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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:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: This study was selected as the key study because the information provided for the hazard endpoint is sufficient for the purpose of classification and labelling and/or risk assessment.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2012
Report Date:
2012

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 403 (Acute Inhalation Toxicity)
Deviations:
no
Remarks:
The study was conducted according to the guideline in effect at the time of study conduct.
Qualifier:
according to
Guideline:
EPA OPPTS 870.1300 (Acute inhalation toxicity)
Deviations:
no
Remarks:
The study was conducted according to the guideline in effect dated 1998.
Qualifier:
according to
Guideline:
EU Method B.2 (Acute Toxicity (Inhalation))
Deviations:
no
Remarks:
The study was conducted according to the guideline in effect dated 2008.
Qualifier:
according to
Guideline:
other: MAFF Japan Agricultural Chemicals Regulation Laws 2-1-3 Notification 12-Nousan-8147 and Notification 13 Seisan 1739 (2000 and 2001)
GLP compliance:
yes
Test type:
fixed concentration procedure
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Purity: 99.99%

Test animals

Species:
rat
Strain:
other: Crl:CD(SD)
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Age at study initiation: 8 weeks
- Weight at study initiation: 319.2-368.2 g (males); 213.0-232.9 g (females)
- Fasting period before study: no data
- Housing: individually in solid bottom caging with bedding and nestlets as enrichment
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: 6 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-26ºC (68-79ºF)
- Humidity (%): 30-70%
- Air changes (per hr): 10
- Photoperiod (hrs dark / hrs light): approximate 12-hour light/dark cycle

Administration / exposure

Route of administration:
inhalation: gas
Type of inhalation exposure:
whole body
Vehicle:
other: air and oxygen
Details on inhalation exposure:
GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: cylindrical glass chamber with a glass baffle inside to promote uniform distribution of the test atmosphere
- Exposure chamber volume: 19 L
- Method of holding animals in test chamber: stainless steel, wire-mesh modules (sexes separate)
- Source and rate of air: houseline compressed air and oxygen; metered into 1-liter 3-neck mixing flasks by Brooks mass flow controllers (MFC); 10 L/minute
- Method of conditioning air: vapour and air mixture left the mixing flasks and entered a glass transfer tube where supplemental chamber oxygen was added to the mixture using a Brooks MFC
- Treatment of exhaust air: exhausted through a dry-ice cold trap and an MSA filter cartridge prior to discharge into the fume hood
- Temperature, humidity, pressure in air chamber: 20-24°C; 30-70%; no data

TEST ATMOSPHERE
- Brief description of analytical method used: gas chromatography 16 times during the 4-hour exposure; Chamber atmosphere was continually drawn from the exposure chamber and directly injected into a gas chromatograph (GC) equipped with a pneumatically operated gas sample valve and a flame ionization detector
- Samples taken from breathing zone: yes
Analytical verification of test atmosphere concentrations:
yes
Duration of exposure:
4 h
Concentrations:
500000 ± 9700 ppm
No. of animals per sex per dose:
5 per sex
Control animals:
no
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of observations: daily for first 7 days after exposure then once on Day 14
- Frequency of weighing: daily for first 7 days after exposure then once on Day 14
- Necropsy of survivors performed: yes

Results and discussion

Effect levels
Sex:
male/female
Dose descriptor:
LC50
Effect level:
> 500 000 ppm
Based on:
test mat.
Exp. duration:
4 h
Mortality:
None
Clinical signs:
None
Body weight:
Three male rats displayed weight losses ranging from 3.4 to 12 grams on the day after the exposure. There were no other body weight losses in male rats throughout the recovery period. Four of 5 female rats displayed weight losses ranging from 0.1 to 19.4 grams on the day following the exposure, and one female rat continued to lose weight (3.8 grams) on post-exposure day 2. This same female rat gained 5.4 grams on post-exposure day 3 but then lost 8.7 grams on post-exposure day 4. There were no other body weight losses observed in female rats throughout the remainder of the recovery period.
Gross pathology:
Gross discoloration of the lungs was present in one male rat, was nonspecific, and is a common finding in rats of this strain and age. No other gross lesions were observed.

Applicant's summary and conclusion

Interpretation of results:
practically nontoxic
Remarks:
Migrated information Criteria used for interpretation of results: expert judgment
Conclusions:
LC50 > 500000 ppm.

The study and the conclusions which are drawn from it fulfil the quality criteria (validity, reliability, repeatability).
Executive summary:

One group of 5 male and 5 female Crl:CD(SD) rats was exposed whole-body to test substance vapours in air. The test atmosphere was generated by dilution of the test substance vapour in air and oxygen. Chamber concentrations of the test substance were measured by gas chromatography. Rats were weighed and observed for clinical signs of toxicity during a 14-day recovery period. After the recovery period, the rats were sacrificed and examined for gross pathologic abnormalities. All animals survived the exposure and subsequent 14-day recovery period.

 

Rats were exposed for 4 hours to a mean concentration of 500000 ± 9700 ppm (mean ± standard deviation). The rats’ startle responses were normal throughout the 4-hour exposure. There were no clinical signs of toxicity observed during the exposure or the recovery period. Three male rats displayed weight losses ranging from 3.4 to 12 grams on the day after the exposure. There were no other body weight losses in male rats throughout the recovery period. Four of 5 female rats displayed weight losses ranging from 0.1 to 19.4 grams on the day following the exposure, and one female rat continued to lose weight (3.8 grams) on post-exposure day 2. This same female rat gained 5.4 grams on post-exposure day 3 but then lost 8.7 grams on post-exposure day 4. There were no other body weight losses observed in female rats throughout the remainder of the recovery period.

Gross discoloration of the lungs was present in one male rat, was nonspecific, and is a common finding in rats of this strain and age. No other gross lesions were observed.

 

Under the conditions of this study, the 4-hour inhalation median lethal concentration (LC50) for the test substance in male and female rats was greater than 500000 ppm.