Tetrachloro-p-benzoquinone

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

other: All information on this study is derived from the review article BUA Report 85, as the complete study report is not at hand. The testing laboratory report no. is 6690-68/04

Data source

Reference

Reference Type:

review article or handbook

Title:

BUA Report 85, Ref. Hazleton 1991

Author:

Beratergremium für umweltrelevante Altstoffe der Gesellschaft Deutscher Chemiker (BUA)

Year:

1992

Bibliographic source:

Hirzel Verlag, Stuttgart

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

not specified

Remarks:

as only the respective review article is at hand

GLP compliance:

not specified

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Tetrachloro-p-benzoquinone

EC Number:

204-274-4

EC Name:

Tetrachloro-p-benzoquinone

Cas Number:

118-75-2

Molecular formula:

C6Cl4O2

IUPAC Name:

2,3,5,6-tetrachloro-1,4-benzoquinone

Test animals

Species:

rat

Strain:

other: CD(SD)BR-strain

Sex:

male/female

Administration / exposure

Route of administration:

inhalation: dust

Type of inhalation exposure:

nose/head only

Vehicle:

other: unchanged (no vehicle)

Analytical verification of test atmosphere concentrations:

no

Duration of exposure:

4 h

Concentrations:

gravimetrically determined mean aerosol concentration: 2.485 mg/L air = 2485 mg/m3

No. of animals per sex per dose:

5

Control animals:

not specified

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LC50

Effect level:

ca. 2.485 mg/L air

Exp. duration:

4 h

Remarks on result:

other: The dust aerosol concentration of 2.485 mg/L air was gravimetrically determined. 95% CL could not be determined, as only 1 aerosol concentration was tested.

Mortality:

50 % (sex was not specified in the review article)

Clinical signs:

other: stringy fur, apathy, cool skin surface, bodily discolouring and respiratory distress lasting in a few animals until the second observation week.

Body weight:

Body weight gain was reduced in the survivors during observation week 1 (post inhalation exposure).

Gross pathology:

Macroscopic alterations in upper respiratory tract and lungs in decedent animals. No noteworthy findings in the survivors at 14 days post inhalation exposure.

Other findings:

Increased lung weights in decedent animals.

Applicant's summary and conclusion

Interpretation of results:

harmful

Remarks:

Migrated information Criteria used for interpretation of results: expert judgment

Conclusions:

Head-nose inhalation exposure of male and female rats to 2,3,5,6-tetrachloro-1,4-benzoquinone for 4 hours at a gravimetrically determined mean dust aerosol concentration of 2.485 mg/L air led to the premature death of 5 of 10 animals. Therefore, 2.485 mg/L air was assumed to represent an approximate LC50 (4 hours) for 2,3,5,6-tetrachloro-1,4-benzoquinone.

Executive summary:

2,3,5,6-tetrachloro-1,4-benzoquinone was tested for inhalation toxicity similar to OECD Guideline 403. Reliability grade 4 (reliability not assignable) was assigned to the study, as all information on this study was attained only from a review article. Over a period of 4 hours, five male and five female rats were exposed nose/head only to the test substance at a mean gravimetrically determined dust aerosol concentration of 2.485 mg/L air. The exposure was followed by a 14-day observation period. Mortality, bodyweights, clinical signs and gross necropsy findings were recorded and lung weights were determined. The attained "average particle diameter" of the generated dust aerosol [(probably meaning "average Mass Median Aerodynamic Diameter (MMAD)"] of 1.76 µm was well within the range of 1 to 4 µm MMAD recommended for acute inhalation toxicity testing in rats by various technical guidelines, e.g. EPA OPPTS 870.1300. Therefore, adequate exposure to the test substance over the whole respiratory tract can be assumed.

 

Exposure to the test substance induced 50% mortality, i.e. the premature death of 5 of 10 animals. Clinical signs comprised stringy fur, apathy, cool skin surface, bodily discolouring and respiratory distress lasting in a few animals until the second observation week. Retardation of body weight gain was evident in the survivors during observation week 1. Necropsy revealed alterations in the upper respiratory tract and lungs as well as increased lung weights in decedent animals, but no noteworthy findings were evident in the survivors at their scheduled necropsy 14 days post exposure.

 

In view of the 50% mortality attained, 2.485 mg/L air was assumed to represent an approximate LC₅₀(4 hours) for 2,3,5,6-tetrachloro-1,4-benzoquinone.