Acetic acid, 2-(ethylamino)-2-oxo-, (1R,2S,5R)-5-methyl-2-(1-methylethyl)cyclohexyl ester

Endpoint summary

Description of key information

Acute oral toxicity: LD50 > 2000 mg/kg bw  (equivalent or similar to EU Method B.1 bis, GLP compliant)
Acute inhalation toxicity: data waiving
Acute dermal toxicity: LD50 > 2000 mg/kg bw (EU method B.3, GLP compliant)

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:

2008-02-27 to 2008-03-26

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method B.1 bis (Acute Oral Toxicity - Fixed Dose Procedure)

Version / remarks:

, 2008

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 420 (Acute Oral Toxicity - Fixed Dose Method)

Version / remarks:

, adopted 2001-12-17

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

signed 2007-10-15

Test type:

fixed dose procedure

Limit test:

yes

Species:

rat

Strain:

Crj: CD(SD)

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River (UK) Ltd, Margate, Kent, UK
- Age at study initiation: eight to twelve weeks of age
- Weight at study initiation: 213 - 234 g
- Fasting period before study: an overnight fast immediately before dosing and for approximately three to four hours after dosing
- Housing: the animals were housed in groups of up to four in suspended solid-floor polypropylene cages furnished with woodflakes.
- Diet (ad libitum, exception see "Fasting period before study" above): Certified Rat and Mouse Diet
- Water (ad libitum): mains drinking water
- Acclimation period: at least five days

ENVIRONMENTAL CONDITIONS
- Temperature: 19 to 25 °C
- Humidity: 30 to 70 %
- Air changes (per hr): at least fifteen changes per hour
- Photoperiod (hrs dark / hrs light): 12/12

The animals were provided with environmental enrichment items which were considered not to contain any contaminant of a level that might have affected the purpose or integrity of the study.

Route of administration:

oral: gavage

Vehicle:

arachis oil

Details on oral exposure:

SIGHTING STUDY / MAIN STUDY
In absence of data regarding the toxicity of the test material 300 mg/kg was chosen as the startind dose. A single animal was treated as follows:
dose level 300 mg/kg; concentration 30 mg/ml; dose volume 10 ml/kg.
In the absence of toxicity at a dose level of 300 mg/kg, an additional animal was treated as follows:
dose level 2000 mg/kg; concentration 200 mg/ml; dose volume 10 ml/kg.
In the absence of toxicity at a dose level of 2000 mg/kg, an additional group of 4 animals was treated as follows:
dose level 2000 mg/kg; concentration 200 mg/ml; dose volume 10 ml/kg.
A total of five animals were therefore treated at a dose level of 2000 mg/kg in the study.

The volume administered to each animal was calculated according to its fasted bodyweight at the time of dosing.

MAXIMUM DOSE VOLUME APPLIED: 10 ml/kg

VEHICLE
- Justification for choice of vehicle: Arachis oil BP was used because the test material did not dissolve/suspend in distilled water.

DOSAGE PREPARATION: The test material was freshly prepared a a solution in arachis oil BP.

Doses:

300 mg/kg bw. (sighting study)
2000 mg/kg bw. (sighting study / main study)

No. of animals per sex per dose:

300 mg/kg bw. one female rat
2000 mg/kg bw. five female rats

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Clinical observations were made 0.5, 1, 2 and 4 hours after dosing and then daily for fourteen days. Morbidity and mortality checks were made twice daily. Individual bodyweights were recorded on Day 0 (the day of dosing) and on Days 7 and 14.
- Necropsy of survivors performed: yes; at the end of the observation period the animals were killed by cervical dislocation. All animals were subjected to gross necropsy. This consisted of an external examination and opening of the abdominal and thoracic cavities. The appearance of any macroscopic abnormalities was recorded. No tissues were retained.

Statistics:

not applicable

Preliminary study:

DOSE LEVEL 300 mg/kg bw:
- There was no mortility.
- No signs of systemic toxicity were noted during the observation period.
- The animal showed expected gains in bodyweight over the observation period.
- No abnormalities were noted at necropsy.

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

There were no deaths.

Clinical signs:

other: No signs of systemic toxicity were noted during the observation period.

Gross pathology:

No abnormalities were noted at necropsy.

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The acute oral median lethal dose (LD50) of the test material in the female Sprague-Dawley CD strain rat was estimated to be greater than 2000 mg/kg bw.
According to the EC-Commission directive 67/548/EEC and its subsequent amendments, the test substance is not classified as acute toxic via the oral route.
According to the EC-Regulation 1272/2008 and subsequent regulations, the test item is not classified as acute toxic via the oral route.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Additional information

Acute oral toxicity

One fully reliable animal study described in Bradshaw (2008) (equivalent or similar to EU Method B.1 bis, GLP compliant, female rats) is considered to be reliable without restrictions. The LD50 was determined to be greater than 2000 mg/kg bw.

Acute inhalation toxicity

The study does not need to be conducted since exposure of humans via the inhalation route is not likely taking into account the vapour pressure of 0.0025 Pa at 20°C (Annex VIII section 8.5.2 Column 2 of regulation 1907/2006). Furthermore, the substance is a liquid at 20°C with a freezing point of 0°C at atmospheric pressure and not a powder with an inhalable size.

Acute dermal toxicity

One reliable animal study described in Vaeth (2008) (EU method B.3, GLP compliant, male and female rats) is considered to be reliable without restrictions. The LD50 was determined to be greater than 2000 mg/kg bw.

Justification for selection of acute toxicity – oral endpoint
One fully reliable animal study described in Bradshaw (2008) (equivalent or similar to EU Method B.1 bis, GLP compliant, female rats) is considered to be reliable without restrictions. The LD50 was determined to be greater than 2000 mg/kg bw.

Justification for classification or non-classification

Acute oral toxicity

Reference Bradshaw (2008) is considered as the key study for acute oral toxicity and will be used for classification. The LD50 was determined to be greater than 2000 mg/kg bw. Thus, according to regulation (EC) 1272/2008 and subsequent amendments the substance is not classified.

Specific target organ toxicant (STOT) - single exposure: oral

The classification criteria according to regulation (EC) 1272/2008 as specific target organ toxicant (STOT) – single exposure, oral are not met since no reversible or irreversible adverse health effects were observed immediately or delayed after exposure and no effects were observed at the guidance value, oral for a Category 1 classification (C≤ 300 mg/kg bw) and at the guidance value, oral for a Category 2 classification (2000 mg/kg bw ≥C > 300 mg/kg bw). No classification required.

Acute dermal toxicity

Reference Vaeth (2008) is considered as the key study for acute dermal toxicity and will be used for classification. The LD50 was determined greater than 2000 mg/kg bw. Thus, according to regulation (EC) 1272/2008 and subsequent amendments the substance is not classified.

Specific target organ toxicant (STOT) - single exposure: dermal

The classification criteria according to regulation (EC) 1272/2008 as specific target organ toxicant (STOT) – single exposure, dermal are not met since no reversible or irreversible adverse health effects were observed immediately or delayed after exposure and no effects were observed at the guidance value, dermal for a Category 1 classification (C≤ 1000 mg/kg bw) and at the guidance value, dermal for a Category 2 classification (2000 mg/kg bw ≥ C > 1000 mg/kg bw). No classification required.