Arson investigators face a bewildering range of ignitable chemicals, all with similar characteristics, making the task of distinguishing and identifying the fuels used to set fires difficult if not impossible.

The good news is identifying those fuels just got easier, thanks to a new arson standard released in March by the National Institute of Standards and Technology.

Standard Reference Material 2285 is NIST's first standard intended to aid arson investigations. The new SRM is a liquid containing 15 compounds from common accelerants in various certified concentrations, intended to be used to calibrate instruments that help arson analysts classify fire scene residues into six categories.

“The classification of ignitable liquid residues is primarily based on the carbon number of the various hydrocarbons, as well as the presence of various aromatic marker compounds,” said Michele Schantz of NIST's Analytical Chemistry Division.

The most common method of separating these compounds is gas chromatography, which is based on their volatility. If one injects a standard mixture like SRM 2285, which contains both aliphatic and aromatic compounds, one can identify similar components in the samples.

SRM 2285 originated from discussions with chemists working in law enforcement laboratories. The calibration of gas chromatographs for the identification of components in accelerants was one of the areas that the chemists expressed a need for a reference material.

SRM 2285 will be used to assess the retention times of these components under the conditions being used by the laboratory for analysis of possible arson residues.

SRM 2285 is currently available from the NIST Standard Reference Materials Office, 301-975-6776 or srminfo@nist.gov.