Cyanide destruction should not be done in the presence of which substance?

Cyanide destruction should not be attempted in the presence of heavy metals due to the potential for deadly reactions that can occur. Heavy metals, such as lead, mercury, or cadmium, can form stable complexes with cyanide compounds, making the cyanide more difficult to break down and potentially leading to the release of toxic compounds.

Furthermore, some heavy metals can catalyze reactions that produce harmful byproducts or can inhibit the effectiveness of the reagents typically used to destroy cyanide. The chemical interactions involved can also present significant safety risks, both to personnel handling the substances and to the environment.

On the other hand, the presence of bases, acids, or oxides does not pose the same level of risk for dangerous interactions during the cyanide destruction process. Bases can neutralize acids that may be produced, while acids can be safely managed in controlled settings, and oxides generally do not interact in a way that will complicate the cyanide destruction process.