Volatile fatty acids are important elements in controlling the anaerobic digestion process. It has two important roles: decomposing organics and generating gasses, methane and carbon dioxide. When both decomposing and generating occur continuously and completely, oxygen demand decreases. Volatile fatty acids can be analyzed by titration, distillation, steam distillation, and chromatography. The acceptable level of volatile fatty acids in environmental waters is up to 50,000 ppm.