Registration Dossier

Administrative data

Endpoint:
acute toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Study period:
from 2008-08-25 to 2008-12-10
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP lab following OECD guidelines

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 423 (Acute Oral toxicity - Acute Toxic Class Method)
Deviations:
yes
Remarks:
without impact on the study
GLP compliance:
yes (incl. QA statement)
Test type:
acute toxic class method

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
other: liquid
Details on test material:
- Name of test material (as cited in study report): 2-ethylhexylal
- Physical state: liquid
- Analytical purity: 99.82%
- Lot/batch No.: 0803181500
- Expiration date of the lot/batch: 2009-03-18
- Storage condition of test material: room temperature

Test animals

Species:
rat
Strain:
other: OFA
Sex:
female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Charles Rivers Laboratories (Wilmington, MA)
- Age at study initiation: between 8-10 weeks
- Weight at study initiation: between 181 and 244g
- Fasting period before study: yes, overnight prior to test item administration
- Housing: group-caged per dose
- Diet (e.g. ad libitum): maintenace diet for rodent
- Water (e.g. ad libitum): ad libitum
- Acclimation period: at least 5 days in the experimental unit before the experiment

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21.5 +- 5.5°C
- Humidity (%): between 45 and 90%
- Air changes (per hr): between 10 and 30
- Photoperiod (hrs dark / hrs light): 12 hours/12 hours

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
corn oil
Doses:
300 and 2000 mg/kg
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: daily
- Necropsy of survivors performed: yes

Results and discussion

Effect levels
Sex:
female
Dose descriptor:
LD50
Effect level:
> 5 000 mg/kg bw
Based on:
test mat.
Remarks on result:
other: following annex 2c of OECD Guideline 423
Mortality:
two deaths were highlighted in the test animal group (2000 mg/kg). However, macroscopic autopsy was impossible for one rat since this last was found partially devoured by other(s) resulting perhaps from an attack. Thus no obvious direct relationship between 2-ethylhexylal administration at about 2000 mg/kg and dead can be established for this animal. For the other rat, macroscopic autopsy highlighted a very slight congestion of the stomach and a slight fading of the liver perilobular areas. Lungs were highly congested and oedemated on the whole organ. The other organs seemed to be exempted from any macroscopic lesions. Nevertheless, it is impossible to exclude that, for this rat, the tested chemical had be perhaps administered in lungs. For the last remaining alive rat, no death or toxicological adverse effect apparitions which could result from the 2-ethylhexylal exposure were highlighted for a 14 days period following a first administration of 2-ethylhexylal at a final dose level of about 2000 mg per body weight. It was finally euthanasied and macroscopically autopsied. As a result from performed autopsies, no obvious pathological tissue alterations were highlighted for these tested animals. Sampled tissues (heart, liver, kidneys, lungs, spleen, brain and stomach) were also stored in the appropriate conservation media.

Applicant's summary and conclusion

Interpretation of results:
Category 5 based on GHS criteria
Remarks:
Migrated information: or Unclassified
Conclusions:
From these experiments and on the basis of the followed experimental scheme recommended by the OCDE guideline 423, we can conclude that the chemical compound 2-ethylhexylal can be classified in the category 5 of the GHS Acute Toxicity scheme which corresponds to a limit LD50 higher to 5000 mg per kg of body weight for this test item and is then classified in the toxicity category 5.
Executive summary:

As recommended by the OECD guideline 423, in a first step the test item solution (2-ethylhexylal mixed with corn oil) was administered at a final 2-ethylhexylal dose level of about 300 mg per kg of body weight. Following administration, animals were regularly inspected for tolerance to the tested chemical compound administration. From the test item administration time (T) to the exposure time T + 4h, 8 to 9 observations were performed and recorded for each animal. The next observations, from D+2 (day ensuing the administration day D+1) to D+14, were performed daily with a frequency of one inspection point per day. After an observation period of 14 days, all three animals were alive without evident toxicological effect apparitions resulting from administration of the test item. Finally animals were humanely killed by 1 ml intraperitoneal injection of Nembutal. After anaesthesia, female rats were macroscopically autopsied. All tissues were cautiously examined with a more special attention to heart, liver, kidneys, lungs, spleen, brain and stomach. As a result from performed autopsies, no obvious pathological tissue alterations resulting from 2-ethylhexylal oral administration were highlighted. Nevertheless, some lesions (especially pulmonary and hepatic congestion) probably caused by Nembutal anaesthesia were reported. Indeed it is known that barbiturate induce in particular respiratory depression and are metabolised by the liver. Finally, all taken organs were individually identified and stored in formaldehyde solutions for further histological analyses, if necessary.

