(E)-3-methyl-4-(2,6,6-trimethylcyclohex-2-en-1-yl)but-3-en-2-one

Endpoint summary

Description of key information

Acute oral toxicity:
 - oral: LD50 cut-off >5000 mg/kg bw (rat, OECD 423), LD50 >5000 (rat)
 - dermal: LD50 >5000 mg/kg bw (rat)

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: guideline study with GLP

Qualifier:

according to guideline

Guideline:

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

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes

Remarks:

BASF AG, Department of Toxicology

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:

- age: young adult
- weights at start of study: 150-300 g (+/- 20% of mean weight)
- identification: individual identification using cage cards and group identification by tail marking
- housing: single housing in fully air-conditioned rooms, central air conditioning guaranteed a range of 20-24°C for temperature and of 30-70% for relative humidity. There were no deviations from these ranges which influenced the results of the study.
- day/night rhythm: 12:12
- type of cage: stainless steel wire mesh cages, type DK-III
- bedding: no bedding in the cages, sawdust in the waste trays
- drinking water: tap water ad libitum per day
- diet: Kliba-Labordiät 343, Klingentalmühle AG, Kaiseraugst, Switzerland, ad libitum
- analysis of drinking water: the drinking water is regularly assayed for chemical contaminants by municipal authorities of Frankenthal and the technical services of BASF AG as well as for the presence of germs by a contract laboratory
- analysis of feed: the feed used in the study was assayed for chemical and microbiological contaminants
- acclimatization period: acclimatization for at least 1 week
- fasting period: the animals were given no feed at least 16 hours before administration, but water was available ad libitum

Route of administration:

oral: gavage

Vehicle:

other: olive oil DAB 10

Details on oral exposure:

- reason for the vehicle: test substance could not be homogeneously distributed in aqua bidest
- form of administration: solution
- amounts administered: dose: 2000 mg/kg; concentration: 40 g/100 ml; administration volume: 5 ml/kg
- time of day of administration: in the morning

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

3

Control animals:

no

Details on study design:

- observation period: 17 days for males / 14 days for females
- body weight determination: individual body weights shortly before application (day 0), weekly thereafter and at the end of the study (before fasting period)
- signs and symptoms: recording of signs and symptoms several times on the day of administration and at least once each workday for the indiviual animals
- mortality: a check for any dead or moribund animals was made twice each workday and once on saturdays, sundays and on public holidays
- pathology: necropsy at the last day of the observation period; withdrawal of food at least 16 hours before killing with CO2; then necropsy with grosspathology examination; necropsy of all animals that died before end of study as early as possible

Key result

Sex:

male/female

Dose descriptor:

LD50 cut-off

Effect level:

5 000 mg/kg bw

Based on:

test mat.

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Remarks on result:

other: no deaths observed

Mortality:

no mortality up to day 14 (females) and day 17 (males)

Clinical signs:

see table

Body weight:

see table

Gross pathology:

necropsy findings of sacrificed animals: organs without particular findings (3 males, 3 females)

Other findings:

clinical symptoms reversible

animal symptoms:

	males		females
	cageside observations	number of animals	cageside observations	number of animals
impaired general state	H1 - H4	3	H0 - H2	2
poor general state			H0 - D2	3
dyspnoea	H1 - H4	3	H0 - D2	3
apathy			H0 - D2	3
staggering	H1 - H4	3	H0 - D2	3
twitching			H4	1
saltatory spasm	H1 - H3	1
spastic gait			D1 - D2	1
piloerection			H0 - D2	3
smeared fur			D2	1
exophthalmos			H0 - H1	3
S5			D2	1

H: hour

D: day

S5: red smeared fur in the anogenital area

body weights:

		day
		0	7	13
male	1	175	244	273
	2	175	230	263
	3	175	230	281
	mean	175	235	272
female	1	170	202	210
	2	171	194	215
	3	172	203	215
	mean	171	200	213

