2-morpholinoethanol

Endpoint summary

Description of key information

Oral: The acute oral LD50 was determined to be 5500 mg/kg bw in rats.
Dermal: The acute dermal LD50 was determined to be 16000 mg/kg bw in rabbits.
Inhalation: No mortalilty was detected when mice were exposed to a saturated atmosphere of the test substance for 8 hours.

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Dose descriptor:

LD50

Value:

5 500 mg/kg bw

Acute toxicity: via dermal route

Endpoint conclusion

Dose descriptor:

LD50

Value:

16 000 mg/kg bw

Additional information

Oral:

In the key study, the test article 2 -morpholinoethanol was administered by gavage to five exposure groups (4000, 6300, 8000 and 10000 mg/kg bw, determined by a prescreen) of 10 Sprague Dawley rats (5/sex) weighing 180 to 360 g after fasting. Study duration was 14 days. Oral LD 50 (males and females) was determined to be 5500 mg/kg bw, by the method of Litchfield and Wilcoxon (1949). Mortality pattern was 4/10 @ 4000 mg/kg bw; 3/10 @ 5000 mg/kg bw; 8/10 @ 6300 mg/kg bw; 9/10 @ 8000 mg/kg bw; and 10/10 @ 10000 mg/kg bw . Necropsy findings (study deaths) were diffused red and fluid-filled stomachs, distended, discolored, and congested intestines. At terminal necropsy no visible lesions were observed (Papciak, 1990).

Both supporting studies are of limited reliability, but confirming the result of the key study, that the test substance is of very acute low toxicity:

- In an acute oral toxicity study, groups of US rats (5/sex) were given a single oral dose of 2-morpholinoethanol in water at doses of 200, 1600, 3200, 6400 µL/kg bw and observed for 7 days.

Oral LD50 ca. 6400 µL/kg bw equivalent to 6784 mg/kg bw (BASF, 1968).

- In an acute oral toxicity study, groups of 10 Sherman rats were given a single oral dose of 2-morpholinoethanol in ethanol.

Oral LD50 = 12060 mg/kg bw (Smyth, 1948).

Dermal:

Four exposure groups (6300, 8000, 10000 and 16000 mg/kg bw, determined by a prescreen) of 4 New Zealand White rabbits (5/sex), weighing 2 to 3 kg, received test article 2 -morpholonoethanol on shaved, intact skin of their backs (about 10 % of total body area), for 24 hours using non-occluding dressings. Study duration was 14 days. The dermal LD 50 (males and females) was determined to be > 16000 mg/kg bw. Mortality pattern was1/10 @ 6300 mg/kg bw; 0/10 @ 8000, 10000 and 16000 mg/kg bw. Necropsy findings (study death) determined that death was not compound related. At terminal necropsy no visible lesions were observed (Papciak, 1990).

Inhalation:

In an acute inhalation toxicity study, one group of rats (6/sex) was exposed for 8 h to a saturated atmosphere of 2-morpholinoethanol at 20°C. Animals then were observed for 7 days. No mortality occurred. Eye secretion was noted (BASF 1968).

Other routes:

In an acute toxicity study, groups of Kisslegg mice (5/sex) were given a single intraperitoneal dose of 2-morpholinoethanol in water at doses of 200, 1600, 2500 and 3200 µL/kg bw and observed for 7 days.

Intraperitoneal LD50 = 2650 mg/kg bw (BASF, 1968)

Justification for classification or non-classification

Based on the test results (oral LD50 = 5500 mg/kg bw, dermal LD50 = 16000 mg/kg bw, no mortality when exposed to a saturated atmosphere for 8 hours), 2 -morpholinoethanol has not to be classified with regard to acute toxicity according to Regulation (EC) No 1272/2008 (CLP, GHS).