Objective: To determine hypochlorite concentration of solutions used for root canal irrigation and compare them with concentrations deemed as “ideal” in scientific literature ( 5.25% and 2.5% (w / v)) Methods Opinion survey among endodontic specialists to ascertain sodium hypochlorite commercial brand most used in root canals irrigation. Iodometric titration to determine solution concentrations. Clorox Regular Bleach ( Oakland, California) commercial brand most referred to in literature. Mean comparison  of different commercial brands and lots. Concentrations deemed ideal 5.25% and 2.5% (w / v). Results Commercial brands of sodium hypochlorite most used by 192 endodontic specialists were as follows: Cloralex ( 43.2%), Concentrated Clorox (30.2%), Viarzoni-t (16.7%), Great Value ( 1.0%), “Los Patitos” (0.5%) and other brands ( 8.3%). Concentration ( mean IC 95%) of Clorox Regular Bleach (6.34%, 6.32 – 6.36) Concentrated Clorox ( 5.43%, 5.42-5.45%), Cloralex  (5.40%, %.38-5.41), Great Value ( 6.21% 6.19-6.23) and “ Los Patitos” ( 5.82%, 5.80-5.83) exceeded a 5.25% sodium hypochlorite concentration. Viarzone-T ( 2.86%, 2.85-2.87)  rated above the 2.5% hypochlorite  concentration. There were statistically significant differences (p≤0.001) among averages of different commercial brands and lots, with respect to concentrations deemed as ideal (5.25% and 2.5% (w/ v ). Conclusion Hypochlorite concentrations in commonly used commercial products are not the concentration recommended in scientific literature ( 5.25% w/v and 2.5 % w/v). This can cause tissue damage in cases when hypochlorite solutions are improperly used without field isolation