Three experiments were conducted to determine the effect of different chemicals on the preservation of crab waste at room temperature. In Exp. 1, .2 and .4% NaOCI and H₂O₂ were used and the waste was stored for 17 d. In Exp. 2, NaCI (10%), NaNO₂ (1%), NaOCI (.4%), NaN₃ (.065%), KN0₃ (.1%), Tert butyl hydroperoxide (TBHP) (50 ppm), and I₂ (25 ppm) were used. After mixing with the chemicals the waste was stored for 21 d. In Exp. 3, the waste was treated with NaCI (100/0), NaNO₂(10/0) and NaN₃(.065%) and the mixtures were kept for 20, 30 and 40 d. In the first experiment the waste treated with .4% NaOCI preserved better than for the other treatments, with lower (P < .05) NH₃ and trimethylamine (TMA). In Exp. 2, treatment with NaCI, NaNO₂ and NaN₃ did not produce any change in the physical characters of the crab waste. The TMA, indole and NH₃ were lower (P < .05) and no H₂S was detected in the waste treated with those chemicals. In Exp. 3, treatment with NaCI did not alter the physical characteristics of crab waste. The waste had lower (P < .05) NH3, TMA and indole on d 20, 30 and 40 than those treated with NaNO₂ and NaN₃. / Ph. D.