3,5,5-trimethylcyclohex-2-enone

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:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference 1

Reference Type:

study report

Title:

Unnamed

Year:

1965

Report date:

1965

Reference 2

Reference Type:

other: OECD SIDS

Title:

3,5,5-Trimethylcyclohex-2-enone (Isophorone), CAS No. 78-59-1

Author:

OECD SIDS

Year:

2003

Bibliographic source:

SIDS Initial Assessment Report for SIAM 16

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

GLP compliance:

no

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

3,5,5-trimethylcyclohex-2-enone

EC Number:

201-126-0

EC Name:

3,5,5-trimethylcyclohex-2-enone

Cas Number:

78-59-1

Molecular formula:

C9H14O

IUPAC Name:

3,5,5-trimethylcyclohex-2-enone

Test animals

Species:

rat

Strain:

Wistar

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Weight at study initiation: 200-225 g
- Housing: wire mesh cages

Administration / exposure

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

whole body

Vehicle:

air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: dynami stainless steel exposure chamber
- Exposure chamber volume: 500 L
- Method of holding animals in test chamber: caged
- System of generating vapors: by means of metering predetermined amounts of the liquid material by a precision metering pump into a stainless steel spray nozzle tip operating under positive air pressure. The material metered through the nozzle were then vaporized by the pressurized air flow directly in the exposure chamber


TEST ATMOSPHERE
- Brief description of analytical method used: nominal dosage concentrations were calculated from the amount of liquid being metered and the total airflow through the chamber.

Analytical verification of test atmosphere concentrations:

no

Duration of exposure:

4 h

Concentrations:

5; 7; 10; 17.8 mg/l

No. of animals per sex per dose:

10

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations: during exposure at 30 min intervals, following exposure once daily
- Necropsy of survivors performed: yes

Results and discussion

Effect levels

Sex:

male

Dose descriptor:

LC50

Effect level:

7 mg/L air

95% CL:

>= 5.7 - <= 8.6

Exp. duration:

4 h

Mortality:

Dose Mortality
[mg/L] 4 hours 14 days
------------------------------------
5 0/10 1/10
7 0/10 4/10
10 10/10 10/10
17.8 10/10 10/10

Clinical signs:

other: see "Other findings"

Gross pathology:

Autopsies of animals that died during exposure and those that survived revealed varying degrees of pulmonary congestion (slight to marked).

Other findings:

During exposure, the animals exposed to the lowest dose level (5 mg/L) showed no effects while those at the higher levels became ataxic and comatose towards the end of the 4-hour exposure period. Following exposure, the surviving animals at the lowest level appeared normal while those at the other levels demonstrated dyspnea, piloerection, depression, and decreased activity.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met