Registration Dossier

Diss Factsheets

Administrative data

Endpoint:
acute toxicity: inhalation
Type of information:
experimental study
Adequacy of study:
key study
Study period:
7 days
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
comparable to guideline study with acceptable restrictions

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1974
Report date:
1974

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 403 (Acute Inhalation Toxicity)
Deviations:
yes
Remarks:
7 days observation instead of 14 days
GLP compliance:
no
Test type:
standard acute method
Limit test:
no

Test material

Constituent 1
Chemical structure
Reference substance name:
Bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate
EC Number:
258-207-9
EC Name:
Bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate
Cas Number:
52829-07-9
Molecular formula:
C28H52N2O4
IUPAC Name:
bis(2,2,6,6-tetramethylpiperidin-4-yl) sebacate

Test animals

Species:
rat
Strain:
other: Tif. RAI
Sex:
male/female
Details on test animals or test system and environmental conditions:
Age: 8-9 weeks old
Weight: 180-220 g
The males and females were segregated and kept in Macrolon cages, type 4, (9 animals to a cage) during an observation period of 7 days in a room maintained at a constant temperature of 22 ± 1 °C and a relative humidity of approximately 50 %.

Administration / exposure

Route of administration:
inhalation: aerosol
Type of inhalation exposure:
nose only
Vehicle:
other: ethanol
Details on inhalation exposure:
GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: modified version of an apparatus described by Niessen et al. (Arch. Toxicol. 20, 44-60 (1963))
- Method of holding animals in test chamber: in PVC tubes positioned radially around the exposure chamber
- System of generating particulates/aerosols: A 20 % dilution in ethanol was sprayed into the exposure chamber by means of a pressure nozzle. The liquid was injected by a motor-driven syringe at a rate of 6, 12 and 30 ml/hr into a stream of compressed air (2 atm.) flowing through a spray nozzle at a rate of 10 lit./min. The aerosol mist thus produced was discharged into the exposure chamber. The animals were exposed to the test substance when the aerosol was evenly dispersed throughout the chamber (15 minutes).
- Method of particle size determination:

TEST ATMOSPHERE
- Brief description of analytical method used: The individual concentrations of the test substance and the particle-size distribution in the aerosol were determined gravimetrically. The aerosol was sampled on Membrane Filters, pore size 0.2 µm hourly after the beginning of the test.
- Samples taken from breathing zone: yes

VEHICLE
- Composition of vehicle (if applicable): ethanol
Analytical verification of test atmosphere concentrations:
yes
Remarks:
hourly
Duration of exposure:
4 h
Concentrations:
measured concentrations: 232 ± 46, 394 ± 72 and 887 ± 138 mg/m³
No. of animals per sex per dose:
9
Control animals:
yes

Results and discussion

Effect levels
Sex:
male/female
Dose descriptor:
LC50
Effect level:
500 mg/m³ air
Exp. duration:
4 h
Mortality:
No animals died after exposure to 232 mg/m³. One animal per sex died within the first 4-hour while exposed to 394 mg/m³. All animals died within the first 4-hour while exposed to 887 mg/m³.
Clinical signs:
other: After 4-hour exposure all rats showed dyspnoea, salivation, trismus, tremor and sedation with a dose-dependent intensity. The surviving animals recovered within 24 hours. Animals treatment with ethanol alone did not show any effect.
Body weight:
No data
Gross pathology:
Dead animals: slight pulmonary edema
Killed animals: no substance related gross organ changes.

Any other information on results incl. tables

Mean particle size distribution (cascade impactor):

232 mg/m³: 29%: > 7 µm; 14%: 3 -7 µm; 14%: 1 -3 µm; 43%: < 1 µm

394 mg/m³: 10% > 7 µm; 27%: 3 -7 µm; 36%: 1 -3 µm; 27%: 1 µm

887 mg/m³: 17% > 7 µm; 21%: 3 -7 µm; 28%: 1 -3 µm; 34%: 1 µm

Applicant's summary and conclusion

Conclusions:
The LC50 was established to be 500 mg/m³ (0.5 mg/l). Based on a split-entry apporach, classification is not required.