zinc, 5,5'-azobis-2,4,6(1H,3H,5H)-pyrimidinetrione complexes and melamine

Endpoint summary

Description of key information

The acute oral, inhalation and dermal toxicity was examined in rats by using the respective guidelines under GLP conditions . 
 LD50 (oral, dermal) > 2000 mg/kg bw; LD50 (inhalation) > 2590 mg/m³.

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:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guidelinestudy under GLP condition

Qualifier:

according to guideline

Guideline:

OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)

GLP compliance:

yes

Test type:

acute toxic class method

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source:
- Age at study initiation: 8 weeks
- Weight at study initiation:´176.9 g - 205.0 g
- Fasting period before study:
- Housing: 3 animals per cage
- Diet ad libitum, fasting of 20 hours prior to administration
- Water ad libitum
- Acclimation period: 5days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22
- Humidity (%): 50
- Air changes (per hr): 10 - 15
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

oral: gavage

Vehicle:

other: water for injection

Details on oral exposure:

The test substance was formulated with water for injection and givel only once by oral gavage. Starting dose level was selected 300 mg/kg bw as recommended by the respective guideline. The dose level was 300 mg/kg bw (1st, 2nd step), 2000 mg/kg bw (3rd, 4th step) and 3 animals were used for each step. these steps showed no mortality in the dosed amimals

Doses:

300 and 2000 mg/kg bw

No. of animals per sex per dose:

3 animals per step , 4 steps

Control animals:

no

Details on study design:

The test substance was formulated with water for injection and given only once by oral gavage. Starting dose level was selected 300 mg/kg bw as recommended by the respective guideline. The dose level was 300 mg/kg bw (1st, 2nd step), 2000 mg/kg bw (3rd, 4th step) and 3 animals were used for each step. These steps showed no mortality in the dosed amimals. Clinical signs were observed for 4 hours after treatment and then once every day for 14 days . Body weight was measured on animal recept day , animal allocation day , just before treatment and on day 7 and day 14 after treatment. On the end of study period all animlas were sacrificed and autopsy was conducted to all animals and the organs were examined for gross lesions

Statistics:

no data

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Remarks on result:

other: no clinical signs, no mortality, body weight gain, no gross pathological findings at necropsy

Mortality:

no animal died

Clinical signs:

no clinical signs were observed

Body weight:

animals gained body weight

Gross pathology:

no findings

Executive summary:

The acute oral toxicity was tested in female rats using the acute toxic class method according to OECD TG 423 under GLP conditions. Azo zinc complex Pigment - Melamine compound was formulated with water for injection and given only once by oral gavage. Starting dose level was selected 300 mg/kg bw as recommended by the respective guideline. The dose level was 300 mg/kg bw (1st, 2nd step), 2000 mg/kg bw (3rd, 4th step) and 3 animals were used for each step. No mortality was observed. Clinical signs related with the substance were not observed. All animals gained body weight. There were no necropsy findings. Based on these results

Azo zinc complex Pigment - Melamine compound is evaluated to be of low acute oral toxicity with LD50 > 2000 mg/kg bw

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

discriminating dose

Value:

2 000 mg/kg bw

Quality of whole database:

This is the only available study which is performed according to OECD TG 423 under GLP conditions and therefore evaluated with Klimisch score 1

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Principles of method if other than guideline:

Male and female rats were exposed nose-only to 2590 mg (maximum attainable concentration) of the test substance/m³ for 4 hours. Mortality, clinical signs, reflex measurements rectal temperature and body weights were examined during the 14 days post observation period. A gross-pathological examination was performed on day 14 after exposure to the test item. To identify exposure-related effects, comparisons with vehicle control were performed. This control was exposed to an atmosphere using essentially similar exposure conditions as were used for the test item.

GLP compliance:

yes

Test type:

standard acute method

Species:

rat

Strain:

Wistar

Sex:

male/female

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

nose only

Vehicle:

air

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Concentrations:

0 mg/m³ (control group)
2590 mg/m³ (test group); 2590 mg/m³ was the maximum attainable concentration)

No. of animals per sex per dose:

N /Group/sex Concentration (mg/m³)
1/m 0
2/m 2590
1/w 0
2/w 2590

Control animals:

yes

Sex:

male/female

Dose descriptor:

LC50

Effect level:

>= 2 590 mg/m³ air

Based on:

test mat.

Exp. duration:

4 h

Remarks on result:

other: 2590 mg/m³ was the maximum attainable concentration.

One group of female and male rats was nose-only exposed to the solid aerosol of the test item at the maximum attainable concentration of 2590 mg/m³ in the animals breathing zone (limit test). In order to achieve the required mass median aerodynamic diameter (MMAD) the test item was micronized using a ball-mill. Rats of the control group were exposed to air under otherwise identical circumstances.

