1-[(2-chloro-4-nitrophenyl)azo]-2-naphthol

Toxicity to reproduction

Administrative data

Endpoint:

two-generation reproductive toxicity

Remarks:

based on test type (migrated information)

Type of information:

migrated information: read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Study period:

2013

Reliability:

1 (reliable without restriction)

Cross-reference

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Report date:

2013

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 421 (Reproduction / Developmental Toxicity Screening Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

1-(4-methyl-2-nitrophenylazo)-2-naphthol

EC Number:

219-372-2

EC Name:

1-(4-methyl-2-nitrophenylazo)-2-naphthol

Cas Number:

2425-85-6

Molecular formula:

C17H13N3O3

IUPAC Name:

1-[(4-methyl-2-nitrophenyl)diazenyl]-2-naphthol

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

Purity: 98.9%

Test animals

Species:

rat

Strain:

other: RccHan: WIST(SPF)

Sex:

male/female

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

polyethylene glycol

Frequency of treatment:

The purpose of this study was to generate preliminary information concerning the possible effects of repeated exposure of C.I. PIGMENT RED 3 over a limited period of time on male and female reproductive performance such as gonadal function, mating behavior, conception, development of the conceptus and parturition.
Four groups of 12 males and 12 females were treated by gavage with C.I. PIGMENT RED 3 once daily. Males were treated over a 14-day pre-pairing period and during the pairing period up to one day before necropsy. Females were treated throughout the pre-pairing, pairing, gestation and lactation period up to the day 3 post partum.

The following dose levels were used:
Group 1: 0 mg/kg body weight/day (control group)
Group 2 100 mg/kg body weight/day
Group 3: 300 mg/kg body weight/day
Group 4 1000 mg/kg body weight/day

A dose volume of 5 mL/kg body weight with a daily adjustment to the actual body weight was used. Control animals were dosed with the vehicle alone (polyethylene glycol 300).

Doses / concentrations

Doses / concentrations 1

Remarks:

Doses / Concentrations:
1000 mg/kgbw/d
Basis:
nominal conc.

Doses / concentrations 2

Remarks:

Doses / Concentrations:
100 mg/kgbw/d
Basis:
nominal conc.

Doses / concentrations 3

Remarks:

Doses / Concentrations:
300 mg/kgbw/d
Basis:

No. of animals per sex per dose:

12

Control animals:

yes, concurrent vehicle

Results and discussion

Results: P0 (first parental generation)

Effect levels (P0)

Dose descriptor:

NOAEL

Effect level:

> 1 000 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Remarks on result:

not determinable

Remarks:

no NOAEL identified Generation not specified (migrated information)

Overall reproductive toxicity

Reproductive effects observed:

not specified

Any other information on results incl. tables

The following results were obtained:

1.1 Parent Animals

Mortality and General Tolerability

Five males died during the course of the study. The cause of death was in four animals related to aspiration of the test item. For one animal that cause of death could not be established because no necropsy was performed, but likely was similar in nature.

All other animals survived until the scheduled necropsy.

Food Consumption

The mean daily food consumption of all test item-treated males compared well with this of the control males during the pre-pairing period.

There were no statistically significant differences between the mean food consumption values of test item-treated females compared with the controls during pre-pairing, gestation and lactation.

Body Weights

There were no test item-related effects upon body weights of either males or females.

 

Reproduction and Breeding Data

No effects on mating performance, fertility, corpora lutea count or duration of gestation were observed at any dose level.

Organ Weights

No test item-related effects on organ weights of males were noted at any dose level.

Macroscopic Findings and Histopathological Examinations

No test item-related macroscopic findings were noted at any dose level.

There were no gross lesions recorded at necropsy that could be attributed to treatment. However, there were findings related to aspiration of the test item into the lungs. All other lesions recorded were within the expected range of gross lesions that may be recorded in animals at this age.

In the reproductive organs, all findings recorded were within the range of normal background lesions which may be recorded in animals of this strain and age. There were only single cases with isolated tubules that showed minor changes. They consisted of single sperm resorptions in stage VIII, IX or X tubules, some cases of single sperm retentions in a Stage IX tubule, and in one case, a single tubule was completely degenerated.

No histological evidence of a direct toxicological property in the reproductive organs and tissues examined was detected. Therefore the No Observed Adverse Effect Level (NOAEL) for reproductive toxicity was considered to be at 1000 mg/kg/day.

1.2 Litter Data - F1 Pups

Findings at First Litter Check and during Lactation

No test item-related findings were noted in pups at any dose level.

The sex ratio of the test item-treated pups did not indicate any effects of toxicological relevance.

