Methanesulfonamide, N-[2-[(4,6-dimethoxy-1,3,5-triazin-2-yl)carbonyl]-6-fluorophenyl]-1,1-difluoro-N-methyl-

Endpoint summary

Description of key information

Oral (OECD 423), rat and mouse: LD50 > 2000 mg/kg bw (limit test)
Inhalation (OECD 403), rat: LCD50 > 5297.5 mg/m³ (limit test)
Dermal (OECD 402), rat: LD50 > 2000 mg/kg bw (limit test)

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:

04 Mar - 14 Apr 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.1 tris (Acute Oral Toxicity - Acute Toxic Class Method)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1100 (Acute Oral Toxicity)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Ministerium für Arbeit, Gesundheit und Soziales des Landes Nordrhein-Westfalen

Test type:

acute toxic class method

Limit test:

yes

Species:

rat

Strain:

other: Wistar HsdCpb:Wu

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan GmbH, 5960 AD Horst, Netherlands
- Age at study initiation: 8-12 weeks old
- Weight at study initiation: for males: 229-287 g; for females: 176-215 g
- Fasting period: Food was withheld form the animals for approximately 16-24 h before administration of the test item, and then they were fed again approximately 2-4 h after administration.
- Housing: the animals were group caged conventionally in polycarbonate cages on low dust wood granulate bedding (Lignocel BK 8-15, Firma Rettenmaier, Germany)
- Diet: standard diet "Provimi Kliba 3883 PM S15 Maus/Ratte Haltung, Kaiseraugst, Switzerland; ad libitum
- Water: tap water; ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22±2
- Humidity (%): 55±5
- Air changes (per hr): approx. 10 changes per hour
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 2010-03-17 To: 2010-04-07

Route of administration:

oral: gavage

Vehicle:

other: 0.5% aqueous methylcellulose

Details on oral exposure:

MAXIMUM DOSE VOLUME APPLIED: 10 mL/kg bw

DOSAGE PREPARATION: The test item was formulated in 0.5% aqueous methylcellulose. The applied formulation was well mixed before administration and prepared at room temperature

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

3 (1st step)
3 (2nd step)

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Clinical signs and mortality were determined several times on the day of administration and subsequently at least once daily for the observation period; the weight gain of the animals was checked weekly until the end of the study.
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Sex:

male/female

Dose descriptor:

LD50

Effect level:

>= 5 000 mg/kg bw

Based on:

test mat.

Remarks on result:

other: LD50 cut-off according to OECD 423

Mortality:

No mortality occurred during the study period.

Clinical signs:

other: No clinical signs were observed in male and female animals.

Gross pathology:

The necropsies performed at the end of the study revealed no particular findings in male and female animals.

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

CLP: not classified
DSD: not classified

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Quality of whole database:

The available information comprises adequate, reliable (Klimisch score 1) and consistent studies, and is thus sufficient to fulfil the standard information requirements set out in Annex VII, 8.5, of Regulation (EC) No 1907/2006.

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

Study period:

25 Feb - 24 June 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1300 (Acute inhalation toxicity)

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: Japan MAFF, Notification No. 12 Nousan-8147 (2000)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Ministerium für Arbeit, Gesundheit und Soziales des Landes Nordrhein-Westfalen

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

other: Wistar, Hsd Cpb:WU (SPF)

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan-Netherland
- Age at study initiation: approximately 2-3 months old
- Weight at study initiation: 178-194 g
- Housing: The animals were housed singly in conventional Makrolon® Type IIIH cages.
- Diet: standard fixed-formula diet (KLIBA 3883 = NAFAG 9441 pellets maintenance diet for rats and mice; PROVIMI KLIBA SA, 4303 Kaiseraugst, Switzerland); ad libitum
- Water: tap water; ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22±3
- Humidity (%): 40-60
- Air changes (per hr): 10
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 2010-03-03 To: 2010-03-17

Route of administration:

inhalation: dust

Type of inhalation exposure:

nose only

Vehicle:

other: The test item was applicated as dry powder atmosphere.

