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Exposure related observations in humans: other data

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Administrative data

Endpoint:
exposure-related observations in humans: other data
Type of information:
experimental study
Adequacy of study:
key study
Study period:
no data
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1965
Report date:
1965

Materials and methods

Type of study / information:
Human sensory irritation
Endpoint addressed:
respiratory irritation
Principles of method if other than guideline:
Experiment was designed to establish the human sensory-irritation threshold of isophorone.
GLP compliance:
no

Test material

Constituent 1
Chemical structure
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
Constituent 2
Reference substance name:
Isophorone
IUPAC Name:
Isophorone
Details on test material:
Origin: Esso Research and Engineering Company, 21 Dec 1964, used as received

Method

Ethical approval:
confirmed and informed consent free of coercion received
Details on study design:
- Criteria:
1. Detection of odor
2. Nose irritation
3. Eye irritation
4. Throat irritation (instead of skin irritation)
5. Mask removal
- Other information:  The test substance did not vaporize immediately, but as there was no  deposition on the walls of the aerosol chamber, 
complete vaporization was assumed. Nominal concentrations were reported.
Exposure assessment:
measured
Details on exposure:
PERSONS EXPOSED: 6
EXPOSURE
- Reason of exposure:  determination of human sensory irritation thresholds
- Type of exposure: gaseous via face mask
- Duration of exposure: 7 minutes per concentration
- Exposure concentrations / dose:   
week 1: 100; 199; 377; 513 mg/m3   
week 2: 359; 595 mg/m3

Results and discussion

Results:
The 7-minute airborne exposure NOAEL for throat and eye irritation in humans are 100 and 199 mg/m3, respectively. The test substance is classified as an irritant to eyes and respiratory system. 100 % odor detection of isophorone was found at 100 mg/m3.

Any other information on results incl. tables

positive observations:
odor detection:     6/6 at 100 mg/m3
nasal irritation:   4/6 at 377 mg/m3; 5/6 at 513 mg/m3
eye irritation:     1/6 at 377 mg/m3; 1/6 at 513 mg/m3
throat irritation:  1/6 at 199 mg/m3; 2/6 at 377 mg/m3
mask removal:       1/6 at 513 mg/m3; 1/6 at 595 mg/m3
second series following week: no significant difference

Conclusion:

Throat irritation < 35 ppm (199 mg/m3) Eye and nasal irritation < 64 ppm (359 mg/m3)

Applicant's summary and conclusion

Conclusions:
In humans irritating effects in eyes, nose and thraot are observed after 7 minutes exposure to concentrations above 100 (= NOAEL, human, throat) and 199 (= NOAEL, human, eyes and nose) mg isophorone/m3.
Executive summary:

The irritating potential of isophorone was determined in an investigation with 6 volunteers. After exposure to 100, 199, 377 and 513 mg/m3 (week 1) and 359 and 595 mg/m3 (week 2) isophorone for 7 minutes, throat irritation was reported at >= 199 mg/m3, and eye and nasal irritation at concentrations of >= 359 mg/m3. The 7-minute airborne exposure NOAEL for throat and eye irritation in humans are therefore 100 and 199 mg/m3, respectively. The test substance is classified as an irritant to eyes and respiratory system. 100 % odor detection of isophorone was found at 100 mg/m3.