Objectives were to evaluate chlorine (Cl) concentrations and stability, oxidation-reduction potential (ORP), and pH of 2 commercially available chlorine-based disinfectant tablets (EfferCept (EF) and EfferCeptSG (SG = EF + extra emollients) at teat dip concentrations for dairy cows. Appropriate dilutions of products based on company recommendations were made and tested in 2 L plastic bottles. Two EfferCept tablets were added to 1893 mL (0.5 gal) of water. One EfferCeptSG tablet was added to 1893 mL (0.5 gal) of water. Following initial measurements, both solutions were put into non-siphoning teat dip cups to mimic on-farm conditions. On Day 33, a new set of EfferCept and EfferCeptSG solutions were made in the 2 l plastic bottles (validation) and all measurements made from plastic bottles. Products were tested for 90 and 60 d (set 2), respectively. ORP (mV) and pH were measured using a Combo pH/ORP and temperature meter (HI 98121, Hanna Instruments, Woonsocket, RI). Measurements were daily the first 2 d, every 2 d the first 2 wk, then every 3–4 d thereafter. Cl concentrations (ppm) were tested when pH and ORP were measured using Cl titration testing kit and compounds (AquaPhoenix, Hanover, PA). Initial pH values were 5.7–5.8 and similar among products. pH increased in the first 6 wk and was higher in EF compared with SG in set 1 (6.6 v. 6.2), then decreased to initial levels at 90 d SG (5.99 v. 5.65). Initial ORP values of the first solutions were 900 mV and increased to 980 mV the first week (EF and SG). ORP levels over the 90 d were 930–960 mV (EG) and 930–980 mV (SG). ORP levels of the 2nd set of EF and SG solutions were initially ~980 mV and increased to >1000 mV by 3 d (>1000 mV at 60 d). Overall ORP values show high oxidizing capacity and stability over time. Cl concentrations of EF and SG initially were 2200–2300 and 3000–3100 ppm, respectively. Cl concentrations remained higher in SG v. EF over the time period. Cl concentration decreased over the 90-d period but were still 1000 and 1200 ppm, well above 200 ppm disinfectant strength. Overall, the 2 chlorine disinfectant solutions showed very high ORP levels and decreased but still very effective chlorine concentrations over time.