1-(2-methyl-4-(2-methylphenylazo)phenylazo)-2-naphthol

Endpoint summary

Description of key information

Acute oral toxicity: 

The acute oral toxicity dose (LD50) was considered based on different studies conducted on rats and mice for the test chemical. The LD50 value is 3600 mg/kg bw. The study concluded that LD50 is >2000 mg/kg bw, for acute oral toxicity. Thus, comparing this value with the criteria of CLP regulation, the given test chemical cannot be classified for acute oral toxicity.

Acute Inhalation Toxicity:

The acute inhalation toxicity study need not be conducted because exposure to humans via inhalation route is not likely taking into account due to the low vapour pressure of the test chemical, which is reported to be 4.57E-012 mm Hg. Thus, exposure to inhalable dust, mist and vapour of the chemical is highly unlikely. Therefore this study is considered for waiver. 

Acute Dermal toxicity:

The acute dermal toxicity dose (LD50) was considered based on different studies conducted on rats for the test chemical. The studies concluded that LD50 value is >2000 mg/kg bw, for acute dermal toxicity. Thus, comparing this value with the criteria of CLP regulation, the given test chemical cannot be classified for acute dermal toxicity.

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:

data from handbook or collection of data

Justification for type of information:

Data is from handbook.

Qualifier:

according to guideline

Guideline:

other: As mentioned below

Principles of method if other than guideline:

Acute oral toxicity study of the given test chemical in Rat.

GLP compliance:

not specified

Test type:

other: not specified

Limit test:

no

Species:

rat

Strain:

not specified

Sex:

not specified

Details on test animals or test system and environmental conditions:

not specified

Route of administration:

oral: unspecified

Vehicle:

not specified

Details on oral exposure:

not specified

Doses:

3600 mg/kg bw

No. of animals per sex per dose:

not specified

Control animals:

not specified

Details on study design:

not specified

Statistics:

not specified

Preliminary study:

not specified

Sex:

not specified

Dose descriptor:

LD50

Effect level:

ca. 3 600 mg/kg bw

Based on:

test mat.

Remarks on result:

other: 50% mortality was observed

Mortality:

50% mortality was observed at 3600 mg/kg bw.

Clinical signs:

other: not specified

Gross pathology:

not specified

Other findings:

not specified

Interpretation of results:

other: Not classified

Conclusions:

The acute oral LD50 value was considered to be 3600 mg/kg bw, when rats were treated with the given test chemical via oral route.

Executive summary:

Acute oral toxicity study of test chemical was conducted in rats at the concentration of 3600 mg/kg. 50% mortality was observed at 3600 mg/kg bw. Therefore, LD50 value was considered to be 3600 mg/kg bw, when rats were treated with test chemical via oral route.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

3 600 mg/kg bw

Quality of whole database:

Data is Klimisch 2 and from handbook.

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Endpoint:

acute toxicity: inhalation

Data waiving:

other justification

Justification for data waiving:

other:

Endpoint conclusion

Quality of whole database:

Waiver

Acute toxicity: via dermal route

Link to relevant study records

Reference

Endpoint:

acute toxicity: dermal

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Remarks:

experimental data from various test chemicals

Justification for type of information:

Data is summarized based on the available information from various test chemicals.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

other: As mentioned below

Principles of method if other than guideline:

WoE report is based on 2 acute dermal toxicity studies as- WoE 2 and WoE 3.
Acute dermal toxicity test was carried out to study the effects of the test chemicals on rodents.

GLP compliance:

not specified

Test type:

other: not specified

Limit test:

no

Species:

rat

Strain:

