NFPA 921-2014
17.4.2* Contamination During Collection. Most contamination
of physical evidence occurs during its collection. This is
especially true during the collection of liquid and solid accelerant
evidence. The liquid and solid accelerant may be absorbed
by the fire investigator’s gloves or may be transferred
onto the collection tools and instruments.


17.4.2.2 An alternative method to limit contamination during
collection is to utilize the evidence container itself as the
collection tool. For example, the lid of a metal can may be
used to scoop the physical evidence into the can, thereby
eliminating any cross-contamination from the fire investigator’s
hands, gloves, or tools.

17.4.2.3 Similarly, any collection tools or overhaul equipment
such as brooms, shovels, or squeegees utilized by the fire
investigator need to be cleaned thoroughly between the collection
of each item of liquid or solid accelerant evidence to
prevent similar cross-contamination. The fire investigator
should be careful, however, not to use waterless or other types
of cleaners that may contain volatile solvents.

Pat Kennedy, CFEI, CFPS, MIFireE
Fire and Explosion Analyst
Sarasota, Florida
[www.kennedy-fire.com]