Chemical weapons are one of the most horrific and deadly weapons used against humanity. They are essentially toxic substances that are used to harm, injure or kill individuals in warfare. While they are predominantly referred to as 'chemical weapons', there are several synonyms that are commonly used as well. These include nerve agents, poisonous gases, biochemical agents, toxic chemicals, and lethal toxins. Although they all refer to the same type of weapon, the terminology used can depend on the specific chemical agent being utilized. The use of any of these weapons is illegal under international law, and their use is considered a violation of basic human rights.