Pent-1-ene

Endpoint summary

Description of key information

- Acute oral toxicity: 2000 < LD50 < 5000 mg/kg bw (sim. OECD 401, rel.2)

- Acute inhalation toxicity: LC50 > 10000 ppm (ca. 28684 mg/m3of pent-1-ene) (based on a read across on butene-2, OECD 403, rel.1)

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:

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.

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

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

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

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

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

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.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

4 597 mg/kg bw

Quality of whole database:

The key study was conducted silmilarly to the OECD Guideline No. 401. This study was considered sufficiently robust to cover this endpoint.

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Reference 1

Endpoint:

acute toxicity: inhalation

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

See RAAF document

Reason / purpose for cross-reference:

read-across source

Preliminary study:

none

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

10 000 ppm

Based on:

test mat.

Exp. duration:

4 h

Remarks on result:

other: no effects observed at the highest concentration tested

Remarks:

10000ppm (nominal) = ca. 28684 mg/m3 of pent-1-ene based on the MW of 70.1329 g/mol

Mortality:

none

Clinical signs:

other: Restless during 1st hour of exposure. No abnormalities during 14 day observation period.

Body weight:

Normal bodyweight gain except for two females that showed reduced bodyweight gain.

Gross pathology:

no abnormalities

Other findings:

none

none

Interpretation of results:

GHS criteria not met

Remarks:

EU : Not classified

Conclusions:

Under the test conditions, and based on the read-across approach, the inhalation LC50 for pent-1-ene is higher than 10,000 ppm (28684 mg/m3) for 4 h in rats, therefore it is not classified according to the Annex I of the Regulation EC No. 1272/2008 (CLP) and to the GHS.

Executive summary:

In an acute inhalation toxicity study performed according to the OECD Guideline No. 403 and in compliance with GLP, 5 rats were exposed (whole body) for 4 hours to 2-butene at a nominal concentration of 10,000 ppm ( 22,948 mg/m3). Animals were observed for mortality, clinical signs and body weight for 14 days and at the end of the study the animals were sacrified for macroscopic examination.

No clinical signs were seen and normal growth occurred over the 14d observation period. No abnormalities were observed at gross necropsy.

Only one concentration was tested. This concentration was at the explosive limit and therefore higher concentrations could not be tested.

Under the test conditions, and based on the read across approach, the inhalation LC50 for pent-1-ene is higher than 10,000 ppm (ca. 28684 mg/m3 based on the MW of 71.1329 g/mol) therefore it is not classified according to the Annex I of the Regulation EC No. 1272/2008 (CLP) and to the GHS.

 

Reference 2

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

GLP, guideline study, available as unpublished report, no restrictions, fully adequate for assessment

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to other study

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

no

Principles of method if other than guideline:

not applicable

GLP compliance:

yes (incl. QA statement)

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

other: Crl:WI (WU) BR

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River, Wiga, Sulzfeld, FRG
- Age at study initiation: 9-10 weeks
- Weight at study initiation: mean weight males 277g, mean weight females 171 g
- Housing: 5/cage
- Diet: TNO Institute stock diet ad libitum
- Water: ad libitum
- Acclimation period: 27 days

ENVIRONMENTAL CONDITIONS
- Temperature: 21.5-23.0°C
- Humidity: 38-67% (up to 87% for short periods during cleaning)
- Air changes: 10 per hr
- Photoperiod: 12hrs dark / 12hrs light

IN-LIFE DATES: From: 30 March 1992 To: 13 April 1992

Route of administration:

inhalation

Type of inhalation exposure:

whole body

Vehicle:

air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: modified H 1000 multi-tiered inhalation chamber with pyramidal top and bottom, constructed of stainless steel with 2 glass doors.
- Exposure chamber volume: 1.2 m3
- Method of holding animals in test chamber: Individually held in wire mesh stainless steel cages
- Rate of air-flow: 21.4 ± 0.6 m3 per hour
- Treatment of exhaust air:
- Temperature, humidity, pressure in air chamber: Mean temp = 23.1±0.1°C, mean RH = 49±2%, negative pressure = 1-4mm water column.

TEST ATMOSPHERE
- Brief description of analytical method used: total carbon analyser
- Samples taken from breathing zone: yes

Analytical verification of test atmosphere concentrations:

yes

Remarks:

10,057 ± 276 ppm

Duration of exposure:

4 h

Concentrations:

Target concentration of 10,000 ppm (23 g/m3), analytical concentration 10,057 ± 276 ppm

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: observed just before, during and immediately after exposure and once daily thereafter. Bodyweights recorded just prior to exposure and on days 7 and 14.,
- Necropsy of survivors performed: yes

Statistics:

none

Preliminary study:

none

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

10 000 ppm

Based on:

test mat.

Exp. duration:

4 h

Remarks on result:

other: no effects observed at the highest concentration tested

Remarks:

(10000ppm = ca. 22,948 mg/m3, 23 mg/L nominal)

Mortality:

none

Clinical signs:

other: Restless during 1st hour of exposure. No abnormalities during 14 day observation period.

Body weight:

Normal bodyweight gain except for two females that showed reduced bodyweight gain.