other: 1. Wistar 2. Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

1. TEST ANIMALS
- Age at study initiation: 8 to 10 weeks
- Weight at study initiation: 200±20g
- Fasting period before study: Animals were fasted overnight prior to test
- Housing: The animals were then housed individually in cages with a collar around the neck in order to avoid the ingestion of the test compound.
- Diet (e.g. ad libitum): food was offered three hours after dosing.
- Acclimation period:The healthy wistar albino rats selected for study acclimatized to standard laboratory condition for period of one week under close Veterinary supervision.
ENVIRONMENTAL CONDITIONS
- Temperature (°C): temperature between 22-25°C
- Humidity (%): relative humidity 40-60%
- Air changes (per hr): Air conditioned rooms with 10-15 air changes per hour
- Photoperiod (hrs dark / hrs light): illumination cycle set to 12 hours artificial fluorescent light and 12 hours dark.
2. TEST ANIMALS
- Source: National Institute of Biosciences, Pune.
- Females (if applicable) nulliparous and non-pregnant: [no]
- Age at study initiation: Young adult male and female rats aged between 6 – 9 weeks were used.
- Weight at study initiation: The weight ranges of approximately 210.2 to 245.4 grams at initiation of dosing were used.
Body weights at the start : Male Mean : 240.40 g (= 100 %); Minimum : 234.6 g (- 2.41 %); Maximum : 245.4 g (+ 2.08 %)
Female Mean : 215.98 g (= 100 %); Minimum : 210.2 g (- 2.68 %); Maximum : 220.6 g (+ 2.14 %)
- Housing: The rats were individually housed in polycarbonate cages with paddy husk as bedding.
- Diet (e.g. ad libitum): Rodent feed supplied by the Nutrivet Life Sciences, Pune, was provided ad libitum from individual feeders.
- Water (e.g. ad libitum): Water was provided ad libitum from individual bottles attached to the cages. All water was from a local source and passed through the reverse osmosis membrane before use.
- Acclimation period: 5 days.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): Room temperature was maintained at 20.1 to 21.9 degree centigrade.
- Humidity (%): Room humidity was maintained at 55.5% to 59.2%.
- Air changes (per hr): The animal room was independently provided with at least ten to fifteen air changes per hour of 100% fresh air that had been passed through the HEPA filters.
- Photoperiod (hrs dark / hrs light): An artificial light and dark cycle of 12 hours each was provided to the room.

Type of coverage:

occlusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

1. TEST SITE
- Area of exposure: The test substance was applied uniformly over an exposed area of skin.
- Type of wrap if used: The test compound was held in contact with the skin with an impervious dressing secured in place with an adhesive tape.
REMOVAL OF TEST SUBSTANCE
- Washing (if done): The dressing was removed and the site of application was cleaned with lukewarm water wiping the test compound.
- Time after start of exposure:24 hours
TEST MATERIAL
- Amount(s) applied (volume or weight with unit): The test compound was applied at the dose level of 2000 mg/kg b.w.t as such (as the compound was in liquid form).TEST SITE
- Area of exposure: back skin of total body surface area
- % coverage: Approximate 10 percent
- Type of wrap if used: The test compound was held in contact with the skin with an impervious dressing secured in place with an adhesive tape.
REMOVAL OF TEST SUBSTANCE
- Washing (if done): The dressing was removed and the site of application was cleaned with lukewarm water wiping the test compound.
- Time after start of exposure:24 hours
TEST MATERIAL
- Amount(s) applied (volume or weight with unit): The test compound was applied at the dose level of 2000 mg/kg b.w.t as such (as the compound was in liquid form).
2. TEST SITE
- Area of exposure: Dorsal surface and sides from scapular to pelvic area.
- % coverage: Approximately 10% of the total body surface area.
- Type of wrap if used: Porous gauze dressing and non-irritating tape.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): Distilled water was used to remove residual test item.

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 2000 mg/kg bw

Duration of exposure:

1. 24 hours
2. 24 hours

Doses:

1. No. of dose group : Two
Group-I: 2000 mg/kg b.wt (limit test)
Group-II: 2000 mg/kg b.wt (confirmatory test)
2. A single dose of 2000 mg of the test item per kilogram of body weight was administered to ten rats (five males and five females).

No. of animals per sex per dose:

1. 10 (5male & 5 female)
2. 10 (5/sex).