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus:aluminium inhalation chamber
- Exposure chamber volume: 3.8 L
- Method of holding animals in test chamber: Animals were exposed to the aerosolized test substance in Plexiglas exposure tubes applying a directed-flow nose-only exposure principle.
- Air flow: During the exposure period air flows were monitored continuously and, if necessary, readjusted to the conditions required. Air flows were measured with calibrated flow-meters. The proper performance of mass flow controller used was measured utilizing a digital precision flow-meter calibration device (Bios Defender 510).
- Method of conditioning air: Compressed air was supplied by Böge compressors and was conditioned (i.e. freed from water, dust, and oil) automatically by a VIA compressed air dryer. Adequate control devices were employed to control supply pressure.
- System of generating dust: (Wright-Dust Feeder; WDF) This dust generator was delivered from BGI Inc. Waltham MA, (USA) and is used for dry powder dispersion with conditioned compressed air (28 L/min). The test substance is first filled into a reservoir of the device and is then compressed to a pellet using approximately 1 metric ton by a carver laboratory press (F.S. Carver INC. Wabash, IN 46992, USA). From this pellet defined amounts of the test substance were scraped off with 1.2 to 1.7 revolution/min and were then effectively dispersed using pressurized air (approx. 100 kPa). The resulting dry powder aerosol was then entrained directly into the chamber.
- Method of particle size determination: The particle-size distribution was analyzed using an ANDERSEN-TYPE Mark II impactor for dry dust application. The individual impactor stages had been covered by an aluminium foil with an adhesive stage coating (silicone spray), which was utilized for characterization of the dry powder atmosphere. Gravimetric analyses were made using a digital balance without drying. The parameters characterizing the particle-size distribution were calculated according to the following procedure: Mass Median Aerodynamic Diameter (MMAD): Construct a 'Cumulative Percent Found - Less Than Stated Particle Size' table; calculate the total mass of test substance collected in the cascade impactor. Start with the test substance collected on the stage that captures the smallest particle-size fraction, and divide this mass of the test substance by the total mass found above. Multiply this quotient by 100 to convert to percent. Enter this percent opposite the effective cut-off diameter of the stage above it in the impactor stack. Repeat this step for each of the remaining stages in ascending order. For each stage, add the percentage of mass found to the percentage of mass of the stages be low it. Plot the percentage of mass less than the stated size versus particle size in a probability scale against a log particle-size scale, and draw a straight line best fitting the plotted points. A weighted least square regression analysis may be used to achieve the best fit. Note the particle size at which the line crosses the 50% mark. This is the estimated Mass Median Aerodynamic Diameter (MMAD).
Calculation of Geometric Standard Deviation (GSD): Refer to the log probability graph used to calculate the Mass Median Aerodynamic Diameter. Provided that the line is a good fit to the data, the size distribution is log normal, and the calculation of the Geometric Standard Deviation is appropriate. Note that particle size at which the line crosses the 84.1% mark. Note the particle size at which the line crosses the 50% mark and calculate as follows: GSD = 84.1% mark / 50% mark.
- Treatment of exhaust air: The exhaust air was purified via cotton-wool/HEPA filters. These filters were disposed of by Bayer Schering Pharma AG.


TEST ATMOSPHERE
- Brief description of analytical method used: The test-substance concentration was determined by gravimetric analysis (filter: Glass-Fiber-Filter, Sartorius, Göttingen, Germany; digital balance). The mass collected by the filter was set to be the test substance (no constituents in the dry test substance powder which can evaporate). In order to get comparable conditions for the gravimetric evaluations of the aerosol atmosphere these glass fibre filters were allowed to equilibrate under specified conditions (15 min at room temperature).
- Samples taken from breathing zone: yes

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Concentrations:

5000 mg/m³ (target concentration)
5297.5 mg/m³ (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 measured before exposure, on Days 1, 3 and 7, and weekly thereafter. Individual weights are also recorded at death. The appearance and behaviour of each rat were examined carefully several times on the day of exposure and at least once daily thereafter. The rectal temperatures were measured shortly after cessation of the exposure. A battery of reflex measurements was made on the first post exposure day.
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, reflexes, rectal temperature, body weight

Statistics:

Analysis of variance (ANOVA): This parametric method checks for normal distribution of data by comparing the median and mean. The groups are compared at a confidence level of (1-a) = 95% (p = 0.05). The test for the between-group homogeneity of the variance employed Box's test if more than 2 study groups were compared with each other. If the above F-test shows that the intra-group variability is greater than the inter-group variability, then "no statistical difference between the groups" are available. If a difference is found then a pair wise post-hoc comparison is conducted (1- and 2-sided) using the Games and Howell modification of the Tukey-Kramer significance test. This program was originally obtained from BCTIC.