Interpretation of results:

GHS criteria not met

Conclusions:

The oral acute toxicity of methylionone was tested in a study under GLP performed according to OECD Guideline 423 (BASF, 1999). Three male and three female Wistar rats were once administered by gavage with 2000 mg/kg bw in 5 ml/kg bw olive oil DAB 10. The following observation time was 17 days for males and 14 days for females. Although signs of toxicity were noted during the first days after application, the animals appeared normal after five days. Since no mortality was observed, the LD50 cut-off value was determined to be 5000 mg/kg bw.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

5 000 mg/kg bw

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

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

Standard method but limited documentation

Reason / purpose for cross-reference:

reference to same study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Principles of method if other than guideline:

rabbits tested, 5000 mg/kg bw, observation period 14d

GLP compliance:

not specified

Test type:

standard acute method

Limit test:

yes

Species:

rabbit

Strain:

not specified

Sex:

not specified

Type of coverage:

not specified

Vehicle:

not specified

Duration of exposure:

not specified

Doses:

5000 mg/kg bw

No. of animals per sex per dose:

8

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Other examinations performed: clinical signs, mortality

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 5 000 mg/kg bw

Mortality:

0/8 at 5000 mg/kg bw

Interpretation of results:

GHS criteria not met

Conclusions:

In this acute dermal toxicity test conducted in 8 rabbits, the LD50 was found to be above the highest tested dose of 5000mg/kg.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

5 000 mg/kg bw

Additional information

Oral

The oral acute toxicity of methylionone was tested in a study under GLP performed according to OECD Guideline 423 (BASF, 1999). Three male and three female Wistar rats were once administered by gavage with 2000 mg/kg bw in 5 ml/kg bw olive oil DAB 10. The following observation time was 17 days for males and 14 days for females. Although signs of toxicity were noted during the first days after application, the animals appeared normal after five days. Since no mortality was observed, the LD 50 cut-off value was determined to be 5000 mg/kg bw.

In another study, ten rats (5 males, 5 females) were administered 5000 mg/kg bw orally (Givaudan, 1978). No deaths were observed within 14 days, thus the LD50 was determined to be >5000 mg/kg bw/day. The dose for the LD50 study had previously been determined in a range-finder test, in which 4 male and 4 female rats were adminstered 0.5, 1, 2, or 5 g/kg bw, no deaths were observed within 14 days (Givaudan, 1978).

In a third study, ten rats were administered orally with 5000 mg/kg bw (Moreno, 1973). As no mortality occurred within the 14 day post dosing observation time, the LD50 values was found to be >5000 mg/kg bw. Although no further data were given, this study was evaluated reliable as it is cited by the FFHPVC Terpene Consortium and the original data are from highly experienced and respected toxicologists.

In an acute oral range-finding toxicity test, individually housed mice aged 4-5 weeks were fasted for 4 hours and then orally intubated with 2, 5, or 10  ml/kg bw of undiluted test substance (2, 6 and 2 mice, respectively) (Quest, 1980). The mice were observed up to 7 days following treatment and dying mice were necropsied. All mice surviving to the end of the observation period were weighed, killed and examined post mortem. Due to observed mortality in the 5 and 10 ml/kg bw groups (1/6 and 2/2 respectively), the LD50 was calculated to be >5 and < 10 ml/kg bw and the methylionone was given a toxicity rating according to Hodge and Sterner’s classification.

Dermal

For evaluating the acute dermal toxicity, a concentration of 5000 mg/kg bw was tested in eight rabbits (Moreno, 1973). Since no mortality was observed during the 14 day observation period, the LD50 was determined as >5000 mg/kg bw. Although the report was short, this study was evaluated reliable as it is cited by the FFHPVC Terpene Consortium and the original data are from highly experienced and respected toxicologists.

Justification for classification or non-classification

Due to the results from different studies including one performed according to OECD Guideline 423, no classification is required.