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

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP status not known, guideline study, published in peer reviewed literature, no restrictions, fully adequate for assessment.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1986

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method B.1 (Acute Toxicity (Oral))

GLP compliance:

no

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

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:

60.2% m-xylene, 13.6% p-xylene, 9.1% o-xylene, and 17.0% ethylbenzene

Test animals

Species:

rat

Strain:

other: F344/N

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Breeding Laboratories (Kingston, NY, USA)
- Age at study initiation: 7 weeks
- Housing: 5 per sex /cage in polycarbonate cages
- Diet: Purina Lab Chow available ad libitum
- Water: ad libitum
- Acclimation period: 18 days

ENVIRONMENTAL CONDITIONS
- Temperature: 22° ± 1°C
- Humidity: 40 - 60%
- Air changes: 15 air changes/hour
- Photoperiod: 12 hour dark/ 12 hour light

IN-LIFE DATES: From: 5 March 1979 To: 19 March 1979

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on oral exposure:

Oral (gavage): 500, 1000, 2000, 4000 or 6000 mg/kg xylenes (mixed) in corn oil; dose volume 8 mL/kg
Preparation: Weighed portions of xylenes (mixed) were placed in a graduated cylinder and mixed with corn oil.

Doses:

Single dose

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

Groups of five rats of each sex were administered a single dose of 500, 1,000, 2,000, 4,000, or 6,000 mg/kg xylenes in corn oil by gavage. The animals were observed twice daily for 14 days and were killed on day 16. A necropsy was not performed.

Statistics:

LD50 calculated by Spearman-Karber procedure.

Results and discussion

Effect levels

Effect levels 1

Sex:

male

Dose descriptor:

LD50

Effect level:

3 523 mg/kg bw

95% CL:

2 707 - 4 587

Effect levels 2

Sex:

female

Dose descriptor:

LD50

Effect level:

> 4 000 mg/kg bw

Mortality:

All the rats that received 6,000 mg/kg and 3 of 5 males that received 4,000 mg/kg died within 48 hours of dosing.

Clinical signs:

other: other: Lack of coordination, prostration, loss of hindleg movement, and hunched posture were detected within 24 hours of dosing in male and female rats that received 4,000 or 6,000 mg/kg. Male and female rats that received 2,000 mg/kg had rough coats. N

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

Criteria used for interpretation of results: EU

Conclusions:

The oral LD50 in rats was 3523 mg/kg/bw for males and greater than 4000 mg/kg/bw for females.

Executive summary:

In a single-administration study, groups of five F344/N rats of each sex received 500, 1,000, 2,000, 4,000, or 6,000 mg/kg. Administration of mixed xylenes caused deaths at 6,000 mg/kg in each sex and at 4,000 mg/kg in males. Clinical signs observed within 24 hours of dosing at 4,000 mg/kg included prostration, muscular incoordination, and loss of hind limb movement; these effects continued through the second week of observation. The LD50 was 3523 mg/kg/bw for males and greater than 4000 mg/kg/bw for females.