Triflumezopyrim

Endpoint summary

Description of key information

Oral LD50 (rat) > 5000 mg/kg; OECD 425; Reliability = 1

Oral LD50 (rat) > 5000 mg/kg; OECD 425; Reliability = 1

Oral LD50 (rat) > 5000 mg/kg (male); 4930 mg/kg (female); > 4930 mg/kg (combined); National Standard of the People’s Republic of China, GB15670; Reliability = 2

Dermal LD50 (rat) > 5000 mg/kg; OECD 402; Reliability = 1

Inhalation LC50 (rat) > 5.04 mg/L; 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:

EPA OPPTS 870.1100 (Acute Oral Toxicity)

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes

Test type:

up-and-down procedure

Species:

rat

Strain:

Sprague-Dawley

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Received from Harlan Laboratories, Inc., Frederick, MD on November 6, 2013.
- Females (if applicable) nulliparous and non-pregnant: yes
- Age at study initiation: Young adult (10-11 weeks)
- Weight at study initiation: 194-200 grams
- Fasting period before study: overnight
- Housing: The animals were individually housed in plastic solid bottom polycarbonate cages which conform to the size recommendations in the most recent Guide for the Care and Use of Laboratory Animals (Natl. Res. Council, 2011). Enrichment (e.g., toy) was placed in each cage. Corncob bedding (1/8 inch bed-o’cobs®) was used and was changed at least once per week.
- Diet (e.g. ad libitum): ad libitum, except during fasting period
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 14-27 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-23°C
- Humidity (%): 43-55%
- Air changes (per hr): 13/hour
- Photoperiod (hrs dark / hrs light): 12-hour light/dark cycle

Route of administration:

oral: gavage

Vehicle:

methylcellulose

Details on oral exposure:

VEHICLE
- Concentration in vehicle: test substance was 25% w/w in mixture
- Vehicle was a solution of 0.1% Tween-80 in 0.5% methylcellulose
- Amount of vehicle (if gavage): 4.5 mL for a dose level of 4,390 mg/kg and 5.3 mL for a dose level of 5000 mg/kg.


MAXIMUM DOSE VOLUME APPLIED: 5.3 mL.

DOSAGE PREPARATION (if unusual): At concentrations higher than 25% w/w, the viscosity was too high to be administered properly. Due to the high dose volume of the dose solution to be administered (23.11 and 26.32 ml/kg), each animal’s dose was divided into two approximately equal portions and administered two hours apart.

CLASS METHOD (if applicable)
- Based on the estimated LD50 (4,930 mg/kg) of the test substance a Main Test was conducted using a default starting dose level of 4,390 mg/kg which was administered to one healthy female rat by oral gavage.

Doses:

One rat was dosed at 4,390 mg/kg (4.5 mL dose volume) and 3 rats were dosed at 5,000 mg/kg (5.3 dose volume).

Due to the high dose volume of the dose solution to be administered (23.11 and 26.32 ml/kg), each animal’s dose was divided into two approximately equal portions and administered two hours apart.

No. of animals per sex per dose:

All rats were female. One rat was dosed at 4,390 mg/kg and 3 rats were dosed at 5,000 mg/kg.

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Day 0, Day 7, and Day 14
- Necropsy of survivors performed: yes
- Other examinations performed: Individual body weights were recorded before test substance administration (initial), on Day 7, and Day 14 (termination). Clinical signs were observed during the first several hours after dosing and at least once a daily thereafter for 14 days after dosing. Gross necropsies were performed on all animals. Tissues and organs of the thoracic and abdominal cavities were examined.

Statistics:

Statistical analysis was limited to the mean density value for dosing.

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

> 5 000 mg/kg bw

Based on:

test mat.

Mortality:

Animals at both dose levels survived the 14-day observation period.

Clinical signs:

other: 4,390 mg/kg Dose Level - no clinical signs during 14-day observation period 5,000 mg/kg Dose Level - all animals exhibited reduced fecal volume but recovered by Day 3

Gross pathology:

At both dose levels no gross abnormalities were noted for when necropsied at the conclusion of the 14-day observation period.

Interpretation of results:

GHS criteria not met

Conclusions:

Under the conditions of this study, the acute oral LD50 of the test substance is greater than 5,000 milligrams per kilogram of body weight in female rats.

