p-cymene

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:

accepted calculation method

Data source

Reference

Reference Type:

other: Unpublished report

Title:

Unnamed

Year:

1962

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

- Principle of test: Rats were exposed to atmospheres saturated with 9.7 mg /L of pcymene for a period of 5 hours. A "lethal concentration time value (LCt)" was calculated based on the "shortest period of exposure causing death", where the concentration was expressed as mg/l and time as minutes.
- Parameters analysed / observed: Clinical signs and mortality were recorded.

GLP compliance:

no

Test type:

other: Acute inhalation toxicity in rats

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

p-cymene

EC Number:

202-796-7

EC Name:

p-cymene

Cas Number:

99-87-6

Molecular formula:

C10H14

IUPAC Name:

1-isopropyl-4-methylbenzene

Test animals

Species:

rat

Sex:

not specified

Details on test animals or test system and environmental conditions:

not specifed

Administration / exposure

Route of administration:

inhalation

Type of inhalation exposure:

not specified

Vehicle:

air

Details on inhalation exposure:

not specifed

Analytical verification of test atmosphere concentrations:

not specified

Duration of exposure:

ca. 5 h

Concentrations:

Rats were exposed to atmospheres saturated with 9.7 mg /L of p-cymene for a period of 5 hours.

No. of animals per sex per dose:

3

Control animals:

not specified

Details on study design:

- Duration of observation period following administration: 30 min, 45 min and 1 day
- Frequency of observations and weighing: not specified
- Necropsy of survivors performed: no
- Other examinations performed: clinical signs

Statistics:

A "lethal concentration time value (LCt)" was calculated based on the "shortest period of exposure causing death", where the concentration was expressed as mg/l and time as minutes

Results and discussion

Preliminary study:

not applicable

Effect levels

Key result

Sex:

not specified

Dose descriptor:

other: lethal concentration time value (LCt)

Effect level:

> 9.7 mg/L air

Based on:

test mat.

Exp. duration:

5 h

Remarks on result:

other: no deaths

Mortality:

No deaths were reported

Clinical signs:

other: other:

Body weight:

not specified

Gross pathology:

not specified

Applicant's summary and conclusion

Interpretation of results:

study cannot be used for classification

Conclusions:

A "lethal concentration time value (LCt)" of >9.7 mg/L was calculated based on the "shortest period of exposure causing death", where the concentration was expressed as mg/l and time as minutes. No deaths were observed during the exposure period. The morning after exposure, the rats appeared fully recovered from the clinical signes observed during the exposure period.
 

Executive summary:

In this study, rats were exposed to atmospheres saturated with 9.7 mg /L of p-Cymene for a period of 5 hours. Clinical signs and mortality were recorded. Surviving animals were removed from the exposure chamber and observed for an additional week.

Signs reported during the first 30 minutes were those typical of irritation: excitement, pawing at the eyes and nose, increased blinking, squinting, and eye closure. After 45 minutes, equilibrium loss and increased salivation were noted. One-half hour later, fine tremors began and increased to quivering after another 15 minutes. Clonic convulsions were reported after another 15 minutes and the rats staggered about aimlessly until the end of the exposure. The morning after exposure, the rats appeared fully recovered.

A "lethal concentration time value (LCt)" of >9.7 mg/Lwas calculated based on the "shortest period of exposure causing death", where the concentration was expressed as mg/l and time as minutes.