imidacloprid (ISO); 1-(6-chloropyridin-3-ylmethyl)-N-nitroimidazolidin-2-ylidenamine

Endpoint summary

Description of key information

WoE, M-028854 -01 -1: Oral (OECD 401), rat: LD50: 642 mg/kg bw (males) and 648 mg/kg bw (females)

WoE, M-025996 -01 -1: Oral (OECD 401), rat: LD50: 424 mg/kg bw (males) and in the range of 450 to 475 mg/kg bw (females)

WoE, M-028901 -1: Oral (OECD 401), rat: LD50: 504 mg/kg bw (males) and 379 mg/kg bw (females)

WoE, M-007509 -01 -1: Oral (OECD 401), mouse: LD50: 131 mg/kg bw (males) and 168 mg/kg bw (females)

 

Inhalation (OECD 403), rat: LC50 (dust): 5.32 mg/L air (males and females)

Dermal (OECD 402), rat: LD50 > 5000 mg/kg bw (males and females)

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Reference 1

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

10 Oct 1990 - 23 Jan 1991

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Version / remarks:

adopted 1987

Deviations:

no

GLP compliance:

yes

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: Laboratory animal breeder Winkelmann (Borchen, Germany)
- Females nulliparous and non-pregnant: Yes
- Age at study initiation: 7 - 8 weeks (males), 10 - 11 weeks (females)
- Weight at study initiation: 167 - 186 g (males), 170 - 183 g (females)
- Fasting period before study: 15 - 17 hours before administration
- Housing: in groups of 5 in Type III Makrolon cages equipped with type S 8/15 low-dust wood granules (Rettemaier & Söhne Füllstoff-Fabriken, Ellwangen-Holzmühle, Germany) as bedding material
- Diet: Altromin 1324 Diet for Rats and Mice (Altromin GmbH and Co KG, Lage, Germany), ad libitum
- Water: tap water, ad libitum
- Acclimation period: at least 5 days
- Method of randomisation in assigning animals to test and control groups: randomized lists generated by a computer program

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19.5 - 22.5
- Humidity (%): 40 - 70
- Air changes (per hr): at least 10
- Photoperiod (hrs dark / hrs light): 12 / 12

IN-LIFE DATES: From: 10 Oct 1990 To: 23 Jan 1991

Route of administration:

oral: gavage

Vehicle:

other: 2 % v/v Cremophor EL in demineralized water

Details on oral exposure:

VEHICLE
- Amount of vehicle: 10 mL/kg bw

Doses:

50, 200, 300, 350, 400, 500, 600 mg/kg bw (males)
100, 200, 300, 350, 400, 500 mg/kg bw (females)

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: appearance and behavior were recorded several times in the day of administration, and at least once a day thereafter. Body weights were recorded before administration, on days 4 and 8 and then weekly.
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight, gross pathological examination

Statistics:

Not reported.

Key result

Sex:

male

Dose descriptor:

LD50

Effect level:

504 mg/kg bw

Based on:

test mat.

95% CL:

> 372 - < 684

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

379 mg/kg bw

Based on:

test mat.

95% CL:

> 324 - < 445

Mortality:

Mortalities occurred at doses from 300 mg/kg bw. The LD50 was determined to be 504 mg/kg bw for males and 379 mg/kg bw for females. For details on mortality please see attached tabular results.

Clinical signs:

other: A dose of 50 mg/kg bw (males) and 100 mg/kg bw (females) was tolerated without symptoms. At higher doses apathy, staggering and spastic gait, labored breathing, reduced motility, spasmodic state (periodic in some cases), periodic tremors, soft feces and

Gross pathology:

No test substance-related gross pathological changes were observed in the animals which were sacrificed at the conclusion of the post-treatment observation period. The following findings were determined in animals which died during the post-treatment observation period: lung distended, mottled, dark; liver dark, bladder distended with clear urine.

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

The study was performed in accordance to OECD TG 401 under GLP conditions and is considered reliable. Under the conditions chosen, the acute oral LD50 was determined to be 504 mg/kg bw for male rats and 379 mg/kg bw for female rats. According to criteria of the CLP Regulation (EU) No. 1272/2008, classification of the test item for acute oral toxicity category 4 is needed.