Executive summary:

An acute oral toxicity test (Up and Down Procedure) was conducted with rats to determine the potential for the test substance to produce toxicity from a single dose via the oral route following the test guidelines OPPTS 870.1100 and OECD 425. Under the conditions of this study, the acute oral LD50 of the test substance greater than 5,000 mg/kg of body weight in female rats.

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

Route of administration:

oral: gavage

Vehicle:

water

Doses:

single

No. of animals per sex per dose:

3 female rats were dosed at 5000 mg/kg

Control animals:

no

Statistics:

not applicable

Sex:

female

Dose descriptor:

LD50

Effect level:

> 5 000 mg/kg bw

Based on:

test mat.

Interpretation of results:

GHS criteria not met

Conclusions:

Under the conditions of this study, the oral LD50 for the test substance was greater than 5,000 mg/kg for female rats.

Executive summary:

A single dose of the test substance was administered by oral gavage to fasted female rats at a dose of 5000 mg/kg. The rats were dosed one or two at a time at a minimum of 48 -hour intervals. All rats were observed for mortality, body weight effects, and clinical signs for 14 days after dosing. The rats were necropsied to detect grossly observable evidence of organ or tissue damage. There were no incidents of mortality or overall (test day 1-15) body weight loss. Between days 2 and 4, the bedding was stained with the color of the test substance for all animals. 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 5,000 mg/kg.

Reference 3

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods with acceptable restrictions

Qualifier:

according to guideline

Guideline:

other: National Standard of the People’s Republic of China, GB15670

Deviations:

no

GLP compliance:

yes

Limit test:

yes

Species:

rat

Strain:

other: Crl:CD(SD)

Sex:

male/female

Route of administration:

other: oral: intragastric intubation

Vehicle:

water

Remarks:

0.1% Tween-80 (V/V) in 0.5% methylcellulose

Doses:

5000, 4375, 3750, 2500 mg/kg

No. of animals per sex per dose:

5000 mg/kg - 5 male, 5 female
4375 mg.kg - 5 female
3750 mg/kg - 5 female
2500 mg/kg - 5 female

Control animals:

no

Statistics:

Not Applicable

Sex:

male

Dose descriptor:

LD50

Effect level:

> 5 000 mg/kg bw

Based on:

test mat.

Sex:

female

Dose descriptor:

LD50

Effect level:

4 930 mg/kg bw

Based on:

test mat.

Interpretation of results:

GHS criteria not met

Conclusions:

Under the conditions of this study, the oral LD50 for DPX-RAB55 was greater than 5000 mg/kg in male rats and 4930 mg/kg for female rats.

Executive summary:

The test substance was administered by intragastric intubation in accordance with the National Standard of the People's Republic of China, GB15670. Initally the test substance was administered to groups of 5 fasted male and 5 fasted female rats at a dose of 5000 mg/kg . Since death occurred in female rats, additional groups of 5 fasted female rats were dosed at 2500, 3750, or 4375 mg/kg. The rats were observed for clinical signs of toxicity and mortality for up to 14 or 15 days following dosing. The rats were examined to detect grossly observable evidence of organ or tissue damage.

Death occured in 4/5 female rats dosed at 5000 mg/kg. No other deaths occured.

Clinical signs included stained bedding, high or low posture, eyelid ptosis, yellow or absent feces, ataxia, cold to touch, dehydration, spasm, slow breathing, moribundity, decreased muscle tone, and or stained skin/fur. With the execption of stained bedding, no clinical signs were observed after Day 2.

Gross findings were present in 3/5 female rats in the 5000 mg/kg group that were found dead or sacrificed prior to scheduled sacrifice.

Under the conditions of this study, the oral LD50 for the test substance was greater than 5000 mg/kg in male rats and 4930 mg/kg for 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:

EPA OPPTS 870.1300 (Acute inhalation toxicity)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.2 (Acute Toxicity (Inhalation))

Deviations:

no

GLP compliance:

yes

Test type:

traditional method

Limit test:

yes

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan Laboratories, Inc.
- Females (if applicable) nulliparous and non-pregnant: yes
- Age at study initiation: Young adult (9 weeks)
- Weight at study initiation: males 233-247 grams, females 170-193 grams
- Fasting period before study: not reported
- Housing: animals were individually housed in plastic solid bottom polycarbonate cages. Enrichment was placed in each cage. Corncob bedding was placed in cage and changed once a week.
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 6 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-23°C
- Humidity (%): 61-75%
- Air changes (per hr): 12-13
- 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):

