picoxystrobin (ISO); methyl (2E)-3-methoxy-2-[2-({[6-(trifluoromethyl)pyridin-2-yl]oxy}methyl)phenyl]acrylate

Endpoint summary

Description of key information

Oral: rat LD50: >5000 mg/kg. OECD 425; Reliability = 1

Oral: mouse LD50: >5000 mg/kg.OECD 425; Reliability = 1

Dermal: rat LD50: >5000 mg/kg. OECD 402; Reliability = 1

Inhalation: rat 4-hour LC50: 3.19 mg/L (3190 mg/m3; females - most sensitive sex); OECD 403; Reliability = 1

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:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 425 (Acute Oral Toxicity: Up-and-Down Procedure)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1100 (Acute Oral Toxicity)

Deviations:

no

GLP compliance:

yes

Test type:

up-and-down procedure

Limit test:

no

Species:

mouse

Strain:

CD-1

Remarks:

(CRL: CD1(ICR))

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Bred at IIBAT animal house facility
- Females nulliparous and non-pregnant: yes
- Age at study initiation: 8-12 weeks
- Weight at study initiation: 23-28 g
- Fasting period before study: 3 hours prior to dosing.
- Housing: Standard polypropylene mouse cages with stainless steel top grills
- Diet: ad libitum except during fasting
- Water: ad libitum
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature: 20.1-23.0°C
- Humidity: 51-58%.
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

oral: gavage

Vehicle:

methylcellulose

Remarks:

0.5% aqueous methylcellulose

Details on oral exposure:

MAXIMUM DOSE VOLUME APPLIED: 10 mL/kg.b.w.

Doses:

1750 and 5000 mg/kg bw

No. of animals per sex per dose:

1750 mg/kg: 1
5000 mg/kg: 3

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: The animals were observed for clinical signs at half an hour, 1, 2, 3 and 4 hours after dosing, then once daily for 14 days. Body weight of each animal was recorded on day 0 (prior to dosing) and on day 7 and 14.
- Necropsy of survivors performed: yes

Statistics:

The LD50 was calculated by using the software AOT425 StatPgm

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

> 5 000 mg/kg bw

Based on:

test mat.

Mortality:

No morbidity/mortality was observed in treated animals throughout the observation period.

Clinical signs:

other: Two mice dosed at 5000 mg/kg b.w. exhibited dullness at 30 minutes after the test substance administration and recovered by 1 hour. No clinical signs were observed in the remaining animals.

Gross pathology:

No macroscopic lesions were present in the animals at necropsy conducted at the end of the experimental period.

Interpretation of results:

GHS criteria not met

Conclusions:

LD50 (Female): >5000 mg/kg bw

Executive summary:

Acute oral toxicity of the test substance was tested in female CD1 mice. The study was conducted as per the OECD guideline (Guideline No. 425, Adopted 3rd October, 2008) and U.S. EPA Heath Effects Test Guidelines OPPTS 870.1100 (2002).

The test substance, mixed with 0.5% aqueous methylcellulose, was administered as a single oral gavage dose to one fasted female mouse at a dose level of 1750 mg/kg and to three fasted female mice at a dose level of 5000 mg/kg using a stainless steel ball tipped oral intubation needle. The animals were dosed in sequence at a minimum of 48 hour intervals.

Animals were observed for clinical signs of toxicity, morbidity/mortality for a 14 day observation period. Weekly body weights were recorded. At the end of the observation period, the animals were sacrificed for gross pathology observation.

No deaths occurred. Two of the mice dosed at 5000 mg/kg exhibited dullness at half an hour after dosing. No other clinical signs were observed. Weekly body weight gain was observed. Gross pathology examination revealed no lesions.

In conclusion, the acute oral LD50 of the test substance was determined to be greater than 5000 mg/kg bw.

