Development of a New Test Procedure for Aqueous Film- Forming Foam

A project was undertaken to develop a new test procedure for Aqueous Film-Forming Foam (AFFF). The basis for the new test procedure was the CGSB-28.74-M90 "Standard for: Liquid Concentrate, Fire Fighting, Aqueous Film Forming Foam", modified to apply the foam from a fixed nozzle. Repeatability of the new test procedures as well as acceptance criteria, were evaluated. A series of tests was conducted to investigate a number of variables including the quantity of water used as a base, the quantity of fuel and the foam application time. The project was carried out in three phases. The NFL's results of three phases of tests showed that: Phases 1 and 2 provided repeatable, consistent test results. The test results in Phase 3 were inconsistent and showed very little agreement with the previous results. Although there is no conclusiveevidence as to the reason for this, the age of the foam concentrates seems to be the most likely cause. Reviewing the test results from the other laboratories involved in the Phase 3 round robin testing will-provide the first step in locating the cause of the inconsistent results obtained in Phase 3.Un projet a \ue9t\ue9 entrepris, qui vise la mise au point d?une nouvelle m\ue9thode d?essai des mousses \ue0 formation de pellicule aqueuse (mousse AFFF). Cette nouvelle m\ue9thode avait pour fondement la norme CAN/CGSB-28.74-M90, \uab Liquide concentr\ue9 moussant formant une couche aqueuse extinctrice \ubb, modifi\ue9e pour application de la mousse \ue0 partir d?une tuy\ue8re fixe. On a \ue9valu\ue9 la r\ue9p\ue9tabilit\ue9 de la nouvelle m\ue9thode d?essai ainsi que les crit\ue8res d?acceptation. Une s\ue9rie d?essais a \ue9t\ue9 r\ue9alis\ue9e dans le but d?examiner un certain nombre de variables, notamment la quantit\ue9 de l?eau utilis\ue9e comme base, la quantit\ue9 de combustible en cause ainsi que le temps d?application de la mousse. Le projet a \ue9t\ue9 r\ue9alis\ue9 en trois (3) phases distinctes. Les r\ue9sultats obtenus au Laboratoire national de l?incendie dans les essais en trois phases ont r\ue9v\ue9l\ue9: 1) que les phases 1 et 2 ont g\ue9n\ue9r\ue9 des r\ue9sultats coh\ue9rents et reproductibles; et 2) que les r\ue9sultats d?essais \ue0 la phase 3 ont \ue9t\ue9 incoh\ue9rents et ont affich\ue9 une tr\ue8s faible concordance avec les r\ue9sultats ant\ue9rieurs. Bien qu?il n?existe aucune justification concluante \ue0 cet effet, il semblerait que l?\ue2ge des concentr\ue9s de mousse soit la cause la plus probable de ce ph\ue9nom\ue8ne. L?examen des r\ue9sultats d?essais des autres laboratoires ayant pris part au test comparatif inter-laboratoires de la phase 3 sera la premi\ue8re \ue9tape de l?identification de la cause de l?incoh\ue9rence des r\ue9sultats obtenus lors de cette phase.Peer reviewed: NoNRC publication: Ye