4-ethylmorpholine

Endpoint summary

Description of key information

Acute toxicity: oral:
A K1 acute oral toxicity test with NEM was performed in male and female rats according to OECD Guideline 401. The LD50 was determined to be between 1500-2000 mg/kg bw (males). Therefore the substance was determined to be classified as acute oral category 4 toxicant.  
Acute toxicity: dermal:
A K1 acute dermal toxicity test with NEM was performed in male and female New Zealand White rabbits according to a guideline similar to OECD Guideline 402. The dermal LD50 for NEM was determined to be 1980 mg/kg.Therefore the substance was determined to be classified as acute dermal category 4 toxicant.  
Acute toxicity: inhalation:
No study was performed. An acute inhalation study is not performed as key studies with administration via two other routes was performed. 

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LD50

Value:

1 500 mg/kg bw

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

1 980 mg/kg bw

Additional information

Acute toxicity: oral

In a K1 acute oral toxicity study according to OECD guideline 401, rats (5 animals/sex/dose) were given 4 -ethylmorpholine, by oral gavage at 0, 500, 1000, 1500 or 2000 mg/kg bw. Death was observed in three males and two females at 2000 mg/kg bw, one male at 1500 mg/kg bw, and one female at 1000 mg/kg bw. Most of males and females at 1000 mg/kg bw and higher showed tonic and/or clonic convulsions and decreased locomotor activity. The body weight gain of both sexes was suppressed at 1500 mg/kg bw and higher. No abnormalities were found at necropsy in surviving animals, although edema and red area in the glandular stomach were found in the dead animals. 

Acute toxicity: dermal

A K1 study was performed with NEM, in male and female New Zealand White rabbits (5 animals per sex per dose) according to the OECD guideline 402. NEM was dosed via occlusive application during 24 hours at dose levels of 1000, 2000 and 3000 mg/kg, followed by a 14 -day observation period. At 1000 mg/kg bw dose, none of the animals died; at 2000 mg/kg 7 out of 10 animals died, and at 3000 mg/kg all animals died (10 out of 10). Clinical signs observed included decreased activity and necrosis of the skin at the application sites. Necropsy revealed irritation of the underlying muscle at the application site. No visible lesions were observed in any animal at terminal necropsy. The acute dermal LD50 in males and females was determined to be 1980 mg/kg. Therefore the substance is considered to be classified as acute dermal category 4 toxicant.

Acute toxicity: inhalation

No study is available with the test substance NEM. This is deemed not required as key studies via two other routes of administration are available.

Justification for selection of acute toxicity – oral endpoint
Three reliable studies available, all concluding category 4 classification.

Justification for selection of acute toxicity – dermal endpoint
Only one reliable study available

Justification for classification or non-classification

Based on the available data NEM is classified for acute oral toxicity category 4 and acute dermal category 4 according to the CLP criteria.

The route of inhalation was not evaluated (waiver).