Reference 2

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 425 (Acute Oral Toxicity: Up-and-Down Procedure)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1100 (Acute Oral Toxicity)

Deviations:

no

GLP compliance:

yes

Test type:

up-and-down procedure

Limit test:

yes

Species:

rat

Strain:

other: Crl:CD(SD)

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories, Inc., Raleigh, North Carolina
- Age at study initiation: approximately 10 or 11 weeks old
- Weight at study initiation: 198.7 to 220.1 g
- Fasting period before study: approximately 16-18 hours prior to dosing
- Housing: all animals were housed singly in stainless steel, wire-mesh cages suspended above cage boards
- Diet: ad libitum except while fasting
- Water: ad libitum
- Acclimation period: at least 6 days

ENVIRONMENTAL CONDITIONS
- Temperature: 18-26°C
- Humidity: 30-70%
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

oral: gavage

Vehicle:

other: Deionized water

Doses:

5000 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: The rats were observed for clinical signs at the beginning of fasting, just before dosing (test day 0), once during the first 30 minutes after dosing and 2 more times on the day of dosing, and once each day thereafter. The rats were weighed on test days –1, 0, 7, and 14.
- Necropsy of survivors performed: yes

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

> 5 000 mg/kg bw

Based on:

test mat.

Mortality:

No deaths occurred

Clinical signs:

other: Two of the rats exhibited diarrhoea on the day of dosing. No clinical signs were observed in the remaining rat.

Gross pathology:

No gross lesions were present in the rats at necropsy.

Interpretation of results:

GHS criteria not met

Conclusions:

LD50 (Female): >5000 mg/kg bw

Executive summary:

A single dose of the test substance was administered by oral gavage to 3 fasted female rats at a dose of 5000 mg/kg. The rats were dosed one at a time at a minimum of 48-hour intervals. The rats were observed for mortality, body weight effects, and clinical signs for 14 days after dosing. All rats were necropsied to detect grossly observable evidence of organ or tissue damage.

No deaths occurred. Two of the rats exhibited diarrhoea on the day of dosing. No clinical signs were observed in the remaining rat. No body weight losses occurred in the rats after dosing. No gross lesions were present in the rats at necropsy.

Under the conditions of this study, the oral LD50 for the test substance was greater than 5000 mg/kg for female rats.

Reference 3

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.1 (Acute Toxicity (Oral))

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPP 81-1 (Acute Oral Toxicity)

Deviations:

no

GLP compliance:

yes

Test type:

fixed dose procedure

Limit test:

yes

Species:

rat

Strain:

other: Alpk:APfSD

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Rodent Breeding Unit, Alderley Park, Macclesfield, Cheshire
- Age at study initiation: approximately 8-12 weeks
- Weight at study initiation: Males: 247-281 g; females: 183-193 g
- Fasting period before study: overnight
- Housing: 5 rats/cage, sexes separate
- Diet: ad libitum except while fasting
- Water: ad libitum
- Acclimation period: atleast 6 days

ENVIRONMENTAL CONDITIONS
- Temperature: 21±2°C
- Humidity: 55±15%
- Air changes (per hr): atleast 15
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 250 mg of test substance per mL of corn oil

MAXIMUM DOSE VOLUME APPLIED: 10 mL/Kg

DOSAGE PREPARATION: To facilitate accurate dosing due to the viscosity of the test substance in the vehicle, a 250mg/mL preparation of the test substance in corn oil was dosed twice with approximately 2 hours between each dose.

Doses:

5000 mg/kg

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

- Duration of observation period following administration: 15 days
- Frequency of observations and weighing: The animals were observed for signs of systemic toxicity twice following dosing on day 1. Subsequent observations were made daily, up to day 15. The animals were weighed prior to fasting (day -1), immediately before each dose (day 1) and day 8 and 15.
- Necropsy of survivors performed: yes

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 5 000 mg/kg bw

Based on:

test mat.

Mortality:

Slight systemic toxicity was observed, but none of the animals died before the scheduled termination.

Clinical signs:

other: Orange staining was seen on the coat and tails of some of the animals during the study.

Gross pathology:

No treatment related findings observed

Interpretation of results:

GHS criteria not met

Conclusions:

LD50 (male/female): >5000 mg/kg bw

Executive summary:

A group of five male and five female rats received an oral dose of 5000 mg/kg of the test substance. Due to the viscosity of the test substance in the vehicle, a 250 mg/mL preparation of the test substance in corn oil was dosed twice within 2 hours.

The animals were assessed daily for the following 14 days for any signs of systemic toxicity and their bodyweights were recorded at intervals throughout the study. At the end of the study all the animals were killed and subjected to a macroscopic examination post mortem.

Slight systemic toxicity was observed, but none of the animals died before the scheduled termination. Orange staining was seen on the coat and tails of some of the animals during the study.