Reference 2

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

25 Oct - 29 Nov 1989

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Version / remarks:

adopted 1987

Deviations:

no

GLP compliance:

yes

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 Experimental Animal Breeders, Borchen, Germany
- Females nulliparous and non-pregnant: yes
- Age at study initiation: 7 - 8 weeks (males), 10 - 12 weeks (females)
- Weight at study initiation: 167 - 187 g (males), 168 - 194 g (females)
- Fasting period before study: about 17 h
- Housing: animals were kept in groups of 5 in Type III Makrolon cages equipped with Type S 8/15 low-dust wood shavings (Rettenmaier & Söhne Füllstoff-Fabriken) used as litter. Cages were changed at least weekly.
- Diet: Altromin 1324 Maintenance Diet for Rats and Mice (Altromin GmbH & Co KG, Lage, Germany), ad libitum
- Water: tap water, ad libitum
- Acclimation period: at least 5 days
- Method of randomisation in assigning animals to test and control groups: randomized lists produced by a computer program

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 - 24
- Humidity (%): about 50
- Air changes (per hr): about 10
- Photoperiod (hrs dark / hrs light): 12 / 12

IN-LIFE DATES: From: 25 Oct To: 29 Nov 1989

Route of administration:

oral: gavage

Vehicle:

other: 2 % v/v Cremophor EL in demineralized water

Details on oral exposure:

VEHICLE
- Amount of vehicle: 10 mL/kg bw

Doses:

50, 100, 250, 315, 400, 450, 500, 1800 mg/kg bw (males)
100, 250, 315, 400, 450, 475, 500, 1800 mg/kg bw (females)

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: appearance and behavior were determined several times on the day of administration, and at least once daily thereafter. Body weights were determined prior to treatment, on study days 4 and 8, and at weekly intervals thereafter.
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight, gross pathological examination

Statistics:

Not reported.

Key result

Sex:

male

Dose descriptor:

approximate LD50

Effect level:

424 mg/kg bw

Based on:

test mat.

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

> 450 - < 475 mg/kg bw

Based on:

test mat.

Remarks on result:

other: estimated

Mortality:

Mortality occurred from 400 mg/kg bw (both sexes). At doses of 500 mg/kg bw and higher, all animals died within one day (both sexes). The LD50 was determined to be 424 mg/kg bw for males and 450 - 475 mg/kg bw for females. For details on mortality please see attached tabular results.

Clinical signs:

other: A dose of 50 mg/kg bw (males) and 100 mg/kg bw (females) was tolerated without symptoms. Symptoms were observed at doses from 100 mg/kg bw (males) and 250 mg/kg bw (females), respectively. The main symptoms were apathy, labored or transiently labored brea

Gross pathology:

No test substance-related findings at any dose level were noted in animals sacrificed at the end of the observation period. For animals which died during the post-treatment observation the following findings were occasionally made in animals at dose levels 400 - 1800 mg/kg bw: liver dark; spleen pale; lung dark, patchy and distended; glandular stomach mucosa slightly reddened.

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

The study was performed in accordance to OECD TG 401 under GLP conditions and is considered reliable. Under the conditions chosen, the acute oral LD50 was determined to be 424 mg/kg bw for male rats and in the range of 450 to 475 mg/kg bw for female rats. According to criteria of the CLP Regulation (EU) No. 1272/2008, classification of the test item for acute oral toxicity category 4 is needed.

Reference 3

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

02 Oct 1990 - 23 Jan 1991

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Version / remarks:

adopted 1987

Deviations:

no

GLP compliance:

yes

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 Experimental Animal Breeders, Borchen, Germany
- Females nulliparous and non-pregnant: Yes
- Age at study initiation: 7 - 8 weeks (males), 10 - 11 weeks (females)
- Weight at study initiation: 168 - 184 grams (males), 169 - 186 grams (females)
- Fasting period before study: 15 - 17 hours
- Housing: in groups of five in Type III Makrolon cages with Type S 8/15 low-dust wood shavings (Rettenmaier & Söhne Füllstoff-Fabriken) as litter
- Diet: Altromin 1324 Maintenance Diet for Rats and Mice (Altromin GmbH % Co KG, Lage), ad libitum
- Water: tap water, ad libitum
- Acclimation period: at least 5 days
- Method of randomisation in assigning animals to test and control groups: randomized lists calculated by a computer program

