Hemolymph of the animal's body and surrounds all cells. It contains hemocyanin, a copper-based protein that turns blue when oxygenated, instead of the iron-based hemoglobin in red blood cells found in vertebrates, thus giving hemolymph a blue-green color rather than the red color of vertebrate blood. When not oxygenated, hemolymph quickly loses its color and appears grey. The hemolymph of lower arthropods, including most insects, is not used for oxygen transport because these animals respirate through other means, such as tracheas, but it does contain nutrients such as proteins and sugars. Muscular movements by the animal during locomotion can facilitate hemolymph
Blood agent immediate cause of death is usually respiratory failure. Blood agents work at the cellular level by preventing the exchange of oxygen and carbon dioxide between the blood and the body's cells. This causes the cells to suffocate from lack of oxygen. Cyanide-based agents do so by interrupting the electron transport chain in the inner membranes of mitochondria. Arsine damages the red blood cells which deliver oxygen throughout the body. Chemical detection methods, in the form of kits or testing strips, exist for hydrogen cyanide. Ordinary clothing provides some protection, but proper protective clothing and masks are recommended. Mask filters containing