2.8 µm

Geometric standard deviation (GSD):

2.17

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: Mini-Nose-Only Inhalation Chamber
- Exposure chamber volume: 6.7 liters
- Method of holding animals in test chamber: individulal polycabronate holding
- Source and rate of air: 30.0 liters per minute supplied by air compressor
- System of generating particulates/aerosols: Wright Dust Generator
- Method of particle size determination: Eight-stage ACFM Andersen Ambient Particle Sizing Sampler
- Temperature, humidity, pressure in air chamber: Temp: 23-24°C, Hum: 28-62%, pressure: slightly negative

TEST ATMOSPHERE
- Samples taken from breathing zone: yes

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Concentrations:

5.04±0.16 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: Prior to test substance administration, Day 1, Day 3, Day 7, and Day 14 (termination)
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight, histopathology

Statistics:

Not Applicable

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 5.04 mg/L air

Based on:

test mat.

Exp. duration:

4 h

Mortality:

All animals survived

Clinical signs:

other: All animals exhibited irregular respiration after exposure but recovered by Day 3 and appeared healthy and active the remainder of the observation period.

Body weight:

4 males and 4 females failed to gain weight after Day 1 but all animals showed continued weight gain thereafter through the exposure period.

Gross pathology:

No gross abnormalities were observed in any of the animals when necropsied at the conclusion of the observation period.

Interpretation of results:

GHS criteria not met

Conclusions:

Under the conditions of this study, the single exposure acute inhalation LC50 of the test substance is greater than 5.04 mg/L in male and female rats.

Executive summary:

An acute inhalation toxicity test was conducted in accordace with OECD 403, OPPTS 870.1300, and EU Method B.2 to determine the potential for the test substance to produce toxicity from a single exposure via the inhalation (nose-only exposure) route. The animals were observed for mortality, signs of gross toxicity, and behavioral changes at least once daily for 14 days following exposure. Body weights were recorded prior to exposure and again on Days 1, 3, 7 and 14 (termination). Necropsies were performed on all animals at terminal sacrifice.

The gravimetric chamber concentration was 5.04 ± 0.16 mg/L (mean ± SD). Based upon graphic analysis of the particle size distribution as measured with an ACFM Andersen Ambient Particle Sizing Sampler, the mass median aerodynamic diameter (MMAD) and geometric standard deviation (GSD) of the 5.04 mg/L atmosphere was 2.80 μm ± 2.17 (MMAD ± GSD).

All animals survived exposure to the test substance. Following exposure, all animals exhibited irregular respiration. However, the animals recovered from this symptom by Day 3 and appeared active and healthy for the remainder of the 14-day observation period. Although four males and four females lost or failed to gain body weight by Day 1, all animals showed a continued weight gain thereafter through Day 14. No gross abnormalities were noted for any of the animals when necropsied at the conclusion of the 14-day recovery period.

Under the conditions of this study, the single 4-hour inhalation medial lethal concentration (LC50) for the test substance is greater than 5.04 mg/L in male and female rats.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LC50

Value:

5.04 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:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1200 (Acute Dermal Toxicity)

Deviations:

no

GLP compliance:

yes

Test type:

fixed dose procedure

Species:

rat

Strain:

Sprague-Dawley

Remarks:

albino

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan Laboratories, Inc., Frederick, MD
- Females (if applicable) nulliparous and non-pregnant: yes
- Age at study initiation: 9 weeks
- Weight at study initiation: males: 240-257 g, females: 175-200 g
- Housing: Individually housed in plastic solid bottom polycarbonate cages. Enrichment was placed in each cage. Corncob bedding was changed at least once per week.
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 7 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-23°C
- Humidity (%): 55-68%
- Air changes (per hr): at or above 10 air changes per hour
- Photoperiod (hrs dark / hrs light): 12/12

Type of coverage:

occlusive

Vehicle:

water

Remarks:

distilled

Details on dermal exposure:

TEST SITE
- Area of exposure: dorsal area
- % coverage: 10% of body surface
- Type of wrap if used: 4-ply gauze and Durapore tape

REMOVAL OF TEST SUBSTANCE
- Washing: Yes. Solution not specified
- Time after start of exposure: 24 hours

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 5000 mg/kg of body weight
- Constant volume or concentration used: yes
- For solids, paste formed: yes, 75% w/w

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: Daily for clinical signs. Weighed on Days 0, 7 and 14 (termination)
- Necropsy of survivors performed: yes

Statistics:

Not applicable

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 5 000 mg/kg bw

Based on:

test mat.

