2-hexyldecanoic acid [4-(6-tert-butyl-7-chloro-1H-pyrazolo[1,5-b][1,2,4]triazol-2-yl)phenylcarbamoyl]methylester

Endpoint summary

Description of key information

Oral (OECD 423), rat: LD50 = 5000 mg/kg bw (cut-off value, 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:

22 Jul - 08 Aug 2003

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP - Guideline study

Qualifier:

equivalent or similar to guideline

Guideline:

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

Version / remarks:

adopted 1996

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

adopted 1996

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1100 (Acute Oral Toxicity)

Version / remarks:

adopted June 1996

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: Japanese Ministry of Agriculture, Forestry and Fisheries (JMAFF), adopted November 2000 and most recent partial revisions

Deviations:

no

GLP compliance:

yes

Test type:

acute toxic class method

Limit test:

yes

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Deutschland, Sulzfeld, Germany (strain: Crl:(WI) BR (outbred, SPF-Quality))
- Age at study initiation: 11 weeks
- Weight at study initiation: male (mean) 343 ± 18 g, female (mean) 212 ± 13 g (did not exceed ±20 % of the mean)
- Fasting period before study: a maximum of 20 hours, up to 3-4 hours after dosing
- Housing: group housing of 3 animals per cage in Makrolon cages (type IV) containing purified sawdust as bedding material
- Diet: standard pelleted laboratory animal diet (Altromin code VRF 1), ad libitum
- Water: tap-water, ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18.1 - 24.5 (actual range)
- Humidity (%): 47 - 79 (actual range)
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12 / 12

Route of administration:

oral: gavage

Vehicle:

propylene glycol

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 200 mg/mL (w/w) (calculated from dose volume of 10 mL/kg and dose of 2000 mg/kg bw)
- Amount of vehicle (if gavage): 10 mL/kg bw
- Justification for choice of vehicle: based on trial formulations performed at the test lab

Doses:

2000 mg/kg bw

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: observations for viabiliy and mortality: twice daily; clinical signs: at periodic intervals at the day of dosing and once daily thereafter until Day15 (for grading of symptoms see Table 1 under "any other information on material and methods including tables"); weighing: Day 1 pre-administration and on Days 8 and 15
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight, gross pathology

Sex:

male/female

Dose descriptor:

LD50

Effect level:

5 000 mg/kg bw

Based on:

test mat.

Remarks on result:

other: No effects were observed up to and including the highest dose level. According to OECD 423, the LD50 cut-off value is set at 5000 mg/kg bw.

Mortality:

No mortalities occurred.

Clinical signs:

Piloerection in 3/3 males and 3/3 females was seen 2 and 4 hours after dosing, in females it was still visible 1 day after dosing. Hunched posture for 3/3 females was noted 4 hours after dosing, for 1/3 females hunched posture was still seen 1 day after dosing. 3/3 male animals showed hunched posture already 2 hours after dosing. For 1/3 males this clinical sign was still detectable 2 days after dosing, whereas for the other 2 males it was reversed by one and two days after dosing. Further, 3/3 females showed uncoordinated movements 2 and 4 hours after dosing and 1/3 females showed chromodacryorrhoea 2 and 4 hours after dosing (see Table 2).

Body weight:

Slight body weight loss or reduced body weight gain was noted in the males between Days 8 and 15 (9.5%). No effects on body weight were noted in the females (see Table 3)

Gross pathology:

No abnormalities were found at macroscopic post mortem examination of the animals.

Table 2. Table for acute oral toxicity.

Dose [mg/kg bw]	Toxicological results*	Duration of clinical signs	Time of death	Mortality (%)
Males
2000	0/3/3	2 h - Day2	---	0
Females
2000	0/3/3	2 h - Day3	---	0
LD50 > 2000 mg/kg bw

* first number = number of dead animals                                 

 second number = number of animals with clinical signs         

 third number = number of animals used           

 

Table 3. Body weights (g)

Sex/Dose Level	Animal	Day1	Day8	Day15
Females/2000 mg/kg bw	1	236	266	277
	2	216	245	254
	3	212	239	247
	Mean	221	250	259
	Standard deviation	13	14	16
	N	3	3	3
Males/2000 mg/kg bw	1	359	410	406
	2	323	371	372
	3	348	403	404
	Mean	343	395	394
	Standard deviation	18	21	19
	N	3	3	3

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

Quality of whole database:

The available information comprises an adequate and reliable study (Klimisch score 1), 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

Endpoint conclusion

Endpoint conclusion:

no study available

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:

21 Jan - 04 Feb 2004

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)

Version / remarks:

adopted 1987

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

adopted 1992

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1200 (Acute Dermal Toxicity)

Version / remarks:

adopted June 1996

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: Japanese Ministry of Agriculture, Forestry and Fisheries (JMAFF), adopted Nov 2000 including the most recent revisions

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: Charles River Deutschland, Sulzfeld, Germany (strain: Crl:(WI) BR (outbred, SPF-Quality))
- Age at study initiation: 8 weeks
- Weight at study initiation: male (mean) 307 ± 15g, female (mean) 228 ± 15g (did not exceed ±20 % of the sex mean)
- Housing: individually in Makrolon cages (type III) containing purified sawdust as bedding material
- Diet: standard pelleted laboratory animal diet (Altromin (code VRF 1)), ad libitum
- Water: tap-water, ad libitum
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18.6 - 22.9 (actual range)
- Humidity (%): 38 - 80 (actual range)
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12

Type of coverage:

semiocclusive

Vehicle:

propylene glycol

Details on dermal exposure:

TEST SITE
- Area of exposure: 25 cm² for males, 18 cm² for females
- % coverage: 10
- Type of wrap if used: surgical gauze patch, successively covered with aluminium foil and Coban elastic bandage

REMOVAL OF TEST SUBSTANCE
- Washing: using water
- Time after start of exposure: 24 h

TEST MATERIAL
- Amount(s) applied: 10 mL/kg bw
- Concentration (if solution): 200 mg/mL (w/w) (calculated from 10 mL/kg bw amount and 2000 mg/kg bw)
- Constant volume or concentration used: yes

VEHICLE
- Amount(s) applied (volume or weight with unit): 10 mL/kg bw

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: mortality and viability: twice daily; clinical signs: at periodic intervals on the day of dosing and once daily thereafter (see Table 1 under "any other information on material and methods including tables")
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight, histopathology

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

No mortalities were observed.

