4-(2-chlorophenyl)-N-cyclohexyl-N-ethyl-5-oxo-4,5-dihydro-1H-tetrazole-1-carboxamide

Endpoint summary

Description of key information

Acute oral toxicity (OECD 401, GLP), rat: LD50> 5000 mg/kg bw

Acute oral toxicity (OECD 401, GLP), mice: LD50> 5000 mg/kg bw

Acute inhaltion toxicity (OECD 403, GLP), rat: LC50> 5085 mg/m³

Acute dermal toxicity (OECD 402, GLP), rat: LD50> 5000 mg/kg bw

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

Study period:

15 - 29 Nov 1994

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 24th February 1987

Deviations:

no

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan Winkelmann GmbH, Borchen, Paderborn
- Females nulliparous and non-pregnant: yes
- Age at study initiation: 7 - 8 weeks (males), 10 - 11 weeks (females)
- Weight at study initiation: 167 - 182 g (males); 174 - 186 g (females)
- Fasting period before study: 17 h ± 1 h
- Housing: five animals per cage in Makrolon cage type III on the first day of study, afterwards one animal per cage in Makrolon type IIa cages
- Diet: Altromin (R) 1324, ad libitum (2 h after exposure)
- Water: tap water, ad libitum
- Acclimation period: at least 7 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3.0
- Humidity (%): 40 - 70
- Air changes (per hr): 12 - 15
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: To: Nov 15 - Nov 29, 1994

Route of administration:

oral: gavage

Vehicle:

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

Details on oral exposure:

MAXIMUM DOSE VOLUME APPLIED: 20 mL/kg bw

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 recorded several times on the day of treatment, and at least once a day thereafter, the body weights of the rats were recorded on day 1 before administration of the test substance and on day 8 and 15
- Necropsy of survivors performed: yes
- Other examinations performed: gross pathology

Statistics:

Mean values and standard errors were calculated.

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 5 000 mg/kg bw

Based on:

test mat.

Mortality:

No mortalities were observed.

Clinical signs:

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

Gross pathology:

Animals sacrificed at the end of the post-treatment observation period showed no evidence of test-substance related grossly visible organ lesions.

Table 1: Summary - acute oral toxicity

Dose (mg/kg bw)	Number of animals	Mortalities/Clinical signs	LD50
5000	5 males	0	> 5000 mg/kg bw
5000	5 females	0	> 5000 mg/kg bw

Interpretation of results:

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

Conclusions:

In this acute oral toxicity study in rats a LD50 value of > 5000 mg/kg bw was determined.

Reference 2

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

3 Dec - Dec 24 1996

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 1983

Deviations:

no

GLP compliance:

yes

Test type:

standard acute method

Limit test:

no

Species:

mouse

Strain:

ICR

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Japan Inc.
- Age at study initiation: 5 weeks
- Weight at study initiation: 22.0 - 25.8 g (males), 17.0 - 22.0 g (females)
- Fasting period before study: animals were fasted overnight prior to administration
- Housing: 5 animals per cage
- Diet: pellet feed (CRF-1, Charles River Japan, Inc.), ad libitum
- Water: tap water, ad libitum
- Acclimation period: 7 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 - 26
- Humidity (%): 30 - 70
- Air changes (per hr): 10 - 20
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: December 3, 1996 To: December 24, 1996

Route of administration:

oral: gavage

Vehicle:

other: Cremophor EL 2 % (w/v)

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 125 and 250 mg/mL

MAXIMUM DOSE VOLUME APPLIED: 0.2 mL per 10 g body weight

DOSAGE PREPARATION: the test substance was grinded with Cremophor EL and then mixed with distilled water to prepare two dosing solutions of 125 mg/mL and 250 mg/mL of YRC 2388. For a vehicle control group, Cremophor EL 2 % (w/v) solution without test substance was prepard.

Doses:

2500 and 5000 mg/kg bw

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: observations were frequently made on the day of administration and at least once a day onward, the individual body weights of the animals were measured immediately before the administration and at 1, 3, 7, 10 and 14 days after the administration.
- Necropsy of survivors performed: yes
- Other examinations performed: gross pathology

Statistics:

Mean values of body weights were determined.

