Morpholine carcinogenicity

Rats given lOg/kg in the diet, plus 0.2% sodium nitrite in the drinking water, had a significantly increased incidence of liver tumors compared with controls. The carcinogenic response is attributed to the in vitro production of N-nitrosomorpholine. In another study morpholine alone produced a low number of tumors of the liver, lung, and brain, and it was suggested that an unknown nitrate source reacted with the morpholine to form the carcinogenic iV-nitrosomorpholine. ... 

Morpholine has also been tested for carcinogenicity by inhalation exposure in rats. Exposure to 10, 50, or 150 ppm 6 hours/day, 5 days/week, for up to 104 weeks was associated with dose-related increases in inflammation of the cornea, inflammation and squamous metaplasia of the turbinate epithelium, and necrosis of the turbinate bones in the nasal cavity, but no significant increase in the incidence of tumors. ... 

The lARC has determined that there is inadequate evidence for the carcinogenicity of morpholine in experimental animals and that morpholine is not classifiable as to its carcinogenicity to humans. ... 

Shank RC, Newheme PM Dose-response study of the carcinogenicity of dietary sodium nitrite and morpholine in rats and hamsters. Food Cosmet Toxicol 14 1-8, 1976... 

Morpholine was tested for carcinogenicity by oral administration in two strains of mice, one strain of rats and one strain of hamsters. The studies in one of the strains of mice and in hamsters were considered inadequate for evaluation. In the other strain of mice, no significant increase in the incidence of tumours was seen in treated animals. In the study in rats, a few tumours of the liver and lung occurred in treated animals. Morpholine was also tested by inhalation exposure in rats it did not increase the incidence of tumours over that found in controls (lARC, 1989). 

No epidemiological data relevant to the carcinogenicity of morpholine were available. 

There is inadequate evidence in experimental animals for the carcinogenicity of morpholine. 

Dibenz[b, e]azepine-6,11 -diones enf-Morphinan nomenclature, 1, 29 Morphinan, 1,2,3,4-tetrahydro-nomenclature, 1, 29 14-a-Morphinan, JV-methyl-synthesis, 1, 480 Morphinans nomenclature, 1, 29 as pharmaceuticals, 1, 148 synthesis, 2, 377 Morphine, 2, 512 as analgesic, 1, 167 as metabolite of normorphine, X, 235 as pharmaceutical, 1, 146, 147, 148 synthesis, 1, 480 Morphine alkaloids structure, 4, 534 Morphin-7-en nomenclature, 1, 29 Morphinone, dihydro-as pharmaceutical, 1, 147 Morpholine — see also 1,4-Oxazine, tetrahydro-carcinogenicity, 1, 229 corrosion inhibitor, 1, 409 metabolism, 1, 226 nomenclature, 3, 996 structure, 2, 5 synthesis, 2, 89 Morpholine, 4-acryIoyl-polymers, 1, 291 Morpholine, alkenyl-polymers, 1, 291... 

Morpholine is a colorless hygroscopic liquid, with a characteristic odor It decomposes on heating and produces nitrous oxides. It is a base that reacts violently with acids, and it is corrosive to aluminum, zinc and copper. Morpholine reacts with oxidants and nitrites. In addition, the carcinogenic N-nitrosomorpholine can be formed from nitrosation of morpholine248. 

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