All animals in the study lost weight initially, due to a pre-dose fast. All animals had exceeded their initial bodyweight by day 8 and continued to gain weight as expected for the remainder of the study. No treatment related findings were seen at examination post mortem.

The acute oral median lethal dose of the test substance was estimated to be in excess of 5000 mg/kg for male and female rats.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

5 000 mg/kg bw

Acute toxicity: via inhalation route

Link to relevant study records

Reference

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

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: Annex V to Council Directive 67/548/EEC, published in the 17th adaptation, Commission Directive 92/69/EEC, OJ L383A 29.12.92 (Acute Toxicity (Inhalation))

Deviations:

no

GLP compliance:

yes

Test type:

traditional method

Limit test:

yes

Species:

rat

Strain:

other: Alpk:APfSD

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Rodent Breeding Unit, Alderley Park
- Age at study initiation: Young adult (8-12 weeks)
- Weight at study initiation: Males: 264-347 g; Females: 207-285 g
- Housing: The rats were housed 5 per cage, sexes separately, in multiple rat racks suitable for animals of this strain and weight range expected during the course of the study. The rats were transferred to clean cages and racks, as necessary, during the study.
- Diet: ad libitum (except during exposure)
- Water: ad libitum (except during exposure)
- Acclimation period: At least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature: 22 ± 3°C
- Humidity: 30-70%
- Air changes: At least 15 changes/hour
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

nose only

Vehicle:

clean air

Mass median aerodynamic diameter (MMAD):

>= 5.89 - <= 6.81 µm

Geometric standard deviation (GSD):

>= 1.73 - <= 3.65

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: PERSPEX expousre chamber
- Exposure chamber volume: 27.6 L
- Method of holding animals in test chamber: Nose-only exposure in restraining tubes
- Source and rate of air: Clean, dry air (dried and filtered using equipment supplied by Atlas-COPCO, Sweden) was passed at a nominal flow rate of 25 L/minute
- System of generating particulates/aerosols: PALAS rotating brush generator (RBG)
- Method of particle size determination: Marple cascade impactor
- Temperature, relative humidity in air chamber: 18.6-19.7°C, 2.0-11.0%, respectively

TEST ATMOSPHERE
- MMAD (Mass median aerodynamic diameter) / GSD (Geometric st. dev.): 1.26 mg/L (5.96 µm/2.65 and 6.31 µm/2.81); 2.22 mg/L (6.81 µm/2.57 and 6.27 µm/3.65); 4.64 mg/L (6.21 µm/3.20 and 5.89 µm/1.73)

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Concentrations:

Target concentrations: 1.0, 2.0, 5.0 mg/L (1.26 ± 0.18, 2.22 ± 0.49, 4.64 ± 0.80 mg/L)
Analyzed concentrations: 1.23, 2.12, 4.59 mg/L
Particulate concentrations: 1.26, 2.22, 4.64 mg/L

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: During exposure, rats were observed for clinical signs frequently and at the end of the 4-hour exposure period. Each rat was given a detailed clinical examination. The body weight of each rat was recorded on day -1 (to ensure animals of one sex were within a similar weight range), 1, 8, and prior to termination on day 15.
- Necropsy: All rats were killed by exsanguination under terminal anaesthesia. All animals were subjected to an examination post mortem. This involved an external observation and a careful examination of all thoracic and abdominal viscera, brain and cranial cavity.

Key result

Sex:

female

Dose descriptor:

LC50

Effect level:

3.19 mg/L air

Based on:

test mat.

Remarks:

particle size 5.9-6.8 μm MMAD

Exp. duration:

4 h

Key result

Sex:

male

Dose descriptor:

LC50

Effect level:

> 2.12 - < 4.59 mg/L air

Based on:

test mat.

Remarks:

particle size 5.9-6.8 μm MMAD

Exp. duration:

4 h

Mortality:

There were no deaths in animals in the 1.23 mg/L group during the exposure or observation periods. One female rat in the 2.12 mg/L group, three male and four female rats in the 4.59 mg/L group died during the exposure period. The remaining animals survived until scheduled termination.

