kg bw/day.

Food efficiency:

effects observed, treatment-related

Description (incidence and severity):

Food efficiencey was affected by the test substance at the dose level of 400 mg/kg bw/day.

Water consumption and compound intake (if drinking water study):

not specified

Ophthalmological findings:

not specified

Haematological findings:

effects observed, treatment-related

Description (incidence and severity):

A significant decline in blood haemoglobin values was found in all groups of both sexes at the dose level of both 200 and 400 mg/kg bw/day. This same result was also evident from an examination of the data obtained on each sex.

Clinical biochemistry findings:

not specified

Urinalysis findings:

not specified

Behaviour (functional findings):

not specified

Immunological findings:

not specified

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

No consistent histopathological changes were observed in the tissues or organs of the female test animal at dose level of 200 and 400 mg/kgbw/day.

Histopathological findings: neoplastic:

not specified

Other effects:

not specified

Reproductive function / performance (P0)

Reproductive function: oestrous cycle:

not specified

Reproductive function: sperm measures:

effects observed, treatment-related

Description (incidence and severity):

Altered spermatogenesis are observed in male test group receiving the dose 400 mg/kgbw/day compare to control.

Reproductive performance:

not specified

Effect levels (P0)

Key result

Dose descriptor:

NOAEL

Effect level:

200 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male

Basis for effect level:

histopathology: non-neoplastic

reproductive function (sperm measures)

other: No significant effect were observed in histopathology and reproductive fuction

Target system / organ toxicity (P0)

Critical effects observed:

no

Results: F1 generation

General toxicity (F1)

Clinical signs:

not specified

Dermal irritation (if dermal study):

not specified

Mortality / viability:

not specified

Body weight and weight changes:

not specified

Food consumption and compound intake (if feeding study):

not specified

Food efficiency:

not specified

Water consumption and compound intake (if drinking water study):

not specified

Ophthalmological findings:

not specified

Haematological findings:

not specified

Clinical biochemistry findings:

not specified

Urinalysis findings:

not specified

Sexual maturation:

not specified

Organ weight findings including organ / body weight ratios:

not specified

Gross pathological findings:

not specified

Histopathological findings:

not specified

Other effects:

not specified

Developmental neurotoxicity (F1)

Behaviour (functional findings):

not specified

Developmental immunotoxicity (F1)

Developmental immunotoxicity:

not specified

Effect levels (F1)

Remarks on result:

not measured/tested

Target system / organ toxicity (F1)

Critical effects observed:

not specified

Overall reproductive toxicity

Reproductive effects observed:

no

Any other information on results incl. tables

Observation on male rat

Product dosage			NO. of rats surviving/ NO. of rats on test		Sex	Mean body weight final		Mean hg	Mean organ weight mg/g	Histopathology
									Testicles	Altered spermatogenesis
0 mg/kgbw/day			4/10		M	251.0±11.0		17.3±0.40	9.7±0.38	0
200 mg/kgbw/day			4/10		M	155.0±18.9*		14.1±0.81*	9.6±1.32	0
400mg/kgbw/day			5/10		M	160±14.0*		12.8±1.50*	9.6±1.65	3

Applicant's summary and conclusion

Conclusions:

When the test animal is exposed orally to the test substance 1-(2,4-dimethylphenylazo)-2-naphthol (Sudan II), no adverse effects were observed at a dose level of 200 mg/kg bw/day.

Executive summary:

The reproductive toxicity study was conducted to evaluate the toxic effects of administration of 1-(2,4-dimethylphenylazo)-2-naphthol (Sudan II) in rats for 20 weeks.

The rats are exposed orally (gavage) to the test substance 1-(2,4-dimethylphenylazo)-2-naphthol (Sudan II) for 20 weeks at a dose conc. of 200 and 400 mg/kg bw/day, no adverse effects were observed at a dose level of 200 mg/kg bw/day.  

Testicular changes are observed in animals receiving the higher concentrations i.e; 400 mg/kg bw/day. 

A significant decline in blood haemoglobin values was found in all groups of both sexes at the dose level of both 200 and 400 mg/kg bw/day. 

Food consumption and food efficiency was affected by the test substance at the dose level of 400 mg/kg bw/day. In a number of cases the organ weights were about the same as the controls but the body weights of the test animals were less than the controls, suggesting the possible utilization of muscle protein. In other cases the body weights of test and control animals were about the same but the organ weights differed significantly. 

By the end of 20 weeks, 6 male rats receiving a dose of 200 mg/kg bw/day had died whereas all 10 female rats has survived for 20 weeks. However, 5 male and 3 female rats receiving a dose of 400 mg/kg bw/day had died by the end of the experiment. 

A detailed examination was made of the haematoxylin-eosin stained paraffin sections of a number of organs including lung, heart, liver, spleen, thyroid, pancreas, stomach, small intestine, kidney, urinary bladder, adrenal, testes, ovaries and thymus. Heart, liver, spleen, kidneys and testes were the organs chiefly affected.No consistent histopathological changes were observed in the tissues or organs of the test animal. Testicular changes are observed in animals receiving the higher concentrations. Therefore, no adverse effects level of 1-(2,4-dimethylphenylazo)-2-naphthol (Sudan II) in rats were observed at a dose level of 200 mg/kg bw/day. Thus, 1-(2,4-dimethylphenylazo)-2-naphthol (Sudan II) is not considered to be a reprotoxic for male and female rats at a dose level of 200 mg/kg bw/day. Hence it is not likely to be classiffied as reprotox.