Morpholine, 4-C12-14-alkyl derivs.

Endpoint summary

Description of key information

The available data suggests that C12-C14 alkylmorpholine has a moderate potential for acute oral toxicity (LD50 cut-off = 500 mg/kg bw) and a low potential for acute dermal toxicity (LD50 > 2000 mg/kg bw).  

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:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The study was conducted according to the OECD Guideline and EU Method in compliance with GLP. However, the guideline at the time applied 200 mg/kg rather than the current 300 mg/mg that is aligned with GHS classification.

Qualifier:

according to guideline

Guideline:

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

Deviations:

yes

Remarks:

(the test method was based on the EEC Guideline B1, but modified according to Schlede et al. (A national validation study of the acute-toxic-class-method - An alternative to the LD50 test. Arch Toxicol 66: 455-470, 1992 )

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes

Test type:

acute toxic class method

Limit test:

no

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Dr. K. Thomae GmbH, Biberach, Germany
- Age at study initiation: Young adult animals were used
- Mean weight at study initiation: 150 - 300 g
- Fasting period before study: At least 16 h before administration
- Housing: Single housing in stainless steel wire mesh cages
- Diet: Kliba-Labordiaet 343 (Klingentalmuehle AG, Kaiseraugst, Switzerland), ad libitum
- Water: Tap water, ad libitum
- Acclimation period: At least 1 week

ENVIRONMENTAL CONDITIONS
- Temperature: 20 – 24°C
- Humidity: 30 – 70 %
- Photoperiod: 12 h dark/12 h light

Route of administration:

oral: gavage

Vehicle:

olive oil

Details on oral exposure:

- Concentration in vehicle: 4 g/100 mL for the low dose level (200 mg/kg bw) and 40 g/100 mL for the high dose level (2000 mg/kg bw).
- Justification for choice of vehicle: Since the test substance is insoluble in water, olive was used as vehicle.
- Maximum dose volume applied: 5 mL/kg bw.

Doses:

200 and 2000 mg/kg bw

No. of animals per sex per dose:

200 mg/kg bw:: 3 males and 3 females
2000 mg/kg bw:: 3 females

Control animals:

no

Details on study design:

OBSERVATION PERIOD
Treatment was followed by an observation period of 14 d for the low dose group (200 mg/kg bw, males and females), and 2 d for the high dose group (2000 mg/kg bw, females).

CLINICAL SIGNS AND MORTALITY
Observation for clinical symptoms was done on several times on the day of administration and at least once each workday thereafter; check for any dead or moribund animal was made twice each workday and once on saturdays, sundays and on public holidays.

BODY WEIGHT
Individual body weights were recorded shortly before administration (Day 0), weekly thereafter and on the last day of observation.

NECROPSY
At the end of the observation period the animals were sacrificed by CO2-inhalation and were subjected to gross pathology. No histological examinations were performed. Examination of all animals that died before test ending was conducted as early as possible after death.

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 200 - <= 2 000 mg/kg bw

Based on:

test mat.

Remarks on result:

other: All animals of the 2000 mg/kg bw group (females) died within 2 d post-treatment. All animals treated with 200 mg/kg bw (males and females) survived.

Mortality:

200 mg/kg bw, males: No mortality
2000 mg/kg bw, females: All 3 females died within 2 d following treatment.

Clinical signs:

other: 200 mg/kg bw, females: No abnormalities 2000 mg/kg bw, females: All 3 females showed a poor general state and suffered from dyspnoea, apathy, ataxia, piloerection and shaking. In 2 cases, tremor and chromodacryorrhea also were noticed. In one case, twitch

Gross pathology:

Necropsy of animals that died: One female showed no abnormalies. The second and the third female showed congestive hyperemia and a moderate postmortal state; in one case, dark red discolouration of the urinary bladder also was noticed.
Necropsy of animals sacrificed at the end of the observation period: Gross pathological examination revealed no abnormalities.

Table:

Dose	Sex	Body weight range (g) for each test group
		Day 0	Day 7	Day 13
200 mg/kg bw	Males (n=3)	182 – 183 g	251 – 254 g	282 – 289 g
	Females (n=3)	173 – 176 g	197 – 201 g	208 – 217 g
2000 mg/kg bw	Females (n=3)	172 – 180 g	Not applicable due to mortality

Interpretation of results:

Category 4 based on GHS criteria

Remarks:

Migrated information

Conclusions:

Under the study conditions, the LD50 of the test substance in rats was >200 and =<2000 mg/kg bw.

