Distillates (petroleum), cracked steam-cracked petroleum distillates

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 for cross-reference:

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

Test material information

Constituent 1

Reference substance name:

Reference substance 001

Cas Number:

77-73-6

Molecular formula:

C10H12

Constituent 2

Reference substance name:

Dicyclopentadiene

IUPAC Name:

Dicyclopentadiene

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.