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19.5 - 22.5
- Humidity (%): 40 - 70
- Air changes (per hr): at least 10
- Photoperiod (hrs dark / hrs light): 12 / 12

IN-LIFE DATES: From: 02 Oct 1990 To: 23 Jan 1991

Route of administration:

oral: gavage

Vehicle:

other: 2 % v/v Cremophor EL in demineralized water

Details on oral exposure:

VEHICLE
- Amount of vehicle: 10 mL/kg bw

Doses:

50, 200, 350, 400, 500, 600, 750 and 1000 mg/kg bw (males)
100, 400, 450, 500, 600 and 1000 mg/kg bw (females)

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: body weights were determined before treatment, on days 4 and 8, and weekly thereafter. Appearance an behavior were recorded several times on the day of treatment, and at least once daily thereafter.
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight, gross pathology

Statistics:

Not reported.

Key result

Sex:

male

Dose descriptor:

LD50

Effect level:

642 mg/kg bw

Based on:

test mat.

95% CL:

> 447 - < 925

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

648 mg/kg bw

Based on:

test mat.

95% CL:

> 414 - < 1 015

Mortality:

Mortality occurred from 350 mg/kg bw (males) and 450 mg/kg bw (females). At the top dose (1000 mg/kg bw), all animals of both sexes died. The LD50 was determined to be 642 mg/kg bw for males and 648 mg/kg bw for females. For details on mortality please see attached tabular results.

Clinical signs:

other: The following findings were observed: apathy, staggering or spastic gait, labored breathing, spasms or transient spasms, transient tremor, decreased motility, increased water intake, diuresis, piloerection, hypersalivation, absence of feces and transient

Gross pathology:

No test substance-related gross pathological changes were observed in the animals which were sacrificed at the conclusion of the post-treatment observation period. The following findings were determined in animals which died during the post-treatment observation period: lungs distended, patchy, dark; liver dark; kidneys slightly pale; bladder engorged with urine; spleen slightly pale. For details please see attached tabular results.

Other findings:

not reported

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

The study was performed in accordance to OECD TG 401 under GLP conditions and is considered reliable. Under the conditions chosen, the acute oral LD50 was determined to be 642 mg/kg bw for male rats and 648 mg/kg bw for female rats. According to criteria of the CLP Regulation (EU) No. 1272/2008, classification of the test item for acute oral toxicity category 4 is needed.

Reference 4

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

31 Oct - 01 Dec 1989

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Version / remarks:

adopted 1987

Deviations:

no

GLP compliance:

yes

Test type:

standard acute method

Limit test:

no

Species:

mouse

Strain:

NMRI

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Rationale for alternative/additional species to rat: the mouse was used as a further mammalian test species beside the rat.
- Source: Winkelmann experimental animal breeders (Borchen, Germany)
- Females nulliparous and non-pregnant: Yes
- Age at study initiation: 4 weeks (males), 4 - 5 weeks (females)
- Weight at study initiation: 21 - 25 g (males), 20 - 24 g (females)
- Fasting period before study: about 17 h
- Housing: during study period animals were kept in groups of 5 in Type III Makrolon cages equipped with Type S 8/15 low-dust wood shavings (Rettenmaier & Söhne Füllstoff-Fabriken, Ellwangen-Holzmühle, Germany) as litter.
- Diet: Altromin 1324 Maintenance Diet for Rats and Mice (Altromin GmbH & Co KG, Lage, Germany), ad libitum
- Water: tap water, ad libitum
- Acclimation period: at least 5 days
- Method of randomisation in assigning animals to test and control groups: using randomizing lists produced by a calculation program

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 - 24
- Humidity (%): about 50
- Air changes (per hr): about 10
- Photoperiod (hrs dark / hrs light): 12 / 12

