1-[(2-methoxyphenyl)azo]-2-naphthol

Endpoint summary

Description of key information

Acute oral toxicity:

LD50 was considered to be > 5000 mg/kg bw when Fischer 344 male and female rats were treated Solvent Red 1 (1-[(2-methoxyphenyl)diazenyl]-2-naphthol) orally.

Acute dermal toxicity:

LD50 was considered to be > 2000 mg/kg bw when New Zealand White male and female rabbits were treated with Solvent Red 1 (1-[(2-methoxyphenyl)diazenyl]-2-naphthol) by dermal application for 24 hours.

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

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 journal

Qualifier:

according to guideline

Guideline:

other: as mentioned below

Principles of method if other than guideline:

Acute oral toxicity study of Solvent Red 1 in rat.

GLP compliance:

no

Test type:

fixed dose procedure

Limit test:

yes

Specific details on test material used for the study:

- Name of test material (as cited in study report): Solvent Red 1
- Molecular formula (if other than submission substance): C17H14N2O2
- Molecular weight (if other than submission substance): 278.31 g/mole
- Substance type: Organic
- Physical state: Solid

Species:

rat

Strain:

Fischer 344

Sex:

male/female

Details on test animals or test system and environmental conditions:

Details on test animal
TEST ANIMALS
- Source: Charies river breeding laboratories, IC (postage NY, facility)
- Age at study initiation: No data available
- Weight at study initiation: 208-221 g male, 174-183 g female.
- Fasting period before study: Yes, fasted overnight.
- Housing: Animals were housed in the appropriate randomly selected cage. Each animal was then assigned a sequential animal number unique within American Biogenics Corporation (ABC) and identified with an ear tag bearing this animal number, The sequential animal number was listed on a cage card that was affixed to the front of the animal's cage. Rooms were cleaned daily and the cages were cleaned and sanitized as specified in ABC SOP's. Urine and feces fell through the wire mesh floor onto animal caging board. The cage boards were changed at least 2 to 3 times per week.
- Diet (e.g. ad libitum): Purina Certified Rodent Chow 5002, ad libitum, except for fasting prior to dosing.
- Water (e.g. ad libitum): Filtered tap water was provided through an automatic watering system and was analyzed periodically, ad libitum.
- Acclimation period: 7 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 7 °C
- Humidity (%): 30-70 %
- Air changes (per hr): No data available
- Photoperiod (hrs dark / hrs light): 6:00 a.m. to 6:00 p.m. (12 hour light/dark, cycle)

IN-LIFE DATES:
From: October 30, 1985
To: November 13, 1985

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on oral exposure:

Details on exposure
VEHICLE
- Concentration in vehicle: 5000 mg/kg bw
- Amount of vehicle (if gavage): 28 mllkg
- Justification for choice of vehicle: com oil
- Lot/batch no. (if required): No data available
- Purity: No data available

MAXIMUM DOSE VOLUME APPLIED: No data available

DOSAGE PREPARATION (if unusual): Solvent Red 1 was suspended in 18 % weight/volume corn oil in two doses and then administered.

CLASS METHOD (if applicable)
- Rationale for the selection of the starting dose: No data available

Doses:

5000 mg/kg bw

No. of animals per sex per dose:

Total:10
5 male , 5 female

Control animals:

not specified

Details on study design:

Details on study design
- Duration of observation period following administration: 14 days (or other?): 14 days

- Frequency of observations and weighing: on day 0 and daily thereafter.
- Necropsy of survivors performed: Yes
- Other examinations performed: clinical signs, body weight, organ weights, histopathology, other: Yes, clinical signs, body weight and histopathology were performed.

Statistics:

The mean, standard deviation, and standard error were calculated for the body weight data and for the amount of test article administered.
For oral LD50 value, the 95 percent confidence interval, the slope of the dose-response curve, and correction factors for 0 and 100 percent observed responses were calculated by computer program employing the methodology of Litchfield and Wilcoxon.

Preliminary study:

not specified

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 5 000 mg/kg bw

Based on:

test mat.

Remarks on result:

other: No mortality observed

Mortality:

No mortality was observed in treated rat at 5000 mg/kg bw

Clinical signs:

other: Red colored urine and stool; loose stool; red stained fur in the perianal region, on the head and ventral portion of the body, on the muzzle and red colored stain on the tail of treated rat

Gross pathology:

No gross pathological abnormal findings were observed in treated rat.

Other findings:

Red colored urine and stool; loose stool was observed in treated rat.

