Fourth Generation Agents

Protective Equip. / Clothing

Boots

Rescuer Protection

  • FGAs are highly potent and contact with small amounts (e.g., even drops) can cause serious health effects. Responders should take measures to avoid any unprotected contact with the agent, suspected contaminated surfaces, or potentially contaminated people. Because of the properties of FGAs, responders should avoid any potential for cross-contamination.
  • If you suspect the presence of an FGA based on your scene assessment, secure the area, implement protocols for a hazardous materials response, and notify hospital emergency departments.
  • Select PPE based on your department or agency’s standard operating procedures, your job task, and potential for exposure to hazards. See the FGA Reference Guide for additional information.
  • It is possible responders may perform lifesaving actions before recognizing that a hazard, including an FGA, is present. Responders performing lifesaving actions should wear appropriate Personal Protective Equipment (PPE) and minimize the number of personnel entering the area. Wear eye protection and double layer nitrile gloves. Change your gloves as needed using proper donning and doffing procedures.
  • Avoid any unprotected contact with agent, suspected contaminated surfaces, or potentially contaminated people.
  • Do not touch your eyes, mouth, nose or skin after touching any potentially contaminated surface. Avoid any potential for cross-contamination.
  • Report any potential exposure and be medically evaluated immediately per your department or agency’s procedures if you are involved in an incident that includes the presence of an FGA. Symptoms may occur up to 3 days post exposure.
Boots

Protective Equipment

A hazardous materials response team, and other emergency responders as appropriate, should consider the following when responding to a known or suspected FGA incident:
  • The minimum level of protection should be positive pressure self-contained breathing apparatus (PP/SCBA) and other appropriate PPE until a hazard and risk assessment has been conducted.
  • The PPE requirements for FGAs are the same as those for VX. The following levels of protection are recommended for incidents involving FGAs:
    • Ensembles certified to National Fire Protection Association (NFPA) 1991 Vapor Protective Ensemble (Occupational Safety and Health Administration (OSHA)/ Environmental Protection Agency (EPA) Level A)
    • Ensembles certified to NFPA 1994 Class 1 Hazardous Material and Terrorism Vapor Protective Ensemble (OSHA/EPA Level A)
    • Ensembles certified to NFPA 1994 Class 2 Hazardous Material and Terrorism Vapor Protective Ensemble (OSHA/EPA Level B)
    • If chemical detection monitoring and hazard identification results confirm the contaminant identity and concentration in air, then ensembles certified to NFPA 1994 Class 3 Hazardous Material and Terrorism Protective Ensemble (OSHA/EPA Level C) can be utilized, provided the airborne concentrations are at a level appropriate for the use of a National Institute for Occupational Safety and Health (NIOSH)-approved Chemical, Biological, Radiological, and Nuclear (CBRN) Air Purifying Respirator (APR) or Powered APR (PAPR).
  • When responses involve releases of chemical substances, use a hazard and risk assessment and adhere to Federal OSHA, OSHA-approved State Plan, or EPA Hazardous Waste Operations and Emergency Response (HAZWOPER) standard (depending on which applies).
  • Chemical resistant boots and chemical resistant butyl rubber gloves that are at least 14 mil thickness are recommended when dermal exposure is possible. NFPA 1991- and NFPA 1994-compliant ensembles include gloves and boots that provide acceptable levels of protective performance.
  • Strict adherence to appropriate PPE donning and doffing procedures is critical. Cross-contamination is a significant concern to emergency responder health and safety in incidents involving FGAs.
  • Downgrading PPE levels can be considered only when the identity and concentration of the contaminant is complete and a risk assessment of dermal and inhalational exposure has been performed. Responders should follow their standard operating procedures and guidance of personnel who have conducted a thorough hazard and risk assessment such as hazardous materials technicians, WMD-CSTs, Certified Industrial Hygienists, or other allied subject matter experts.

PPE Protection Levels

Level A

Level A provides the greatest level of skin (fully encapsulating suit), respiratory (SCBA), and eye protection when the contaminant identity or concentration is unknown. Select Level A when the concentration is unknown and when there is a potential of ocular or dermal exposure.