IN-LIFE DATES: From: 31 Oct To: 01 Dec 1989

Route of administration:

oral: gavage

Vehicle:

other: 2 % v/v Cremophor EL in demineralized water

Details on oral exposure:

VEHICLE
- Amount of vehicle: 10 mL/kg bw

Doses:

10, 71, 100, 120, 140, 160, 250 mg/kg bw (males)
10, 100, 120, 140, 160, 250 mg/kg bw (females)

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 or 15 days
- Frequency of observations and weighing: appearance and behavior were determined several times on the day of administration, and at least once daily thereafter. Body weights were determined prior to treatment, on study days 4 and 8, and at weekly intervals thereafter.
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight, gross pathological examination

Statistics:

Not reported.

Key result

Sex:

male

Dose descriptor:

LD50

Effect level:

131 mg/kg bw

Based on:

test mat.

95% CL:

> 111.5 - < 156

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

168 mg/kg bw

Based on:

test mat.

95% CL:

> 142.3 - < 200.1

Mortality:

Mortalities occurred at doses from 100 mg/kg bw. The LD50 was determined to be 131 mg/kg bw for males and 168 mg/kg bw for females. For details on mortality please see attached tabular results.

Clinical signs:

other: A dose of 10 mg/kg bw was tolerated by both sexes without symptoms. Symptoms were observed at doses from 71 mg/kg bw. The main symptoms were apathy, labored or transiently labored breathing, decreased motility, transient staggering gait, transient trembli

Gross pathology:

No test substance-related findings at any dose level were noted in animals sacrificed at the end of the observation period.

For animals which died during the post-treatment observation the following findings were occasionally made in single animals at dose levels 100 - 250 mg/kg bw: liver pale, occasionally dark; spleen pale, occasionally dark; lung dark, patchy and distended.

Interpretation of results:

Category 3 based on GHS criteria

Conclusions:

The study was performed in accordance to OECD TG 401 under GLP conditions and is considered reliable. Under the conditions chosen, the acute oral LD50 was determined to be 131 mg/kg bw for male mice and 168 mg/kg bw for female mice. According to criteria of the CLP Regulation (EU) No. 1272/2008, classification of the test item for acute oral toxicity category 3 is needed.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

131 mg/kg bw

Quality of whole database:

Several suitable studies are available, almost all conducted with rats, except for one study conducted with mice. The LD50 reported above refers to the most sensitive result, which was the one obtained within the mouse study.

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Reference 1

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

08 - 22 Sep 1987

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Version / remarks:

adopted 1981

Deviations:

no

GLP compliance:

yes

Limit test:

no

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: laboratory animal breeder Winkelmann, Borchen, Germany
- Females nulliparous and non-pregnant: yes
- Age at study initiation: 8 - 12 weeks
- Weight at study initiation: 160 - 210 g
- Fasting period before study: not reported
- Housing: animals were housed in groups of 5 in Makrolon cages type III with low-dust wood granulate type 8/15 (Ssniff Co, Soest, Germany) for bedding material.
- Diet: Altromin 1324 Diet for rats and mice (Altromin GmbH, Lange, Germany), ad libitum
- Water: tap water, ad libitum
- Acclimation period: at least 5 days
- Method of randomisation in assigning animals to test and control groups: randomizing lists produced by a computer program were used

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 - 24
- Humidity (%): approximately 50
- Air changes (per hr): approximately 10
- Photoperiod (hrs dark / hrs light): 12 / 12

IN-LIFE DATES: From: 08 Sep 1987 To: 22 Sep 1987

Route of administration:

inhalation: dust

Type of inhalation exposure:

nose/head only

Vehicle:

air

Mass median aerodynamic diameter (MMAD):

> 10.6 - <= 20 µm

Geometric standard deviation (GSD):

