Submitted to: Food Additives & Contaminants
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/28/2021
Publication Date: 11/3/2021
Citation: Smith, D.J., Scapanski, A.R., Herges, G.R. 2021. The fate of sodium chlorite in simulated gastric and intestinal fluids and residues of chlorate in broiler chickens after oral administration of sodium chlorite. Food Additives & Contaminants. 39(2):242-255. https://doi.org/10.1080/19440049.2021.1992513.
Interpretive Summary: Chickens may be exposed to trace level chlorine-containing oxidants in processed drinking water or possibly through the presence of additives in feed that are proposed to control pathogens. Although chlorine-based disinfection products have been used for decades, very little is known about their fate in food animals such as chickens. A study was conducted to describe the fate of a chlorine-based compound, chlorite, in simulated intestinal fluids and an additional study was conducted to determine the fate of chlorate, a by-product of chlorite, in meat chickens. In simulated intestinal fluid chlorite was converted very consistently to an unstable product, chlorine dioxide, and to two relatively stable compounds, chlorate and chloride ion (chloride is a major ingredient of table salt). When broilers were fed high levels of chlorite for 7 days, chlorate residues were either not present or were present at low levels in muscle, liver, and kidney. The study demonstrated that even after fairly high levels of chlorite exposure, chlorate residues were low in edible tissues of meat-type chickens.
Technical Abstract: The fate of sodium chlorite in simulated intestinal fluids, and residues of chlorate in broiler chickens fed 0, 10, 100, or 1000 mg/kg of dietary sodium chlorite for 7 days was determined. Chlorite was stable in water and simulated intestinal fluid during 6 h incubations, but was rapidly degraded to chlorine dioxide, sodium chloride, and sodium chlorate in simulated gastric fluid. Addition of starch, citrate, or soybean shifted the relative proportions of chloroxyanions formed; addition of ferrous chloride caused quantitative formation of sodium chloride in gastric and intestinal fluids. Residues of chlorate in broiler chickens ranged from 3.5 to 374 ng/g in gizzard, were not detectable to 126 ng/g in liver and were not detectable to 190 ng/g in muscle when slaughtered with no withdrawal period. Data are presented suggesting that reductive processes govern the fate of chlorite when present in closed biological systems.