Executive summary:

The acute toxicity of C12-14 alkylmorpholine was determined according to the EU Method B.1 and OECD Guideline 423 in compliance with GLP.

The guideline at the time applied 200 mg/kg rather than the current 300 mg/mg that is aligned with GHS classification. This is not considered to have an impact on the validity of the study.

A group of rats received an oral gavage dose of the test substance olive oil, at a dose level of 2000 (one test group comprising 3 females) and 200 mg/kg bw (one test group comprising 3 males and one test group comprising 3 females).

All animals of the 2000 mg/kg bw group died within 2 d after administration; thus, mortality at 2000 mg/kg bw was 100%. All animals treated with 200 mg/kg bw survived. Clinical symptoms of toxicity only were noticed and reported at 2000 mg/kg bw, almost consisting of a poor general state, apathy, dyspnoea, ataxia, piloerection and shaking. The findings almost were seen immediately after treatment and lasted up to death. Regarding body weight and body weight gain, these parameters were inconspicuous for both, the males and the females treated with 200 mg/kg bw. Necropsy of the sacrificed animals revealed no abnormalities. Gross pathological examination of those animals that died during the experiment revealed congestive hyperemia and a moderate postmortal state in two animals, accompanied in one case by dark red discolouration of the urinary bladder; the third animal showed no abnormalities.

Thus, the LD50 of the test substance in rats was >200 and =<2000 mg/kg bw.

According to OECD 423 Annex 2d, when all three animal died at 2000 mg/kg, and 0 -2 of the six animals at 300 mg/kg, the LD50 cut-off is set at 500 mg/kg bw. As 6/6 animals treated in this study at 200 mg/kg showed no signs of toxicity, no mortality is likely the case at 300 mg/kg.

Consqurently the LD50 cut-off is set at 500 mg/kg bw.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

500 mg/kg bw

Quality of whole database:

Reliable guideline-compliant acute oral toxicity studies available meeting the tonnage information requirements.

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:

From 27 March 2013 to 10 April 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study was conducted according to the OECD Guideline and EU Method in compliance with GLP.

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

GLP compliance:

yes (incl. QA statement)

Test type:

other: Limit test

Limit test:

yes

Species:

rat

Strain:

other: Wistar (RccHan:WIST)

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan Laboratories UK Ltd., Oxon, UK.
- Age at study initiation: 8-12 week
- Weight at study initiation: 200 g ±20%
- Housing: The animals were housed in suspended solid floor polypropylene cages furnished with woodflakes. The animals were housed individually during the 24 h exposure period and in groups of five, by sex, for the remainder of the study.
- Diet: 2014C Teklad Global Rodent diet supplied by Harlan Laboratories UK Ltd., Oxon, UK ( ad libitum)
- Water: Free access to mains drinking water
- Acclimation period: 5 d

ENVIRONMENTAL CONDITIONS
- Temperature 19 to 25 °C
- Humidity: 30 to 70%
- Air changes: 15/h
- Photoperiod: 12 h dark/ 12 h light

Type of coverage:

semiocclusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

On the day before treatment the back and flanks of each animal were clipped free of hair. The calculated volume of test substance, as received, using a graduated syringe. A piece of surgical gauze was placed over the treatment area and semi occluded with a piece of self adhesive bandage. The animals were caged individually for the 24 h exposure period. Shortly after dosing the dressings were examined to ensure that they were securely in place. After the 24-h contact period the bandage was carefully removed and the treated skin and surrounding hair wiped with cotton wool moistened with distilled water to remove any residual test substance. The animals were returned to group housing for the remainder of the study period.

Duration of exposure:

24 h

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

5/sex

Control animals:

not required

Details on study design:

The animals were observed for deaths or overt signs of toxicity ½, 1, 2 and 4 h after dosing and subsequently once daily for 14 d. After removal of the dressings and subsequently once daily for 14 d, the test sites were examined for evidence of primary irritation and scored according to the scale from Draize J H (1977). Individual body weights were recorded prior to application of the test substance on Day 0 and on Days 7 and 14. At the end of the study 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.

Sex:

male/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.

Other findings:

Signs of dermal irritation noted were well-defined erythema, very slight edema, crust formation, small superficial scattered scabs and scab lifting at edges to reveal bleeding or dried blood.

