Pent-1-ene

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

05.07.1982-13.08.1982

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

Fully documented, non GLP Study.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1982

Report date:

1982

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Deviations:

yes

Remarks:

Maximum test volume of 14.7 ml/kg body weight slightly exceeded the recommended maximum volume of 10 ml/kg for non-aqueous solutions. The weight of the animals was not recorded. The number of animals affected by symptoms of toxication is not specified.

GLP compliance:

no

Remarks:

Study too old. However, the study was found to be reliable based on criteria laid out in the TGD IR & CSA R4 (2008).

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Pent-1-ene

EC Number:

203-694-5

EC Name:

Pent-1-ene

Cas Number:

109-67-1

Molecular formula:

C5H10

IUPAC Name:

pent-1-ene

Test material form:

not specified

Details on test material:

- Name of test material (as cited in study report): Pentene-1

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Winkelmann, Borchen
- Age at study initiation: Females: 56 - 62 days old; Males: 48 - 51 days old
- Weight at study initiation: Females: 129 - 147 g; Males: 129-147 g
- Fasting period before study: 16 h
- Housing: single
- Diet (e.g. ad libitum): Standardized feed for test animals ALTROMIN
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21 +/- 2°C
- Humidity (%): 50 - 60 %
- Air changes (per hr): not reported
- Photoperiod (hrs dark / hrs light): 12h/12h

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Doses:

Females: 2022, 2970, 4358, 6400, 9408 mg/kg (corresponding to 3.16, 4.64, 6.81, 10.0, 14.7 ml/kg)
Males: 2970, 4358, 5280, 6400 mg/kg (corresponding to 4.64, 6.81, 8.25, 10.0 ml/kg)

No. of animals per sex per dose:

5 animals per dose

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: not indicated
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs

Results and discussion

Effect levels

Effect levels 1

Sex:

female

Dose descriptor:

LD50

Effect level:

4 960 mg/kg bw

Based on:

test mat.

95% CL:

> 3 486 - < 7 056

Remarks on result:

other: Range as indicated in the report, the statistical method is not given

Effect levels 2

Sex:

male

Dose descriptor:

LD50

Effect level:

4 597 mg/kg bw

Based on:

test mat.

95% CL:

> 3 732 - < 5 663

Remarks on result:

other: Range as indicated in the report, the statistical method is not given

Mortality:

FEMALES
2022 mg/kg: 0/5 animals died within 0.5h after ingestion
2970 mg/kg: 1/5 animals died within 0.5h after ingestion
4358 mg/kg: 2/5 animals died within 0.5h after ingestion
6400 mg/kg: 3/5 animals died within 0.5h after ingestion
9408 mg/kg: 5/5 animals died within 0.5h after ingestion

MALES:
2970 mg/kg: 0/5 animals died within 0.5h after ingestion
4358 mg/kg: 1/5 animals died within 0.5h after ingestion
5280 mg/kg: 3/4 animals died within 0.5h after ingestion and 1/4 died within 24 h after ingestion
6400 mg/kg: 5/5 animals died within 0.5h after ingestion

Clinical signs:

other: - Locomotion decrease (narcotic effect) - staggering, labored breathing, inflated abdomen - higher dosages: inflation of whole body (generalized emphysema) due to intragastral evaporation of 1-pentene - premortal: decrease of muscle tone, general failure

Gross pathology:

- after canulation of the abdominal cavity and the subcutane connective tissue gas escaped which, from the smell, was identical with liquid 1-pentene
- hence, 1-pentene evaporation and penetration of the walls of the hollow organs and the abdominal cavity with subcutane accumulation was the explanation for this finding

Applicant's summary and conclusion

Interpretation of results:

Category 5 based on GHS criteria

Conclusions:

Under the test conditions, the oral LD50 for the registered substance is 2000 < Oral LD50 ≤ 5000 mg/ kg bw in male and female rats, therefore the test material is not classified according to the annex I of the Regulation EC No. 1272/2008 (CLP) but classified as ‘Category 5’ according to the GHS. Based on narcotic effects observed, the test material is classified as a specific target organ toxicant after single exposure, H336: May cause drowsiness or dizziness according to the Regulation (EC) No. 1272/2008 (CLP) and to the GHS.

Executive summary:

In an acute oral toxicity study performed similarly to OECD Guideline No. 401, groups of Wistar rats were administered a single oral dose of 1-pentene by gavage as followed:

Females: 2022, 2970, 4358, 6400, 9408 mg/kg (corresponding to 3.16, 4.64, 6.81, 10.0, 14.7 ml/kg)

Males: 2970, 4358, 5280, 6400 mg/kg (corresponding to 4.64, 6.81, 8.25, 10.0 ml/kg)

Animals were then observed for mortality and clinical signs during the 14-days observation period and at the end of the study the surviving animals were subjected to macroscopic examination.

As intoxication signs, primarily locomotion decrease (narcotic effect) and labored breathing were observed. Premortally, a decrease of muscle tone, general failure of reflexes, considerable inflation of the body and apnoea were observed. The inflation (emphysema) was similarly detectable in all dosing groups but graduated depending on dose. The course of intoxication was peracute.

Macroscopic-anatomically the internal organs of the deceased animals and the animals killed at the end of the observation period were not abnormal. Before laparotomy gas excaped after canulation of the inflated abdominal cavity and the subcutane connective tissue. The smell of the gas was the same as for 1 -pentene.

2000 < Rat Oral LD50 (combined) ≤ 5000 mg/kg bw

Under the test conditions, the test material is not classified according to the annex I of the Regulation EC No. 1272/2008 (CLP) and classified as ‘Category 5’ according to the GHS. Based on narcotic effects observed, the test material is classified as a specific target organ toxicant after single exposure, H336: May cause drowsiness or dizziness according to the Regulation (EC) No. 1272/2008 (CLP) and to the GHS.

This study is considered as acceptable and satisfies the requirement for acute oral toxicity endpoint.