False positive with Class A foam

[SJNorman]

I am researching the effect of fire extinguisher usage on accelerant detecting including masking and/or false positives. I am told that Class A foam is known to be a false positive in some cases. Can anyone give me more information about class A foam? Is it used in Australia or only the US/Canada? Who noted this false positive and did they publish any papers to that effect. Also your help in suggesting any relevant literature would be greatly appreciated.

Regards Sam Norman
3rd Year Undergraduate Student
Bachelor Applied Science (Forensic Investigation)
Canberra Institute of Technology, Australia

[George Wendt, CFI]

Class A foam is used in the US. I read one Material Safety Data Sheet from US Foam which indicated that there was a minute amount of kerosene in the mixture.

Be advised that this is not a FALSE positive. There would actually be a hydrocarbon in the sample. the challenge here is to isolate it as an accelerant or as innocently added to the scene.

The only answer maybe to secure a comparison sample from the engine or to advise the chemist of the possibility of an added volatile material.

[paulp]

Class A foam is used by the CFA in Victoria Australia. We have it fitted to our 3.2D tanker. The CFA has fitted it to many vehicles in the last 2 years. I think the MFB are not using it due to union safety issues. Contact either myself or CFA for more information.