> 1.82 - <= 2.15

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: PVC inhalation chamber
- Exposure chamber volume: approximately 20 L
- Method of holding animals in test chamber: animals were confined to plexiglass exposure tubes matching the animals sizes
- Source and rate of air (airflow): see 'any other information on materials and methods incl tables' section for further information
- Method of conditioning air: in-line VIA compressed air dryer type A110, i.e. water, dust and oil were removed
- System of generating particulates: Bayer Dust Generator (see 'any other information on materials and methods incl tables' for further description)
- Method of particle size determination: aerodynamic particle sizer with laser velocimeter (TSI-APS 3300)
- Treatment of exhaust air: purified using an absolute filter
- Temperature, humidity, pressure in air chamber: 22 - 25 °C, 5 - 34 %, not reported

TEST ATMOSPHERE
- Brief description of analytical method and equipment used: gravimetrical evaluation of 10 - 50 L of air using filters (SM 11106, pore size 0.45 µm)
- Samples taken from breathing zone: yes
- Particle size distribution: number of particles < 5 µm: 71 % (1.22 mg/L air), 65 % (2.57 mg/L air), 70 % (5.32 mg/L air)
- MMAD (Mass median aerodynamic diameter) / GSD (Geometric st. dev.): 10.6 µm, 1.82 µm (1.22 mg/L air), 14.2 µm, 1.92 µm (2.57 mg/m³ air), 20.0 µm, 2.15 µm (5.32 mg/L air)

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Remarks on duration:

1 x 4h (dust)

Concentrations:

1.22, 2.57, and 5.32 mg/L air (dust)

No. of animals per sex per dose:

5 for treatment groups and 10 for air control

Control animals:

yes

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: body weights were recorded before exposure and on day 3, 7 and 14 (1 x 4h). Appearance and behavior were assessed several times on the day of exposure, but not during exposure.
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight, histopathology, gross pathological examination, organ weights

Statistics:

Please refer to 'any other information on materials and methods incl. tables' section.

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 5.32 mg/L air

Based on:

test mat.

Exp. duration:

4 h

Mortality:

No mortality occurred during the study period.

Clinical signs:

other: difficult breathing, reduced motility and piloerection, slight tremors.

Remarks:

Doses up to 1.22 mg/L air were tolerated without symptoms by both sexes. At 2.57 mg/L air difficult breathing, reduced motility and piloerection and additionally at 5.32 mg/L air slight tremors were observed.

Body weight:

No effect on body weight was noted during the course of the study

Gross pathology:

Gross pathological examination revealed no substance-related findings.

Other findings:

No obvious treatment-related effects on relative organ weight were noticed for liver and lung.

Histopathological examination of lung and liver exhibited no signs of treatment-related changes.

Interpretation of results:

other: CLP/EU GHS criteria not met, no classification required according to Regulation (EC) No 1272/2008

Conclusions:

The study is in accordance with OECD 403, was performed under GLP conditions and is considered to be valid and reliable. Under the conditions chosen, the acute inhalation LC50 was determined to be >5.32 mg/L air (dust; 1x4h) in male and female rats. According to criteria of the CLP Regulation (EU) No. 1272/2008, classification of the test item for acute inhalation toxicity is not required.

Reference 2

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

07 - 21 Sep 1987

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Version / remarks:

adopted 1981

Deviations:

no

GLP compliance:

yes

Limit test:

no

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: laboratory animal breeder Winkelmann, Borchen, Germany
- Females nulliparous and non-pregnant: yes
- Age at study initiation: 8 - 12 weeks
- Weight at study initiation: 160 - 210 g
- Fasting period before study: not reported
- Housing: animals were housed in groups of 5 in Makrolon cages type III with low-dust wood granulate type 8/15 (Ssniff Co, Soest, Germany) for bedding material.
- Diet: Altromin 1324 Diet for rats and mice (Altromin GmbH, Lange, Germany), ad libitum
- Water: tap water, ad libitum
- Acclimation period: at least 5 days
- Method of randomisation in assigning animals to test and control groups: randomizing lists produced by a computer program were used

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 - 24
- Humidity (%): approximately 50
- Air changes (per hr): approximately 10
- Photoperiod (hrs dark / hrs light): 12 / 12

IN-LIFE DATES: From: 07 Sep 1987 To: 21 Sep 1987

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

nose/head only

Vehicle:

other: polyethylene glycol E-400-ethanol 1:1 mixture (Lutrol)

Mass median aerodynamic diameter (MMAD):