Control animals:

not specified

Details on study design:

1. - Duration of observation period following administration: 14 days
- Frequency of observations and weighing: The treated animals were observed for clinical signs of intoxication and mortality at different time interval for a period of 14 days. The body weight of each rat was observed on day 0 (pre treatment), 7th and 14th (post treatment).
- Necropsy of survivors performed: yes. The necropsy was performed on all animals which was died during the study or were sacrificed at termination of the study.
2. - Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Twice daily
- Necropsy of survivors performed: Yes
- Other examinations performed: Clinical Observations and General Appearance: Animals were observed for clinical signs, mortality, until sacrifice.
Onset, duration and severity of any sign were recorded. The clinical signs and mortality observations were conducted at 10, 30, 60 minutes, 2, 4 and 6 hours on the day of dosing and once daily thereafter for 14 day. Daily observation was done as far as possible at the same time.
The observations were included general clinical signs, observations of eyes, mucous membranes, respiratory, circulatory system and behavior pattern.
Evaluation of Dermal Reaction: Dermal reaction was observed daily for study period of 14 days.
Body weights: Individual animal body weights were recorded pre-test (prior to administration of the test item), day 7 and at termination on day 14.
Gross Pathology: Necropsy was performed on animals surviving at the end of the study. Macroscopic examination of all the orifices, cavities and tissues were made and the findings were recorded. All animals surviving the study period were sacrificed by the carbon dioxide asphyxiation technique (day 15).

Statistics:

1. not specified
2. not specified

Preliminary study:

1. not specified
2. not specified

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:

1. No mortality was recorded in treated rats after administration of test compound at the dose level of 2000 mg/kg b.wt. throughout observation period of 14 days.
2. Sex : Male Group I - Animal treated at the dose level of 2000 mg/kg: All animals survived through the study period of 14 days.
Sex : Female Group I – Animal treated at the dose level of 2000 mg/kg: All animals survived through the study period of 14 days.

Clinical signs:

other: 1. No any clinical sign of toxicity throughout the observation period of 14 days were observed in treated rat. 2. Sex : Male Group I - Animal treated at the dose level of 2000 mg/kg body weight did not result in any signs of toxicity during the study per

Gross pathology:

1. NECROPSY FINDING
EXTERNAL
i.Skin- Skin and hair coat was observed wet.
ii.All external orifices- Normal
B. INTERNAL
i. Subcutaneous- No changes were observed.
ii. Superficial and deep lymph nodes- No change in mesenteric lymph node.
ABDOMINAL CAVITY
i.Opening and general examination- In the abdominal cavity all the organs were present in normal position.
ii.Spleen- No changes were recorded.
iii.Digestive system- No gross changes were observed in stomach and intestine.
iv.Liver and biliary ducts- No gross pathological changes were observed
v.Excretory system- No gross pathological changes were observed.
vi.Adrenal- Observed normal.
vii.Male/female genital organs – Showed normal colour, consistency and no inflammatory changes.
2. THORACIC CAVITY
i.Opening and general examination- Thoracic cavity was found to be normal without any fluid, mucous or blood etc.
ii.Lungs- No changes were recorded.
iii.Heart- No changes were observed in color and consistency. Heart found normal.
iv.Thyroid- Normal in shape, size and surface.
3. CRANIAL CAVITY
i.Brain- Normal in shape and size.
2. Gross pathological examination did not reveal any abnormalities in animals from 2000 mg/kg dose group.

Other findings:

1. not specified
2. - Other observations: Evaluation of Dermal Reaction
Sex : Male Group I - Animal treated at the dose level of 2000 mg/kg body weight did not result in any skin reaction during the study period of 14 days.
Sex : Female Group I - Animal treated at the dose level of 2000 mg/kg body weight did not result in any skin reaction during the study period of 14 days.

Interpretation of results:

other: Not classified

Conclusions:

According to CLP regulation, the test chemical cannot be classified for acute dermal toxicity, as the LD50 value is >2000 mg/kg bw.

