Research on the use of peracetic acid as an environmentally safe alternative to sodium hypochlorite in multistage bleaching processes conducted bleaching tests on samples of cotton and linen. The tests showed that peracetic acid was most effective in a pH range of between 6 and 7. The optimal temperature range for bleaching was between 50 and 80 degrees centigrade. Dwell time for the two bleaching agents was comparable. The bleaching time was typically between 20 and 60 minutes depending on the temperature. The degree of brightness increased proportionally with the concentration of the bleaching agent. The tests bleached samples of 100 percent cotton fabric in rope form in a J-box with peracetic acid at a concentration of between 1.5 and 2.5 grams per liter at room temperature followed by an alkaline hydrogen peroxide treatment at 90 degrees centigrade, which yielded a brightness of greater than 90. The process for linen yarns involved scouring, alkaline hydrogen peroxide bleaching, and peracetic acid bleaching and yielded linen with a brightness of 78 (the raw linen had a brightness of 20). The peracetic acid damaged the fibers significantly less than the sodium hypochlorite. 8 refs.