Pup Weights to Day 4 Post Partum

No test item-related effects on pup body weights were noted at any dose level.

Macroscopic Findings

No test item-related findings were found in pups at any dose level.

The test item caused no indication of toxicity in the testes. The stages were complete in all animals. There was no indicator for induced maturation arrest, increased resorption, necrosis or any other injury. Furthermore, there was no lesion in interstitial cells.

There were no lesions recorded in the ovaries.

Applicant's summary and conclusion

Conclusions:

Because fecal discoloration (i.e. a secondary passive finding) was noted in treated rats at all dose levels, a NOEL (No Observed Effect Level) could not be established.
Based on the data generated from this reproduction / developmental toxicity screening test, the no observed adverse effect level (NOAEL) is established at 1000 mg/kg body weight for general toxicity and reproduction in parental animals and for developmental toxicity in the pups.

Executive summary:

The purpose of this study was to generate preliminary information concerning the possible effects of repeated exposure of C.I. PIGMENT RED 3 over a limited period of time on male and female reproductive performance such as gonadal function, mating behavior, conception, development of the conceptus and parturition.

 

Four groups of 12 males and 12 females were treated by gavage with C.I. PIGMENT RED 3 once daily. Males were treated over a 14-day pre-pairing period and during the pairing period up to one day before necropsy. Females were treated throughout the pre-pairing, pairing, gestation and lactation period up to the day 3 post partum.

 

The following dose levels were used:

 

Group 1: 0 mg/kg body weight/day (control group)

Group 2 100 mg/kg body weight/day

Group 3: 300 mg/kg body weight/day

Group 4 1000 mg/kg body weight/day

 

A dose volume of 5 mL/kg body weight with a daily adjustment to the actual body weight was used. Control animals were dosed with the vehicle alone (polyethylene glycol 300).

 

The following results were obtained:

 

1.1 Parent Animals

Mortality and General Tolerability

Five males died during the course of the study. The cause of death was in four animals related to aspiration of the test item. For one animal that cause of death could not be established because no necropsy was performed, but likely was similar in nature.

 

All other animals survived until the scheduled necropsy.

 

Clinical Signs or Observations

No test item related clinical signs beside reddish discolored feces were noted.

Food Consumption

The mean daily food consumption of all test item-treated males compared well with that of the control males during the pre-pairing period.

There were no statistically significant differences between the mean food consumption values of test item-treated females compared with the controls during pre-pairing, gestation and lactation.

 

Body Weights

There were no test item-related effects upon body weights of either males or females.

Reproduction and Breeding Data

No effects on mating performance, fertility, corpora lutea count or duration of gestation were observed at any dose level.

Organ Weights

No test item-related effects on organ weights of males were noted at any dose level.

Macroscopic Findings and Histopathological Examinations

No test item-related macroscopic findings were noted at any dose level.

There were no gross lesions recorded at necropsy that could be attributed to treatment. However, there were findings related to aspiration of the test item into the lungs. All other lesions recorded were within the expected range of gross lesions that may be recorded in animals at this age.

In the reproductive organs, all findings recorded were within the range of normal background lesions which may be recorded in animals of this strain and age. There were only single cases with isolated tubules that showed minor changes. They consisted of single sperm resorptions in stage VIII, IX or X tubules, some cases of single sperm retentions in a stage IX tubule, and in one case, a single tubule was completely degenerated.

The test item caused no indication of toxicity in the testes. The stages were complete in all animals. There was no indicator for induced maturation arrest, increased resorption, necrosis or any other injury. Furthermore, there was no lesion in interstitial cells.

There were no lesions recorded in the ovaries.

No macroscopic or histological evidence of a direct toxicological property in the organs and tissues examined was detected. Therefore the No Observed Adverse Effect Level (NOAEL) for general toxicity and for reproductive toxicity was considered to be 1000 mg/kg/day.

 

1.2 Litter Data - F1 Pups

Findings at First Litter Check and during Lactation

No test item-related findings were noted in pups at any dose level.

The sex ratio of the test item-treated pups did not indicate any effects of toxicological relevance.

Pup Weights to Day 4 Post Partum

No test item-related effects on pup body weights were noted at any dose level.

Macroscopic Findings

No test item-related findings were noted in pups at any dose level.

 

1.3 Conclusion

Because fecal discoloration (i.e. a secondary passive finding) was noted in treated rats at all dose levels, a NOEL (No Observed Effect Level) could not be established.

Based on the data generated from this reproduction / developmental toxicity screening test, the no observed adverse effect level (NOAEL) is established at 1000 mg/kg body weight for general toxicity and reproduction in parental animals and for developmental toxicity in the pups.