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Training Guidelines for the Fire Debris Analyst 

Lesson Plan (Module) 4 

Date: November 2006 Instructor: Qualified Instructor 

Subject: Effects of Fire Total Time: 12 hours 

Learning Objectives 

3⁄4 Understand the effects of heat and fire including melting, evaporation, distillation, 

pyrolysis and combustion. 

3⁄4 Understand and predict the effects of evaporation and combustion on ignitable 

liquids. 

3⁄4 Describe the process of pyrolysis as it applies to solid fuels. 

3⁄4 List pyrolysis products commonly encountered in fire debris containing ordinary 

combustibles. 

3⁄4 Understand the effects and possible contributions of chemicals used in fire 

suppression 

Suggested Reading 

1. Kirk’s Fire Investigation, 5th Edition, John DeHaan, Ed. Brady/Prentice Hall, 

Upper Saddle River, NJ, 2002, ISBN:0130604585, Chapters 2-5. 

2. The Chemical History of a Candle, M. Faraday. Dover Publications, 2002 

(Reprint) ISBN:04864254. 

3. NFPA 921, Guide for Fire and Explosion Investigation. NFPA, Quincy, MA. 

2004, Chapters 5 and 6. 

4. “Baseline Characteristics of Residential Structures Which Have Burned to 

Completion: The Oakland Experience.” Lentini, JJ, Smith, DM, and 

Henderson, RW Fire Technology, 28, August 1992. 

5. “Basic concepts of pyrolysis for fire debris analysts.” Eric Stauffer. Science 

and Justice, 43(1), pp29-40, 2003. 

6. Fire Suppression Practices and Procedures. E. Mahoney, Brady Publishing, 

Englewood Cliffs, NJ, 1992. 

7. “The effects of surfactants and microbes on the identification of ignitable 

liquids in fire debris analysis.” D. Byron, Fire and Arson Investigator, 53(1), 

p.50, 2002. 

8. “The possible contamination of fire scenes by the use of positive pressure 

ventilation fans.” T. Lang and BM Dixon. Canadian Society of Forensic 

Sciences Journal, 33(2), pp. 55-60, 2000. 

9. Ignition Handbook, Babrauskas, V., Fire Science Publishers, Issaquah, WA, 

2003. (See for specific reference data.) 
 

 

 

10. “The effect of compressed air foam on the detection of hydrocarbon fuels in 

fire debris samples”, Coulson, SA, et al., Science and Justice 40(4), pp. 257-

260, 2000. 

Introduction 

This lesson will cover the effects of heat and fire on various fuels and how they relate to 

the interpretation of laboratory results. The effects of fire suppression techniques on fire 

debris evidence will also be discussed. 

Outline 

1. Effects of heat and fire 

a. melting 

b. evaporation 

c. distillation 

d. pyrolysis 

e. combustion 

2. Effects of evaporation and combustion of ignitable liquids 

a. single component liquids 

b. multi-component liquids 

c. immiscible liquids 

3. Pyrolysis processes of fuels 

a. physical conditions - surface temperatures, melting (thermoplastic), 

 thermal degradation (thermosetting, elastomers) 

b. petroleum products – waxes, asphalts, polymers 

c. non-petroleum products – wood, natural fibers, biological materials 

d. pyrolysis of liquids 

4. Thermal degradation products from ordinary combustibles 

a. physical processes - distillation (terpenes, water) 

b. chemical mechanisms and products - (styrene, alkenes, aromatics, fatty 

 acids, alcohols) 

5. Fire Suppression 

a. foams 

b. positive pressure ventilation 

c. dry chemicals 

d. remediation agents 

e. equipment 

Teaching Aids 
 

 

 Handout 

 PowerPoint presentation 

 Practical exercises 

Summary 

Laboratory analysis of fire debris can reveal a wide range of volatile products and less 

volatile residues produced by the effects of heat, fire, and suppression methods on 

materials present in the fire scene. These effects can range from simple melting, 

evaporation, and distillation to pyrolysis (thermal degradation) and combustion. The fire 

debris analyst must be familiar with the results of these processes on common household 

products as well as ignitable liquids. The analyst must be able to understand the basic 

physical and chemical processes, including pyrolysis, and interpret the effects of 

evaporation and combustion on solid and liquid fuels. The analyst must also understand 

how the fire and evidence recovery processes affect separation and characterization 

techniques. 

Test Questions: 

1. The primary route of fire control when foam is applied to a fire is by: 

a. cooling 

b. interruption of chemical process 

c. exclusion of air 

d. dilution 

2. The vapor pressure curve of a liquid can be used to determine its: 

a. freezing point 

b. boiling point 

c. flammability range 

d. a and b 

e. b and c 

3. The effects of combustion on component ratios in a multi-component liquid 

fuel can be distinguished from the effects of simple evaporation. True or 

False 

4. Thermosetting polymers undergo reversible melting without chemical 

degradation. True or False 

5. Pyrolysis is the thermally induced degradation of a material into simple 

molecules without interaction with oxygen. True or False 
 

 

6. Flaming combustion of nearly all solid fuels requires pyrolysis to occur first. 

True or False 

7. The first pyrolysis products generated by heating wood include water, 

terpenes and methanol. True or False