Disodium 3-hydroxy-4-[(4-methyl-2-sulphonatophenyl)azo]-2-naphthoate

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

11 February 1981 - 25 February 1981

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1981

Report date:

1981

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

Ten male and ten female rats were exposed to the highest achievable concentration of D&C Red 6 for 4 hous (head and nose exposure). The animals were observed for 14 days following exposure, after which pathological exminations were performed. Mortality and clinical signs were checked on a daily base, weights were measured before the study and weekly thereafter. Concentration of the test item in air was monitored analytically.

GLP compliance:

no

Remarks:

pre-GLP study

Test type:

fixed concentration procedure

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Disodium 3-hydroxy-4-[(4-methyl-2-sulphonatophenyl)azo]-2-naphthoate

EC Number:

227-497-9

EC Name:

Disodium 3-hydroxy-4-[(4-methyl-2-sulphonatophenyl)azo]-2-naphthoate

Cas Number:

5858-81-1

Molecular formula:

C18H12N2Na2O6S

IUPAC Name:

disodium 3-hydroxy-4-[(4-methyl-2-sulphonatophenyl)azo]-2-naphthoate

Test material form:

solid: particulate/powder

Details on test material:

- Physical appearance: orange powder

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: WIGA Versuchstierzuchtanstalt, Sulzfeld, Germany (strain: Caw-Ico-Wiga)
- Females (if applicable) nulliparous and non-pregnant: not indicated
- Age at study initiation: 7-10 weeks
- Weight at study initiation: Average 186.5 g (males), 185 g (females)
- Housing: in groups of 5 animals in cages without bedding material
- Diet: Herilan MRH (H. Eggersmann KG, Rinteln/Weser, Germany), ad libitum
- Water: tapwater, ad libitum
- Acclimation period: not indicated

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 2
- Humidity (%): 55 ± 5
- Air changes (per hr): not indicated
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: 11 February 1981 - 25 February 1981

Administration / exposure

Route of administration:

inhalation: dust

Type of inhalation exposure:

nose/head only

Vehicle:

air

Mass median aerodynamic diameter (MMAD):

0.7 µm

Geometric standard deviation (GSD):

4

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE
- Source and rate of air: 3000 L/h
- Method of conditioning air: the air system for outgoing air was set 10% lower than the fresh air system (overpressure method) to ensure that the substance-air mixture in the breathing zone of the animals was not diluted by laboratory air.
- System of generating particulates/aerosols: using vibration technique an aerosol was produced
- Method of particle size determination: gravimetric concentration determination by cascade impactor: after taking the samples, the impactor was disconnected and the disks and the filter, containing particle residues, were weighed. The content of the impactor was determined gravimetrically.
- Temperature, humidity, pressure in air chamber: not indicated

TEST ATMOSPHERE
- Brief description of analytical method used: concentration was determined gravimetrically
- Samples taken from breathing zone: Samples were taken once every 30 minutes during the exposure at 1,25 m/s (total 1 liter) with a probe with a diameter of 4 mm; samples were taken in proximity to the nose area of the exposed rats.

TEST ATMOSPHERE
- Particle size distribution: ranging from 53.77 - 99.12% between samples
- MMAD (Mass median aerodynamic diameter): 0.7 µm
- GSD (Geometric st. dev.): 4.0

Analytical verification of test atmosphere concentrations:

yes

Remarks:

gravimetric concentration determination

Duration of exposure:

4 h

Concentrations:

- Nominal concentration: 19.2 mg/L
- Mean measured concentration of test item: 5.4 +/- 0.09 mg/L
- Efficiency: 27.9%

No. of animals per sex per dose:

10 males, 10 females

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing:
Bodyweight: at the start, after 7 days and at the end of the test
Clinical symptoms and lethal effects: daily
- Necropsy of survivors performed: yes
- Other examinations performed: pathological examination after necropsy

Statistics:

None performed.

Results and discussion

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LC0

Effect level:

> 5.4 mg/L air

Based on:

test mat.

Exp. duration:

4 h

Mortality:

No mortality occurred.

Clinical signs:

other: No clinical signs as an effect of exposure to the test item were observed.

Body weight:

Body weights were comparable to historical control data and were therefore concluded not to be negatively influenced by the exposure to the test item.

Gross pathology:

No pathological effects were found.

Other findings:

Discoloration of the head area due to the test item was observed until 5 days after exposure.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

In an acute inhalation study, performed before OECD test guidelines, an LC0 for D&C Red 6 towards male and female rats was established to exceed the highest achievable test concentration (i.e. >5.4 mg/L, based on an analytically verified test concentration).