CFI Accelerant Detection & Fire Debris Analysis

Question 1

Which analytical method is considered the gold standard for identifying ignitable liquid residues in fire debris laboratory samples?

Accepted Answer

Gas chromatography-mass spectrometry (GC-MS)

Answer

GC-MS is the accepted gold standard because it separates compounds by boiling point and identifies them by molecular weight, providing a definitive chemical fingerprint.

Question 2

What does an alert from an accelerant detection canine (ADC) at a fire scene indicate to the investigator?

Accepted Answer

The potential presence of ignitable liquid residues requiring sample collection

Answer

A canine alert indicates the potential presence of ignitable liquid residues and should prompt sample collection, but does not by itself confirm arson.

Question 3

Which collection method is most widely used for extracting ignitable liquid residues from fire debris samples in the laboratory?

Accepted Answer

Passive headspace concentration using activated charcoal strips

Answer

Passive headspace concentration with activated charcoal strips captures volatile ignitable liquid residues from the air space above the debris without disturbing the sample.

Question 4

According to ASTM E1618, into how many categories are ignitable liquids classified for fire debris analysis?

Accepted Answer

10

Answer

ASTM E1618 classifies ignitable liquids into 10 categories based on chemical composition and chromatographic profiles, including gasoline, petroleum distillates, and oxygenated solvents.

Question 5

What effect does firefighting water application typically have on ignitable liquid accelerant evidence?

Accepted Answer

It can dilute but may not eliminate ignitable liquid residues trapped in substrates

Answer

Water dilutes accelerant residues but heavier petroleum products bind to substrates and often survive water application, remaining detectable by laboratory analysis.

(CFI) Certified Fire Investigator Practice Test

(CFI) Certified Fire Investigator Practice Test

CFI Accelerant Detection & Fire Debris Analysis