Registration Dossier

Administrative data

Endpoint:
acute toxicity: inhalation
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
4 (not assignable)
Rationale for reliability incl. deficiencies:
secondary literature
Justification for type of information:
Data is from NTRL report

Data source

Reference
Reference Type:
secondary source
Title:
Evaluation of the acute toxicity of selected groundwater contaminants
Author:
Edwin R. Kinkead, Harold F. Leahy
Year:
1987
Bibliographic source:
National Technical Information Service. AAMRL-TR-87-021, APRIL 1987

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other: as below
Principles of method if other than guideline:
Acute inhalation toxicity study of 2,3-dimethylphenol in male Fischer rats
GLP compliance:
not specified
Test type:
other: no data
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid
Details on test material:
- Name of test material (as cited in study report): 2,3-Dimethylphenol (Synoynm: 2,3-xylenol)
- Molecular formula (if other than submission substance): C8H10O
- Molecular weight (if other than submission substance): 122.17 g/mole
- Substance type: Organic
- Physical state: Solid
- Purity: Reported 97.0% snd Measured 98.1%
- Impurities (identity and concentrations): No data available
Specific details on test material used for the study:
- Name of test material (as cited in study report): 2,3-Dimethylphenol (Synoynm: 2,3-xylenol)
- Molecular formula (if other than submission substance): C8H10O
- Molecular weight (if other than submission substance): 122.17 g/mole
- Substance type: Organic
- Physical state: Solid

Test animals

Species:
rat
Strain:
Fischer 344
Sex:
male
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River Laboratories in Wilmington, MA
- Age at study initiation: No data available
- Weight at study initiation: 200 to 250g
- Fasting period before study: No data available
- Housing: No data available
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period:

ENVIRONMENTAL CONDITIONS
- Temperature (°C): No data available
- Humidity (%):No data available
- Air changes (per hr): No data available
- Photoperiod (hrs dark / hrs light): 12 h light (beginning at 6 a.m.) and 12 h darkness

IN-LIFE DATES: From: October 1985 To: February 1986

Administration / exposure

Route of administration:
inhalation
Type of inhalation exposure:
whole body
Vehicle:
air
Details on inhalation exposure:
CLASS METHOD (if applicable)
- Rationale for the selection of the starting dose: No data availableGENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: ptexiglas chamber
- Exposure chamber volume: 120-L
- Method of holding animals in test chamber: cage drawer system
- Source and rate of air: chamber was controlled by metering air through a column packed with pulverized
- Method of conditioning air:
- System of generating particulates/aerosols:
- Method of particle size determination: A Miran 1A infrared analyzer (Foxboro) was used to monitor the concentration stability and w~ile the actual concentration of DMPwas determined by GC analysis of impinger samples collected in water. The GC detector peak areas were compared to DMPstandards in water.
- Treatment of exhaust air:
- Temperature, humidity, pressure in air chamber:

TEST ATMOSPHERE
- Brief description of analytical method used: A Miran 1A infrared analyzer (Foxboro) was used to monitor the concentration stability of DMP in the chamber, w~ile the actual concentration of DMPwas determined by GC analysis of impinger samples collected in water. The GC detector peak areas were compared to DMPstandards in water.
- Samples taken from breathing zone: no

VEHICLE
- Composition of vehicle (if applicable): air
- Concentration of test material in vehicle (if applicable):85.5 mg/m3
- Justification of choice of vehicle: air
- Lot/batch no. (if required):
- Purity:

TEST ATMOSPHERE (if not tabulated)
- Particle size distribution:No data available
- MMAD (Mass median aerodynamic diameter) / GSD (Geometric st. dev.): No data available

CLASS METHOD (if applicable)
- Rationale for the selection of the starting concentration:No data available
Analytical verification of test atmosphere concentrations:
not specified
Duration of exposure:
4 h
Concentrations:
85.5 mg/m3
No. of animals per sex per dose:
5 male animals
Control animals:
yes
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: The rat were weighed and observed at 1, 2, 4, 7 and 14 days post exposure
- Necropsy of survivors performed: no data available
- Other examinations performed: Mortality, clinical signs, body weight and gross pathology were examined.
Statistics:
No data available

Results and discussion

Preliminary study:
No data available
Effect levels
Sex:
male
Dose descriptor:
LC50
Effect level:
> 85.5 mg/m³ air
Based on:
test mat.
Exp. duration:
4 h
Remarks on result:
other: No mortality observed
Mortality:
No mortality was observed in treated male rat at 85.5 mg/m3
Clinical signs:
other: No data available
Body weight:
At 85.5 mg/m3 Body weight gain observed in exposed rats compared favorably with weight gains of the control rats
Gross pathology:
At 85.5 mg/m3 No exposure-related lesions were observed.
Other findings:
No data available

Applicant's summary and conclusion

Interpretation of results:
other: not classified
Conclusions:
LD50 was considered to be > 85.5 mg/m3 when Fischer 344 male rat were exposed to saturated vapors of 2,3-dimethylphenol for 4 h.
Executive summary:

In a acute inhalation toxicity study, Fischer 344 male rat were exposed to saturated vapors of 2,3-dimethylphenol for 4 h in a clear, 120-L ptexiglas chamber. No mortality was observed in treated male rat at 85.5 mg/m3. No effect on body weight gain and no gross lesions were observed in treated rats as compared to control. Therefore, LD50 was considered to be > 85.5 mg/m3when Fischer 344 male rat were exposed to saturated vapors of 2,3-dimethylphenol for 4 h.