2,4-di-tert-butylphenyl 3,5-di-tert-butyl-4-hydroxybenzoate

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1973

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:

1973

Report date:

1973

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Version / remarks:

2009

Deviations:

yes

Remarks:

Oberservations for only 7 days and not for 14 days, only one concentration level tested.

Principles of method if other than guideline:

Oberservations for only 7 days and not for 14 days, only one concentration level tested.

GLP compliance:

no

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

2,4-di-tert-butylphenyl 3,5-di-tert-butyl-4-hydroxybenzoate

EC Number:

224-166-0

EC Name:

2,4-di-tert-butylphenyl 3,5-di-tert-butyl-4-hydroxybenzoate

Cas Number:

4221-80-1

Molecular formula:

C29H42O3

IUPAC Name:

2,4-di-tert-butylphenyl 3,5-di-tert-butyl-4-hydroxybenzoate

Test animals

Species:

rat

Strain:

other: Tif. RAI

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Own breeding unit
- Age at study initiation: Animals used were 8-9 weeks old
- Weight at study initiation: 195-200 g
- Fasting period before study: not given
- Housing: Segregated by sex and kept in Macrolon cages, type 4 (9 animals to a cage)

ENVIRONMENTAL CONDITIONS
- Temperature: 22 +/- °C
- Humidity: 50 %

Administration / exposure

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

nose/head only

Vehicle:

air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: Pressure nozzle
- Exposure chamber volume: 10L/min.
- Method of holding animals in test chamber: Kept in separate PVC tubes positioned radially around the exposure chamber.
- Source and rate of air: Compressed air (2 atm.)
- System of generating particulates/aerosols: A 20 % suspension in ethanol of the test substance was injected by a motor-driven syringe at a rate of 60 mL/h into a stream of compressed air flowing through a spray nozzle at a rate of 10 L/min.

TEST ATMOSPHERE
- Brief description of analytical method used: The aerosol was sampled on Membrane Filters, pore size 0.2 µm (Satorius, 34 Göttingen, Germany) in the immediate vicinity of the animals hourly after the beginning of the test.
- Samples taken from breathing zone: yes

VEHICLE
- Composition of vehicle: A 20 % suspension of the test article in ethanol was sprayed into the exposure chamber

TEST ATMOSPHERE (if not tabulated)
- Particle size distribution: The particle-size distribution in the aerosol was determined gravimetrically on Selectron-Filters, pore size 0.2 µm (Schleicher and Schuell, 8714 Feldbach, Switzerland) every hour with the aid of a "Cascade Impactor" (CT. Casella and Co. Ltd., London N.l, England). Results:
> 7 µm = ca. 6%
3-7 µm = ca. 12%
1-3 µm = ca. 35%
< 1 µm = ca. 48%

Analytical verification of test atmosphere concentrations:

yes

Remarks:

Gravimetrically

Duration of exposure:

4 h

Concentrations:

448 +/- 37 mg/m3 (highest possible concentration)

No. of animals per sex per dose:

9 female
9 male

Control animals:

no

Details on study design:

- Duration of observation period following administration: 7 days
- Frequency of observations: 0-4 h, 24 h, 48 h, 7 days
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, histopathology

Results and discussion

Preliminary study:

none

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 500 mg/m³ air

Based on:

test mat.

Exp. duration:

4 h

Remarks on result:

other: no higher concentrations possible

Mortality:

no mortality

Clinical signs:

other: The rats showed lateral position and apathy after 4h.

Body weight:

not measured

Gross pathology:

No substance related gross organ changes were observed.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The LC50 of the test material determined after an observation period of 7 days in rats of both sexes, exposed to the substance for four hours is greater than 500 mg/m3 air.