There are two NFPA standards that contain the design, performance and testing methods that provide assurance that certified ensembles that provide adequate vapor protection are consistent with the protective characteristics of Level A garments: NFPA 1991 Standard on Vapor-Protective Ensembles for Hazardous Materials Emergencies and CBRN Terrorism Incidents and NFPA 1994 Standard on Protective Ensembles for First Responders to Hazardous Materials Emergencies and CBRN Terrorism Incidents (Class 1 ensemble). The SCBA should be certified to NFPA 1981 Standard on Open-Circuit Self-Contained Breathing Apparatus (SCBA) for Emergency Services. This SCBA standard contains a mandatory requirement that the unit has a NIOSH CBRN SCBA approval.

Level B

Level B provides the highest level of respiratory protection (SCBA) when a lesser level of skin protection is required. Select Level B when the FGA concentration is unknown and dermal exposure is less of a risk. Level B differs from Level A in that the chemical protective garment design can be either totally encapsulating or a non-encapsulating, splash-protective, chemical-resistant outer suit that provides protection against most liquids but may not be airtight.

The SCBA should be certified to NFPA 1981 Standard on Open-Circuit Self-Contained Breathing Apparatus (SCBA) for Emergency Services. This SCBA standard contains a mandatory requirement that the unit has a NIOSH CBRN SCBA approval. There are two NFPA ensembles that function in similar manner to Level B garments. NFPA 1994 Class 2 does provide an appropriate level of vapor protection.[1] Only the NFPA 1994 Class 2 garments have been tested and certified against CWA agent hazards.

Level C

Select Level C when the contaminant identity and concentration are known and the respiratory protection criteria factors for the use of APR or PAPR (e.g., < Immediately Dangerous to Life and Health, < maximum use concentrations, and warning properties) are met. Level C may be appropriate when decontaminating personnel or equipment.

NFPA 1994 Class 3 provides a limited level of vapor protection and can be used with a NIOSH approved CBRN APR or PAPR.


[1] NFPA 1992 Standard on Liquid Splash-Protective Ensembles and Clothing for Hazardous Materials Emergencies may not provide an appropriate level of vapor protection.

Boots

Rescuer Protection

FGAs present a significant risk of secondary exposure if responders come into contact with agent on patients, their clothing, personal effects, or contaminated surfaces. Just as importantly, patient decontamination is a medical intervention because FGAs can deposit on and in skin and absorption can continue until the patient is fully decontaminated. As long as FGAs are on or in the skin, they pose a medical risk to the exposed individual even if that individual does not yet look or feel sick.

Personal Protective Equipment

Painstaking attention to protective zones, decontamination protocols, and donning and doffing of personal protective equipment (PPE) is essential to prevent secondary exposure and spread of agent in the environment.

Employers must comply with Occupational Safety and Health Administration (OSHA) standards on PPE (29 CFR 1910.132): https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.132, Respiratory Protection (29 CFR 1910.134): https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.134, Hazardous Waste Operations and Emergency Response (29 CFR 1910.120): https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.120, and other requirements, including state regulations, whenever such requirements apply.

The Occupational Safety and Health Administration (OSHA) provides general guidance for EMS and hospitals that receive and treat victims of hazardous substance releases in the following documents:

Key Safe Work Practices include:

  • Ensure that personnel take sufficient time to don and doff PPE carefully and correctly without distraction.
  • Avoid using hand sanitizer or other products containing alcohol, as they may enhance absorption of agent and spread it over a larger area of skin. Do not use bleach to decontaminate skin.
  • Establish an exposure management plan that addresses decontamination and monitoring of personnel in the case of any exposure. Training and follow-up should be part of the personnel training.
  • At the hospital, minimize the number of personnel entering the patient’s room and take precautions to avoid cross-contamination.

Managing Patients Before they are Decontaminated:

Responders and hospital personnel providing or assisting with patient care before and during decontamination should select PPE based on the employer’s standard operating procedures, the job task, and the potential for exposure to hazards. The PPE section of the FGA Reference Guide (https://chemm.nlm.nih.gov/nerveagents/FGAReferenceGuide.htm) outlines recommendations for PPE selection.