Clinical signs:

other: During exposure: Abnormalities generally associated with restraint (wetness, staining around the snout ) were seen in all groups. Test substance around the snout was also seen in all groups and is a common occurrence in studies involving nose only exposur

Body weight:

All surviving animals, with the exception of one 1.23 mg/L female and the one remaining 4.59 mg/L female, had gained weight by day 8. All had gained weight by day 15, with the exception of the remaining 4.59 mg/L female.

Gross pathology:

In the intercurrent animals exposed to the highest concentration (4.59 mg/L), 3 out of 4 female animals, and all male animals had dark liver, which is indicative of typical post mortem changes. In addition, 2 male animals had mottled lungs though it is unclear whether this effect is related to treatment.

There were no gross findings at terminal necropsy related to treatment.

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

The median lethal concentration was 3.19 mg/L for female rats and >2.12 but <4.59 mg/L for male rats.

Executive summary:

Groups of five male and five female rats were exposed nose-only for a single four-hour period to aerosolized test substance at target concentrations of 1, 2 or 5 mg/L. Test atmospheres were analyzed for particulate concentration and test substance. The particle size distribution of each test atmosphere was analyzed at least twice during the exposure period. Following exposure, the animals were retained without treatment for 14 days. Clinical observations and bodyweights were recorded and at the end of the scheduled period, the animals were killed and subjected to an examination post mortem.

A number of deaths occurred during exposure (1 female rat at 2.12 mg/L; 3 male rats and 4 female rats at 4.59 mg/L). Clinical signs indicative of toxicity were seen in the remaining animals at these concentrations, from which the surviving animals had made a complete recovery by the end of the study.

The median lethal concentration was 3.19 mg/L for female rats and in excess of 2.12 mg/L for male rats.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LC50

Value:

3 190 mg/m³ air

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1200 (Acute Dermal Toxicity)

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: MAFF Japan Agricultural Chemicals Regulation Laws Notification 12 Nousan 8147 (2000)

Deviations:

no

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

other: Crl:CD(SD)

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories, Inc., Raleigh, North Carolina.
- Age at study initiation: Males 12 and females 10 weeks old
- Weight at study initiation: Males: 393 to 465 g; Females: 209 to 246 g
- Housing: All animals were housed singly in stainless steel, wire-mesh cages suspended above cage boards.
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: At least 6 days

ENVIRONMENTAL CONDITIONS
- Temperature: 18-26°C
- Humidity: 30-70%
- Photoperiod (hrs dark / hrs light): 12/12

Type of coverage:

semiocclusive

Vehicle:

other: Deionized water

Details on dermal exposure:

TEST SITE
- Area of exposure: 37 square centimeters
- % coverage: Approximately 10% of the total body surface area
- Type of wrap if used: stretch gauze bandage and self-adhesive bandage

REMOVAL OF TEST SUBSTANCE
- Washing: Yes with warm water
- Time after start of exposure: 24 hours

TEST MATERIAL
- Amount applied: 1.0 mL
- For solids, paste formed: yes

Duration of exposure:

24 hours

Doses:

5000 mg/kg

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: Observations for mortality and signs of illness, injury, and abnormal behaviour were made daily throughout the study. Observations for clinical signs of toxicity and dermal irritation were made daily throughout the study (weekends excluded for dermal irritation). The rats were weighed prior to treatment (test Day 0) and on test days 7 and 14.
- Necropsy of survivors performed: yes

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 5 000 mg/kg bw

Based on:

test mat.

Mortality:

None

Clinical signs:

other: The rats exhibited no clinical signs of systemic toxicity during the study. One rat exhibited stained fur/skin on test days 1 and 2. This clinical sign is commonly seen in wrapped rats and therefore is not considered test substance related.

Gross pathology:

No gross lesions were present in the rats at necropsy.

Interpretation of results:

GHS criteria not met

Conclusions:

LD50 (Male/female): > 5000 mg/kg

Executive summary:

A single dose of the test substance was applied to the shaved, intact skin of 5 male and 5 female rats at a dose of 5000 mg/kg of body weight. The male group and female group were dosed a week apart. The application site was covered with a semi-occlusive dressing for 24 hours, after which the test substance was removed. The rats were observed for 14 days following application. The rats were necropsied to detect grossly observable evidence of organ or tissue damage or dysfunction at the end of the 15-day test period.

No deaths occurred. The rats exhibited no clinical signs of systemic toxicity or biologically important body weight loss. No dermal irritation was observed. No gross lesions were present in the rats at necropsy.

