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Acute Toxicity: inhalation

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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:
other: The study was not conducted according to guideline/s and GLP but the report contains sufficient data for interpretation of study results
Cross-referenceopen allclose all
Reason / purpose for cross-reference:
reference to same study
Reason / purpose for cross-reference:
reference to other study

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

Constituent 1
Chemical structure
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 Laborat
ories 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 vaporized by metering DVB-55 at a constant rate into a glass J-tube ( Miller et al., 1980). 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 vaporize the test material. The nominal concentration (ratio of the amount of test material to vaporized 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:
Groups o f 5 male and 5 female r a t s 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. 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

Preliminary study:
None
Effect levelsopen allclose all
Sex:
male/female
Dose descriptor:
LC0
Effect level:
5 mg/L air (nominal)
Exp. duration:
6 h
Remarks on result:
other: rats
Sex:
male/female
Dose descriptor:
LC0
Effect level:
0.8 mg/L air (nominal)
Exp. duration:
6 h
Remarks on result:
other: mice
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-Rats exposed to 5 mg/l of DVB-55 appeared to be sedated during the exposure period and had a reddish material around the face for at most 2 days following the exposure period. No other exposure related effects were observed in rats. Mice-Mice expose
Body weight:
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- 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

Any other information on results incl. tables

Since a single exposure of 6 hrs duration to a concentration 16 times higher than the TLV of 0.05 mg/l resulted in only transient effects in this study, acute exposure to concentrations of DVB-55 at or below the TLV is not expected to result in adverse effects.

Applicant's summary and conclusion

Interpretation of results:
not classified
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
Since a single exposure of 6 hrs duration to a concentration 16 times higher than the TLV of 0.05 mg/l resulted in only transient effects in this study, acute exposure to concentrations of DVB-55 at or below the TLV is not expected to result in adverse effects.
The LC50 in rats is greater than 5 mg/l (highest concentration tested in this study).
Executive summary:

Groups o f 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.

Since a single exposure of 6 hrs duration to a concentration 16 times higher than the TLV of 0.05 mg/l resulted in only transient effects in this study, acute exposure to concentrations of DVB-55 at or below the TLV is not expected to result in adverse effects.