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 5 000 mg/kg bw

Based on:

test mat.

Mortality:

No mortalities were observed.

Clinical signs:

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

Gross pathology:

No macroscopical findings were observed at the end of the test period.

Table 1: Summary - acute oral toxicity

Dose (mg/kg bw)	Number of animals	Mortalities/Clinical signs	LD50
5000	5 males	0/0	> 5000 mg/kg bw
2500	5 males	0/0	> 5000 mg/kg bw
5000	5 females	0/0	> 5000 mg/kg bw
2500	5 females	0/0	> 5000 mg/kg bw

Table 2: Body weight females

females 5000 mg/kg bw
animal	day of administration	day 1	day 3	day 7	day 10	day 14	body weight increase	mean
1	19,7	22,7	23,9	23,4	24,3	24,7	5	6,32
2	21,2	24,8	24,9	24,7	25,8	25,9	4,7
3	19,7	22,5	23,9	23,7	24,6	26,2	6,5
4	22	24,7	27,36	27,6	28,9	30,2	8,2
5	17	21,2	22,4	22,3	22,8	24,2	7,2
females 2500 mg/kg bw
animal	day of administration	day 1	day 3	day 7	day 10	day 14	body weight increase	mean
1	21,8	24	25,1	26,4	26,8	27,7	5,9	5,9
2	19,7	21,8	22,8	23,8	24,8	26,8	7,1
3	19,3	22,5	23,9	24,1	24,6	25,3	6
4	20,7	23,3	23,5	23,2	23,7	24,5	3,8
5	19,1	22,5	23	23,6	25,2	25,8	6,7
females control
animal	day of administration	day 1	day 3	day 7	day 10	day 14	body weight increase	mean
1	20,7	22,5	24,7	24,7	25,3	25,8	5,1	4,92
2	18,7	20,4	21,1	23,3	23,2	24,4	5,7
3	21,7	23,5	25	25,6	25,4	26,9	5,2
4	19,6	22	22,8	22,2	22,2	22,3	2,7
5	20,3	24	25,3	24	25,7	26,2	5,9

Interpretation of results:

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

Conclusions:

In this acute oral toxicity study in mice a LD50 value of > 5000 mg/kg bw was determined.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

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 VIII, 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:

7 - 29 March 1995

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 12 May 1981

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: EG Guideline 92/69/EWG. Journal of the European Community - Legal Specifications L 2383 A, 35.

Version / remarks:

29 December 1992

Qualifier:

according to guideline

Guideline:

other: U.S. Environmental Protection Agency. Pesticide assessment guidelines, subdivision F, hazard evaluation: Human and domestic animals (Revised) § 81-3 Acute Inhalation Toxicity Study. NTIS Report PB86-108958, Washington, DC

Version / remarks:

1984

Qualifier:

according to guideline

Guideline:

other: U.S. Environmental Protection Agency. Hazard evaluation division: Standard evaluation procedure, inhalation toxicity testing, NTIS Report PB89-100366, Washington, DC.

Version / remarks:

1988

GLP compliance:

yes

Limit test:

no

Species:

rat

Strain:

Wistar

Remarks:

Hsd Win:WU

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan Winkelmann GmbH, Borchen, Germany
- Females nulliparous and non-pregnant: yes
- Age at study initiation: 2 - 3 months
- Weight at study initiation: 170 - 205 g (males), 169 - 187 g (females)
- Housing: individually in Makrolon cages type II during the acclimation and study periods
- Diet: Altromin® 1324 diet, ad libitum
- Water: tap water, ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 2.0
- Humidity (%): approximately 50
- Air changes (per hr): 10
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

inhalation: dust

Type of inhalation exposure:

nose only

Vehicle:

other: test substance was aerosolized as dust without a carrier or vehicle

Mass median aerodynamic diameter (MMAD):

ca. 2.6 µm

Geometric standard deviation (GSD):

ca. 2

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: Plexiglas exposure tubes (TSE, Bad Homburg, Germany)
- Exposure chamber volume: 3.8 L (dimensions of the inhalation chamber: inner diameter =14 cm, outer diameter = 35 cm (two-chamber system), height = 25 cm)