Under the conditions of this study, the skin absorption of the test substance was greater than 5000 mg/kg of body weight when applied to the skin of male and female rats for 24 hours.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

5 000 mg/kg bw

Additional information

Five male and five female rats received an oral dose of 5000 mg/kg bw prepared in corn oil. The rats were assessed for any signs of systemic toxicity and body weights were recorded for 14 days. None of the animals died before scheduled termination. Orange staining was seen on the coats and tails of some of the animals during the study. All animals in the study lost weight initially due to a pre-dose fast and exceeded their initial body weight by day 8 and continued to gain weight for the remainder of the study. No gross lesions were observed at necropsy. The acute oral LD50 for picoxystrobin in this study was >5000 mg/kg bw.

In an acute oral toxicity study, a single dose of the test substance was administered by oral gavage to three fasted female rats at a dose of 5000 mg/kg bw suspended in deionised water. The rats were dosed one at a time at a minimum of 48-hour intervals. The rats were observed for mortality, body weight effects, and clinical signs for 14 days after dosing. No deaths occurred. Two rats exhibited diarrhoea on the day of dosing; there were no body weight effects noted. Under the conditions of this study the oral LD50 was greater than 5000 mg/kg bw for female rats.

A single oral dose of the test substance, suspended in 0.5% aqueous methylcellulose, was administered by oral gavage to 4 fasted female mice at a dose of 1750 or 5000 mg/kg bw. One mouse was initially dosed at 1750 mg/kg bw. Due to the absence of mortality in the first animal, the remaining 3 animals were dosed sequentially at least 48 hours later at a dose of 5000 mg/kg bw. No mortalities were observed. Two animals dosed at 5000 mg/kg bw exhibited dullness at 30 minutes post dose but recovered by one hour. There were no test substance effects on body weight or gross lesions at necropsy. Under the conditions of this study, the oral LD50 in female mice was greater than 5000 mg/kg bw.

In an acute dermal toxicity study, a single dose of the test substance, moistened with 1.0 mL of deionised water, was applied to the shaved, intact skin of 5 male and 5 female rats at a dose of 5000 mg/kg bw body weight. The application site was semi-occluded for 24 hours after which the test substance was removed. No mortality, clinical signs of toxicity, dermal irritation, body weight effects, or gross lesions were observed. The dermal LD50 was greater than 5000 mg/kg bw body weight for both male and female rats. 

In an acute 4-hour inhalation study, groups of five male and five female rats were exposed nose-only for a single four-hour period to aerosolised test substance (MMAD 5.9-6.8 µm) at target concentrations of 1, 2 or 5 mg/L (analysed concentrations of 1.23, 2.12, and 4.59 mg/L, respectively). During exposure a number of deaths occurred in groups exposed to 2.12 mg/L (1 female) and 4.59 mg/L (3 males and 4 females). At the two lowest concentrations, reduced response to sound was seen in all animals at 180 minutes. At the highest concentration, this response was seen at earlier time points, together with reduced breathing rate and increased breathing depth. Following cessation of exposure, surviving animals exposed to 4.59 mg/L showed respiratory abnormalities but had returned to normal by Day 3. All surviving animals had gained weight by Day 15, with the exception of the surviving female exposed to 4.59 mg/L. The median lethal concentration of the test substance by inhalation was >2.12 but <4.59 mg/L for male rats and 3.19 mg/L for female rats. Data from female rats were used for classification as they are the more sensitive sex.

Justification for classification or non-classification

Based on oral and dermal LD50s in rats of >5000 mg/kg, no classification is required for acute oral or dermal toxicity endpoints according to EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008.

Acute inhalation toxicity was dependent on the particle size of test substance administered to the animals. The particle size of unmilled picoxystrobin is ~204 μm, with less than 4% of material <4 μm, indicating that an LC50 of ~3.2 mg/L is an appropriate estimate of the acute inhalation toxicity of technical material. The potential for picoxystrobin to be present in a form which would be respirable is extremely low. Therefore, based on a 4-hour LC50 in rats of 3.19 mg/L in females based on the observed greater sensitivity of females, the test substance is classified for acute inhalation toxicity as Cat 4 (H332: Harmful if inhaled) according to EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008.