Executive summary:

In different studies, the given test chemical has been investigated for acute dermal toxicity to a greater or lesser extent. Often are the studies based on in-vivo experiments in rodents, i.e. most commonly in rats for test chemical. The studies are summarized as below –

1. The acute dermal toxicity study was conducted as per OECD Guideline 402 (standard acute method) in Wistar rats. Ten healthy wistar albino rats of both sex (ranging b.wt 200±20 gm) selected for study after acclimatization. Approximate 10 percent back skin of total body surface area was prepared 24 hrs prior to application of test compound. The test compound was applied at the dose level of 2000 mg/kg b.w.t as such (as the compound was in liquid form) dermally for each animal. The treated animals were observed for clinical signs of intoxication and mortality at different time interval for a period of 14 days. The body weight of each rat was observed on day 0 (pre treatment), 7th and 14th (post treatment). The necropsy was performed on all animals which was died during the study or were sacrificed at termination of the study. No mortality was recorded in treated rats after administration of test compound at the dose level of 2000 mg/kg b.wt. throughout observation period of 14 days. No any clinical sign of toxicity throughout the observation period of 14 days were observed in treated rat. 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. No gross pathological changes were observed. Therefore, the LD50 value was considered to be >2000 mg/kg bw, when Wistar male and female rats were treated with test chemical by dermal application.

2. The reported study was designed and conducted to determine the acute dermal toxicity profile of the given test chemical in Sprague Dawley rats. The test item was applied to shorn skin of 5 male and 5 female animals at 2000 mg/kg body weight. Administration of the test item at 2000 mg/kg did not result in any skin reaction at the site of application during the study period of 14 days. Administration of the test item did not result in any signs of toxicity and mortality during the study period of 14 days. Animals exhibited normal body weight gain through the study period of 14 days. Gross pathological examination did not reveal any abnormalities attributable to the treatment. It was concluded that the acute dermal median lethal dose (LD50) of the given test chemical, when administered to male and female Sprague Dawley rats was considered to be >2000 mg/kg body weight. Thus by considering the CLP criteria for acute toxicity rating for the chemicals, it infers that the given test chemical does not exhibit acute toxicity by the dermal route.

Thus, based on the above summarised studies on test chemical, it can be concluded that LD50 value is >2000 mg/kg bw. Thus, comparing this value with the criteria of CLP regulation, the given test chemical cannot be classified for acute dermal toxicity.

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 study report.

Additional information

Acute oral toxicity:

In different studies, the given test chemical has been investigated for acute oral toxicity to a greater or lesser extent. Often are the studies based on in-vivo experiments in rodents, i.e. most commonly in rats and mice for test chemical. The studies are summarized as below –

1. Acute oral toxicity study of test chemical was conducted in rats at the concentration of 3600 mg/kg. 50% mortality was observed at 3600 mg/kg bw. Therefore, LD50 value was considered to be 3600 mg/kg bw, when rats were treated with test chemical via oral route.

2. In an acute oral toxicity study, rats were treated with test chemical in the concentration of 5000 mg/kg bw orally. No mortality observed in treated rats at 5000 mg/kg bw. Therefore, LD50 was considered to be >5000 mg/kg bw, when rats were treated with test chemical orally.

3. The reported study was designed and conducted to determine the acute oral toxicity profile of the given test chemical in wistar albino female rats. The study was conducted under the OECD Guideline-423 for testing of chemicals. The healthy wistar albino rats of body weight 200±20 gm were selected for study after acclimatization to standard laboratory condition and divided into test compound and vehicle control group each having three animals. Initially, the test compound was mixed with distilled water and administered orally at the dose level of 2000 mg/kg body weight (dose volume 10ml/kg) to three female rats. However; vehicle control group treated with distilled water at the dose level of 10 ml/kg b.wt. The treated animals were closely observed for clinical signs of intoxication during first 4 hours of test compound administration. Thereafter, all the animals were observed periodically at 1 hour interval for 24 hrs and twice daily for a period of 14 days. The necropsy was performed on all animals at the termination of the study. The test compound did not produce any mortality at the dose level of 2000 mg/kg body weight during the entire observation period. Animals did not produce any clinical signs of toxicity during the entire observation period. Animals showed normal gain in body weight on day 7th and 14th as compared to control group. No significant gross pathological changes related to compound toxicity were observed. Skin and hair coat was observed wet. It was concluded that the test compound is non-toxic at the tested dose level 2000 mg/kg body weight. According to criteria of CLP, it comes under the “Category Not classified".

