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Toxicological information

Acute Toxicity: inhalation

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Administrative data

Endpoint:
acute toxicity: inhalation
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Comparable to guideline study with acceptable restrictions: 3 animals per sex; observation period 7 days;

Data source

Referenceopen allclose all

Reference Type:
study report
Title:
Unnamed
Year:
1989
Report date:
1989
Reference Type:
other company data
Title:
Unnamed
Year:
1989
Report date:
1989

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 403 (Acute Inhalation Toxicity)
Deviations:
yes
Remarks:
: 3 animals per sex; short observation period
GLP compliance:
yes
Test type:
standard acute method
Limit test:
yes

Test material

Constituent 1
Chemical structure
Reference substance name:
Butyric acid
EC Number:
203-532-3
EC Name:
Butyric acid
Cas Number:
107-92-6
Molecular formula:
C4H8O2
IUPAC Name:
butanoic acid
Details on test material:
- Analytical purity: 99.5 %

Test animals

Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Charles River Breeding Laboratories, Inc.
- Age at study initiation: males: 9 weeks; females: 10 weeks
- Weight at study initiation: males: 291 - 295 g; females: 198 - 200 g
- Housing: individually in suspended, stainless steel, wire mesh cages
- Diet: standard pellets (Purina Rodent Laboratory Chow), ad libidum
- Water: ad libitum
- Acclimation period: 16 days


ENVIRONMENTAL CONDITIONS
- Temperature: 67 -76 ° F
- Humidity (%): 40 - 70
- Photoperiod (hrs dark / hrs light): 12/12

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
- Exposure apparatus: Plexiglas chamber with glass front
- Exposure chamber volume: 100 liter
- Method of holding animals in test chamber: whole body exposure
- Source and rate of air: air flow rate was 20 liters per minutes, which provides a complete air change every 5 min.
- System of generating vapor: compressed air was directed through a wash bottle filled with 60 mL liquid test material, and further diluted with additional air
- Particle size measurement: yes, using a TSI Aerodynamic Particle Size analyzer
- Temperature: 24 °C; humidity: 36 - 39 %

TEST ATMOSPHERE
- Brief description of analytical method used: absorbance of airsamples was examined in a MIRAM 1A Ambient Air analyzer, using a calibration curve in the range 0-7 mg/l
- Samples taken from breathing zone: yes, hourly during exposure
Analytical verification of test atmosphere concentrations:
yes
Duration of exposure:
4 h
Concentrations:
5.1 mg/L
No. of animals per sex per dose:
3
Control animals:
no
Details on study design:
- Duration of observation period following administration: 7 days
- Frequency of observations and weighing: Animals were observed as a group every 15 min. during the first hour of exposure and afterwards hourly. Individually the animals were observed upon removal of the chamber, than hourly for two hours and afterwards daily; viability was assessed twice daily. Weighing: prior to exposure and on day 8
- Necropsy of survivors performed: no
- Other examinations performed: clinical signs, body weight

Results and discussion

Effect levels
Sex:
male/female
Dose descriptor:
LC0
Effect level:
5.1 mg/L air
Exp. duration:
4 h
Mortality:
No mortality was observed during the exposure and the 7 day post-exposure period.
Clinical signs:
other: Respiratory irritation, lacrimation, closed eyes and decreased activity were noted during the exposure, but the animals recovered rapidly during the 2-hour Post-Exposure Period, and showed virtually no signs during the 7-day Post Exposure Period.
Body weight:
Most animals were in excess of their pre-exposure body weight by end of the study.
Gross pathology:
no post-mortem examination

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Conclusions:
Butyric acid was relatively nontoxic, because all rats exposed for 4 hours to 5.1 mg/L survived with moderate clinical signs
Executive summary:

All 6 rats receiving a single four-hour exposure to 5.1 mg/L of butyric acid as a vapor survived the exposure and the 7 day observation period. While moderate signs of irritation were noted during the exposure, the animals recovered quickly and showed no adverse effects on body weight or clinical signs. Therefore, the LC0 was 5.1 mg/L (LC50 > 5 mg/L) in this study (Biodynamics, 1989).