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Toxicological information

Acute Toxicity: inhalation

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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, non-guideline study, published in peer reviewed literature, limitations in design and/or reporting but otherwise adequate for assessment.

Data source

Reference
Reference Type:
publication
Title:
Petroleum hydrocarbon toxicity studies: V. Animal and human response to vapors of mixed xylenes.
Author:
Carpenter CP, Kinkead ER, Geary DJ, et al.
Year:
1975
Bibliographic source:
Toxicol Appl Pharmacol 33:543-558.

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
EU Method B.2 (Acute Toxicity (Inhalation))
Principles of method if other than guideline:
Male rats were exposed to measured concentrations of mixed xylenes for 4 hours and observed for up to 14 days. Gross necropsy was performed at the end of the exposure period.
GLP compliance:
not specified
Test type:
standard acute method
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Type:
Constituent
Details on test material:
Mixed xylenes (m- 65.01%, o- 7.63%, p- 7.84%).

Test animals

Species:
rat
Strain:
not specified
Sex:
male
Details on test animals and environmental conditions:
no data

Administration / exposure

Route of administration:
inhalation: vapour
Type of inhalation exposure:
whole body
Vehicle:
other: air
Details on inhalation exposure:
no data
Analytical verification of test atmosphere concentrations:
no
Duration of exposure:
4 h
Concentrations:
43, 26, 12, 5.8 and 2.5 mg/L (9900, 6000, 2800, 1300 and 580 ppm)
No. of animals per sex per dose:
15
Control animals:
not specified
Details on study design:
For 4 hour periods, 15 male rats were exposed to measured concentrations of mixed xylenes that varied by a twofold factor. In each group, ten of the rats were followed for up to 14 days to determine the LC50 and five were sacrificed for gross autopsy at the end of the exposure period.
Statistics:
LC50 with its fiducial range, was calculated according to the methods of Thompson and of Weil.

Results and discussion

Effect levels
Sex:
male
Dose descriptor:
LC50
Effect level:
6 700 ppm
95% CL:
5 100 - 8 500
Exp. duration:
4 h
Remarks on result:
other: 29091 mg/m3
Mortality:
Mortalities occurred as follows: 43 mg/L (9900 ppm) 10/10; 26 mg/L (6000 ppm) 4/10; and 12 mg/L (2800 ppm), 5.8 mg/L (1300 ppm), and 2.5 mg/L (580 ppm) 0/10 rats. Deaths at the 43 mg/L level occurred within 2.25 hr. At 26 mg/L, rats were prostrate in 30 min and four died within 3.5 hr.
Clinical signs:
All survivors were prostrate as the exposure ended but recovered promptly and appeared normal throughout the 14-day observation period.
Gross pathology:
Of the rats that died within 2.25 hr at 43 mg/L there were 2 cases each of atelectasis, haemorrhage, and interlobular oedema of the lungs.

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 6700 ppm (29000 mg/m3) in male rats.
Executive summary:

Groups of 10 male rats were exposed to measured concentrations of mixed xylenes for 4 hours followed by a 14 day observation period. Five survivors per dose level were then subject to gross necropsy. All exposures caused CNS depression, with a LOAEC of 580 ppm (2.5 mg/L). The LC50 of mixed xylene in male rats after 4 hours exposure was 6700 ppm (29091 mg/m3).