Reaction mass of divinylbenzene and ethylstyrene

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1984

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Remarks:

The study was not conducted according to guideline/s and GLP but the report contains sufficient data for interpretation of study results

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1984

Report date:

1984

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

GLP compliance:

no

Test type:

other: Standard acute method except the exposure duration was 6 hours, instead of the typical 4 hour exposure period used for acute studies, because this study was intended to help set dose levels for a 2-week inhalation study..

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Reaction mass of divinylbenzene and ethylstyrene

EC Number:

910-757-7

Cas Number:

N/A

Molecular formula:

Divinylbenzene: C10H10 Ethylstyrene: C10H12

IUPAC Name:

Reaction mass of divinylbenzene and ethylstyrene

Details on test material:

Divinylbenzene 55 ( lot #840329-007) was obtained from The Dow Chemical Company production facilities, Midland, MI.

Capillary gas chromatographic analysis o f the test material revealed that 96.6% was composed of the following four compounds:
meta-divinylbenzene 38.3%
para-divinylbenzene 15.4%
meta-ethylvinyl benzene 31.5%
para-ethylvinylbenzene 11.2%

Test animals

Species:

other: rat and mice

Strain:

other: Fischer 344 rats and B6C3F1 mice

Sex:

male/female

Details on test animals or test system and environmental conditions:

Male and female Fischer 344 (F-344) rats (4-weeks of age) and B6C3F1 mice ( 7 weeks of age) were obtained from Charles River Breeding Laboratories Inc., Kingston, NY and Portage, M I , respectively. All animals were 9-10 weeks of age when exposed to DVB-55. Animals were fed Certified Rodent Chow (Purina Co., St. Louis, MO) and water ad libitum except during exposure.

Administration / exposure

Route of administration:

inhalation: vapour

Type of inhalation exposure:

whole body

Vehicle:

other: unchanged (no vehicle)

Details on inhalation exposure:

The test material was vapourized by metering DVB-55 at a constant rate into a glass J-tube. Heated compressed air passed through the J-tube to volatize the test material prior to entering the chamber. The compressed air was heated with a flameless heat torch (Master FHT-4) to the minimum extent necessary (70-90°C) to completely vapourize the test material. The nominal concentration (ratio of the amount of test material to vapourized to the total amount of air flowing through the chamber) was calculated for each exposure period.

Stainless and glass 157L Rochester-type chambers were used for this study. The chamber airflow was maintained at 30 L/inin. The minimum and maxinium chamber temperature for the 4 exposures ranged from 70-80°F and the relative humidity for the 4 exposures ranged from 34-62%.

Analytical verification of test atmosphere concentrations:

no

Duration of exposure:

6 h

Concentrations:

Rats - 0 or 5.0 mg/L
Mice - 0, 0.8, 2.3 or 5.0 mg/L

No. of animals per sex per dose:

5/sex/dose

Control animals:

yes

Details on study design:

Animals were weighed and examined prior to exposure to the test material. Animals were observed during the exposure period and at least daily during the two-week post-exposure period for any exposure related effects. All surviving rats were weighed on the first day after exposure and approximately twice per week during the two-week post-exposure period.

Statistics:

None

Results and discussion

Effect levels

Effect levels 1

Sex:

male/female

Dose descriptor:

LC0

Effect level:

5 mg/L air (nominal)

Exp. duration:

6 h

Remarks on result:

other: rats

Effect levels 2

Sex:

male/female

Dose descriptor:

LC0

Effect level:

0.8 mg/L air (nominal)

Exp. duration:

6 h

Remarks on result:

other: mice

Effect levels 3

Sex:

male/female

Dose descriptor:

LC100

Effect level:

2.3 mg/L air (nominal)

Exp. duration:

6 h

Remarks on result:

other: mice

Mortality:

Rats: no mortality
Mice: 5 mg/L- 5/5 male and female mice died, 2.3 mg/L- 5/5 males died and 4/5 females died, 0.8 mg/L and controls - no deaths

Clinical signs:

other: Rats (5 mg/L) appeared to be sedated during exposure and had a reddish material around the face (up to 2 days) Mice sedated at ≥2.3 mg/L during exposure and (0.8 mg/L) slightly lethargic at the end of the 6-hr exposure period

Body weight:

In rats, a slight body weight loss was observed following exposure to DVB-55. Two weeks after exposure to DVB-55, the animal weights were comparable to control values.

Mice exposed to 0.8 mg/L DVB-55 had a greater body weight loss (approximately 10%) than control animals immediately after the exposure period. These mice quickly recovered and their body weights were comparable to control values within 2 weeks. No other effects were observed in these animals which were considered to be exposure related.

Gross pathology:

None

Other findings:

None

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The LC50 in rats is greater than 5 mg/L (highest concentration tested in this study).

Executive summary:

Groups of 5 male and 5 female rats were exposed for 6 hours to 0 or 5.0 mg/L divinylbenzene 55 (DVB-55); groups of 5 male and 5 female mice were exposed for the same time period to 0, 0.8, 2.3 or 5.0 mg/L DVB-55.

 

Exposure of rats to 5 mg/L of DVB-55 resulted in sedation during the exposure period with a reddish material around the face for at most 2 days following the exposure period. A slight body weight loss was observed following exposure to DVB-55. Two weeks after exposure to DVB-55, the animal weights were comparable to control values.

 

Mice exposed to 5 mg/L DVB-55 were sedated like the rats but died several hours after the exposure terminated. Similarly, mice exposed to 2.3 mg/L were sedated with 9 out of 10 dying shortly after the exposure terminated. Mice exposed to 0.8 mg/L DVB-55 were slightly lethargic at the end of the 6-hr exposure period and had a greater body weight loss than control animals immediately after the exposure period. These mice quickly recovered and were comparable to control values within 2 weeks. No other effects were observed in these animals which were considered to be exposure related.