Managing Patients After they are Decontaminated:

Limited data are available on the risk of post-decontamination handling of patients who have been exposed to FGAs, but there are concerns that FGAs can persist in body fluids, posing a potential hazard to personnel. Due to a depot effect in the skin, repeated decontamination over a course of days may be beneficial. For these reasons, the following specific PPE recommendations provide a precautionary approach to worker protection measures. This guidance will be updated as more evidence becomes available.

Because of the concerns that FGAs can persist in body fluids, the following guidance provides a precautionary approach to protect EMS and hospital personnel from exposure when treating a patient, following decontamination, who was suspected or confirmed to have been exposed to FGAs:

  • Two pairs of single-use (disposable) nitrile examination gloves with extended cuffs. Outer gloves should be a minimum of 7 mil thickness at the palm and inner gloves should be a minimum of 5 mil thickness at the palm. Gloves should be changed every 15 minutes or when they become soiled.

    or

    One pair of single-use (disposable) 15 mil nitrile or 14 mil butyl rubber gloves. Gloves should be changed every 2 hours or when soiled.

  • Single-use (disposable) surgical or isolation gown; a single-use (disposable) apron that covers the torso to the level of the mid-calf; and single-use (disposable) sleeves. Gown should pass ANSI/AAMI PB70 Level 3 or 4 requirements and apron and sleeves should be constructed of fabric that provides protection against VX (such as TyChem® F, Microchem® 4000, or Zytron® 300 fabric).

    or

    Single-use (disposable) coverall. Coverall should be constructed of fabric and seams that provides protection against VX (such as TyChem® F, Microchem® 4000, Zytron® 300 fabric with taped seams).

  • Single-use (disposable) full-face shield.

When it is not possible to implement the precautionary approach above, EMS and hospital personnel at a minimum should wear appropriate PPE and take blood and body fluid precautions, including:

  • Two pairs of nitrile medical exam gloves,
  • Gown,
  • Eye or face protection, and
  • Take all measures to prevent direct contact with secretions and body fluids as they may contain chemical agent.

It should be recognized that this level of PPE may not provide sufficient exposure reduction. Therefore, gloves should be changed every 15 minutes, or when they become soiled, or between patients if possible, whichever occurs soonest, and gowns should be changed when they become soiled. Limited real world experience in the U.K. demonstrated this approach was adequate to protect workers given the specifics associated with the March and June 2018 incidents.

Responders and hospital personnel should report any potential exposure and be medically evaluated immediately per your department or agency’s procedures. Symptoms may occur up to 3 days post exposure.

In order to determine when it is appropriate to downgrade PPE, employers are encouraged to perform a risk and hazard assessment, taking into account patient status. See the FGA Reference Guide (https://chemm.nlm.nih.gov/nerveagents/FGAReferenceGuide.htm) for information necessary to conduct the risk and hazard assessment.

General recommendations for handling PPE include:

  • PPE should be inspected prior to donning for any defects and those that are punctured, torn, or otherwise damaged should be discarded and replaced.
  • PPE should be taken off in a dedicated area when exiting the patient room to prevent cross-contamination.

PPE, linens, and other waste that have come into contact with the patient should be segregated from other waste and disposed of properly. Consult with experts for disposal recommendations.

Protect Yourself

To Protect Yourself from Exposure

  • FGAs are highly potent; contacting small amounts can cause serious health effects.
  • Avoid any unprotected contact with agent, suspected contaminated surfaces, or potentially contaminated people.
  • Avoid any potential for cross-contamination. Painstaking attention to protective zones, decontamination protocols, and donning and doffing of personal protective equipment (PPE) is essential to prevent secondary exposure and spread of agent in the environment.
  • Report any potential exposure per your employer’s procedures. Symptoms may occur up to 3 days post exposure.
  • Handle blood and body fluids with extra caution, as though they are contaminated with FGA. Limited data are available on the risk, but there are concerns that FGAs can persist in body fluids, posing a potential hazard to personnel.
  • PPE should be selected based on the employer’s standard operating procedures, the job task, and the potential for exposure to hazards. For specific PPE recommendations, see below.
Find more information on this substance at: Hazardous Substances Data Bank , TOXNET , PubMed