5-ethylidene-8,9,10-trinorborn-2-ene

Exposure related observations in humans: other data

Administrative data

Endpoint:

exposure-related observations in humans: other data

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Remarks:

Basic data given. Meets generally accepted scientific principles.

Data source

Reference

Reference Type:

publication

Title:

The Mammalian Toxicity of Ethylidenenorbornene [5-Ethylidenebicyclo(2,2, 1)hept-2-ene]

Author:

KINKEAD ER, POZZANI UC, GEARY DL, AND CARPENTER CP

Year:

1971

Bibliographic source:

Toxicol Appl Pharmacol 20: 250-259

Materials and methods

Type of study / information:

Odor threshold and sensory response

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

5-ethylidene-8,9,10-trinorborn-2-ene

EC Number:

240-347-7

EC Name:

5-ethylidene-8,9,10-trinorborn-2-ene

Cas Number:

16219-75-3

Molecular formula:

C9H12

IUPAC Name:

5-ethylidenebicyclo[2.2.1]hept-2-ene

Details on test material:

- Name of test material (as cited in study report): Ethylidenenorbornene [5-Ethylidenebicyclo(2,2, 1)hept-2-ene]

Method

Ethical approval:

not specified

Exposure assessment:

estimated

Details on exposure:

Odour Theshold:
In order to ascertain the odour threshold of ENB vapour for human beings, a group of 6 volunteers between 22 and 49 years of age sniffed a series of concentrations for approximately 10 seconds. The series consisted of 3 vapour concentrations and 1 control air concentration, breathed in random order on 2 occasions. This was accomplished in a glass-lined 12,800 L room through which the vapour-air mixture was moved at 2000-3200 L/min. The vapour concentrations were not analyzed for this series of inhalations, but they are reported as corrected concentrations. (These metered concentrations are reduced 44 % to match the mean percent recovery in the repeated inhalation animal study.) The volunteers, who were neither screened nor selected for their olfactory prowess had no knowledge of the concentrations they were inhaling. The intervals between each concentration were at least 45 min.

Sensory Response:
To determine the human sensory response to ENB vapor, 2 male subjects inhaled a corrected concentration of 11.2 ppm, and 4 subjects (3 males and 1 female) inhaled a corrected concentration of 5.6 ppm for 30-min intervals.

Results and discussion

Any other information on results incl. tables

Odour Threshold:

The responses for 10-sec inhalation periods are summarized below:

 

Corrected concentrations (ppm)	0.028	0.014	0.007	0.0
Number of subjects	6	6	6	6
Number of trials	2	2	2	2
Incidence of odour detection(%)	100	100	0	8.3

The odor threshold of ENB vapor for human beings appears to be between a corrected 0.014 ppm and 0.007 ppm.

 

Sensory Response:

Both subjects detected the odor of 11.2 ppm for the entire 30-min exposure. One subject experienced transitory eye and nose irritation at 21 min and eye irritation again at 30 min. One subject reported tasting the vapor during the exposure, and both thought they could taste the material for approximately 10 min after leaving the exposure chamber. One also mentioned slight throat irritation during the first 10 min postexposure. The 4 subjects inhaling 5.6 ppm were able to detect the odor for the entire 30 min. Three subjects, including the female, reported transitory eye irritation, and I male reported tasting the material sporadically. At the start of exposure I male reported a slight dizzy sensation which lasted less than 2 min. Three subjects, including the female, reported tasting the chemical for 10-15 min after the exposure.

Applicant's summary and conclusion

Executive summary:

Kinkead et al. (1971) published results of human volunteer exposures designed to investigate odour threshold and sensory irritation.

The odour threshold was estimated in six volunteers (22-49 years) who sniffed a series of ENB vapour concentrations for ca. 10 seconds in random order. All volunteers detected odour at 0.028 and 0.014 ppm, but none at 0.007 ppm. This small series suggests that the odour threshold for ENB was between 0.007 and 0.014 ppm.

 

Peripheral sensory irritant effects were studied in a few subjects exposed to either 5.6 or 11.2 ppm ENB vapour. At 11.2 ppm, two subjects detected the odour over a 30-min exposure period. One subject had transient nose and eye irritation at 21 min, and a repeat of eye irritation at 30 min. At 5.6 ppm all of four subjects detected the odour, three had transient eye irritation and one had a slight dizzy sensation. Based on this limited information, the human sensory irritant threshold appears to be ca. 5 ppm.