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 5 297.5 mg/m³ air

Based on:

test mat.

Exp. duration:

4 h

Mortality:

Mortality did not occur during the study period (see Table 2).

Clinical signs:

other: All rats tolerated the exposure without specific clincial signs or changed reflexes.

Body weight:

Statistical evaluations did not identify significant changes between the control and exposure groups, which may be of toxicological relevance.

Gross pathology:

Necropsy findings were unremarkable after exposure.

Other findings:

- Rectal temperature: Statistical comparison between the rats revealed slight but significant change at exposed female rats. This change is within biological range and not considered to be of toxicological relevance.

Technical information concerning generation of test atmospheres is provided below.

Table 1: Generation conditions and characterization of chamber aerosol atmosphere (average values)

Parameters	Control group	Exposed group
Target Conc. (mg/m³)	0	5000
Gravimetric Conc. (mg/m³)	Control air	5297.5
Dust Generator Type	-	WDF
Inlet Air Flow (L/min)	15	28
Exhaust Air Flow (L/min)	13	24
Temperature (mean, °C)	22.7	22.8
Rel. Humidity (mean, %)	≤ 5.5	≤ 5.1
MMAD (µm)	-	3.18
GSD	-	2.03
Aerosol Mass < 3 µm (%)	-	47.0
Mass recovered (mg/m³)	-	4705.0

MMAD: mass median aerodynamic diameter

GSD: geometric standard deviation

-: not applicable

WDF: Wright dust feeder II

Characterization of the test atmospheres: The real-time monitoring and filter analyses of the aerosol atmosphere from the breathing zone indicated that the exposure condition was appropriate over the 4-h exposure period. Repeated measurements made during exposure lead to an adjustment of the dust generation. Analysis of the particle-size distribution from the breathing zone demonstrated that the dust atmosphere generated was in the respirable range. It is demonstrated that particle-size distributions are equal over the exposure period. The total gravimetric concentration recovered by the cascade impactor was in the range of that concentration found by filter analyses. Humidity was lower in the dust atmosphere because of utilizing dry air for the dispersion. Temperature value in the inhalation chamber was in the range suggested by the testing guidelines.

Table 2: Acute inhalation toxicity 

Target Concentration[mg/L air]	Mortality	Clinical Signs
	N*	N*
Males
0	0/5	0/5
5.2975	0/5	0/5
Females
0	0/5	0/5
5.2975	0/5	0/5

*N= Number of animals/ number of animals used

 

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

DSD: not classified
CLP: not classified

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LC50

Value:

5 297.5 mg/m³ air

Quality of whole database:

The available information comprises an adequate and reliable study, and is thus sufficient to fulfil the standard information requirements set out in Annex VII, 8.5, of Regulation (EC) No 1907/2006.

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:

23 Feb - 14 Apr 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

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:

EPA OPPTS 870.1200 (Acute Dermal Toxicity)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Ministerium für Arbeit, Gesundheit und Soziales Des Landes Nordrhein-Westfalen

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

other: Wistar; HsdCpb:Wu

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan GmbH, 5960 AD Horst, Netherlands
- Age at study initiation: 8-12 weeks old
- Weight at study initiation: for males: 273-279 g; for females: 235-251 g
- Housing: the animals were caged individually in polycarbonate cages on low dust wood granulate bedding (Lignocel BK 8-15, Firma Rettenmaier, Germany)
- Diet: standard diet "Provimi Kliba 3883 PM S15 Maus/Ratte Haltung, Kaiseraugst, Switzerland; ad libitum
- Water: tap water; ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22±2
- Humidity (%): 55±5
- Air changes (per hr): approx. 10 changes per hour
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 2010-03-10 To: 2010-04-24

Type of coverage:

occlusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST SITE
- Area of exposure: 6.0 cm x 5.0 cm = 30.0 cm²
- % coverage: ca. 10% of the body surface area
- Type of wrap if used: The test material was transferred to a wet gauze-layer of a "cutiplast steril" coated with air-tight "Leukoflex". The gauze strip was placed on the rat´s back and secured in place using "Peha-Haft" cohesive stretch tape and additionally covered with a "Lomir biomedical Inc rat jacket", which was connected with a safety pin to the stretch tape to ensure that the animals could not ingest the test substance.