1.61 µm

Geometric standard deviation (GSD):

1.44

Details on inhalation exposure:

AEROSOLS (1x4h) - T2025951

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: PVC inhalation chamber
- Exposure chamber volume: approximately 20 L
- Method of holding animals in test chamber: animals were confined to plexiglass exposure tubes matching the animals sizes
- Source and rate of air (airflow): 10 L compressed oil-free air per minute
- Method of conditioning air: in-line VIA compressed air dryer type A110, i.e. water, dust and oil were removed
- System of generating aerosols: nebulization of 200 µL/min of vehicle-NTN 33893 solution into baffle of inhalation chamber by means of a nozzle and compressed air with the use of a Braun infusion pump with ground glass jet
- Method of particle size determination: aerodynamic particle sizer with laser velocimeter (TSI-APS 3300)
- Treatment of exhaust air: purified using an absolute filter
- Temperature, humidity, pressure in air chamber: 23 - 25 °C, 14 - 34 %, not reported

TEST ATMOSPHERE
- Brief description of analytical method and equipment used: Determination of the NTN 33893 concentration in the test atmosphere was performed using HPLC.
- Samples taken from breathing zone: yes
- Time needed for equilibrium of exposure concentration before animal exposure: 6 min

VEHICLE
- Composition of vehicle: polyethylene glycol E-400-ethanol 1:1 mixture (Lutrol)

TEST ATMOSPHERE
- Particle size distribution: mass fraction < 5 µm: 100 %.
- MMAD (Mass median aerodynamic diameter) / GSD (Geometric st. dev.): 1.61 µm, 1.44 µm

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Remarks on duration:

1 x 4h (aerosols)

Concentrations:

0.5 mg/L air (nominal concentration),
0.069 mg/L air (analytical concentration)

No. of animals per sex per dose:

5

Control animals:

yes

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: body weights were recorded before exposure and on day 3, 7 and 14 after exposure. Appearance and behavior were assessed several times on the day of exposure, but not during exposure.
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight, histopathology, gross pathological examination, organ weights

Statistics:

Please refer to 'any other information on materials and methods incl. tables' section.

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 0.069 mg/L air (analytical)

Based on:

test mat.

Exp. duration:

4 h

Mortality:

No mortality occurred during the study period.

Clinical signs:

other: No clinical signs were observed during the study period

Body weight:

No effects observed

Gross pathology:

Gross pathological examination revealed no substance-related findings.

Other findings:

No obvious treatment-related effects on relative organ weight were noticed for liver and lung.

Histopathological examination of lung and liver exhibited no signs of treatment-related changes.

Interpretation of results:

other: CLP/EU GHS criteria not met, no classification required according to Regulation (EC) No 1272/2008

Conclusions:

The study is in accordance with OECD 403, was performed under GLP conditions and is considered to be valid and reliable. Under the conditions chosen, the acute inhalation LC50 was determined to be >0.69 mg/L air in male and female rats. This tested aerosol concentration was the highest technically achievable concentration. Thus, according to criteria of the CLP Regulation (EU) No. 1272/2008, classification of the test item for acute inhalation toxicity is not required.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LC50

Value:

5.32

Quality of whole database:

Two acute inhalation toxicity studies are available, which are both considered reliable since they were conducted according to the OECD TG 403 and under GLP conditions. One of these studies was conducted with the test item as aerosol and resulted in a LC50 > 0.069 mg/L air, which was the maximal technically producible concentration. For the second study, the rats were exposed to the test item as dust, resulting in a LC50 > 5.32 mg/L. The latter of these 2 studies was considered the most representative for classification and labelling purpose.

