Registration Dossier

Administrative data

Endpoint:
acute toxicity: inhalation
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1991
Reliability:
1 (reliable without restriction)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1991
Report Date:
1991

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
EPA OPP 81-3 (Acute inhalation toxicity)
GLP compliance:
yes
Test type:
acute toxic class method

Test material

Reference
Name:
Unnamed
Type:
Constituent

Test animals

Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female

Administration / exposure

Route of administration:
inhalation
Type of inhalation exposure:
whole body
Vehicle:
clean air
Details on inhalation exposure:
Piperonyl Butoxide was aerosolized and diffused by an air atomizing nozzle (Spraying Systems Company, ¼ inch JCO-SS nozzle with a #1A set-up)
Analytical verification of test atmosphere concentrations:
yes
Duration of exposure:
4 h
Concentrations:
Nominal concentration a.i. 28 g/m³
Analytical concentration a.i. 5.9 mg/L
No. of animals per sex per dose:
10
Control animals:
yes

Results and discussion

Effect levels
Sex:
male/female
Dose descriptor:
LC50
Effect level:
> 5.9 mg/L air
Exp. duration:
4 h
Mortality:
All animals survived the duration of the study.
Clinical signs:
other: During exposure nasal discharge, excessive salivation, eye closure and decreased activity were noted. On day one and during the first week excessive lacrimation and salivation nasal discharge and laboured breathing were noted. Most of these responses abat
Body weight:
Slight or no weight losses were observed on the day following exposure. This was considered a minimal response to exposure. Generally normal weight gains were seen thereafter.
Gross pathology:
Red foci were observed in the lungs of 2/5 female. The toxicologic significance of this finding on the basis of gross examination only is equivocal.

Applicant's summary and conclusion

Interpretation of results:
Category 5 based on GHS criteria
Conclusions:
The mean analytical exposure concentrations was 5.9 g/m³ resulted in no mortalities. Treatment related decreases in body weight were observed, however, recovery occurred by day 3 and all surviving animals were well in excess of their pre-exposure body weight by day 5.
Clinical signs included secretory responses during exposure. Respiratory and secretory observations seen following exposure abated within a week afterwards.
Post mortem findings were also considered unremarkable.
The LC50 was found to be greater than 5.9 g/m³. EPA Category IV is determined for the acute inhalation toxicity of Piperonyl Butoxide.
Executive summary:

Ten of ten rats receiving a single four hour exposure to 5.9 mg/L Piperonyl Butoxide as a liquid aerosol, survived the exposure and subsequent 14day post exposure observation period. signs of treatment inclueded secretory responses during the exposure. respiratory and secretory responses were also seen following the exposure but generally abated within a week afterwards.

A minimal effect upon body weight was produced by treatment. Gross postmortem observations were also considered unremarkable.