The results can be summarized as follows:

The respirability of the aerosol was adequate and in compliance of test guidelines [the mass median aerodynamic diameter (MMAD) was 3.86 µm, the geometric standard deviation (GSD) was 2.59]. Efforts have been made to generate the maximum attainable concentration of 2590 mg/m³ test item in consideration of particle size distribution according OECD test guideline 403.

Mortality did not occur during the course of the study. All rats exposed to 2590 mg/m³ revealed clinical symptoms (e.g. bradypnea, labored breathing, irregular breathing, motility reduced, atony, high-legged gait, cyanosis, piloerection, haircoat ungroomed, fur orange stained, reduced reflexes). Furthermore animals exposed to the test item showed significant reduction in incremental body weight gain and absolute body weight when compared to control animals as well as significant decreased body temperatures in comparison to controls. Gross pathological findings were seen in all six animals exposed to 2590 mg/m3 on day 14 (light-colored areas and orangecolored areas in the lungs, orange discolorations in the lung-associated lymph nodes).

In summary, there is evidence of low acute inhalation toxicity in rats after exposure (4h) of the aerosolized test item. The LC50 is> 2590 mg/m³.

Executive summary:

A study on the acute inhalation toxicity of Zinc-Azo barbituric acid / Melamine (henceforward referred to as test item) in rats has been conducted in accordance with OECD TG#403 (2009). Test procedures were adapted so as to comply also with the EU Directive 92/69/EEC, and especially OECD GD#39 (2009). One group of female and male rats was nose-only exposed to the solid aerosol of the test item at the maximum attainable concentration of 2590 mg/m³ in the animals breathing zone (limit test). In order to achieve the required mass median aerodynamic diameter (MMAD) the test item was micronized using a ball-mill. Rats of the control group were exposed to air under otherwise identical circumstances.

The results can be summarized as follows:

The respirability of the aerosol was adequate and in compliance of test guidelines [the mass median aerodynamic diameter (MMAD) was 3.86 µm, the geometric standard deviation (GSD) was 2.59]. Efforts have been made to generate the maximum attainable concentration of 2590 mg/m³ test item in consideration of particle size distribution according OECD test guideline 403.

Mortality did not occur during the course of the study. All rats exposed to 2590 mg/m³ revealed clinical symptoms (e.g. bradypnea, labored breathing, irregular breathing, motility reduced, atony, high-legged gait, cyanosis, piloerection, haircoat ungroomed, fur orange stained, reduced reflexes). Furthermore animals exposed to the test item showed significant reduction in incremental body weight gain and absolute body weight when compared to control animals as well as significant decreased body temperatures in comparison to controls. Gross pathological findings were seen in all six animals exposed to 2590 mg/m3 on day 14 (light-colored areas and orangecolored areas in the lungs, orange discolorations in the lung-associated lymph nodes).

In summary, there is evidence of low acute inhalation toxicity in rats after exposure (4h) of the aerosolized test item. The LC50 is> 2590 mg/m³.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LC50

Value:

2 590 mg/m³

Quality of whole database:

This is the only available study which is performed according to OECD TG 403 under GLP conditions and therefore evaluated with Klimisch score 1

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:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study under GLP condition

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

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
- Source:
- Age at study initiation: 7 weeks
- Weight at study initiation: males,206.6 g-215.0 g; females 209.7 g-229.2 g
- Fasting period before study: no data
- Housing: individually
- Diet (e.g. ad libitum):
- Water (e.g. ad libitum):
- Acclimation period: 7 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22
- Humidity (%): 50
- Air changes (per hr): 10-15
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: To:

Type of coverage:

semiocclusive

Vehicle:

CMC (carboxymethyl cellulose)

Details on dermal exposure:

The test substance was applied uniformly over an area which was approximately 10% of the total body surface area. Test substance were held in contact with the skin with a porous gauze dresssing and non-irritating tape throughout the 24-hour exposure period.

Duration of exposure:

24 hours

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

5

Control animals:

yes, concurrent vehicle

Details on study design:

The test substance (2000 mg/kg bw) was applied uniformly over an area which was approximately 10% of the total body surface area. Test substance were held in contact with the skin with a porous gauze dresssing and non-irritating tape throughout the 24-hour exposure period. The wrappings were removed at 24 hours after applicatiopn. the applied areas were washed out gently with distilled water. the animals were observed for clinical signs and mortality and changes of body weight over a period of 14 days.