- Source and rate of air: compressed air supplied by Boge compressors
- Method of conditioning air: automatically by a VIA compressed air dryer
- System of generating particulates/aerosols: In order to obtain the high concentration of respirable aerosol an EXACTOMAT 4200 (TSE, 61348 Bad Homburg, Germany) and for the lower concentration a wright-dust-feeder (BGI Inc., Waltham, MA, USA) was used.
- Method of particle size determination: gravimetric analyses (cascade impactors)
- Treatment of exhaust air: the exhaust air was purified via cotton-wool/activated charcoal and HEPA filters. These filters were disposed of.
- Temperature, humidity, pressure in air chamber: 22°C, humidity: control group: 15%, 535 mg/m³: 8% and 5085 mg/m³: 4%

TEST ATMOSPHERE
- Brief description of analytical method used: gravimetric analysis with cellulose-acetate filter
- Samples taken from breathing zone: yes

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Concentrations:

535 mg/m³
5085 mg/m³

No. of animals per sex per dose:

5

Control animals:

yes

Details on study design:

- Duration of observation period following administration: 14 and 28 days
- Frequency of observations and weighing: clinical signs: several times on the day of exposure and at least once daily thereafter; body weights: measured prior to exposure and on Day 3 and 7 and weekly thereafter
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight, gross pathology

Statistics:

Statistically significant differences (vs control) are indicated by asterisks (*for p < 0.05, **for p < 0.01).

Necropsy: evaluation of respiratory tract findings in surviving rats(pairwise Fisher test after the RxC chi-squared test) The Fisher test was only performed if differences occurred between groups in the RxC chi-squared test or if a frequency value of < 5 was calculated (according to with Gad and Weil, 1982). For calculation of the unilateral p value a symmetrical distribution was assumed (p unilateral = (p bilateral)/2).

Body weights: Means and single standard deviations of body weights are calculated. Since in acute studies individual group means may differ prior to commencement of the first exposure, the body weight gain was statistically evaluated for each group (one-way ANOVA (vide infra))

Physical measurements: means + single standard deviation

Physiological data: rectal temperature measurements (ANOVA (vide infra))

Calculation of the LC50: according to the method of A.P. Rosiello et al (1977) as modified by Pauluhn (1983) (based on the maximum-likelihood method of C.I. Bliss (1938)). If only 2 pairs of values with greater than 0% lethality and less than 100% are available then the first linear approximation is based on these values and a x²-homogeneity test is not performed. The interpolated concentration at 50% lethality in this case was designated the approximate LC50.

Randomization: computerized list of random numbers (animals)

Analysis of variance (ANOVA): groups are compared at a confidence level of (1-oc) = 95% (p = 0.05). The test for the between-group homogeneity of the variance employed Box's test if more than 2 groups were compared. If the F-test shows that the intra-group variability> inter-group variability, this is shown as "no statistical difference between the groups". If a difference is found then a pairwise post-hoc comparison is conducted (1- and 2-sided) (Games and Howell modification of the Tukey-Kramer significance test)

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 5 085 mg/m³ air

Based on:

test mat.

Exp. duration:

4 h

Mortality:

No mortality occured until the end of the observation period.

Clinical signs:

other: All rats tolerated the treatment without any clinical sign.

Body weight:

Decreased body weights were determined in both treatment groups. However, these changes were minor and transient in nature and are therefore considered to be toxicologically insignificant.

Gross pathology:

No findings related to treatment were observed.

Other findings:

Rectal temperature:
Statistical comparison between groups exposed to the test substance with those in the control group did indicate concentration-dependent effect on body temperature in all groups exposed to the test compound. The changes observed, however, are considered to be toxicologically insignificant.