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:

Jul - Aug 1989

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity: Fixed Dose Procedure)

Version / remarks:

adopted 2017

Deviations:

yes

Remarks:

dressing occlusive instead of semi-occlusive

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Version / remarks:

adopted 1987

Deviations:

no

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: Breeder Winkelmann, Borchen, Germany
- Females nulliparous and non-pregnant: yes
- Age at study initiation: about 9 - 14 weeks
- Weight at study initiation: 207 - 234 g (males), 204 - 214 g (females)
- Fasting period before study: not specified
- Housing: animals were individually housed in type III Makrolon cages equipped with low-dust wood shavings type S 8/15 (Spezialdiaeten GmbH, Soest, Germany) as litter.
- Diet: Altromin 1324 diet for rats and mice (Altromin GmbH & Co KG, Lage, Germany), ad libitum
- Water: tap water, ad libitum
- Acclimation period: at least 7 days
- Method of randomisation in assigning animals to test and control groups: with the aid of random lists produced with a computer program.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 - 24
- Humidity (%): approximately 50
- Air changes (per hr): at least 10
- Photoperiod (hrs dark / hrs light): 12 / 12

IN-LIFE DATES: From: Jul To: Aug 1989

Type of coverage:

occlusive

Vehicle:

physiological saline

Details on dermal exposure:

TEST SITE
- Area of exposure: 6.0 x 6.0 cm
- Type of wrap if used: occlusive

REMOVAL OF TEST SUBSTANCE
- Washing: with soap and water
- Time after start of exposure: 24 h

TEST MATERIAL
- Amount(s) applied: 30.5 mg/cm2 (males), 29 mg/cm2 (females)
- Constant volume used: no
- For solids, paste formed: yes

VEHICLE
- Amount(s) applied: 1.5 mL per gram test item

Duration of exposure:

24 h

Doses:

5000 mg/kg bw

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: appearance and behavior were noted several times on the day of study, and then at least once a day. Body weights were recorded before administration, and on the 4th, 8th and 15th study day.
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight, gross examination

Statistics:

Not reported.

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 5 000 mg/kg bw

Based on:

test mat.

Mortality:

No mortality occurred during the study period.

Clinical signs:

other: No clinical signs of toxicity were observed up to the end of the 14-day observation period.

Gross pathology:

Gross pathological examination revealed no substance-related findings.

Other findings:

The treatment areas did not show grossly apparent alterations.

Interpretation of results:

other: CLP/EU GHS criteria not met, no classification required according to Regulation (EC) No 1272/2008

Conclusions:

The study was performed in accordance to OECD 402 under GLP conditions and is considered reliable. Under the conditions chosen, the acute dermal LD50 was determined to be greater than 5000 mg/kg bw/day for male and female rats. According to criteria of the CLP Regulation (EU) No. 1272/2008, no classification of the test item for acute dermal toxicity is required.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

5 000 mg/kg bw

Quality of whole database:

One acute dermal toxicity study is available. This study was performed according to OECD TG 402 and under GLP conditions and is therefore considered reliable and valid. The LD50 obtained is greater than 5000 mg/kg bw; no mortalities were noted during the study period.

Additional information

Acute toxicity: oral

Four weight of evidence acute oral toxicity studies are available. All were performed according to OECD Guideline 401 and are in compliance with GLP (M-028854-01-1, M-025996-01-1, M-028901-01-1 and M-007509-01-1).

 

Wistar rats (5 per sex and dose) were administered to single doses of 50, 200, 350, 400, 500, 600, 750, and 1000 mg/kg bw (males) and 100, 400, 450, 500, 600, and 1000 mg/kg bw (females) via gavage (M-028854-01-1). Mortalities occurred from 350 mg/kg bw (males) and 450 mg/kg bw (females). At the top dose all animals died (both sexes). The LD50 was determined to be 642 mg/kg bw for male rats and 648 mg/kg bw for female rats.

 

Wistar rats (5 per sex and dose) were administered to single doses of 50, 100, 250, 315, 400, 450, 500, and 1800 mg/kg bw (males) and 100, 250, 315, 400, 475, 500, and 1800 mg/kg bw (females) via gavage (M-025996-01-1). Mortalities occurred from 400 mg/kg bw (both sexes). At doses higher than 500 mg/kg bw all animals died within one day (both sexes). The LD50 was determined to be 424 mg/kg bw for male rats and 450 - 475 mg/kg bw for female rats.

 

Wistar rats (5 per sex and dose) were administered to single doses of 50, 200, 300, 350, 400, 500, and 600 mg/kg bw (males) and 100, 200, 300, 350, 400, and 500 mg/kg bw (females) via gavage (M-028901-01-1). Mortalities occurred from 300 mg/kg bw. The LD50 was determined to be 504 mg/kg bw for male rats and 379 mg/kg bw for female rats.