4. Acute oral toxicity study was conducted in male Sprague-Dawley white mice by using test chemical at the concentrations of 1250 mg/kg, 2500 mg/kg, 3750 mg/kg, 5000 mg/kg, 6250 mg/kg bw. 6 animals/dose were administered the given test chemical via oral gavage route and control animals were received distilled water. The mice were observed for 3 days for the signs and symptoms of toxicity as well as the death rate of each group were recorded. The LD50 of the substances was calculated using the arithmetic method of Karber. 50% mortality was observed at 4166.66 mg/kg bw. The clinical signs such as, loss of appetite, drowsiness, tachycardia, decrease in locomotion and anorexia were distinctive signs observed in the mice before dead. Therefore, LD50 was considered to be 4166.66 mg/kg bw, when male Sprague- Dawley white mice were treated with test chemical for 3 days via oral gavage route.

Thus, based on the above summarised studies on test chemical, it can be concluded that LD50 value is >2000 mg/kg bw. Thus, comparing this value with the criteria of CLP regulation, the given test chemical cannot be classified for acute oral toxicity.

Acute Inhalation Toxicity:

The acute inhalation toxicity study need not be conducted because exposure to humans via inhalation route is not likely taking into account due to the low vapour pressure of the test chemical, which is reported to be 4.57E-012 mm Hg. Thus, exposure to inhalable dust, mist and vapour of the chemical is highly unlikely. Therefore this study is considered for waiver. 

Acute Dermal Toxicity:

In different studies, the given test chemical has been investigated for acute dermal toxicity to a greater or lesser extent. Often are the studies based on in-vivo experiments in rodents, i.e. most commonly in rats for test chemical. The studies are summarized as below –

1. The acute dermal toxicity study was conducted as per OECD Guideline 402 (standard acute method) in Wistar rats. Ten healthy wistar albino rats of both sex (ranging b.wt 200±20 gm) selected for study after acclimatization. Approximate 10 percent back skin of total body surface area was prepared 24 hrs prior to application of test compound. The test compound was applied at the dose level of 2000 mg/kg b.w.t as such (as the compound was in liquid form) dermally for each animal. The treated animals were observed for clinical signs of intoxication and mortality at different time interval for a period of 14 days. The body weight of each rat was observed on day 0 (pre treatment), 7th and 14th (post treatment). The necropsy was performed on all animals which was died during the study or were sacrificed at termination of the study. No mortality was recorded in treated rats after administration of test compound at the dose level of 2000 mg/kg b.wt. throughout observation period of 14 days. No any clinical sign of toxicity throughout the observation period of 14 days were observed in treated rat. 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. No gross pathological changes were observed. Therefore, the LD50 value was considered to be >2000 mg/kg bw, when Wistar male and female rats were treated with test chemical by dermal application.

2. The reported study was designed and conducted to determine the acute dermal toxicity profile of the given test chemical in Sprague Dawley rats. The test item was applied to shorn skin of 5 male and 5 female animals at 2000 mg/kg body weight. Administration of the test item at 2000 mg/kg did not result in any skin reaction at the site of application during the study period of 14 days. Administration of the test item did not result in any signs of toxicity and mortality during the study period of 14 days. Animals exhibited normal body weight gain through the study period of 14 days. Gross pathological examination did not reveal any abnormalities attributable to the treatment. It was concluded that the acute dermal median lethal dose (LD50) of the given test chemical, when administered to male and female Sprague Dawley rats was considered to be >2000 mg/kg body weight. Thus by considering the CLP criteria for acute toxicity rating for the chemicals, it infers that the given test chemical does not exhibit acute toxicity by the dermal route.

Thus, based on the above summarised studies on test chemical, it can be concluded that LD50 value is >2000 mg/kg bw. Thus, comparing this value with the criteria of CLP regulation, the given test chemical cannot be classified for acute dermal toxicity.

Justification for classification or non-classification

Based on the above studies on test chemical, it can be concluded that LD50 value is >2000 mg/kg bw, for acute oral and acute dermal toxicity. Thus, comparing this value with the criteria of CLP regulation, the given test chemical cannot be classified for acute oral and acute dermal toxicity. For acute inhalation toxicity wavier was added so, not possible to classify.