In a second step, the initial administered dose (about 300 mg/kg) was once again orally injected to three other female rats in order to confirm the results obtained in the first step. From the test item administration time (T) to the exposure time T + 4h, 9 observations were performed and recorded for each animal. The next observations, from D+2 (day ensuing the administration day D+1) to D+14 were performed daily with a frequency of one inspection point per day. From this second injection, after an observation period of 14 days, the same observations as those highlighted for the step 1 (namely, no mortality in the test animal group and no evident external and internal pathological alterations resulting from administration of a 2-ethylhexylal solution) were highlighted. After anaesthesia (1 ml Nembutal), rats were autopsied and sampled tissues (heart, liver, kidneys, lungs, spleen, brain and stomach) were examined. Results of the second step led to the following conclusion: administration of a 2-ethylhexylal solution at a final dose volume of 300 mg/kg induces no acute toxicity in female rats.

Since no death and no toxicological effects were observed after a 300 mg/kg administration of a test item dose, the tested chemical compound was administered at a higher dose to three other female rats. The test item solution was administered at a final oral dose of about 2000 mg per kg of body weight as recommended in the acute toxic class method assay (see Annex 2). As for the steps 1 and 2, following oral administration, animals were carefully observed (5 to 6 observations for day D+1 and daily thereafter) for any toxicological adverse effect apparition as described previously.

Contrary to the test item administration at an oral dose of about 300 mg per kg of body weight, two deaths were highlighted in the test animal group. Indeed two female rat died in the first 24 hours after oral administration of about 2000 mg per kg of body weight of 2-ethylhexylal.

Macroscopic autopsy was impossible for one rat since this last was found partially devoured by other(s) resulting perhaps from an attack. Thus no obvious direct relationship between 2-ethylhexylal administration at about 2000 mg/kg and dead can be established for this animal.

For the other rat, macroscopic autopsy highlighted a very slight congestion of the stomach and a slight fading of the liver perilobular areas. Lungs were highly congested and oedemated on the whole organ. The other organs seemed to be exempted from any macroscopic lesions. Nevertheless, it is impossible to exclude that, for this rat, the tested chemical had be perhaps administered in lungs. For the last remaining alive rat, no death or toxicological adverse effect apparitions which could result from the 2-ethylhexylal exposure were highlighted for a 14 days period following a first administration of 2-ethylhexylal at a final dose level of about 2000 mg per body weight. It was finally euthanasied and macroscopically autopsied. As a result from performed autopsies, no obvious pathological tissue alterations were highlighted for these tested animals. Sampled tissues (heart, liver, kidneys, lungs, spleen, brain and stomach) were also stored in the appropriate conservation media. Since no direct implication of the test item can be highlighted with evidence for the rat 409, 2-ethylhexylal was not considered as the principal death cause and only one death could be correlated with 2-ethylhexylal administration at a final dose level of about 2000 mg/kg. This approach allowed us to continue experimentation and to consolidate obtained results with a second administration of the test item at 2000 mg/kg while remaining consistent with the OECD guideline (schema of the annex 2).

Repetition of the same exposure conditions (about 2000 mg/kg) to three other female rats led to three remaining alive animals and no evident external and internal pathological alterations resulting from a 2000 mg acute 2-ethylhexylal oral administration could be highlighted after macroscopic autopsies.

From these experiments and on the basis of the followed experimental scheme recommended by the OECD guideline 423, we can conclude that the chemical compound 2-ethylhexylal can be classified in the category 5 of the GHS Acute Toxicity scheme which corresponds to a limit LD50 higher to 5000 mg per kg of body weight for this test item.