Aerosol generation:

The aerosol generated was of adequate respirability in the lower exposure group (i.e. MMAD ca. 2.6 |um, GSD ca. 2, relative mass < 3 \im ca. 60%). It appeared not to be feasible to generate concentrations approximating 5000 mg/m³ air using a cyclone to seperate off larger particles. This, in fact, resulted in a decreased respirability of particles in the highest esposure group. Despite the lower respirability rats experienced a hypothermia in the higher exposure groups.

Table 2: Summary of acute inhalation

Group/Sex	Gravimetric Concentration (mg/m³)	Toxicological Result	Onset and duration of signs	Rectal temperature (°C)	Onset of Mortality
1/m	0	0/0/5	-	38.2	-
2/m	535	0/0/5	-	37.3**	-
2/m	5085	0/0/5	-	35.8**	-
1/f	0	0/0/5	-	38.6	-
2/f	535	0/0/5	-	37.0**	-
3/f	5085	0/0/5	-	35.4**	-

m = males, f = females, — not applicable

Values given in the 'Toxicological results' column are:

1st = number of dead animals.

2nd = number of animals with signs after cessation of exposure.

3rd = number of animals exposed.

 

Table 3: Mean Bodyweights with standard deviations [g]

Dose [mg/m^3]	Sex	exposure day	3 days after exposure	1 week after exposure	2 weeks after exposure
control	m	197.2 ± 5.1	202 ± 4.6	221.0 ± 6.3	254.8 ± 9,5
535	m	170.8 ± 1.3	177 ± 4.4	204.4 ± 5.9	239.4 ± 9.5
5085	m	192.6 ± 6.2	200.6 ± 8.4	224.2 ± 10.0	255.0 ± 10.6
control	f	185.2 ± 1.5	184.0 ± 2.5	187.2 ± 2.5	198.2 ± 5.6
535	f	171.6 ± 2.9	167.0 ± 7.6	174.8 ± 7.5	185 ± 8.0
5085	f	178.2 ± 4.4	174.6 ± 6.3	176.8 ± 6.9	188.4 ± 7.3

m male, f female

 

Table 4: Gross pathology findings

Group	Dose [mg/m^3]	Animals with effects	Time of death	Sacrificed after	Pathology findings
1 m	control	0/5	-	28 days	no observable effects
2 m	535	1/5	-	14 days	lung: foci slightly dark red
3 m	5085	0/5	-	14 days	no observable effects
1 f	control	0/5	-	28 days	no observable effects
2 f	535	0/5	-	14 days	no observable effects
3 f	5085	0/5	-	14 days	no observable effects

m male, f female

Interpretation of results:

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

Conclusions:

In this acute inhalation toxicity study in rats a LC50 value of > 5085 mg/m³ air was determined.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Quality of whole database:

The available information comprises an adequate, reliable (Klimisch score 1) and consistent study, and is thus sufficient to fulfil the standard information requirements set out in Annex VIII, 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:

8 - 22 November 1994

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Version / remarks:

adopted 9 October 2017

Deviations:

yes

Remarks:

exposure under occlusive conditions, exposure of males and females

Qualifier:

according to guideline

Guideline:

other: Pesticide Assessment Guidelines, Subdivision F, Hazard Evaluation: Human and Domestic Animals, Series 81-2 Acute Dermal Toxicity Study

Version / remarks:

November 1984

Qualifier:

according to guideline

Guideline:

other: Annex V, Part B.3. (acute toxicity [dermal]) to Directive 67/548/EEC of the Council of the European Communities in its current version as amended for the seventeenth time by Directive 92/69/EEC of the Commission of the European Communities

Version / remarks:

31 July 1992

GLP compliance:

yes

Test type:

fixed dose procedure

Limit test:

yes

Species:

rat

Strain:

Wistar

Remarks:

Hsd Win:WU

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan Winkelmann GmbH, Borchen, District of Paderborn, Germany
- Females nulliparous and non-pregnant: yes
- Age at study initiation: 10 - 12 weeks (males), > 16 weeks (females)
- Weight at study initiation: 262 - 298 g (males), 229 - 242 g (females)
- Housing: 5 animals in Makrolon cages type III during the acclimation period, individually in type IIA cages during test period
- Diet: Altromin® 1324 diet, ad libitum
- Water: tap water, ad libitum
- Acclimation period: at least 7 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3.0
- Humidity (%): 40 - 70
- Air changes (per hr): 12 - 15
- Photoperiod (hrs dark / hrs light): 12/12

Type of coverage:

occlusive

Vehicle:

other: Natriumchlorid (NaCl)

Details on dermal exposure:

TEST SITE
- Area of exposure: 5 x 5 cm²
- Type of wrap if used: foil (fermoflex), occlusive dressing

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

TEST MATERIAL
- Amounts applied: 5000 mg/kg bw (43.3-49.3 mg/cm², males and 37.9 - 40.0 mg/cm² females)
- For solids, paste formed: yes

VEHICLE
- Amount applied: 1.5 ml NaCl solution/g test substance
- Concentration (if solution): 0.9%

Duration of exposure:

24 h

Doses:

5000 mg/kg bw

No. of animals per sex per dose:

5 males and 5 females

Control animals:

not required

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Appearance and behavior was recorded several times on the day of treatment, and at least once a day thereafter, and individual body weights were determined on Day 1 before administration and on Day 8 and 15
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight, gross pathology examination

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 5 000 mg/kg bw

Based on:

test mat.

Mortality:

No mortalities were observed up to the end of the 14-day observation period.

Clinical signs:

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

Gross pathology:

Necropsy and histopathological examination revealed no substance-related findings.

Table 1: Body weights [g]

Animal number	Sex	Day 1	Day 8	Day 15
1	male	287	305	336
2	male	298	321	254
3	male	272	292	323
4	male	276	307	341
5	male	262	281	308
Mean		279 ± 13.9	301 ±15.3	332 ± 17.6
1	female	241	233	233
2	female	229	228	234
3	female	235	239	244
4	female	240	241	246
5	female	242	231	240
Mean		237 ± 5.4	234 ± 5.5	239 ± 5.8

 

Interpretation of results:

GHS criteria not met

Conclusions:

CLP: not classified

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Quality of whole database:

The available information comprises an adequate, reliable (Klimisch score 1) and consistent 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 oral toxicity

Acute toxicity of the test substance was tested in Wistar rats according to OECD TG 401 and GLP (1995a). The test substance was dissolved in cremophor EL 2% (v/v) in demineralized water. Groups of 5 male and 5 female rats each were exposed to 5000 mg/kg bw (20 ml/kg bw) via gavage. No mortality was observed until the end of the observation period of 14 days. No clinical signs of toxicity, effects on body weight or body weight development and no gross pathological findings were identified. Thus, a LD50 > 5000 mg/kg bw was derived.

 

Further, acute toxicity of the test substance was tested in ICR mice according to OECD TG 401 and GLP (1997d). The test substance was grinded with Cremophor EL 2% (w/v) and then mixed with distilled water to prepare two dosing solutions of 125 mg/mL and 250 mg/mL. Groups of 5 male and 5 female rats each were exposed to 2500 or 5000 mg/kg bw (0.2 ml per 10g/ bw) via gavage. A vehicle group received cremophor EL 2 % (w/v) solution without test substance. No mortality was observed until the end of the observation period of 14 days. A transient body weight loss in females dosed at 5000 mg/kg bw was considered to be incidental, showing no relation to test substance administration. No clinical signs of toxicity and no gross pathological findings were identified. Thus, a LD50 > 5000 mg/kg bw was derived.

