Carbaryl (Sevin) (1-Napthy1-N-methylcarbamate) 
Labeled carbaryl was administered intraperitoneally in polyethylene 
glycol to guinea pigs and rats. Within 24 hours, 85% of the administered 
count was recovered in the urine in both cases (806). 
When naphthyl labeled catbaryl was administered to the rat, clo, 
was not found. However, methyl and carbonyl labeled carbaryl gave rise 
after four days to residues amounting to 11 and 32% respectively, of the 
dose as clig,. N-methylcarbamic acid rose by hydrolysis of the ester 
bond and then decomposed to CO») and methylamine. The latter was oxidatively 
demethylated to CO» and formate. Excretion of naphthyl and carbonyl labels 
was essentially complete with 95% and 99% of the label, respectively, 
recovered. The methyl label was excreted to the extent of 88% and residues 
were detected in the intestinal tract, carcass and organs (630, 806). 
In the urine of rats in addition to l-naphthol (IV) (226), l-naphthyl 
methylcarbamate N-glucuronide (V), l-naphthyl methylimido-carbonate 
O-glucuronide (VI), 4-(methylcarbamoyloxy)-l-naphthyl glucuronide (VII), 
l-naphthyl glucuronide (IX), l-naphthyl sulfate (X), 4-(methylcarbamoyloxy)- 
l-naphthyl sulfate (VIII), three unidentified compounds (806, 808, 836) and 
a compound believed to be l-naphthyl N-hydroxymethylcarbamate (III) were 
observed (630). Similar results were observed with guinea pigs. 
In dogs administered naphthy1-c!4 and N-methy1-c!*, 35% and 112, 
respectively, of the labels were excreted in feces; 40 and 23%, respectively, 
in urine over a seven day period. None of the major metabolites observed 
in urine of rats was observed with dogs. The dog can conjugate napthol 
and appears to conjugate carbaryl directly. A hydrolytic pathway involving 
the N-methyl group was indicated (809). 
Rabbits, treated with carbaryl, excreted in the urine small amounts 
of about eleven metabolites, six of which were identified as compounds 
II, III, IV, XI, XII and XIII (857, 858). 
After administration of C!*-labeled carbaryl to lactating cows, 
radioactive residues were observed in whole milk and milk fat, tissues, 
urine and feces. In addition to l-naphthol in the urine, five compounds 
were observed in feces and milk: 5,6-dihydroxy-5,6~—dihydronaphthyl N-methyl 
carbamate; 1,5,6-Trihydroxy-5 ,6-dihydronaphthalene; 1l-naphthyl-N-hydroxy- 
methylcarbamate; 4-hydroxy-l-naphthyl N-methylcarbamate; and unchanged 
carbaryl (374, 1495, 1550). 
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