[No public or meaningful name is available]

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

No data

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP compliant, near guideline study, available as unpublished report, adequate for assessment

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1981

Report date:

1981

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

yes

Remarks:

6 hour exposure

GLP compliance:

yes

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Reference substance 001

Cas Number:

77-73-6

Molecular formula:

C10H12

Details on test material:

- Name of test material (as cited in study report): Dicyclopentadiene (DCPD)
- Physical state: clear colourless liquid at room temperature
- Analytical purity: ~97% endo- and ~1% cyclopentadiene

Test animals

Species:

mouse

Strain:

B6C3F1

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan Industries Inc., Indianapolis, Indiana, USA
- Age at study initiation: approximately 6-7 weeks old
- Weight at study initiation: no data
- Fasting period before study: no data
- Housing: 2 per cage in stainless steel cages
- Diet: powdered chow diet ad libitum except during exposure
- Water: ad libitum except during exposure
- Acclimation period: approximately 2 weeks

ENVIRONMENTAL CONDITIONS
- Temperature: 69-74°F
- Humidity: 30-63%
- Photoperiod: 12 hrs dark /12 hrs light

IN-LIFE DATES: no data

Administration / exposure

Route of administration:

inhalation: vapour

Type of inhalation exposure:

whole body

Vehicle:

other: air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Dicyclopentadiene vapour was generated inside a heated Pyrex tube to achieve complete vaporization while keeping temperature below the point (35°C) at which fracturing to monomer occurred.

TEST ATMOSPHERE
- Chamber concentrations of DCPD and cyclopentadiene (CPD) were monitored by gas chromatography/flame ionization detection with detection limit of 0.05 ppm for both compounds.

Analytical verification of test atmosphere concentrations:

yes

Remarks:

by gas chromatography/flame ionization detection

Duration of exposure:

6 h

Concentrations:

Target concentrations were 50, 150, 300 and 600 ppm.
Actual exposure concentrations were 46, 130, 260 and 557ppm.

No. of animals per sex per dose:

6

Control animals:

not specified

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations: animals were observed daily for clinical signs
- Necropsy of survivors performed: yes

Statistics:

LC50 was calculated by the method of moving averages.

Results and discussion

Effect levels

Effect levels 1

Sex:

male

Dose descriptor:

LC50

Effect level:

143 ppm

95% CL:

130 - 157

Exp. duration:

6 h

Remarks on result:

other: 774 mg/m3 air (analytical)

Effect levels 2

Sex:

female

Dose descriptor:

LC50

Effect level:

130 ppm

95% CL:

103 - 153

Exp. duration:

6 h

Remarks on result:

other: 703 mg/m3 (analytical)

Effect levels 3

Sex:

male/female

Dose descriptor:

LC50

Effect level:

738.5 mg/m³ air (analytical)

Exp. duration:

6 h

Effect levels 4

Sex:

male/female

Dose descriptor:

other: NOAEC for irregular breathing, stereotypic behaviour

Effect level:

46 ppm

Remarks on result:

other: 248.74 mg/m3

Mortality:

There were mortalities in male and female mice exposed to 557 and 260 ppm. (The actual numbers of mice dying at the various exposure levels were not presented in the report)

Clinical signs:

other:

Remarks:

At 557 ppm, loss of righting reflex, impaired gait, stereotypic behaviour, laboured breathing, clear nasal discharge and deaths. At 260 ppm, both sexes showed stereotypic behaviour, respiratory difficulty, impaired gait, hunched posture.

Body weight:

No data

Gross pathology:

There were no gross pathological effects noted at necropsy.

Any other information on results incl. tables

Incidence of mortality following single 6-hour inhalation exposure

Target Concentration (ppm)	Dead/dosed		Comment
	male	female
600	6/6	6/6	Males: 3 dead during exposure. 1 died immediately post-exposure and 1 post-exposure. 1 died the day following exposure. Females: 1 dead during exposure. 2 died immediately post-exposure. 3 died the day following exposure.
300	6/6	6/6	Males: All found dead the day after exposure. Females: 1 dead during exposure. 3 died immediately post-exposure. 2 died the day following exposure.
150	2/6	3/6	Males: 2 found dead the day after exposure. Females: 1 died immediately post-exposure. 2 died the day following exposure.
50	0/6	0/6

 

Applicant's summary and conclusion

Interpretation of results:

Category 2 based on GHS criteria

Remarks:

Criteria used for interpretation of results: EU

Conclusions:

Following a 6 hour whole body, inhalation exposure to dicyclopentadiene vapour, the LC50 was 143 (130-157) ppm (male) and 126 (103-153) ppm (emale). The results were not confounded by the fracturing of dicyclopentadiene into cyclopentadiene. The male/female 6 hour LC50 is equivalent to 738.5 mg/m3.

Executive summary:

Groups of 6 male and 6 female B6C3F1 mice were exposed (whole body) to 46, 130, 260 or 557 ppm dicyclopentadiene vapour for 6 hours and then observed daily for up to 14 days. At 557 and 260 ppm, all animals died within 24 hours of exposure. At 130 ppm, 2 males were found dead on the day after exposure, 1 female died immediately post exposure and 2 died on the day following exposure. There were no deaths at 46 ppm. Clinical signs included loss of righting reflex, impaired gait, stereotypic behaviour, laboured breathing, clear nasal discharge, loss of coordination and convulsions prior to death. The LC50 was 143 ppm (male) and 126 ppm (female), equivalent to 774 and 703 mg/m3, respectively.