Interpretation of results:

Category 5 based on GHS criteria

Conclusions:

LD50 was considered to be > 5000 mg/kg bw when Fischer 344 male and female rats were treated Solvent Red 1 (manganese(2+) bis(phosphinate)) orally.

Executive summary:

In acute oral toxicity study, Fischer 344 male and female rats were treated Solvent Red 1 (manganese(2+) bis(phosphinate)) in the concentration of 5000 mg/kg bw in corn oil orally by gavage. No mortality was observed in treated rat at 5000 mg/kg bw. Red colored urine and stool; loose stool; red stained fur in the perianal region, on the head and ventral portion of the body, on the muzzle and red colored stain on the tail of treated rat. Overall body weight gain was observed in treated rat. No gross pathological abnormal findings were observed in treated rat. Therefore, LD50 was considered to be > 5000 mg/kg bw when Fischer 344 male and female rats were treated Solvent Red 1 (manganese(2+) bis(phosphinate)) orally.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

5 000 mg/kg bw

Quality of whole database:

Data is Klimisch 2 and from peer-reviewed journal

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

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 fis rom peer-reviewed journal

Qualifier:

according to guideline

Guideline:

other: No data

Principles of method if other than guideline:

Acute dermal toxicity study of Solvent Red 1 in rabbit.

GLP compliance:

not specified

Test type:

standard acute method

Limit test:

yes

Specific details on test material used for the study:

- Name of test material (as cited in study report): Solvent Red 1
- Molecular formula (if other than submission substance): C17H14N2O2
- Molecular weight (if other than submission substance): 278.31 g/mole
- Substance type: Organic
- Physical state: Solid

Species:

rabbit

Strain:

New Zealand White

Sex:

male/female

Details on test animals or test system and environmental conditions:

Details on test animal
TEST ANIMALS
- Source: Kuiper’s rabbit ranch, Gary, IN.
- Age at study initiation: No data available
- Weight at study initiation: 2.14 – 2.84 kg
- Fasting period before study: No data available
- Housing: Animals were housed in the appropriate randomly selected cage. Each animal was then assigned a sequential animal number unique within American Biogenics Corporation (ABC) and identified with an ear tag bearing this animal number, The sequential animal number was listed on a cage card that was affixed to the front of the animal's cage. Rooms were cleaned daily and the cages were cleaned and sanitized as specified in ABC SOP's. Urine and feces fell through the wire mesh floor onto animal caging board. The cage boards were changed at least 2 to 3 times per week.

- Diet (e.g. ad libitum): Purina Certified Rodent Chow 5002, ad libitum, except for fasting prior to dosing.

- Water (e.g. ad libitum): Filtered tap water was provided through an automatic watering system and was analyzed periodically, ad libitum.

- Acclimation period: 14 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 7 °C
- Humidity (%): 30-70 %
- Air changes (per hr): No data available
- Photoperiod (hrs dark / hrs light): 6:00 a.m. to 6:00 p.m. (12 hour light/dark, cycle)

IN-LIFE DATES: From: September 12, 1985
To: September 26, 1985

Type of coverage:

other: Dermal

Vehicle:

physiological saline

Details on dermal exposure:

TEST SITE
- Area of exposure: dorsal and lateral trunk
- % coverage: approximately 10% of the body surface area
- Type of wrap if used: plastic wrap and stockinette were used.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): Yes, by Each application site was gently wiped with gauze sponges moistened with an appropriate vehicle (known not to cause any dermal toxic reactions) to remove any remaining test article
- Time after start of exposure: After 24 hours

TEST MATERIAL
- Amount(s) applied (volume or weight with unit):2000 mg/kg bw
- Concentration (if solution): 2000 mg/kg bw
- Constant volume or concentration used: yes
- For solids, paste formed: yes

Duration of exposure:

24 hours

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

5 male and 5 female rabbits

Control animals:

yes, concurrent vehicle

Details on study design:

Details on study design
- Duration of observation period following administration: 14 days (or other?): 14 days
- Frequency of observations and weighing: Mortality once daily and body weight on day 0, 3, 7, 10 and prior to sacrifice on day 14, or at the time animal found dead.
- Necropsy of survivors performed: Yes
- Other examinations performed: clinical signs, body weight, organ weights, histopathology, other: clinical signs, gross pathology and histopathology were performed.

Statistics:

The mean, standard deviation, and standard error were calculated for the body weight data and for the amount of test substance applied. The approximate amount of test article applied was calculated in milligrams per square centimeter of exposed skin.