 

Bor:NMRI-SPF mice (5 per sex and dose) were administered to single doses of 10, 71, 100, 120, 140, 160, and 250 mg/kg bw (males) and 10, 100, 120, 140, 160, and 250 mg/kg bw (females) via gavage (M-007509-01-1). Mortalities occurred from 100 mg/kg bw. At the top dose all animals died within one hour (both sexes). The LD50 was determined to be 131 mg/kg bw for male mice and 168 mg/kg bw for female mice.

 

Acute toxicity: inhalation

A GLP-conform acute inhalation toxicity study was performed according to OECD TG 403 (M-027586-01-1). The test item was administered as an aerosol in a single dose of 0.069 mg/L air (analytical) on 5 male and 5 female Wistar rats for 4h with the nose/head only procedure. The dose used was the highest technically achievebale concentration. Neither mortalities nor gross pathological findings nor differences in body weight were observed until the end of the 15-day observation period. The LC50 obtained was therefore > 0.069 mg/L air for aerosols.

 

A GLP-conform acute inhalation toxicity study was performed according to OECD Guideline 403 (M-027586-01-1). Single doses of 1.22, 2.57 and 5.32 mg/L air (analytical) for dust were used on 5 male and female Wistar rats for 4h with the nose/head only procedure. No mortalities nor gross pathological findings nor differences in body weight changes were observed until the end of the 15-day observation period. Clinical signs observed include difficult breathing, reduced motility and piloerection at the level of 2.57 mg/L air and slight tremors at 5.32 mg/L air. Thus, the acute inhalation toxicity LC50 value is > 5.32 mg/L air for the application of dust on male and female rats.

 

Acute toxicity: dermal

A GLP-conform acute dermal toxicity study was performed according to OECD Guideline 402 (M-025697-01-1). A limit dose of 5000 mg/kg bw were topically applied for 24 h to the clipped skin of 5 male and female Wistar rats under occlusive dressing. Neither mortality nor clinical signs of toxicity were observed until the end of the 15-day observation period. An effect on the body weights for male rats in the 5000 mg/kg bw dose group was not noted during the observation period. Female animals showed a minimal retarding of body weight development at this dose, which was not due to the treatment but regarded as related to the animals feeling unwell because of the occlusive dressing. Further, macroscopical examinations did not reveal abnormalities. Thus, the acute dermal toxicity  LD50 value is > 5000 mg/kg bw for male and female rats.

 

Acute toxicity: intraperitoneal

A GLP-conform acute interperitoneal toxicity study was performed based on OECD Guideline 401 (M-025708-01-1). The test item was formulated in sterile 0.9 % NaCl solution with the aid of Cremophor EL 2 % and administered to Wistar rats (5 per sex and dose) via a single intraperitoneal injection (10 mL/kg bw). The doses used were in the range of 10 to 500 mg/kg bw. Mortalities occurred from 150 mg/kg bw. At the top dose, all animals died. The LD50 was determined to be in the range of 160 to 170 mg/kg bw for male rats and 186 mg/kg bw for female rats.

 

In conclusion, the test substance is not expected to induce acute toxicity following inhalation or dermal exposure. However, after oral exposure acute toxicity was observed in rats and mice. The mouse seems to be the most vulnerable species with respect to acute oral toxicity, with a LD50 set at a dose level of 131 mg/kg bw. Thus, based on this value, classification as Cat 3 with respect to acute oral toxicity reflects the results of the most sensitive species, which is further in line with the harmonized classification of the test item according to Annex VI of the CLP Regulation (EC) No. 1272/2008 and the recommendation of the commitee for risk assessment (RAC, 2019).

 

References not included in IUC:

Detailed information on references not included in IUC are available in the CSR and in chapter 13.

Justification for classification or non-classification

The available data on acute toxicity meet the criteria for classification of the test substance for acute oral toxicity as Cat. 3 H301; no classification is needed with respect to acute dermal and inhalation toxicity.