reaction mass of ethylbenzene and m-xylene and p-xylene

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP status not known, near guideline study, published in peer reviewed literature, minor restrictions in design and/or reporting but otherwise adequate for assessment.

Data source

Reference

Reference Type:

publication

Title:

The toxicological properties of hydrocarbon solvents

Author:

Hine CH, Zuidema HH

Year:

1970

Bibliographic source:

Industrial Medicine 39, 215-200.

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method B.2 (Acute Toxicity (Inhalation))

Principles of method if other than guideline:

Groups of 10 male rats were exposed to (unspecified) concentrations of C-8 aromatics for 4 hours followed by a 14 day observation period.

GLP compliance:

not specified

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

mixed xylenes

EC Number:

924-522-1

IUPAC Name:

mixed xylenes

Constituent 2

Reference substance name:

Xylene

EC Number:

215-535-7

EC Name:

Xylene

Cas Number:

1330-20-7

Molecular formula:

C8H10

IUPAC Name:

xylene

Details on test material:

C-8 aromatics (ortho, meta and para xylene, ethylbenzene composition not defined). Boiling range 138-141°C.

Test animals

Species:

rat

Strain:

Long-Evans

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
Body weight 150 - 300 g.

Administration / exposure

Route of administration:

inhalation: vapour

Type of inhalation exposure:

whole body

Vehicle:

other: air

Details on inhalation exposure:

A 250 L chamber was used for the vapour exposures. Air entering the chamber was bubbled through the sample, heated to 25°C in a water bath in order to obtain an atmosphere as close to saturated as possible. Vapour concentration in the chamber was monitored by means of a Wilkens Aerograph GLC and compared with the vapour concentration obtained from a bottle known to contain vapours saturated at 25C. For graded concentrations less than saturated, the air flow entering the chamber was divided so that only part of it passed through the sample. Rats were exposed for four hours and ten rats were used for each exposure.

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Concentrations:

not stated

No. of animals per sex per dose:

10

Control animals:

not specified

Details on study design:

Animals were retained for a minimum of 14 days after exposure and mortality values were based on the number of animals which died during this interval.

Statistics:

LD50 values were determined by the method of Litchfield and Wilcoxon

Results and discussion

Effect levels

Sex:

male

Dose descriptor:

LC50

Effect level:

6 350 ppm

95% CL:

4 670 - 8 640

Exp. duration:

4 h

Remarks on result:

other: 27571 mg/m3

Mortality:

All deaths (number not reported) occurred during exposure.

Clinical signs:

other: Survivors were comatosed but recovered shortly following removal from the chamber.

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The inhalation LC50 was 6350 ppm in the rat.

COMMENT TO TSC: conversion to mg/L required once phys-chem properties confirmed.

Executive summary:

Groups of male rats were exposed to (unspecified) concentrations of C-8 aromatics for 4 hours followed by a 14 day observation period. All exposures caused CNS depression (animals described as being in a comatose state), with an overall LC50 of 6350 ppm.

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