text: One of the key factors associated with the toxicity of CYN is its stability. Although the toxin has been found to degrade rapidly in an algal extract when exposed to sunlight, it is resistant to degradation by changes in pH and temperature, and shows no degradation in either the pure solid form or in pure water. As a result, in turbid and unmoving water the toxin can persist for long periods, and although boiling water will kill the cyanobacteria, it may not remove the toxin.