Naphtha (petroleum), light steam-cracked, debenzenized, C8-16-cycloalkadiene conc.

Acute Toxicity: inhalation

Some information in this page has been claimed confidential.

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other: GLP compliant, near guideline study, available as unpublished report, adequate for assessment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

Cross-reference 1

Reason / purpose for cross-reference:

read-across: supporting information

Cross-reference 2

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

Principles of method if other than guideline:

Fischer 344 rats, 6/sex, subjected to single (6 h) whole-body exposure of 46, 130, 260 or 557 ppm DCPD.

GLP compliance:

yes

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Details on test material:

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

Test animals

Species:

rat

Strain:

Fischer 344

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Microbiological Associates, Walkersville, Maryland, US
- Age at study initiation: no data
- Weight at study initiation: no data
- Fasting period before study: no
- 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
- DCPD 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 557 ppm.

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

Key result

Sex:

male

Dose descriptor:

LC50

Effect level:

284 ppm

95% CL:

236 - 341

Exp. duration:

6 h

Remarks on result:

other: 1536 mg/m³ air (analytical)

Effect levels 2

Key result

Sex:

female

Dose descriptor:

LC50

Effect level:

353 ppm

95% CL:

322 - 387

Exp. duration:

6 h

Remarks on result:

other: 1910 mg/m³ air (analytical)

Effect levels 3

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

1 723 mg/m³ air (analytical)

Exp. duration:

6 h

Mortality:

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

Clinical signs:

other:

Body weight:

No data.

Gross pathology:

There were no gross pathological effects noted at necropsy.

Any other information on results incl. tables

Mortality in Fischer 344 rats following single 6-hour inhalation exposure

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

Applicant's summary and conclusion

Interpretation of results:

other: toxic

Remarks:

Criteria used for interpretation of results: EU

Conclusions:

Following a single, whole body, inhalation exposure to vapours of DCPD, the 6 hour LC50 was 284 (236-341) ppm in males and 353 (322-387) ppm in females. The LC50s reflect the effects of DCPD. Results were not confounded by fracturing of DCPD into CPD. The male/female 6 hour LC50 is equivalent to 1723 mg/m3.

Executive summary:

Groups of 6 male and 6 female Fischer 344 rats were exposed (whole body) to vapours of 46, 130, 260 or 557 ppm DCPD for 6 hours and were then observed daily for up to 14 days.  At 557 ppm, one male died during exposure, 3 died immediately post-exposure and 2 were found dead on the day after exposure; all females were found dead on the day after exposure. At 260 ppm, two males were found dead on the day after exposure, all females survived. Clinical signs included loss of righting reflex, impaired gait, stereotypic behaviour, laboured breathing, nasal discharge and convulsions.

The LC₅₀ was 284 ppm for males and 353 ppm for females, equivalent to 1536 and 1910 mg/m³ respectively..