Sodium 3-[[3-methoxy-4-[(4-methoxyphenyl)azo]phenyl]azo]benzenesulphonate

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Study completion date - 02 August 1976.

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1976

Report date:

1976

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

not specified

GLP compliance:

no

Test type:

acute toxic class method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Sodium 3-[[3-methoxy-4-[(4-methoxyphenyl)azo]phenyl]azo]benzenesulphonate

EC Number:

264-129-6

EC Name:

Sodium 3-[[3-methoxy-4-[(4-methoxyphenyl)azo]phenyl]azo]benzenesulphonate

Cas Number:

63405-85-6

Molecular formula:

C20H18N4O5S.Na

IUPAC Name:

sodium 3-({3-methoxy-4-[(4-methoxyphenyl)diazenyl]phenyl}diazenyl)benzenesulfonate

Test material form:

other: Dust

Details on test material:

None

Specific details on test material used for the study:

Test Material: MA 23, D 956

Test animals

Species:

rat

Strain:

other: Charles River Rats

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Housing: Housed individually in stock cages
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum):ad libitum
- Acclimation period: 5 days

Administration / exposure

Route of administration:

inhalation: dust

Type of inhalation exposure:

whole body

Vehicle:

air

Details on inhalation exposure:

Test animals were exposed in a specially constructed inhalation chamber. The chamber was designed so that the animals could be introduced into the test atmosphere after the desired dust concentration was established. Each animal was caged separately during exposure to minimize filtration of inspired air by animal fur. Dust was suspended with a specially designed dust feeder capable of producing high concentrations over a long period of time. The test material powder was passed through a high-velocity stream of clean, dry air (-40 °C dewpoint). The air-jet velocity was adjusted to obtain the desired concentration of suspended dust. The test atmosphere was then introduced into the exposure chamber at the top center, dispersed by a baffle plate and exhausted at the bottom of the chamber. Air flow rate through the system was measured with a rotameter connected in the air supply line upstream of dust contamination. The rotameter was calibrated with a wet-test meter after the exposure was completed.

Analytical verification of test atmosphere concentrations:

not specified

Duration of exposure:

4 h

Concentrations:

193.8, 850, 2850 mg/m³ air

No. of animals per sex per dose:

5 animals per group

Control animals:

yes

Details on study design:

Dust was suspended with a specially designed dust feeder capable of producing high concentrations over a long period of time. The test material powder was passed through a high-velocity stream of clean, dry air (-40 °C dewpoint). The air-jet velocity was adjusted to obtain the desired concentration of suspended dust. The test atmosphere was then introduced into the exposure chamber at the top center, dispersed by a baffle plate and exhausted at the bottom of the chamber. Air flow rate through the system was measured with a rotameter connected in the air supply line upstream of dust contamination. The rotameter was calibrated with a wet-test meter after the exposure was completed. The concentration of test material dust present in the exposure chamber was determined by sampling the test atmosphere in the breathing zone of the animals being exposed. The total weight of dust collected on a glass fiber filter was divided by the total volume of air drawn through the filter during the sampling period. Air flow rate for sampling was regulated by a calibrated Limiting orifice. The average analytical concentration of airborne dust was obtained by repeated air sampling. A sample of airborne dust was collected from the exposure chamber for the purpose of conducting a microscopic determination of particle size distribution. Particles were counted with respect to 4 size ranges, viz., 5 microns or smaller, 6 to 10 microns, 11 to 25 microns and larger than 25 microns. Particles less than 10 microns are generally considered to be respirable. The smallest particle which can be detected by the light-field technique employed is approximately 1µm. The largest particle observed was also recorded.

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LC50

Effect level:

873.1 mg/m³ air

Based on:

test mat.

Exp. duration:

4 h

Mortality:

All deaths occurred between 8 and 18 hours after exposure.

Clinical signs:

other: The only reaction observed during the 3 exposures was hypoactivity.

Body weight:

Body weight gains for all surviving animals were within the normal limits.

Gross pathology:

No gross tissue changes attributable to the effects of the test material were observed in any of the rats that survived to completion of the study.

Any other information on results incl. tables

Result:

 

Group No	Total Number of Animals      Male/ Female	Nominal Concentration	Mortality Male-Female	Weight Gain Male-Female (grams)
1	5 /5	193.8 mg/m³ air	0/5 - 1/5	82.-48
2	5 /5	850.0 mg/m^³air	4/5 - 3/5	94-36
3	5 /5	2850.0 mg/m^³air	3/5 - 4/5	67-31

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The LC50 of a 4 hour aerosol exposure for rats of both sexes is 873.1 mg/m³ air, when evaluated for a 14-day post treatment observation period.

Executive summary:

The acute inhalation toxicity test was performed with young adult rats. This study was conducted according to method similar or equivalent to OECD test guideline 403. 4 hour inhalation exposure was given to rats by specially constructed inhalation chamber of the animals. Body weight, clinical signs, mortality were monitored throughout an observation period of 14 days. The LC50 of a 4-hours aerosol exposure for rats of both sexes is 873.1 mg/m³ air, when evaluated for a 14 day post-treatment observation period.