Transcript CHEMICAL AGENTS - Chemical Agent Instructor
LCT
50
Formulation
LCT
50
Course Overview
1. Purpose 2. History 3. Philosophy: CATO vs. NTOA 4. Formula and Calculations 5. Practical Applications 6. Tactical Case Study
LCT
50
Purpose
1. Helps determine amount of chemical agent to use.
2. Estimates the time a suspect can remain in agent environment.
3. Provides a guideline for command staff and for potential criminal & civil litigation.
LCT
50
Defined
“Concentration (LC 50 ) multiplied by the time (T) of exposure that is lethal to 50% of exposed personnel.
”
(Usually expressed in minutes of exposure.)
LCT
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History
Formula developed from an Edgewood Arsenal study of CS exposure in 1967.
• Edgewood Arsenal is a chemical research facility (now known as US Army Medical Research Institute of Chemical Defense).
Conducted for the U.S Army who was replacing CN with CS for outside riot control. Not inside or for civil law enforcement!
Conducted in a static, sealed container.
Formula values determined concentration levels were lethal for 50% of population.
LCT
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Philosophy
National Tactical Officer’s Association California Association of Tactical Officers
LCT
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Philosophy
NTOA
Based on use of force “reasonableness” standard (Graham vs. Connor). Don’t need a formula to use other forms of force.
LCT 50 based on faulted research: No consideration given to biological/metabolic differences. Conducted in static sealed containers. CS was intended for outside riot control, not inside sealed environments.
LCT
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Philosophy
CATO
Formula and incident based. Uses Edgewood Arsenal Study as a “baseline.” Bases concentration variable (i.e. .004, .008, etc) on tactical situation. Estimates the time a suspect can remain in the agent.
LCT
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Formula
3-Step Process 1.
Compute room(s) volume ( L x W x H ) Equals = CUBIC FEET 2.
CUBIC FEET X CONCENTRATION VARIABLE Equals = GRAMS of AGENT NEEDED 3.
CUBIC FEET GRAMS of AGENT NEEDED X .71 (CS Constant) = LCT 50 in minutes
LCT
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Formula (CV)
Concentration Variable
• • • • •
Equates to grams of agent per 1000 cubic feet. US Department of Energy research determined 4 grams per 1000 cubic feet ( or .004) as the smallest concentration to yield agent symptoms. A higher variable will give a higher concentration of agent, but a shorter LCT 50 .
A lower variable will yield a lower agent concentration, but a higher LCT 50 . For Example:
– – –
.012 = 60 minutes .008 = 89 minutes .004 = 178 minutes
•
Concentration variables should be based on SWAT chemical agent deployment philosophy.
LCT
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Formula (Constant)
Constant (.71)
• • •
Based on US Army research. Research that was based on how much agent would kill a human.
Will never change.
LCT
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Worksheet (part 1)
1. _______ x _______ x _______ = ___________
Length Width Height Cubic Feet
2. _________ x CV = _________________
Cubic Feet Total Grams Needed
3. __________ ________ x .71 = _____________
Cubic Feet Total # of LCT 50 (minutes) Grams
LCT
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Worksheet (part 2)
Proposed LCT 50 - Time 1. _______ x _______ x _______ = ___________
Length Width Height Cubic Feet
2. _________ x .71 _______________ = ________________
Cubic Feet Proposed LCT 50 Grams of Agent
LCT
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Worksheet (part 2)
Amount of Agent Used 1. _______ x _______ x _______ = ___________
Length Width Height Cubic Feet
2. __________ ______________ x .71 = _______________
Cubic Feet Grams of Agent LCT 50 (minutes)
LCT
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Munitions Needed
Now that we know the “total # of grams of agent” and our LCT 50 , how many munitions will we need? ANSWER: Divide total # of grams of agent by the amount of agent in your munition of choice. This is where a munitions data card comes in handy!