REMOVAL OF TEST SUBSTANCE
- Washing: the area of exposure was rinsed with tepid water using soap and gently patting the area dry
- Time after start of exposure: 24 h

TEST MATERIAL
- Amount(s) applied: Depending on the body weight of the animals and the surface area on which the test substance was applied, the following dose range (mg/cm²) was applied: males: 18.2-18.6 mg/cm²; females: 15.7-16.7 mg/cm²

Duration of exposure:

24 h

Doses:

2000 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: Clinical signs and mortality rates were determined several times on the day of application and subsequently at least once daily for the observation period. The weight gain of the animals was checked weekly until the end of the study.
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

No mortality occurred during the study period.

Clinical signs:

other: No clinical signs were observed during the study period.

Gross pathology:

The necropsies performed at the end of the study revealed no particular findings.

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

CLP: not classified
DSD: not classified

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Quality of whole database:

The available information comprises an adequate and reliable study, and is thus sufficient to fulfil the standard information requirements set out in Annex VII, 8.5, of Regulation (EC) No 1907/2006.

Additional information

Acute toxicity: oral

There are two acute oral toxicity studies according to OECD 423 and under GLP conditions available, one in rats and another in mice.

Triafamone was tested in rats with a starting dose level of 2000 mg/kg bw formulated in 0.5% aqueous methylcellulose (M-366933-01-0). In a first step, 3 male and 3 female rats received the test substance in a single oral administration by gavage. Since no deaths were observed, a second test with a dose level of 2000 mg/kg bw was performed again in males and females. No deaths and no signs of toxicity were noted during the study period. Macroscopic examinations at necropsy did not reveal any abnormalities. The LD50 of Triafamone is > 2000 mg/kg bw in rats.

In mice, also a starting dose level of 2000 mg Triafamone/kg bw formulated in 0.5% aqueous methylcellulose was selected. The test substance was orally administered via gavage to 3 male and 3 female mice. As no deaths were noted, the experiment was repeated. A dose level of 2000 mg/kg bw was tolerated by male and female mice without mortalities, clinical signs, effects on weight gain and gross pathological findings. The LD50 of Triafamone is > 2000 mg/kg bw in mice.

Acute toxicity: inhalation

A study on the acute inhalation toxicity of Triafamone on rats has been conducted in accordance with OECD 403 and under GLP conditions. Male and female rats were nose-only exposed to a mean dry powder dust atmosphere with a concentration of 5297.5 mg/m³. The atmosphere generated was respirable to the rats (MMAD = 3.18 µm with GSD 2.03 (dry powder)). All rats tolerated the exposure without specific clinical signs or changed reflexes. Mortality did not occur during the study period and at necropsy no abnormal findings were noted.

For both gender, the LC50 value of Triafamone is > 5297.5 mg/m³ in rats.

Acute toxicity: dermal

In accordance with OECD 402 and under GLP conditions, the undiluted test substance was applied to the intact skin of 5 female and 5 male rats at a dose level of 2000 mg/kg bw. The test substance was secured in place using "Peha-Haft" cohesive stretch tape and additionally covered with a "Lomir biomedical Inc rat jacket" to ensure that the animals could not ingest the test substance. After 24 h, the dressing was removed and the treated skin site was cleaned with water and soap. There were no deaths and no signs of toxicity during the study period. No abnormal findings were noted at necropsy. The LD50 of Triafamone is > 2000 mg/kg bw.

Justification for selection of acute toxicity – oral endpoint
Two GLP compliant OECD Guideline studies using rats and mice are available. Both studies are reliable. The selected study was performed in rats.

Justification for selection of acute toxicity – inhalation endpoint
The reliable GLP compliant OECD Guideline study was chosen.

Justification for selection of acute toxicity – dermal endpoint
The reliable GLP compliant OECD Guideline study was chosen.

Justification for classification or non-classification

The available data on acute toxicity via the oral, inhalation and dermal route do not meet the criteria for classification according to Regulation (EC) 1272/2008 or Directive 67/548/EEC, and are therefore conclusive but not sufficient for classification.