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Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

03 Jun - 17 Jun 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 436 (Acute Inhalation Toxicity: Acute Toxic Class Method)

Version / remarks:

adopted in 2009

Deviations:

no

GLP compliance:

yes

Test type:

acute toxic class method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

2-ethylhexyl oleate

EC Number:

247-655-0

EC Name:

2-ethylhexyl oleate

Cas Number:

26399-02-0

Molecular formula:

C26H50O2

IUPAC Name:

2-ethylhexyl octadec-9-enoate

Test animals

Species:

rat

Strain:

other: Crl:WI (Han)

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Deutschland, Sulzfeld, Germany
- Age at study initiation: 9 weeks old
- Weight at study initiation: max. ± 20% of the sex mean
- Housing: Before exposure: Group housing of maximally 5 animals per sex per cage in labeled Makrolon cages (type IV; height 18cm.) containing sterilised sawdust as bedding material (Litalabo, S.P.P.S., Argenteuil, France) and paper as cage-enrichment (Enviro-dri, Wm. Lillico & Son (Wonham Mill Ltd), Surrey, UK). After exposure - Group housing as described above, maximally 3 animals per sex per cage.
- Diet: pelleted rodent diet (SM R/M-Z from SSNIFF Spezialdiäteb GmbH, Soest, Germany), ad libitum except during exposure to the test substance.
- Water: tap-water, ad libitum except during exposure to the test substance.
- Acclimation period: 5 days before the start of treatment under laboratory conditions.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21 ± 3
- Humidity (%): 40 - 70
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12 / 12

Administration / exposure

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

nose only

Vehicle:

air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION

- Exposure apparatus: The design of the exposure chamber is based on the flow past nose-pnly inhalation chamber (Am.Ind.Hyg Assoc.J. 44(12): 923-928, 1983). The chamber consists of animal sections with eight animal ports each. Each animal port has its own atmosphere inlet and exhaust outlet.

- Method of holding animals in test chamber: Animals are placed in restraining tubes, which is then connected to the exposure chamber.

- Source and rate of air: The theoretical air flow was at least 1 L/min.

- System of generating aerosols: An aerosol was generated by nebulization of the test substance by means of a nebulizer (type 950,
Hospitak Inc., Lindenhurst, NY, USA). The primary aerosol was diluted with pressurized air before it entered the exposure chamber. The mean total airflow was 16 L/min. From the exposure chamber the test atmosphere was passed through a filter before it was released to the exhaust of the fume hood.

- Method of conditioning air: The direction of the flow of the test atmosphere guarantees a freshly generated atmosphere for each individual animal.

- Temperature, humidity, pressure in air chamber: The temperature of the atmosphere was between 20.0 and 20.7 °C and relative humidity was between 28 and 30%. These conditions were considered appropriate for the relatively short 4 hours exposure duration.

TEST ATMOSPHERE
- Brief description of analytical method used: Samples were drawn through a glass fiber filter (type APFC04700, Millipore, Billerica, MA, USA). The collected amount of test substance in the air sample was measured gravimetrically. Sample volumes were measured by means of a dry gas meter (type G 1.6, Actaris Meterfabriek B.V., Dordrecht, The Netherlands).
- Samples taken from breathing zone: yes

VEHICLE
- The test substance was used as delivered by the sponsor

TEST ATMOSPHERE (if not tabulated)
- MMAD (Mass median aerodynamic diameter) / GSD (Geometric st. dev.): The MMAD was 2.5 µm (GSD 2.4) and 2.6 µm (GSD 2.3).

CLASS METHOD (if applicable)
- Rationale for the selection of the starting concentration: Target concentrations were based on the cut off concentration values specified in the UN and EC classification guidelines.

Analytical verification of test atmosphere concentrations:

yes

Remarks:

gravimetrically

Duration of exposure:

4 h

Concentrations:

The mean actual concentration was 5.7 ± 0.4 mg/L. The nominal concentration was 15.4 mg/L. The generation efficiency (ratio of actual and nominal concentration) was 37%. Data obtained from the opacity monitor showed that the aerosol was sufficiently stable.

No. of animals per sex per dose:

3

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing:
Mortality/Viability: twice daily
Clinical signs: twice on the day of dosing (1 and 3 hours after exposure); daily thereafter until day 15
Body weight: recorded on day1 (pre-exposure), 2, 4, 8 and 15
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight,organ weights, histopathology
All animals were sacrificed at the end of the observation period by an intraperitoneal injection with Euthasol® (AST Farma BV, Oudewater, The Netherlands).

Statistics:

No statistical analysis was performed (the method used was not intended to calculate a LC50 value).

Results and discussion

Effect levels

Effect levels 1

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 5.7 mg/L air (analytical)

Based on:

test mat.

Exp. duration:

4 h

Effect levels 2

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 15.4 mg/L air (nominal)

Based on:

test mat.

Exp. duration:

4 h

Mortality:

No mortality occured during the 14-day observation period.

Clinical signs:

other: Hunched posture was shown by all animals on Day 2 after exposure. No clinical signs were noted during exposure.

Body weight:

Body weight gain in males and females were within the range expected for rats of this strain and age used in this type of study.

Gross pathology:

No abnormalities were found at macroscopic post mortem examination of the animals.

Applicant's summary and conclusion

Interpretation of results:

other: CLP/EU GHS criteria not met, no classification required according to Regulation (EC) No. 1272/2008

Conclusions:

In this acute inhalation toxicity study in male and female rats a LD50 value of > 5.7 mg/L air after 4 h nose only exposure to an aerosol of the test substance was determined.