Registration Dossier

Toxicological information

Direct observations: clinical cases, poisoning incidents and other

Administrative data

Endpoint:
direct observations: clinical cases, poisoning incidents and other
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Non-GLP, non guideline study, human case study, limitations in design and/or reporting but otherwise adequate for assessment.
Cross-reference
Reason / purpose:
reference to same study

Data source

Reference
Reference Type:
publication
Title:
Unnamed
Year:
1971

Materials and methods

Study type:
study with volunteers
Endpoint addressed:
eye irritation
respiratory irritation
Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
Determination of odour threshold and human sensory response
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): dicyclopentadiene
- Physical state: Clear colourless liquid
- Analytical purity: 96.7%, isomeric mixture of endo/exo in a 95:5 ratio
- Molecular weight: 132.21
- Boiling point at 100 mm Hg: 105°C
- Specific gravity: 0.9816 at 20/20°C
- Flash point (Tag upon cup): 150°F
- Vapour pressure at 20°C, 1.4 mm
- Melting point: 16-18°C
- Inhibitor (tertiary butyl catechol), 141 ppm

Method

Type of population:
other: volunteers
Subjects:
- Number of subjects exposed: 3 (odour threshold), 2 (sensory response)
- Age: 24-47 years
- Subjects: blind to inhaled concentration
Ethical approval:
not specified
Route of exposure:
inhalation
Reason of exposure:
intentional
Exposure assessment:
measured
Details on exposure:
Exposure concentrations not analysed in odour threshold study. Analysed by gas chromatography in the sensory response test.
Exposure was in a glass-lined 12800 L room from which the vapour-air mixture was exhausted at 2500-3200 L/min.

Results and discussion

Clinical signs:
Human sensory response test: During the 30-min exposure to 1 ppm, one subject experienced slight eye and throat irritation at 7 min and one subject reported olfactory fatigue after 24 min.
No olfactory fatigue was reported by either subject during the 30-min exposure to 5.5 ppm dicyclopentadiene vapour. Eye irritation was reported by one subject after 10 min at this concentration. One subject could taste dicyclopentadiene for 1 hr after the 5.5 ppm exposure.
Results of examinations:
Odour threshold study: The odour threshold of dicyclopentadiene vapour for man appears to be slightly below a corrected 0.003 ppm.
.Responses for 10 second inhalation period as follows: % incidence of odour detection 100, 67 and 0 % for corrected concentrations of 0.006, 0.003 and 0.0006 ppm respectively (no of subjects 6, 6 and 12 respectively).

Human sensory response test: During the 30-min exposure to 1 ppm, one subject experienced slight eye and throat irritation at 7 min and one subject reported olfactory fatigue after 24 min. No olfactory fatigue was reported by either subject during the 30-min exposure to 5.5 ppm dicyclopentadiene vapour. Eye irritation was reported by one subject after 10 min at this concentration. One subject could taste dicyclopentadiene for 1 hr after the 5.5 ppm exposure.

Applicant's summary and conclusion

Conclusions:
Human sensory response studies showed that dicyclopentadiene vapour can be detected at 0.003 ppm. Following inhalation of 1 ppm or 5.5 ppm for 30 minutes, sporadic eye and throat irritation was reported. It was therefore recommended that workmen should not inhale more than 5 ppm dicyclopentadiene for extended periods (i.e. 8 hours/day, 5 days/week).
Executive summary:

Human sensory response studies showed that dicyclopentadiene vapour can be detected at 0.003 ppm. Following inhalation of dicyclopentadiene vapour at concentrations of 1 ppm or 5.5 ppm for 30 minutes, sporadic eye and throat irritation was reported in two volunteers.