Mortality:

No mortality

Clinical signs:

other: Besides mechanical damage due to unwrapping of the dose site, all animals were active and healthy during the observation period.

Gross pathology:

No gross abnormalities were noted for any of the animals when necropsied at the conclusion of the 14-day observation period.

Interpretation of results:

GHS criteria not met

Conclusions:

Under the conditions of this study, the single dose acute dermal LD50 of the test substance is greater than 5,000 mg/kg of body weight in male and female rats.

Executive summary:

An acute dermal toxicity test was conducted with rats to determine the potential for the test substance to produce toxicity from a single topical application according to OECD 402 and OPPTS 870.1200. One dose of 5000 mg/kg of body weight was moistened with distilled water and then applied to the skin of ten healthy rats (five male and five female) for 24 hours. The animals were observed for mortality, signs of gross toxicity, and behavioral changes 1 and 5.5 hours post-dosing and at least once daily for 14 days. Body weights were recorded prior to application and again on Days 7 and 14 (termination). Necropsies were performed on all animals at terminal sacrifice.

 

All animals survived, appeared active and healthy and gained body weight during the study. Apart from mechanical damage due to unwrapping around the dose site of all rats between Days 1 and 3, there was no dermal irritation recorded for any animal over the 14-day observation period. No gross abnormalities were noted for any of the animals when necropsied at the conclusion of the 14-day observation period.

 

Under the conditions of this study, the single dose acute dermal LD50of the test substance is greater than 5,000 mg/kg of body weight in male and female rats.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

5 000 mg/kg bw

Additional information

The key acute oral toxicity test was conducted via the up and down procedure in female rats following the test guidelines OPPTS 870.1100 and OECD 425. Under the conditions of this study, the acute oral LD50 of the test substance was > 5000 mg/kg of body weight in female rats. One rat was dosed at 4390 mg/kg and 3 rats were dosed at 5000 mg/kg. Animals at both dose levels survived the 14-day observation period. No clinical observations were observed at 4390 mg/kg. All animals at 5000 mg/kg exhibited reduced fecal volume but recovered by Day 3. At both dose levels, no gross abnormalities were noted when necropsied at the conclusion of the 14-day observation period.

 

Several other acute oral toxicity tests were conducted with the same batch and other batches of the test substance. The key study was conducted with batch 037. An additional study in rats with this batch resulted in a LD50 in male rats of > 5000 mg/kg and LD50 in female rats > 4930 mg/kg. This same batch was tested in mice with a resultant LD50 in male and female mice of > 5000 mg/kg. Three other acute oral studies were conducted in female rats with other batches of the test substance and the LC50s in all three studies were > 5000 mg/kg.

 

In an acute dermal toxicity study (OECD 402), 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. The application site was occluded for 24 hours after which the test substance was removed. No mortality, clinical signs of toxicity, body weight effects, or gross lesions were observed. The dermal LD50 was greater than 5000 mg/kg for both male and female rats.  A similar study conducted with a different batch of the test substance also resulted in a LD50 > 5000 mg/kg in male and female rats.

 

In an acute 4-hour inhalation study (OECD 403), groups of five male and five female rats were exposed nose-only for a single four-hour period to aerosolised test substance (MMAD 2.8 µm) at target concentrations of 5 mg/L (analysed concentrations of 5.07 mg/L, respectively).  No mortality was observed during the study. All animals exhibited irregular respiration after exposure but recovered by Day 3 and appeared healthy and active the remainder of the observation period.  Four males and 4 females failed to gain weight after Day 1 but all animals showed continued weight gain thereafter through the exposure period. No gross abnormalities were observed in any of the animals when necropsied at the conclusion of the observation period. The inhalation LC50 in male and female rats was > 5/04 mg/L. A second acute inhalation study conducted with a different batch of the test substance according to OECD 436 resulted in a similar LC50 value (LC50 > 5.15 mg/L in male and female rats).

Justification for classification or non-classification

Based on oral and dermal LD50s in rats of >5000 mg/kg, and on acute inhalation LC50 value > 5.04 mg/L (dust/mist) no classification is required for acute oral, dermal, or inhalation toxicity endpoints according to EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008.