3,3'-[methylenebis(oxymethylene)]bisheptane

Endpoint summary

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

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

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

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

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

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.

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.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

5 000 mg/kg bw

Quality of whole database:

The test was performed according to OECD TG 423 and GLP (Klimisch code 1)

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Link to relevant study records

Reference

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

June 04-21, 2012

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

EU Method B.3 (Acute Toxicity (Dermal))

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

GLP compliance:

yes

Test type:

fixed dose procedure

Limit test:

yes

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Breeding farm VELAZ s.r.o., Koleč u Kladna, Czech Republic, RČH CZ 21760152
- Age at study initiation: not specified
- Weight at study initiation: average of 254.72 kg for males; average of 2175.75 kg for females
- Fasting period before study: not specified
- Housing: animal room with monitored conditions – one animal in one plastic cage
- Diet (e.g. ad libitum): ST 1 BERGMAN – standard pelleted diet ad libitum (producer: Ing.Mrkvička Miroslav - Výroba krmných směsí, Mlýn Kocanda, 252 42 Jesenice u Prahy).
- Water (e.g. ad libitum): drinking tap water ad libitum (quality corresponding to the Regulation No. 252/2004 of Czech Coll. of Law)
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): room temperature 22 + 3 °C, permanently monitored
- Humidity (%): 30 – 70 %, permanently monitored
- Air changes (per hr): not specified
- Photoperiod (hrs dark / hrs light): 12/12

Type of coverage:

semiocclusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

Preparation of experimental animals
Approximately 24 hours before application, a skin area of about 6 x 6 cm on the back of animals was shaved (aprox. 10% of the body surface). The animals were weighed immediately before application.

Preparation and application of the test substance
The amount of test substance for each animal was weighed out (according to its body weight and the dose) immediately before application.
The test substance in delivered form was applied on the depilated area of skin. The application site was covered by mull and held in contact by plaster (strapping). After 24 hours the semiocclusive dressing was removed, and remains of the test substance were wiped off with water.

Duration of exposure:

24 hours

Doses:

The study was performed as limit test: two groups of animals – 5 males and 5 females and the dose of 2000 mg/kg. The pre-test was performed with 1 male and 1 female of the groups of the five animals. The pre-test was started one day before the start of limit test.

No. of animals per sex per dose:

5

Control animals:

not required

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing:

Body weight recording
The animals were weighed at the start of the study (before application), at 8th day and at the end of experiment (15th day). The average body weight of the groups was calculated from individual body weights. Body weight increments were calculated from the body weight at the start of the study, during the first week and at the end of the study.

Clinical observation
After application the animals were observed individually – at the first day: twice (30 minutes and 3 hours after application), at the second day: twice (in the morning and in the afternoon) and daily thereafter for 14 days. Observations included changes in skin and fur, eyes, visible mucous membranes, nutritive
condition, autonomic and central nervous systems, psychic activity, somatomotor activity, reactions to stimuli, function of respiratory, circulatory, digestive and urogenital system. Also presence of tremors, convulsions, salivation, diarrhoea, lethargy, sleep and coma was carefully observed.

- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight,organ weights, histopathology, other:
All test animals survived to the end of study were sacrificed on the 15th day by injection of
veterinary preparation T61 (1 ml iv.) and gross necropsy was carried out. Nutritious status,
body surface, body foramina, thoracic, abdominal and cranial cavity were evaluated. All gross
macroscopic changes of organs and tissues were recorded on special data sheets.

Statistics:

Not necessary

Preliminary study:

For male:
no death
30 minutes: no clinical signs of intoxication
3 hours: no clinical signs of intoxication
2nd – 14th day: no clinical signs of intoxication

For female:
no death
30 minutes: no clinical signs of intoxication
3 hours: no clinical signs of intoxication
2nd – 14th day: no clinical signs of intoxication

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

No mortality was recorded

Clinical signs:

other: No clinical signs of intoxication were detected after application in all animals

Gross pathology:

No macroscopic changes were diagnosed during pathological examination in all animals

Other findings:

None

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The test substance toxicity was evaluated on the basis of mortality, body weight changes, and clinical signs of toxicity during the observation period and necropsy findings at the end of study.
The test substance applied on skin at a dose of 2000 mg/kg of animal weight did not cause death of animals.
No clinical signs of intoxication were observed. No macroscopic changes were diagnosed during pathological examination of animals.
According to the results of study, the value of LD50 (dermal) of the test substance, 2-ETHYLHEXYLAL, is higher than 2000 mg/kg of body weight for rats of both sexes.

Executive summary:

Acute dermal toxicity of 2 -ethylhexylal was evaluated in an in vivo test performed according to OECD TG 402 (limit test).

The test substance toxicity was evaluated on the basis of mortality, body weight changes, and clinical signs of toxicity during the observation period and necropsy findings at the end of study. The test substance applied on skin at a dose of 2000 mg/kg of animal weight did not cause death of animals. No clinical signs of intoxication were observed. No macroscopic changes were diagnosed during pathological examination of animals. According to the results of study, the value of LD50 (dermal) of the test substance, 2-ETHYLHEXYLAL, is higher than 2000 mg/kg of body weight for rats of both sexes.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Quality of whole database:

The test was performed according to OECD TG 402 and GLP (Klimisch code 1)

Additional information

Justification for selection of acute toxicity – oral endpoint

This test was selected as the only one available and is relevant as performed according to OECD 423 (GLP).

Justification for selection of acute toxicity – inhalation endpoint

This test via inhalation route is not required as the dermal route is more appropriate.