Dipotassium disulphate

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

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

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: This study was selected as the key study because the information provided for the hazard endpoint is sufficient for the purpose of classification and labelling and/or risk assessment.

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

publication

Title:

The toxicity of H2SO4 aerosols to CD-1 mice and Fischer-344 rats

Author:

Runkle BK and Hahn FF

Year:

1976

Bibliographic source:

Annual Report of the Inhalation Toxicology Research Institute, p. 435-439

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

yes

Remarks:

Animals observed for 21 days

GLP compliance:

not specified

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Sulphuric acid

EC Number:

231-639-5

EC Name:

Sulphuric acid

Cas Number:

7664-93-9

IUPAC Name:

sulfuric acid

Details on test material:

- Purity: not reported

Test animals

Species:

rat

Strain:

Fischer 344

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: 6-7 weeks

Administration / exposure

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

whole body

Vehicle:

other: humid air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: 27-inch Rochester-type chronic exposure chamber
- Method of holding animals in test chamber: individual cages
- System of generating particulates/aerosols: mixing SO3 with humid air to produce H2SO4 droplets
- Source and rate of air: 10 cfm
- Temperature, humidity, pressure in air chamber: 40% humidity; temperature and pressure not reported

TEST ATMOSPHERE (if not tabulated)
- MMAD (Mass median aerodynamic diameter): 1.1 - 2.2 µm

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

>= 1 - <= 8 h

Remarks on duration:

selected exposure times were 1, 2, 4 and 8 hours for each concentration

Concentrations:

240, 470, 730, 800, 1080 and 1090 mg/m³

No. of animals per sex per dose:

8

Control animals:

no

Details on study design:

- Duration of observation period following administration: 21 days
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight, organ weights, histopathology; Animals dying spontaneously and sacrificed animals were necropsied. The time of death was noted, and the lung, trachea, stomach and turbinates were removed, fixed in 10% formalin and processed for histologic examination using standard procedures.

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LC50

Effect level:

ca. 375 mg/m³ air (nominal)

Based on:

test mat.

Exp. duration:

4 h

Mortality:

Mortality was 0, 63, 63, 75, 63 and 88% after 4-hour exposure to 240, 470, 730, 800, 1090 and 1080 mg/m³, respectively.
The majority of rats died during the 2 weeks after exposure. Exceptions to this were early deaths which occurred when rats were exposed to H2SO4 concentrations above 700 mg/m3 for 4 to 8 hours.

Gross pathology:

Examination of rat tissues revealed ulceration of turbinates, trachea and larynx in animals dying during exposure or shortly thereafter. Lesions noted in rats dying 1-2 weeks after exposure included fibrosis of the larynx and bronchopneumonia associated with aspirated foreign material.

Other findings:

Rats showed increased mortality with increased concentration. This appeared more dramatically in mice than in rats during the first 24 hours. The fact that deaths occurred within 24 hours in the mouse group exposed for 1 and 2 hours and not in the rat group may be interpreted as an indication of greater sensitivity in the mouse. When total deaths in 21 days were considered, however, the rat appeared to exhibit increased sensitivity with increased H2S04 concentration as did the mouse. In fact, rat mortality increased more rapidly with increased concentration than mouse mortality. No deep lung lesions were noted in rats that could be attributed to direct test substance insult. Animals died from upper respiratory tract lesions before test substance aerosol concentrations affected the deep lung.

Applicant's summary and conclusion

Interpretation of results:

moderately toxic

Remarks:

Migrated information Criteria used for interpretation of results: expert judgment

Conclusions:

This study and the conclusions which are drawn from it fulfil the quality criteria (validity, reliability, repeatability).
LC50 was approximately 375 mg/m³ for rats.

Executive summary:

Rats (Fischer-344) were exposed to various concentrations of test substance aerosols for 1 to 8 hours. Mortality and histologic changes resulting from these exposures were determined. Mortality in the majority of rats occurred 1-2 weeks following exposure, the exception being early deaths resulting from very high aerosol concentrations. Examination of tissues revealed ulceration of the turbinate, trachea and larynx in rats dying during exposure or shortly thereafter. Lesions noted in rats dying 1-2 weeks after exposure included bronchopneumonia associated with aspirated foreign material. No deep lung lesions were noted in rats that could be attributed to direct test substance insult. Animals died from upper respiratory tract lesions before test substance aerosol concentrations affected the deep lung. The LC₅₀ for rats was approximately 375 mg/m³.