2-ethylhexanal

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study is comparable to OECD 401 with acceptable restrictions mostly due to reduced reporting in times before GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1964

Report date:

1964

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

GLP compliance:

no

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

2-ethylhexanal

EC Number:

204-596-5

EC Name:

2-ethylhexanal

Cas Number:

123-05-7

Molecular formula:

C8H16O

IUPAC Name:

2-ethylhexanal

Details on test material:

- Name of test material (as cited in study report): Äthylhexanal (German)
- Physical state: fluid
- Analytical purity: ca. 98 %
- Expiration date of the lot/batch: not reported
- Stability under test conditions: not reported
- Storage condition of test material: not reported

Test animals

Species:

rat

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Weight at study initiation: males 209 ± 17.7 g, females 167 ± 15.7 g

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

other: aqueous emulsion containing Traganth

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 2 %, 20 %, 30 % (V/V)
- Amount of vehicle (if gavage): 0.004 to 1.92 ml

MAXIMUM DOSE VOLUME APPLIED: ca. 4.4 ml animal in the highest dose dose group (male), lower dose groups about 2 ml per animal

Doses:

0.2, 1.6, 3.2, 6.4 ml/kg bw, equals 164, 1315, 2630, 5261 mg/kg bw (calculated): density 0.822 g/ml at 20 °C

No. of animals per sex per dose:

- 0.2 ml/kg bw dose: 5 male per dose
- 1.6 ml/kg bw dose: 5 female per dose
- 3.2 and 6.4 ml/kg bw doses: 5 female and 5 male per dose

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Weighing was only performed at the beginning of the study for dose calculation. Observation of clinical signs was several times on the day of administration and once daily afterwards with the except on weekends and on holidays.
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs

Statistics:

none

Results and discussion

Effect levels

Effect levels 1

Sex:

male/female

Dose descriptor:

LD50

Effect level:

ca. 3.2 mL/kg bw

Effect levels 2

Sex:

male/female

Dose descriptor:

LD50

Effect level:

ca. 2 600 mg/kg bw

Remarks on result:

other: calculated

Mortality:

- 0.2 ml/kg bw: no mortality (0 f)
- 1.6 ml/kg bw: 2/5 animals died (2 m)
- 3.2 ml/kg bw: 3/10 animals died (0 m/3 f)
- 6.4 ml/kg bw: 10/10 animals died (5 m/5 f)

Clinical signs:

- 0.2 and 1.6 ml/kg: no substance related effect observed
- 3.2 and 6.4 ml/kg: moderate restlessness subsequent to gavage, later on stagger, apathy, abdominal position, diarrhea (day 1). Abdominal position, atonia, narcosis (day 2). Survivors were without symptoms after 6 d

Body weight:

Weighing was done only at initiation of the Study for dose calculation

Gross pathology:

Animals found dead: organs without abnormalities (all animals), blood in the urine bladder (2x)

Any other information on results incl. tables

Mortality (male /female):

ml/kg	Conc. %	Animals (rats)	Mortality within:
			1 h	24 h	48 h	7 d	14 d
6.4	30	10	0/10	7/10	9/10	10/10	10/10
3.2	30	10	0/10	2/10	2/10	3/10	3/10
1.6	20	5	0/5	0/5	0/5	1/5	2/5
0.2	2	5	0/5	0/5	0/5	0/5	0/5

Applicant's summary and conclusion

Executive summary:

The study has acceptable restrictions mostly due to limited documentation (e.g. only body weights at the begin of the study are reported) and no GLP. Different doses (0.2, 1.6, 3.2, 6.4 ml/kg bw) of the test substance were administered via gavage to male and female rats. Mortality was observed at doses >= 1.6 ml/kg bw. The acute oral LD50 for male and female rats is 3.2 ml/kg bw (2600 mg/kg bw). No substance related effects were observed at necropsy. Observed clinical signs were apathy and abdominal positions during exposure. After exposure (1 day p.a.) atonia, narcosis and again abdominal position were reported.

Conclusion:

2 -ethylhexanal is of low oral toxicity (LD50 ca. 2600 mg/kg bw).