Gross pathology:

no abnormalities

Other findings:

none

none

Interpretation of results:

GHS criteria not met

Remarks:

EU : Not classified

Conclusions:

Under the test conditions, the inhalation LC50 for 2-butene is higher than 10,000 ppm (22,948 mg/m3, 23 mg/L) for 4 h in rats, therefore it is not classified according to the Annex I of the Regulation EC No. 1272/2008 (CLP) and to the GHS.

Executive summary:

In an acute inhalation toxicity study performed according to the OECD Guideline No. 403 and in compliance with GLP, 5 rats were exposed (whole body) for 4 hours to 2-butene at a nominal concentration of 10,000 ppm ( 22,948 mg/m3). Animals were observed for mortality, clinical signs and body weight for 14 days and at the end of the study the animals were sacrified for macroscopic examination.

No clinical signs were seen and normal growth occurred over the 14d observation period. No abnormalities were observed at gross necropsy.

Only one concentration was tested. This concentration was at the explosive limit and therefore higher concentrations could not be tested.

Under the test conditions, the inhalation LC50 for 2 -butene is higher than 10,000 ppm (ca. 22,948 mg/m3) therefore it is not classified according to the Annex I of the Regulation EC No. 1272/2008 (CLP) and to the GHS.

 

Endpoint conclusion

Endpoint conclusion:

no study available

Dose descriptor:

LC50

Value:

28 684 mg/m³ air

Quality of whole database:

The key study was conducted on the analogue substance butene-2 according to the OECD Guideline No. 403. Based on the read across approach, this study was considered sufficiently robust to cover this endpoint.

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Acute toxicity: oral

A key study was identified (ASTA-WERKE AG, 1982, rel.2). In this acute oral toxicity study, which was 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 ; Males: 2970, 4358, 5280, 6400 mg/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 ≤5000 mg/kg bw

Acute toxicity: inhalation

A key study performed in the analogue sustance 2-butene was identified. In an acute inhalation toxicity study performed according to the OECD Guideline No. 403 and in compliance with GLP, 5 rats were exposed (whole body) for 4 hours to 2-butene at a nominal concentration of 10,000 ppm ( 22,948 mg/m3). Animals were observed for mortality, clinical signs and body weight for 14 days and at the end of the study the animals were sacrified for macroscopic examination.

No clinical signs were seen and normal growth occurred over the 14d observation period. No abnormalities were observed at gross necropsy.

Only one concentration was tested. This concentration was at the explosive limit and therefore higher concentrations could not be tested.

Rat inhalation LC50(2 -butene) > 10000 ppm (ca. 22948 mg/m3)

Based on the read across approach and the molecular weight of pent-1 -ene of 70.1329 g/mol :

Rat inhalation LC50(Pent-1 -ene) > 10000 ppm (ca. 28684 mg/m3, 28.7 mg/L, nominal)

Justification for classification or non-classification

Harmonized classification:

The substance has no harmonized classification according to the Regulation (EC) No. 1272/2008.

Self classification:

Acute toxicity via Oral route:

Under the test conditions, the substance is not classified according to the Annex I of the Regulation (EC) No. 1272/2008 (CLP) as 2000 < oral LD50 < 5000 mg/kg bw but classified as Category 5 according to the GHS.

Moreover, based on its hydrocarbon structure and viscosity, test substance should be classified for aspiration hazard (H304) according to the Annex I of the Regulation (EC) No. 1272/2008 (CLP).

Acute toxicity via Dermal route:

No data was available.

Acute toxicity (Inhalation):

Under the test conditions and based on the read across approach, no additional classification is required regarding acute toxicity by inhalation according to the Annex I of the Regulation (EC) No. 1272/2008 (CLP) and to the GHS as the LC50 is higher than 20 mg/L and GHS criteria for Category 5 are not met.

Specific target organ toxicity: single exposure (Oral):

The classification criteria according to the Annex I of the Regulation (EC) No. 1272/2008 as specific target organ toxicant (STOT) – single exposure, oral are not met since no reversible or irreversible adverse health effects were observed immediately or delayed after exposure and no effects were observed at the guidance value (oral) for a Category 1 classification (C≤ 300 mg/kg bw) and at the guidance value (oral) for a Category 2 classification (2000 mg/kg bw≥C > 300 mg/kg bw). No classification is required.

The criteria for Transient Organ effects (STOT-SE Category 3) according to Annex I of the Regulation (EC) No. 1272/2008 are met since narcotic effects were observed in the acute oral toxicity study, therefore the test material should be classified as a specific target organ toxicant after single exposure, H336: May cause drowsiness or dizziness.

Specific target organ toxicity: single exposure (Dermal):

No data was available.

Specific target organ toxicity: single exposure (Inhalation):

The classification criteria according to the Annex I of the Regulation (EC) No. 1272/2008 as specific target organ toxicant (STOT) – single exposure, oral are not met since no reversible or irreversible adverse health effects were observed immediately or delayed after exposure and no effects were observed at the guidance value (inhalation, gas) for a Category 1 classification (C≤ 10 mg/L) and at the guidance value (inhalation, gas) for a Category 2 classification (20 ≥C > 10 mg/L). No classification is required.

The criteria for Transient Organ effects (STOT-SE Category 3) according to Annex I of the Regulation (EC) No. 1272/2008 are not met since no narcotic effects and no respiratory tract irritation were observed in the acute inhalation toxicity study. No classification required.