Statistics:

statistical analysis were performed by comparing the treatment group and the control group. Variance of numerical data was checked by F-test; then the student t-test was conducted to determine the singnificant difference between two groups

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Remarks on result:

other: no clinical signs, no mortality, body weight gain, no findings at necropsy

Mortality:

No death occurred in all animals during the experimental period

Clinical signs:

clinical signs related with the substance wer not observed in any amimals during the observation period

Body weight:

all living animals showed the normal increase in body weight

Gross pathology:

In all animals there were no lesons caused by administration of test substance

Executive summary:

Acute dermal toxicity was examined in male and female Sprague-Dawley rats in accordance with OECD TG 402 under GLP conditions.The test substance (2000 mg/kg bw) was applied uniformly over an area which was approximately 10% of the total body surface area. Test substance were held in contact with the skin with a porous gauze dresssing and non-irritating tape throughout the 24-hour exposure period. The wrappings were removed at 24 hours after applicatiopn. the applied areas were washed out gently with distilled water. the animals were observed for clinical signs and mortality and changes of body weight over a period of 14 days.

No mortality was observed in the present study. Clinical signs related with the substance were not observed in any animal during the observaion period. All tested animals showed normal gains in body weight. In all animals there were no necropsy findings caused by administration of test substance.

Based on these results the LD50 value was considered to be higher than 2000 mg/kg bw

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

discriminating dose

Value:

2 000 mg/kg bw

Quality of whole database:

This is the only available study which is performed according to OECD TG 402 under GLP conditions and therefore evaluated with Klimisch score 1

Additional information

ACUTE TOXICITY: ORAL

The acute oral toxicity was tested in female rats using the acute toxic class method according to OECD TG 423 under GLP conditions. Azo zinc complex Pigment - Melamine compound was formulated with water for injection and given only once by oral gavage. Starting dose level was selected 300 mg/kg bw as recommended by the respective guideline. The dose level was 300 mg/kg bw (1st, 2nd step), 2000 mg/kg bw (3rd, 4th step) and 3 animals were used for each step. No mortality was observed. Clinical signs related with the substance were not observed. All animals gained body weight. There were no necropsy findings. Based on these results Azo zinc complex Pigment - Melamine compound is evaluated to be of low acute oral toxicity with LD50 > 2000 mg/kg bw.

ACUTE TOXICITY: INHALATION

A study on the acute inhalation toxicity of Azo zinc complex Pigment - Melamine in rats has been conducted in accordance with OECD TG 403 under GLP conditions. One group of female and male rats was nose-only exposed to the solid aerosol of the test item at the maximum attainable concentration of 2590 mg/m³ in the animals breathing zone (limit test).

Mortality did not occur during the course of the study. All rats exposed to 2590 mg/m³ revealed clinical symptoms (e.g. bradypnea, labored breathing, irregular breathing, motility reduced, atony, high-legged gait, cyanosis, piloerection, haircoat ungroomed, fur orange stained, reduced reflexes). Furthermore animals exposed to the test item showed significant reduction in incremental body weight gain and absolute body weight when compared to control animals as well as significant decreased body temperature in comparison to controls. Gross pathological findings were seen in all six animals exposed to 2590 mg/m3 on day 14 (light-colored areas and orange colored areas in the lungs, orange discolorations in the lung-associated lymph nodes).

Azo zinc complex Pigment - Melamine compound is evaluated to be of low acute inhalation toxicity with LC50 > 2590 mg/m³.

AUTE TOXICITY: DERMAL

Acute dermal toxicity was examined in male and female Sprague-Dawley rats in accordance with OECD TG 402 under GLP conditions. Azo zinc complex Pigment - Melamine (2000 mg/kg bw) was applied uniformly over an area which was

approximately 10% of the total body surface area. Test substance was held in contact with the skin with a porous gauze dressing and non-irritating tape throughout the 24-hour exposure period. The wrappings were removed at 24 hours after application. The applied areas were washed out gently with distilled water. The animals were observed for clinical signs and mortality and changes of body weight over a period of 14 days.

No mortality was observed in the present study. Clinical signs related with the substance were not observed in any animal during the observation period. All tested animals showed normal gains in body weight. In all animals there were no necropsy findings caused by administration of test substance.

Based on these results the LD50 value was considered to be higher than 2000 mg/kg bw

Justification for selection of acute toxicity – oral endpoint
This is the only available study which is performed according to OECD TG 423 under GLP conditions and therefore evaluated with Klimisch score 1

Justification for selection of acute toxicity – inhalation endpoint
This is the only available study which is performed according to OECD TG 403 under GLP conditions and therefore evaluated with Klimisch score 1

Justification for selection of acute toxicity – dermal endpoint
This is the only available study which is performed according to OECD TG 402 under GLP conditions and therefore evaluated with Klimisch score 1

Justification for classification or non-classification

Based on the results of the available studies (LD50 (oral, dermal) > 2000 mg/kg bw; LD50 (inhalation) > 2590 mg/m³ (maximum attainable concentration)) a classification is not required.