Preliminary study:

No data available

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Remarks on result:

other: No mortality observed

Mortality:

No mortality were observed in treated rabbits.

Clinical signs:

other: Red stain on teat site, feet and head discolored red in treated male and female rabbits. Few stools and loose stool were observed in treated male rabbits.

Gross pathology:

Red discoloration of treated skin, red discoloration of fur, a liver with a dark red discoloration, and 2 lungs with red discoloration was observed in treated male and female rabbits.

Interpretation of results:

Category 5 based on GHS criteria

Conclusions:

LD50 was considered to be > 2000 mg/kg bw when New Zealand White male and female rabbits were treated with Solvent Red 1 (1-[(2-methoxyphenyl)diazenyl]-2-naphthol) by dermal application for 24 hours.

Executive summary:

In acute dermal toxicity study, New Zealand White male and female rabbits were treated with Solvent Red 1 (1-[(2-methoxyphenyl)diazenyl]-2-naphthol) in the concentration of 5000 mg/kg bw in physiological saline applied on dorsal and lateral trunk (approximately 10% of the body surface area) of each animal was clipped free of hair with Oster electric clippers equipped with a number 40 (surgical) blade ofr 24 hours. No mortality was observed in treated rabbits. Red stain on teat site, feet and head discolored red in treated male and female rabbits. Few stools and loose stool were observed in treated male rabbits. Gained overall body weight was observed in treated male and female rabbits. Red discoloration of treated skin, red discoloration of fur, a liver with a dark red discoloration, and 2 lungs with red discoloration was observed in treated male and female rabbits. Therefore, LD50 was considered to be > 2000 mg/kg bw when New Zealand White male and female rabbits were treated with Solvent Red 1 (1-[(2-methoxyphenyl)diazenyl]-2-naphthol) by dermal application for 24 hours.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Quality of whole database:

Data is Klimisch 2 and from peer-reviewed journal

Additional information

Acute oral toxicity:

In different studies, 1-[(2-methoxyphenyl)diazenyl]-2-naphthol has been investigated for acute oral toxicity to a greater or lesser extent. Often are the studies based on in vivo experiments and estimated data in rodents, i.e. most commonly in rats for 1-[(2-methoxyphenyl)diazenyl]-2-naphthol along with on structurally similar read across substance Sudan orange R (RA 842-07-9). The predicted data using the OECD QSAR toolbox has also been compared with the experimental studies.

In a experimental study conducted by Mayhew et al (American College of Toxicology, Part B.15(Suppl 1),S43,1996) and given by NTRL (U.S. Army Medical Bioengineering Research and development Laboratory, 1986), Fischer 344 male and female rats were treated Solvent Red 1 (1-[(2-methoxyphenyl)diazenyl]-2-naphthol) in the concentration of 5000 mg/kg bw in corn oil orally by gavage. No mortality was observed in treated rat at 5000 mg/kg bw. Red colored urine and stool; loose stool; red stained fur in the perianal region, on the head and ventral portion of the body, on the muzzle and red colored stain on the tail of treated rat. Overall body weight gain was observed in treated rat. No gross pathological abnormal findings were observed in treated rat. Therefore, LD50 was considered to be > 5000 mg/kg bw when Fischer 344 male and female rats were treated Solvent Red 1 (1-[(2-methoxyphenyl)diazenyl]-2-naphthol) orally.

In another prediction done by SSS (2017) using the OECD QSAR toolbox with log kow as the primary descriptor, the acute oral toxicity was estimated for 1-[(2-methoxyphenyl)diazenyl]-2-naphthol. The LD50 was estimated to be 2016 mg/kg bw when Sprague-Dawley male and female rats were orally exposed with 1-[(2-methoxyphenyl)diazenyl]-2-naphthol.

Also it is further supported by experimental study conducted by BSF Company (1977)on structurally similar read across substanceSudan orange R (RA 842-07-9), acute oral toxicity was evaluated in rats by using Sudan orange R in the concentration of 10000 mg/kg bwas a 5-35% suspension in 0.5% aqueous CMC preparation orally by gavage and observed for 14 days. No mortality was observed in treated rat at 10000 mg/kg bw and skin, feces and urine orange discolored were observed in treated rats. Therefore, LD50 was considered to be > 10000 mg/kg bw when rats were treated with Sudanorange R as a 5-35% suspension in 0.5% aqueous CMC preparation orally by gavage. 

