Fourth Generation Agents

Agent Identification


Agent Identification

Patients may demonstrate some combination of SLUDGE and DUMBBELS.

SLUDGE – Salivation, Lacrimation, Urination, Defecation, Gastrointestinal upset, Emesis

DUMBBELS – Defecation, Urination, Miosis/Muscle weakness, Bronchospasm/Bronchorrhea, Bradycardia, Emesis, Lacrimation, Salivation/Sweating

Note that:

  • The above are mostly muscarinic effects, with the exception of musculoskeletal effects, which are mediated by nicotinic receptors; there may be other nicotinic effects.

    Nicotinic effects include MTWHF:

    Monday Mydriasis

    Tuesday Tachycardia

    Wednesday Weakness

    THursday Hypertension

    Friday Fasciculations

  • Patients may have some but not all of these signs and symptoms. In some cases, miosis (pinpoint pupils) and bronchospasm (severe bronchoconstriction) may not be prominent or may even be absent.

Exposures to nerve agents, including FGAs, may be difficult to distinguish clinically from overdoses of opioids or other street drugs. Polysubstance mixtures and novel preparations of illicit drugs have become increasingly frequent in street drug intoxications. Some can present with unusual physiological profiles and signs and symptoms that could be confused with those of chemical warfare agents.


Agent Identification

  • FGA poisoning causes symptoms similar to those from other nerve agents. FGAs are at least as toxic as VX.
  • FGAs are low volatility nerve agents (highly persistent; pose a significant cross-contamination hazard; do not easily evaporate; unlikely to present vapor hazard) and are most likely to be encountered as a liquid. FGAs are more persistent than other nerve agents and are at least as toxic as VX. Early recognition may be extremely challenging due to the possibility of delayed onset of symptoms for up to 3 days post exposure.
  • The most likely route of exposure is skin contact, but FGAs can also be absorbed into the body by mucous membrane contact (eyes, nose, mouth), inhalation, or ingestion. FGAs may cause rapid or delayed onset of symptoms, depending on the specific agent, dose, and route of exposure.
  • Patients may demonstrate some combination of the following symptoms:
    • SLUDGE – Salivation (drooling), Lacrimation (tearing of the eyes), Urination, Defecation, Gastrointestinal upset, Emesis (vomiting)
    • DUMBBELS – Defecation, Urination, Miosis (pinpoint pupils)/Muscle weakness, Bronchospasm/Bronchorrhea (excessive bronchial secretions), Bradycardia (decreased heart rate), Emesis, Lacrimation, Salivation/Sweating
  • Patient symptoms may be the only initial FGA indication. Detecting FGAs is more challenging than detecting other chemical agents and hazardous materials response teams have a limited fielded capability within hazardous materials response teams to detect, characterize, and identify FGAs. Failure to detect does not mean that FGAs are not present. U.S. government specialized assets may be the only way to determine if FGAs are present.


  • FGAs are chemical warfare agents (CWAs) that are unique organophosphorus compounds. They are more persistent than other nerve agents and are at least as toxic as VX.
  • If you suspect a potential nerve agent incident, implement protocols for a hazardous materials response and ensure the local FBI Weapons of Mass Destruction (WMD) Coordinator is notified immediately. The FBI will investigate the threat or presence of any nerve agent, including FGAs, as a violation of federal law.
  • The National Guard WMD-Civil Support Teams (WMD-CSTs) possess unique training and may perform field identification with specialized U.S. government fielded equipment when assisting local and state responders. Your state Emergency Operations Center can contact the WMD-CSTs if you suspect a nerve agent release.
Find more information on this substance at: PubChem, PubMed