Bromophos (0-(4-Bromo-2 ,5-dichlorophenyl) 0,0-dimethy1lphosphorothioate) 
Labeled bromophos was administered orally ‘to rats. Absorption was 
good and elimination practically complete after 24 hours. There was no 
accumulation in examined organs. Some inorganic phosphate was incorpo- 
rated into the organism phosphate pool. The phenolic moiety of bromophos 
was excreted rapidly in urine and feces as the glucuronide or sulfate. 
Six metabolites were detected in the urine of rats: phosphate, dimethyl 
thionophosphate, monodesmethylbromophos, dichlorobromophenol, and two 
unidentified compounds. Neither bromophos, broméxon, nor monodesmethyl- 
bromoxon were found in the urine (1362). 
Bromophos was applied to stored wheat grains and the decomposition 
studied over a 10 week period. Although only traces of dimethyl 
phosphorothionate were found, indicating that desmethyl bromophos is the 
main phosphatase degradation product, large amounts of monomethy1l- 
phosphorothionate were detected. Bromoxon was found only during the first 
20 days in amounts up to 10% of the original bromophos, level (1246). 
Degradation of bromophos proceeded rapidly for about ./ days. 
Degradation then stopped for about 3 weeks because of accumulation of 
desmethyl bromophos, which inhibits phosphatase hydrolysis of bromophos. 
After the desmethyl bromophos had been degraded, bromophos degradation 
resumed. The level of free dichlorobromophenol did not increase signifi- 
cantly until degradation of desmethyl bromophos was well under way, 
indicating formation of the phenol from the desmethyl or oxon compounds. 
When bromophos was applied to autoclaved grains, only dimethyl 
phosphorothionate and dichlorophenol were produced (1246). 
Oxidation: of bromophos to bromoxon occurred in the seed coats and 
germs of wheat grains. Hydrolytic activity was found in the germ and 
endosperm (1247). 
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