Emergency Response Decision Support System (ERDSS)

 The Emergency Response Decision Support System (ERDSS, aka Chemical Companion) provides first responders with decision support for hazardous environments  including Hazmat, Fire, EOD, and more. 

This software tool, which operates on Windows and iOS, is provided free-of-charge to the military, law enforcement, and fire departments. 

ERDSS is the property of MEPSS.  Hazard3 is the authorized training partner of MEPSS. 

The current software version is 4.8.6 which was released in March 2022. 



Focus on setting-up and utilizing ERDSS in planning, training, and operations utilizing scenario-based exercises. This in-person, instructor-led course ranges from 6 - 8 hours in length depending upon lengths of discussions.


A series of 3 on-line Modules focusing on basic tools sets, advanced hazmat, and explosives/fire response.  Modules combine guidance on operations and scenarios to optimize use.  Modules are 2.5 - 3 hours in length to minimize on-line learning fatigue.


Use the Hazard3 online software or mobile app to learn about each ERDSS module and solve scenarios using a microlearning approach where each segment is limited to 5-7 minutes and one topic area.

ERDSS Overview

Basic Tool Sets

The basic tools sets within ERDSS include navigation, settings, reporting, known chemical search, unknown chemical search, chemical comparer. and unit converter.

Hazmat Calculators

ERDSS contains a series of calculators which use data from a variety of sources to calculate end points for you. Hazmat calculators include absorption, canister life, ventilation, volume, gas expansion, and pH neutralization.

Hazmat Decision Support Tools

Decision support tools are more complex than the hazmat calculators. These walk the operator through a series of questions or steps and help determine the next steps. Current hazmat decision support tools include decontamination, detector, detection environment, binary reactions, respiratory protection, lab identifier, and the Emergency Response Guidebook.

Explosives Tools

There are a series of tools to assist EOD response or tactical entry personnel or those supporting them. They range from simple BLEVE tables and bomb threat stand-off distances to blast tools and crater calculators.

Fire Tools

The current Firefighting tools within ERDSS include recommended fire suppression media for chemical fires (per individual chemical), expected combustion products for chemicals fires (per individual chemical), foam calculations, acetylene cylinder response guidelines, a calculator for thermal protective performance of turnout gear, and a decision support tool to minimize exposure to combustion byproducts.

ERDSS 2024 Application

Collect Hazard Information

Utilize the Known Chemical, Unknown Chemical, and the Emergency Response Guidebook Tools to gather hazard information.

ID Containers & Stresses

Utilize Container Recognition, Gas Cylinder Recognition, and Munitions Tools to ID containers and potential stresses.

Predict Behavior

Utilize the Binary Reactions, BLEVE, Bomb Threat Stand-Off Distances, Blast Tools, and Gas Expansion Tools to Predict Material Behaviors.

Plan the Response

Utilize Respiratory Protection, Canister Life, Skin Protection, Heat Stress, Decontamination, Detection Environment, Detector, and Lab Identifier to Plan the Response.

Implement the Response

Utilize the SCBA Air Management, Absorption, pH Neutralization, Destruction, and Ventilation Tools to Implement the Response.

EOD and Tactical Entry Response Tools

There are a series of tools designed to assist the EOD response or tactical entry personnel or those support them. The tools include Blast Calculator, BLEVE, Bomb Threat Stand-Off Distances, Crater Calculator, Destruction (HME), Lab Identifier, and Munitions Identification.

Firefighting Tools

The current Firefighting tools within ERDSS include Acetylene Cylinder Response, Fire Combustion, Fire Extinguishment, Firefighter Guidance, Foam, SCBA Air Management, and Thermal Protective Performance.