3-cyano-3,5,5-trimethylcyclohexanone

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1999-01-05 to 1999-02-16

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1999

Report date:

1999

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1300 (Acute inhalation toxicity)

GLP compliance:

yes

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

3-cyano-3,5,5-trimethylcyclohexanone

EC Number:

411-490-4

EC Name:

3-cyano-3,5,5-trimethylcyclohexanone

Cas Number:

7027-11-4

Molecular formula:

C10H15NO

IUPAC Name:

3-cyano-3,5,5-trimethylcyclohexanone

Details on test material:

Isophorone nitrile of Creanova (former Hüls, later Degussa) from continous production on 16 Nov 1998.
Purity 99.6 % (GC)

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ORGANISMS: 
- Strain: HanIbm:WIST(SPF) = HanBrl:WIST(SPF)
- Source: RCC Ltd., Biotechnology & Animal Breeding Division, Füllinsdorf  (CH)
- Age: 9-10 weeks
- Weight at study initiation: males 210.6-238.1 g,females 193.7-224.0 g
- Number of animals: 5 per dose and gender
- Housing: groups of five
- Diet: ad libitum, rat maintenance diet Kliba 3433
- Water: ad libitum, tab water
- Acclimation period: 5 to 6 days
ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20°C +/- 1 °C
- Humidity (%): 43 - 66 %
- Air changes (per hr): 10 - 15 per hour
- Photoperiod (hrs dark / hrs light): 12 hours darkness, 12 hours artifical light

Administration / exposure

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

nose only

Vehicle:

other: compressed filtered air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Type of exposure: nose-only, flow-past according to Sachsse et al.  (1973, 1976)
- Method of holding animals in test chamber: separatley in restraint tubes, positioned radially around the exposure chamber
- Source and rate of air: compressed filtered air, 5.0 - 5.6 l/min
- Method of conditioning air: calibrated pressure gauge and flow meter
- Type or preparation of particles: Warming to 76-88 °C in a  polyethyleneglycol 400 bath followed by aerosol generation with a glass  
nebulizer with stainless steel nozzle and inlet
- Method of particle size determination: gravimetrically determination using a Mercer 7 stage cascade impactor
- Temperature, humidity: T: 22.1 - 22.6°C, H: 8.0 - 11.2 % RH,
TEST ATMOSPHERE
- Concentrations: 291; 1554; 3566 mg/m3 nominal (i.e. decrease in weight  of test material divided by airflow volume)   
256 +/- 17 (n=5); 979 +/- 50 (n=10); 3031 +/- 272 (n=9) mg/m3  analytical (using glass fiber filters)
- Brief description of analytical method used: Gravimetric determination of aerosol concentrations, samples from test atmosphere were collected
during the exposure (5/Group 1, 10/Group 2, 9/Group 3) on Gelman glass fiber filters, loaded in a 47 mm inline stainless steel filter sampling
device (Gelman Science Inc.)
- Particle size: in order of increasing test concentration mass median aerodynamic diameters 2.86; 2.21; 1.70 µm   
geometric standard deviations 3.05 (n=3); 2.33 (n=2); 1.81 (n=2)
- Samples taken from breathing zone: yes, from an empty port of the exposure chamber

Analytical verification of test atmosphere concentrations:

yes

Remarks:

Gravimetric determination of aerosol concentrations. In view of the fairly low vapor pressure and high purity of the test article, determination of aerosol concentrations by chemival analysis were not deemed necessary.

Duration of exposure:

4 h

Concentrations:

256 +/- 17; 979 +/- 50; 3031 +/- 272 mg/m3

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

EXAMINATIONS: 
- Post dose observation period: 14 days
- body weights: before and 3, 7, and 14 days after treatment   mortality: once per hour during, and once after treatment on day of  exposure; 
thereafter twice daily
- clinical signs: three times during exposure, at end of exposure,  thereafter once daily including day of treatment, including: changes in  behavior, 
somatomotor activity, body position, respiratory and  circulatory effects, autonomic effects, central nervous system effects,  reactivity to handling 
or sensory stimuli, altered strength, alteration  of skin, fur, nose, and eyes. 
- Necropsy: all animals (macroscopic) when found dead or at terminal  sacrifice

Statistics:

LOGIT-Model (Program for Dosa-Response Analysis) was used to evaluate the toxicity of isophorone nitril and to calculate the LC50 value with its
95 % confidence limits

Results and discussion

Effect levels

Effect levels 1

Sex:

male/female

Dose descriptor:

LC50

Effect level:

1.34 mg/L air

95% CL:

0.84 - 2.75

Exp. duration:

4 h

Remarks on result:

other: no remarks

Effect levels 2

Sex:

male

Dose descriptor:

LC50

Effect level:

1.4 mg/L air

95% CL:

0.66 - 6.82

Exp. duration:

4 h

Remarks on result:

other: no remarks

Effect levels 3

Sex:

female

Dose descriptor:

LC50

Effect level:

1.2 mg/L air

95% CL:

0.59 - 4.02

Exp. duration:

4 h

Remarks on result:

other: no remarks

Mortality:

MORTALITY:- Number of deaths at each dose:     
256 mg/m3: no deaths    
979 mg/m3: 0 males, 1 female dead within 48 minutes after end of  exposure   
3031 mg/m3: 5 males, 5 females dead within 3 hours 24 minutes after  beginning of exposure

Clinical signs:

other: CLINICAL SIGNS: Salivation (256 and 979 mg/m3); effects on breathing  (bradypnea and/or tachypnea; 979 and 3031 mg/m3); ruffled fur and   behavioral effects (restlessness and decreased spontaneous activity; 979  mg/m3); 1 male and 1 female with red skin/f

Body weight:

BODY WEIGHT: Body weight gain was transiently inhibited only in surviving  females at 979 mg/m3.

Gross pathology:

NECROPSY FINDINGS: There were no macroscopical pathology findings which  could be attributed to treatment with the test article. 

Other findings:

no other findings

Any other information on results incl. tables

no further remarks

Applicant's summary and conclusion

Interpretation of results:

harmful

Remarks:

Migrated information Criteria used for interpretation of results: other: EU Directive 67/548/EEC

Conclusions:

The LC 50 of isophorone nitrile for acute inalation toxicity (4 h) was estimated to be 1.34 mg/l air. The no toxic level was 0.256 mg/l air whist one of ten animals died at 0.979 mg/l air and all animals at 3.031 mg/l air.

Executive summary:

The aim of this acute 4-hour inhalation study was to assess the acute inhaltion toxicity of isophorone nitrile when administered to rats for a single continuous 4-hour period followed by an observation period of 15 days. 3 groups of five male and five female Wistar rats were exposed by nose only, flow past inhaltion with concentrations of 0.256; 0.979 and 3.031 mg/l air. Principal clinical signs were salivation seen at 0.256 and 0.979 mg/l air, effects on breathing (bradypnea and/or tachypnea) at 0.979 ans 3.031 mg/l air, and behavioural effects (restlessness and decreased spontaneous activity) and ruffled fur at 0.979 mg/l air. Body weight development was not adversely affected in both genders at 0.256 mg/l air and in males at 0.979 mg/l air. A transient slight loss of body weight was seen in the surviving females at 0.979 mg/l air. There were no macroscopical pathology findings which could be attributed to treatment with the test article. The LC 50 of isophorone nitrile for acute inalation toxicity (4 h) was estimated to be 1.34 mg/l air. The no toxic level was 0.256 mg/l air whist one of ten animals died at 0.979 mg/l air and all animals at 3.031 mg/l air.