Registration Dossier

Administrative data

Endpoint:
developmental toxicity
Type of information:
experimental study
Adequacy of study:
key study
Study period:
3 January 2012 to 13 March 2012
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Study conducted according to GLP

Data source

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

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 414 (Prenatal Developmental Toxicity Study)
Deviations:
yes
Remarks:
see "Principles of method if other than guideline"
Principles of method if other than guideline:
Deviations from OECD guideline 414:

1. The type of environmental enrichment given to the animals was not documented prior to the week of 16 January 2012.
2. Mechanical difficulties caused the daily mean chamber concentration value (262 ppm) to be below the acceptable range of 300 ppm +/- 10%.
3. A paper jam occured on 29 January 2012 causing improper sample collection for chambers one and three. Manual samples were taken and replaced the incorrect data.
4. The carcass and fetuses in group 1 had been placed in Bouin's solution rather than 100% ethyl alcohol. A skeletal examination was therefore not possible for this carcass.

These deviations did not negatively impact the quality or integrity of the data nor the outcome of the study.
GLP compliance:
yes
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): MTDID 5789
- Substance type: Clear, colorless liquid
- Physical state: Liquid
- Analytical purity: 99.90%
- Lot/batch no.: Lot no. 21451
- Expiration date of the lot/batch: 16 January 2014
- Stability under test conditions: Stable
- Storage condition of test material: Room temperature, protected from light

Test animals

Species:
rat
Strain:
other: Sprague Dawley [Crl:CD(SD)]
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River Laboratories, Inc., Raleigh, N.C.
- Age at study initiation:79 days
- Sex: female
- Fasting period before study: No Data
- Housing: Individually in stainless steel wire-mesh cages. Rats were paired for mating in the home cage of the male.
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 14 days
ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 degrees C +/- 3 degrees C
- Humidity (%): 50% +/- 20%
- Air changes (per hr): 10 changes/hour
- Photoperiod (hrs dark / hrs light): 12 dark/ 12 light
IN-LIFE DATES:
From: 3 January 2012 To: 13 March 2012

Administration / exposure

Route of administration:
inhalation: vapour
Type of inhalation exposure (if applicable):
whole body
Vehicle:
other: filtered air
Details on exposure:
GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: 1 cubic meter stainless-steel and glass exposure chambers. (Four chambers one for each exposure concentration and one for the control group exposures)
- Method of holding animals in test chamber: No data
- Source and rate of air: 12 to 15 air changes per hour
- System of generating particulates/aerosols: Vapors were generated using a glass-bead column-type vaporization system
- Temperature, humidity, pressure in air chamber: 18 to 26 degrees C, 30 to 70% humidity, under slight negative pressure
- Air change rate: 12 to 15 air changes per hour
- Method of particle size determination: Casella Microdust 880 nm Aerosol Monitoring System was used for particle evaluation
- Treatment of exhaust air: No data
TEST ATMOSPHERE
- Brief description of analytical method used: Exposure concentrations were calculated for each test substance chamber from the total amount of the substance consumed during the exposure and the total volume of air passed through the chamber during exposure. Analyzed exposure concentrations were also determined at approximately 45-minute intervals using a gas chromatograph (GC) under the control of the WINH system
- Samples taken from breathing zone: yes
USE OF RESTRAINERS FOR PREVENTING INGESTION: No data
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Analyzed exposure concentrations were determined at approximately 45-minute intervals using a gas chromatograph (GC) under the control of the WINH system
Details on mating procedure:
- Impregnation procedure: cohoused
- M/F ratio per cage: 1/1
- Length of cohabitation: Until evidence of mating
- Age at mating of the mated animals in the study: Approximately 14 weeks
- Further matings after two unsuccessful attempts: No data
- Verification of same strain and source of both sexes: yes
- Proof of pregnancy: vaginal plug or sperm in vaginal smear referred to as day 0 of pregnancy
- Any other deviations from standard protocol: None
Duration of treatment / exposure:
6 hours daily, from gestation days 6 through 19
Frequency of treatment:
Daily from gestation days 6 through 19
Duration of test:
Exposures occured from gestation days 6 through 19
No. of animals per sex per dose:
3 groups of 25 bred females (25 per exposure group) and 25 bred control females exposed to filtered air
Control animals:
yes, concurrent vehicle
Details on study design:
- Dose selection rationale: Doses were determined based on a previous 13 week inhalation study
- Rationale for animal assignment (if not random): Random

Examinations

Maternal examinations:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Observed twice daily for mortality and moribundity
- Cage side observations checked in table were included
DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: "Appropriate intervals"
BODY WEIGHT: Yes
- Time schedule for examinations: "Appropriate intervals"
POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day # 20
- Organs examined: Uteri, placentae, ovaries, fetuses
Ovaries and uterine content:
The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: Yes
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes
Fetal examinations:
- External examinations: Yes: all per litter
- Soft tissue examinations: Yes: all per litter
- Skeletal examinations: Yes: all per litter
- Head examinations: Yes: all per litter

Results and discussion

Results: maternal animals

Maternal developmental toxicity

Details on maternal toxic effects:
Maternal toxic effects:no effects

Effect levels (maternal animals)

Dose descriptor:
NOAEL
Effect level:
>= 3 000 ppm (analytical)
Basis for effect level:
other: other:

Results (fetuses)

Details on embryotoxic / teratogenic effects:
Embryotoxic / teratogenic effects:no effects

Fetal abnormalities

Abnormalities:
not specified

Overall developmental toxicity

Developmental effects observed:
not specified

Applicant's summary and conclusion

Conclusions:
The no-observed-adverse-effect-level (NOAEL) for maternal toxicity and embryo/fetal development when the test article was administered via whole body inhalation to bred Crl:CD(SD) rats was 3000 ppm.
Executive summary:

A reproduction/development study was conducted on the test article by exposing bred Sprague Dawley Crl:CD(SD) rats to 300, 1000, and 3000 ppm in a whole body inhalation chamber. The rats were exposed to the test article for 6 hours daily from gestation days 6 through 19. A concurrent control group composed of 25 bred females was exposed to filtered air on a comparable regimen. All animals were observed twice daily for mortality and moribundity. Clinical observations, body weights, and food consumption were recorded at appropriate intervals. On gestation day 20, a laparohysterectomy was performed on each female. The uteri, placentae, and ovaries were examined, and the numbers of fetuses, early and late resorptions, total implantations, and corpora lutea were recorded. Gravid uterine weights were also recorded, and net body weights and net body weight changes were calculated. The fetuses were weighed, sexed, and examined for external visceral and skeletal malformations and developmental variations. All females survived to necropsy on gestation day 20. There were no test substance-related clinical observations noted at any exposure level. Additionally, there were no test substance-related maternal macroscopic findings noted at the scheduled necropsy. Intrauterine growth and survival were unaffected by the test substance exposure at all exposure levels tested. There were no test substance-related external, visceral, or skeletal malformations or developmental variations observed at any dosage level. Based on the results of the study the no-observed-adverse-effect-level (NOAEL) for maternal toxicity and embryo/fetal development when the test article was administered via whole body inhalation to bred Crl:CD(SD) rats was 3000 ppm.