Clinical signs:

5/5 males showed flat or hunched posture starting 2 hours after dsoing until 1 day after dosing in 4/5 animals and 2 days after dosing in 1/5 males. Chromodacryorrhoea (Snout) was seen in 5/5 males starting 2 hours after dosing and was completely reversed in all males 2 days after dosing. 1/5 male animals showed diarrhoea 1 day post dosing. Additionally, 1/5 males and 1/5 females showed ptosis 4 h after dosing.
5/5 females showed flat posture 2 and 4 hours after dsoing, 4/5 females showed hunched posture thereafter, until 2 days post dosing. Chromodacryorrhoea (Snout) was seen starting 2 hours after dosing until 1 day after dosing in 5/5 females. 4/5 females showed general erythema starting 1-2 days after dosing at the treated skin site, erythema was visible until the third day post dosing in 3/5 females and 1/5 females still had erythema visible 5 days after dosing. Scales were visible on the treated skin site of 2/5 females. 1/5 showed scales only 5 days after dosing. For the other female scales were visible starting 4 days post dosing until the end of the observation period and additionally, scabs were seen from day 6 post dosing until the end of the observation period (see Table 2).

Body weight:

The changes noted in body weight gain in males and females were within the range expected for rats in this type of study.

Gross pathology:

No abnormalities were found at macroscopic post mortem examination of the animals.

Table 2. Table for acute oral toxicity. 

Dose [mg/kg bw]	Toxicological results*	Duration of clinical signs	Time of death	Mortality (%)
Males
2000	0/5/5	2 h - Day3	---	0
Females
2000	0/5/5	2 h – Day15	---	0
LD50 > 2000 mg/kg bw

* first number = number of dead animals                                 

 second number = number of animals with clinical signs         

 third number = number of animals used           

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

Quality of whole database:

The available information comprises an adequate and reliable study (Klimisch score 1), 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

The acute toxicity of 2-hexyldecanoic acid [4-(6-tert-butyl-7-chloro-1H-pyrazolo[1,5-b][1,2,4]triazol-2-yl)phenylcarbamoyl]methylester (UM-235) was assessed in an oral toxicity study and a dermal toxicity study. No inhalation toxicity study is available.

In an acute oral toxicity study performed according to OECD 423, the limit dose of 2000 mg/kg bw UM-235 was administered to 3 male and then to 3 female Wistar rats by gavage, in two steps (Teunissen, 2003a). Animals were observed daily for clinical signs and body weight was determined weekly. Macroscopic examination was performed at the end of the 14-day observation period at terminal sacrifice. There were no mortalities during the observation period. Clinical signs in all animals included hunched posture and piloerection starting 2 h after dosing. Piloerection was only seen on the day of dosing whereas, hunched posture was still observed 1 day after dosing in 1/3 females and 2 days after dosing in 1/3 males. Additionally, 3/3 females showed uncoordinated movements and 1/3 females showed chromodacryorrhoea on the day of dosing. A mean body weight loss of 9.5% was noted in the males between Days 8 and 15. No effects on body weight were noted in the females. It is not clear of these effects were caused by the gavage treatment or the test substance. No treatment-related abnormalities were found at macroscopic post mortem examination of the animals. According to the acute toxic class method described in the OECD guideline 423, if there is no mortality following administration of 2000 mg/kg bw in two separate steps, the LD50 cut-off limit is 5000 mg/kg bw. Therefore, the LD50 is considered to be 5000 mg/kg bw for male and female rats.

The acute dermal toxicity of UM-235 was assessed in a limit test performed in 5 Wistar rats/sex/dose according to OECD 403 (Hooiveld, 2004a). A single dose of 2000 mg/kg bw of the test substance dissolved in propylene glycol was applied to the shaved skin of rats under semi-occlusive conditions and left for 24 hours. There was no mortality and no effects on body weight during the 14-day observation period. Hunched and/or flat posture was seen in all animals starting 2 hours after dosing until 2 days post dosing. Additionally, chromodacryorrhoea (snout) was seen 2 hours after dosing until 1 day post dosing. 1 male animal showed diarrhea on Day 1 after dosing and 1 male and 1 female each showed ptosis 4 hours after dosing. These effects are known stress reactions and it is unclear if they are treatment-related rather than substance-related. The necropsy and gross pathological examination did not show any treatment-related effects. Erythema (grade 1 on a scale of 4), scales and/or scabs were noted in the treated skin area of all female animals after removal of the dressing. The erythema had cleared completely in all animals by Day 9 but the scales/scabs were still visible in 1/5 animals at terminal sacrifice. The LD50 for systemic toxicity is considered to be > 2000 mg/kg bw.

Justification for selection of acute toxicity – oral endpoint
There is only one study available.

Justification for selection of acute toxicity – dermal endpoint
There is only one study available.

Justification for classification or non-classification

The available data on acute oral and dermal toxicity of the test substance 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.

No study on acute inhalation toxicity is available.