 

In addition, an acute oral neurotoxicity screening study with the test substance was performed in Wistar rats according to (OPPTS, U.S. Environmental Protection Agency, Health Effects Test Guideline 870.6200, Neurotoxicity Screening Battery) and GLP (2002a). The test substance was dissolved in 0.5% methylcellulose/0.4% Tween 80 in deionized water. Doses of 200, 500 and 2000 mg/kg bw were administered by gavage (12 animals/sex/dose level). A concurrent control group receiving the vehicle was included in this study. No deaths were observed up to a dose level of 2000 mg/kg bw in males and females. Compound-related clinical signs were not evident in either sex at any dose level. Body weight was not affected by treatment in males or females at any dose level. There were no compound-related gross lesions and microscopic lesions at terminal sacrifice in males or females at any dose level. Furthermore, results from the functional observational battery (FOB) revealed no compound-related effects in males or females at any dose level. There were no compound-related changes in activity in the figure-eight maze in either sex at any level of exposure and also habituation was not affected by treatment.

Thus, acute exposure to the test aubstance produced no evidence of toxicity up to and including 2000 mg/kg bw. Based on these results, an acute oral LD50 of the test substance in male and female Wistar rats of > 2000 mg/kg bw was derived.

 

Acute inhalation toxicity

Acute inhalation toxicity was tested in Wistar rats according to OECD Guideline 403 and in compliance with GLP (1996b). In this study 5 male and 5 female rats were exposed (nose only) to an aerosol (dust) of the test substance at an average concentration of 535 or 5085 mg/m3 air for 4 h. The aerosol generated was of adequate respirability in the lower exposure group (i.e. MMAD ca. 2.6 |um, GSD ca. 2, relative mass < 3 \im ca. 60%). It appeared not to be feasible to generate concentrations approximating 5000 mg/m3 air using a cyclone to seperate off larger particles. This, in fact, resulted in a decreased respirability of particles in the highest exposure group. Despite the lower respirability rats experienced a hypothermia in the higher exposure groups. Control animals were exposed to conditioned air. After exposure animals were examined for a period of 14 Days. Examinations included daily observation of clinical signs, determination of body weights and gross pathology examination. All rats tolerated the treatment without clinical signs of toxicity and showed normal reflexes. Statistical comparison between groups exposed to the aerosolized test substance with those in the control group indicated a concentration-dependent effect on body temperature in all groups exposed to the test substance. However, the observed changes were not considered toxicologically relevant. In addition, decreased body weights were observed in both treatment groups, but weretransient in nature and were therefore considered to be toxicologically insignificant.Aerosol (dust) concentrations up to and including 5085 mg/m3 did not induce test substance related mortality, thus and median lethal concentration (LC50, aerosol, 4 h) of > 5085 mg/m3 was determined for both sexes.

 

Acute dermal toxicity

Acute dermal toxicity of the test substance was tested in Wistar rats according to OECD Guideline 402 and in compliance with GLP (1995b). Five rats per sex were exposed to the test substance dissolved in NaCl solution at a dose of 5000 mg/kg bw (43.3-49.3 mg/cm², males and 37.9 - 40.0 mg/cm² females) under occlusive conditions. After an exposure period of 24 h the test substance was removed. Subsequently animals were examined for a period of 14 days. Examinations included daily clinical observations and determination of body weights. At the end of the observation period, gross pathology was performed. The maximum dose of 5000 mg/kg bw was tolerated by both sexes without clinical signs of toxicity. A transient decrease in body weights was observed in 3/5 female rats on Day 8. However, this weight loss and/or retardation of body weight development was not considered related to the test substance, but is regarded as a consequence of the stress provoked by the body wrap. Gross pathology examinations did not reveal test-substance-related grossly visible organ lesions. None of the exposed rats died, thus a dermal LD50 of >5000 mg/kg bw was determined for both males and females.

 

Overall conclusion

In summary, the available data on acute oral toxicity in rats and mice, acute dermal toxicity in rats and acute inhalation toxicity in rats consistently indicate a very low level of acute toxicity following oral, dermal and inhalation administration of the test substance. Therefore the test substance is not considered as hazardous after acute exposure.

Justification for classification or non-classification

The available data on the target substance for acute toxicity following oral, dermal and inhalation exposure do not meet the criteria for classification according to Regulation (EC) No. 1272/2008 (CLP). Data are therefore conclusive but not sufficient for classification.