Experimental results of non-thermal plasma (NTP) utilization for degradation of 4-chlorphenol (4CP) with screening of toxicity were presented in this study. Degradation of 4CP was tested in the presence of homogeneous catalysts: hydrogen peroxide (H2O2) and iron (II) (Fe2+). The rate of degradation through eight consecutive passes of the 4CP solution in the NTP reactor was considered. Products of degradation as organic acids (acetic, formic or oxalic acid) and chloride were quantified using ion chromatography (IC). Anemia salina was used for the toxicity screening assay in order to estimate the potential and consequences of NTP reactor application in water treatment. The measured concentration of 4CP and degradation products confirmed very efficient removal of these substances from the water during the NTP treatment with the addition of a catalyst. Concerning bioassay, a significant difference in toxicity was determined between initial solution of 4CP in comparison with the solution exposed to catalytic NTP treatment. (C) 2015 Elsevier B.V. All rights reserved.