This further supported by experimental study conducted by National Toxicology Program (1982) and National Technical Information Service (1981) on structurally similar read across substanceSudan orange R (RA 842-07-9), acute oral toxicity was evaluated in F344 male and female rats and B6C3F1 male and female micewere treated with C. I. Solvent Yellow 14 in the concentration of 0, 600, 1250, 2500, 5000 and 10000 mg/kg/day and 0, 1200, 2500, 5000, 1000 and 20000 mg/kg/dayorally in feed and observed for 14 days. No effect on survival and signs of toxicity were observed in treated mice and rat. Therefore, LD50 was considered to be > 10000 mg/kg bwfor rats and > 20000 ma/kg bw for mice when F344 male and female rats and B6C3F1 male and female micewere treated with C. I. Solvent Yellow 14 orally by feed.

Thus, based on the above studies and predictions on 1-[(2-methoxyphenyl)diazenyl]-2-naphthol, it can be concluded that LD50 value is greater than 2000 mg/kg bw. Thus comparing this value with the criteria of CLP regulation, 1-[(2-methoxyphenyl)diazenyl]-2-naphthol can be “Not Classified” for acute oral toxicity.

Acute dermal toxicity:

In different studies, 1-[(2-methoxyphenyl)diazenyl]-2-naphthol has been investigated for acute dermal toxicity to a greater or lesser extent. Often are the studies based on in vivo experiments data in rodents, i.e. most commonly in rabbit and rats for 1-[(2-methoxyphenyl)diazenyl]-2-naphthol along with on structurally similar read across substance 2-Naphthalenol, 1-[[4-(phenylazo)phenyl]azo]-, ar',ar''-Me derivs (CAS no70879-65-1).

In a experimental study conducted by Mayhew et al (American College of Toxicology, Part B.15(Suppl 1),S43,1996) and given by NTRL (U.S. Army Medical Bioengineering Research and development Laboratory, 1986), New Zealand White male and female rabbits were treated with Solvent Red 1 (1-[(2-methoxyphenyl)diazenyl]-2-naphthol) in the concentration of 5000 mg/kg bw in physiological saline applied on dorsal and lateral trunk (approximately 10% of the body surface area) of each animal was clipped free of hair with Oster electric clippers equipped with a number 40 (surgical) blade ofr 24 hours. No mortality was observed in treated rabbits. Red stain on teat site, feet and head discolored red in treated male and female rabbits. Few stools and loose stool were observed in treated male rabbits. Gained overall body weight was observed in treated male and female rabbits. Red discoloration of treated skin, red discoloration of fur, a liver with a dark red discoloration, and 2 lungs with red discoloration was observed in treated male and female rabbits. Therefore, LD50 was considered to be > 2000 mg/kg bw when New Zealand White male and female rabbits were treated with Solvent Red 1 (1-[(2-methoxyphenyl)diazenyl]-2-naphthol) by dermal application for 24 hours.

In another experimental study conducted by Sustainability Support Services (Europe) AB (2013)on structurally similar read across substance2-Naphthalenol, 1-[[4-(phenylazo)phenyl]azo]-, ar',ar''-Me derivs (CAS no70879-65-1). Wistar male and female rats were treated with 2-Naphthalenol, 1-[[4-(phenylazo)phenyl]azo]-, ar',ar''-Me derivs in the concentration of 2000 mg/kg bw by dermal application. No mortality and any clinical sign of toxicity were observed throughout the observation period of 14 days in treated rats. The body weight of each animal recorded on day 0, 7th and 14th showed normal increase and there was no significant increase or decrease in weight was recorded. Therefore, LD50 was considered to be > 2000 mg/kg bw when Wistar male and female rats were treated with 2-Naphthalenol, 1-[[4-(phenylazo)phenyl]azo]-, ar',ar''-Me derivs by dermal application.

Thus, based on the above studies and predictions on 1-[(2-methoxyphenyl)diazenyl]-2-naphthol, it can be concluded that LD50 value is greater than 2000 mg/kg bw. Thus comparing this value with the criteria of CLP regulation, 1-[(2-methoxyphenyl)diazenyl]-2-naphthol can be “Not Classified” for acute dermal toxicity.

Justification for classification or non-classification

Based on the above studies and predictions on 1-[(2-methoxyphenyl)diazenyl]-2-naphthol, it can be concluded that LD50 value is greater than 2000 mg/kg bw. Thus comparing this value with the criteria of CLP regulation, 1-[(2-methoxyphenyl)diazenyl]-2-naphthol can be “Not Classified” for acute oral and dermal toxicity.