
EA-2192 is an extremely toxic degradation product of the VX nerve agent. It is a white solid that is very soluble and stable in water.

EA-3148 is a "V-series" nerve agent related to the better-known compounds VX and VR. It was studied by both the US and Soviet chemical weapons programmes during the Cold War, and is notable as the only V-series organophosphate nerve agent specifically identified in public domain sources as having a higher absolute potency as an acetylcholinesterase inhibitor than VX. However, both the US and Soviet investigations of the compound concluded that despite its high potency, the physicochemical properties of the substance made it unsuitable for weaponisation, and further research was not conducted. The chemical structure of EA-3148 falls within the scope of compounds designated "Toxic chemicals" under Schedule 1 of the Chemical Weapons Convention and so it is illegal throughout the world under international law and may only be used for certain types of scientific and medical research.

EPN is an insecticide of the phosphonothioate class. It is used against pests such as European corn borer, rice stem borer, bollworm, tobacco budworm, and boll weevil.

O-Ethyl methylphosphonothioic acid (EMPTA) is an organophosphate compound. A dual-use chemical, it has constructive uses in the synthesis of pesticides and pharmaceuticals, and it is also a precursor in the synthesis of nerve agents such as Agent VM and Agent VX. The detection of EMPTA is cited as a major influence in the United States' 1998 decision to destroy the Al-Shifa pharmaceutical factory in Sudan.

GD-42 (methylsulfomethylate) is an irreversible acetylcholinesterase inhibitor. It has a positively charged sulfonium group.

VE is a "V-series" nerve agent closely related to the better-known VX nerve agent.

VM (Edemo) is a "V-series" nerve agent closely related to the better-known VX nerve agent.

VR is a "V-series" unitary nerve agent closely related to the better-known VX nerve agent. It became a prototype for the series of Novichok agents. According to chemical weapons expert Jonathan Tucker, the first binary formulation developed under the Soviet Foliant program was used to make Substance 33, differing from VX only in the alkyl substituents on its nitrogen and oxygen atoms. "This weapon was given the code name Novichok."

VX is an extremely toxic synthetic chemical compound in the organophosphorus class, specifically, a thiophosphonate. In the class of nerve agents, it was developed for military use in chemical warfare after translation of earlier discoveries of organophosphate toxicity in pesticide research. In recent years, VX was found to be the agent used in the assassination of Kim Jong-nam. In its pure form, VX is an oily, relatively non-volatile, liquid that is amber-like in color. Because of its low volatility, VX persists in environments where it is dispersed.