the yellow color disappeared the following experiments were performed to determine the degree of degradation of the fabric based on the warp yarn which contains the dye grab break tests were determined using astm test method d 1682 five breaks for the warp yarn were made for each sample and averaged abrasion tests were determined according to astm method d 3885 stoll flex five samples were run and averaged the fabrics were standard levi style 501 garments the overall results are given in table 1 a standard ice wash procedure was used as the control the results for chlorine sodium hypochloride treatments are shown both in table 1 the treatment was done at normal c1 medium c2 and high c3 chlorine contents in order to obtain increasing levels of color removal ranging from a medium blue to white these treatments were matched to various ozone treatment times needed to achieve the same level of color removal for example c1 matched the ozone treatment for 1 hour while c2 matched the ozone treatment for 1 5 hours no ozone treatment matched the c3 totally white jeans which is included for completeness from the results it is observed that the ozone treated fabrics do not loose as much warp strength as the chlorine bleached fabrics it is the warp yarns which contain the indigo dye fabrics were treated with ozone for 0 5 to 2 0 hours the test results are given in table 1 and shown graphically in the attached bar graphs the fabric color become lighter with increasing time of ozone treatment the color dye level in the garments was monitored by a bausch and lomb color scan spectrophotometer an ice washed garment control was treated for 15 minutes in an ozone atmosphere sample.