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The acute dermal median lethal dose (LD50) of the test substance in the Wistar strain rat was found to be greater than 2000 mg/kg bw.

Executive summary:

The study was performed to assess the acute dermal toxicity of C12-14 alkylmorpholine in the Wistar strain rat according to the OECD Guideline 402 and EU Method B3 in compliance with GLP.

A group of ten animals (five males and five females) was given a single, 24 h, semi-occluded dermal application of the undiluted test substance to intact skin at a dose level of 2000 mg/kg bw. Clinical signs and body weight development were monitored during the study. All animals were subjected to gross necropsy.

There were no deaths or signs of systemic toxicity. Signs of dermal irritation noted were well-defined erythema, very slight edema, crust formation, small superficial scattered scabs and scab lifting at edges to reveal bleeding or dried blood. No abnormalities were noted at necropsy.

Under the study conditions, the acute dermal median lethal dose (LD50) of the test substance in the Wistar strain rat was found to be greater than 2000 mg/kg bw.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Quality of whole database:

Reliable guideline-compliant acute oral toxicity studies available meeting the tonnage information requirements.

Additional information

Oral:

The acute toxicity of C12-14 alkylmorpholine was determined according to the EU Method B.1 and OECD Guideline 423 in compliance with GLP. A group of rats received an oral gavage dose of the test substance olive oil, at a dose level of 2000 (one test group comprising 3 females) and 200 mg/kg bw (one test group comprising 3 males and one test group comprising 3 females). All animals of the 2000 mg/kg bw group died within 2 d after administration; thus, mortality at 2000 mg/kg bw was 100%. All animals treated with 200 mg/kg bw survived. Clinical symptoms of toxicity only were noticed and reported at 2000 mg/kg bw, almost consisting of a poor general state, apathy, dyspnoea, ataxia, piloerection and shaking. The findings almost were seen immediately after treatment and lasted up to death. Regarding body weight and body weight gain, these parameters were inconspicuous for both, the males and the females treated with 200 mg/kg bw. Necropsy of the sacrificed animals revealed no abnormalities. Gross pathological examination of those animals that died during the experiment revealed congestive hyperemia and a moderate postmortal state in two animals, accompanied in one case by dark red discolouration of the urinary bladder; the third animal showed no abnormalities. Thus, the LD50 of the test substance in rats was >200 and =<2000 mg/kg bw.

The LD50 cut-off is set at 500 mg/kg bw based on the mortality of all three animals at first step at 2000 mg/kg.

Inhalation:

In accordance with Annex VIII Column 2 of REACH, the acute toxicity study by inhalation does not need to be conducted as the test substance has a low vapour pressure. Also, studies are available on the acute oral and dermal routes.

Dermal:

The study was performed to assess the acute dermal toxicity of C12-14 alkylmorpholine in the Wistar strain rat according to the OECD Guideline 402 and EU Method B3 in compliance with GLP. A group of ten animals (five males and five females) was given a single, 24 h, semi-occluded dermal application of the undiluted test substance to intact skin at a dose level of 2000 mg/kg bw. Clinical signs and body weight development were monitored during the study. All animals were subjected to gross necropsy. There were no deaths or signs of systemic toxicity. Signs of dermal irritation noted were well-defined erythema, very slight edema, crust formation, small superficial scattered scabs and scab lifting at edges to reveal bleeding or dried blood. No abnormalities were noted at necropsy. Under the study conditions, the acute dermal median lethal dose (LD50) of the test substance in the Wistar strain rat was found to be greater than 2000 mg/kg bw.

Justification for selection of acute toxicity – oral endpoint
Only one guideline-compliant study is available.

Justification for selection of acute toxicity – dermal endpoint
Only one guideline-compliant study is available.

Justification for classification or non-classification

Based on an acute oral LD50 cut-off of 500 mg/kg bw, C12-C14 alkylmorpholine qualifies for classification Acute Tox. 4 (H302 - Harmful if swallowed) according to Regulation (EC) 1272/2008. The available data indicates a low potential for acute dermal toxicity, and based on no observed toxicity at the limit dose of 2000 mg/kg bw, no GHS classification for acute toxicity by dermal route is required.

 

As C12-C14 alkylmorpholine has no low viscosity and low surface tension, no classification of aspiration hazard is required.